The MDG Centre
E A S T
&
S O U T H E R N
A F R I C A
Managing pests of stored maize
in Kenya, Malawi and Tanzania
Submitted To:
By:
The MDG Centre
East and Southern Africa
Box 30677-00100
Nairobi, Kenya
Tel: +254 20 7224485
Fax: +254 20 7224490
CABI Africa
UN Avenue, ICRAF Complex
Box 633-00621
Nairobi, Kenya
Tel.: +254 20 7224450
Fax: +254 20 7122150
Email: [email protected]
JUNE 2008
Prepared by:
Noah Anthony Phiri
Gordon Otieno
This study was
funded by the
MDG Centre East
& Southern Africa
The MDG Centre
E A S T
&
S O U T H E R N
A F R I C A
Table of contents
1.
EXECUTIVE SUMMARY
2.
INTRODUCTION
10
3.
GENERAL FLOW OF MAIZE FROM THE PRODUCER
11
3.1 STAGES WHERE MAIZE IS STORED
11
4.
8
3.1.1 Home/household
11
3.1.2 Community Grain banks/Community Cereal banks
11
3.1.3 School storage facilities
12
3.1.4 Vendors and maize traders
12
3.1.5 The Cereal Boards – the National Food Reserve Agency (Malawi) and the Cereals
and Produce Board (Kenya), Agriculture Development and Marketing Corporation
(ADMARC) (Malawi)
12
MAJOR PESTS AND THEIR RELATED LOSSES
15
4.1 MAJOR PESTS
15
4.1.1 Larger grain borer (Prostephanus truncatus (Horn))
15
4.1.2 Maize weevil (Sitophilus zeamais Motschulsky)
15
4.1.3 Angoumois grain moth (Sitotroga cerealella (Olivier))
15
4.1.4 Lesser grain weevil (Sitophilus oryzae (Linnaeus))
15
4.1.5 Aflatoxin contamination (Aspergillus flavus Link)
16
4.2 LOSSES CAUSED BY MAJOR PESTS
5.
16
4.2.1 Losses from literature
16
4.2.2 Maize storage losses to pests – information from maize experts and agriculture staff
17
Larger grain borer (Prostephanus truncatus (Horn))
1.
Maize weevil (Sitophilus zeamais Motschulsky)
2.
Lesser grain weevil (Sitophilus oryzae (Linnaeus))
3.
Angoumois grain moth (Sitotraga cerealella (Olivier))
Larger grain borer (Prostephanus truncatus (Horn))
Larger grain borer (Prostephanus truncatus (Horn))
Maize storage losses as experienced by farmers
OFFICIAL RECOMMENDATIONS AND CURRENT STRATEGIES FOR MANAGEMENT OF PESTS 20
5.1 GENERAL RECOMMENDATIONS AND MANAGEMENT STRATEGIES
5.1.1 Early maize harvesting and drying
20
20
5.2 INSECTICIDES RECOMMENDED FOR TREATING MAIZE FOR STORAGE:
21
5.2.1 Kenya
21
5.2.2 Malawi
22
5.2.3 Tanzania
24
5.3 MAIZE STORAGE STRUCTURES
24
5.3.1 Bags
24
5.3.2 Stores
25
5.3.3 Traditional Granaries
25
3
6.
7.
5.3.4 Improved granaries/cribs
25
5.3.5 Small Metal silos/drums
26
5.3.6 Community metal silos
26
5.3.7 Community Grain Stores
26
5.3.8 Costs of the different storage structures (where available)
26
27
A summary of costs of different storage structures are presented in Table 11.
KNOWLEDGE GAPS: DISCREPANCIES BETWEEN EXPERTS,
FARMERS AND MILLENNIUM VILLAGES
28
6.1 MAIZE VARIETIES AND STORAGE PESTS
28
6.2 MAIZE HARVESTING PROCESSES
30
6.3 PRE-STORAGE STRUCTURES
31
6.4 STORAGE STRUCTURES
32
6.4.1 Use of bags (sacks)
32
6.4.2 Traditional cribs/granaries
32
6.4.3 Improved granaries
32
6.4.4 Small Metal silos/Drums
33
6.4.5 Summary of storage structures in the different Millennium Villages
33
6.5 TREATMENT OF GRAIN BY FARMERS
34
ANALYSIS
37
7.1 IMPORTANCE OF MAIZE STORAGE IN MALAWI, TANZANIA AND KENYA
37
7.2 IMPORTANCE OF STORAGE PESTS IN THE MILLENNIUM VILLAGES
38
7.3 MAIZE LOSS TO STORAGE PESTS AND THE CORRESPONDING MONETARY LOSS IN THE
DIFFERENT COUNTRIES
39
7.4 FACTORS INFLUENCING MAIZE LOSSES TO STORAGE PESTS AT EACH LEVEL OF MAIZE
STORAGE
39
7.4.1 Factors influencing losses at household level
8.
9
39
RECOMMENDATIONS
48
8.1 SHORT TERM RECOMMENDATIONS
48
8.1.1 Short term recommendations for Millennium Village Project in Malawi
48
8.1.2 Short term recommendation for Millennium Villages in Tanzania
50
8.1.3 Short term recommendations for Millennium Villages in Kenya
53
8.1.4 Summary of recommendations (all countries)
55
8.2 LONG TERM RECOMMENDATIONS FOR MALAWI, KENYA AND TANZANIA
56
REFERENCES
60
ANNEXES
61
4
List of figures
Fig. 1. A large scale community grain bank at Mwandama Millennium Village
11
Fig. 2. Maize being fumigated in a mass storage facility at ADMARC Depot in Limbe, Malawi
12
Fig. 3. The flow of maize in Kenya
13
Fig. 4. The flow of maize in Malawi
14
Fig. 5. Drying cribs – (a) Recommended but need to be thatched to prevent spoilage of maize
from rain water); (b) a different variation of a drying crib 20
Fig. 6. Non mudded (a) and mudded (b) granaries (right)
25
Fig.7. Improved granaries/cribs (cemented types)
25
Fig. 8. Small scale metal silos - standard (left), and collapsible (right)
26
Fig. 9. Community metal silos
26
Fig. 10. Some large scale storage buildings (left = brick type, and right =
one constructed from iron sheets) which can be used for community grain storage 26
Fig.11. Stoked maize before harvesting; a common practice in Inonelwa Millennium Village, Tabora, Tanzania.
30
Fig. 12. A non thatched drying crib
32
Fig.13. A version of a drying crib which was constructed under a tobacco shade in
Gumulira Village (left), and a drying structure constructed by a farmer in
Mbola Millennium Research Village (right) 32
Fig. 14. Super grain bag (left) and a Hessian bag (right)
32
Fig. 15. (a) Traditional granaries in Malawi (first two) and (b) inside a house in Tanzania (far right) 32
Fig. 16. An improved granary
32
Fig. 17. A type of a two hundred l litre drum being used for storing maize in Kenya
33
Fig. 18. A traditional non-mudded granary in Malawi 39
Fig. 19. Soft (left) and hard (right) grain hybrids grown in Mwandama Research Village 40
Fig. 20. Insecticide treated maize seed reduced to flour (left) by Larger grain borer (being shown to
farmers in the middle), and a comparison of the destroyed seed with the non infested seed (far right) 41
Fig. 21. Milled maize reduced to flour by Larger grain borer and Maize weevil
42
5
List of tables
Table 1a.Larger grain borer (prostephanus truncatus (horn))
16
Table 1b.Maize weevil (sitophilus zeamais motschulsky) and lesser grain weevil (sitophilus oryzae (linnaeus))
16
Table 1c.Angoumois grain moth (sitotraga cerealella (olivier))
16
Table 1d.The maize flour beetle (tribolium sp)
17
Table 1e.Aflatoxin contamination
17
Table 2. Maize losses to pests as given by maize experts and agriculture staff in malawi
17
Table 4. Maize losses to pests as given by maize experts and agriculture staff in kenya
18
Table 3. Maize losses to pests as given by maize experts and agriculture staff in tanzania
18
Table 5. Maize losses in storage due to storage pests as per the farmers’ experiences with losses
from storage insect pests.
19
Table 6. Additional information for tanzania on maize losses in storage due to storage pests as
per the farmers’ experiences with losses from storage insect pests
19
Table 7a.Storage insecticides recommended by the national maize storage experts in kenya
21
Table 7b.Storage insecticides being sold by farm choice agro-vet, kisumu
21
Table 7c.Storage insecticides being sold by mwanga agro-vet, kisumu
22
Table 8a.Storage insecticides recommended by the national maize storage experts in malawi
22
Table 8b.Storage insecticides being sold by farmers world in blantyre
23
Table 8c.Storage insecticides being sold by chemicals and marketing in lilongwe
23
Table 8d.Other storage products being sold by chemicals and marketing in lilongwe
24
Table 9. Storage insecticides recommended by the national maize storage experts in tanzania
24
Table 10.Summary of recommendations regarding use of bags in all the three countries
25
Table 11.Costs of different storage structures
26
Table 12.A list of varieties grown by farmers in the different millennium villages and their preferred varieties and
reasons for preference
28
Table13. Summary of maize harvesting practices
30
Table 14.Number and proportion of farmers using the different storage structures in the respective millennium
villages
33
Table 15.Number and proportion of farmers using the different maize treatment insecticides in the respective
millennium villages
35
Table 16.Amount of money farmers would save if they treated their maize with insecticides and store in the different
millennium villages – assuming losses would be negligible if the maize is properly treated and stored 37
Table 17. Relative importance of storage pests in the different millennium villages
38
Table 18.Monetary loss to storage pests at national level in malawi, tanzania and kenya
39
Table 19.Short term recommendations for all millennium villages in malawi
48
Table 20.Specific short term recommendations for mwandama and nambande millennium villages in zomba
50
Table 21.Short term recommendations for all millennium villages in tanzania
51
Table 22.Short term recommendations for mbola millennium research village
52
Table 23.Short term recommendations for millennium villages in kenya
53
Table 24.Short term recommendation for the sauri millennium research village
55
Table 25.Summary of recommendations for malawi, kenya and tanzania
55
Table 26.Long term recommendations for malawi, kenya and tanzania
56
Table 27.Long term recommendations specific to malawi only
59
6
Abbreviations
%
Percentage
ADMARC Agriculture Development Marketing Corporation
AI
Active Ingredient
DE Diatomaceous Earths
EC
Emulsifiable concentrate
FFS
Farmer Field School
GBB
Greater Grain Borer
ha
Hectare
KSh
Kenyan Shillings
LGB
Larger Grain Borer
MC
Moisture Content
MDG
Millennium Development Goal
MDGC
Millennium Development Goal Centre
MK
Malawi Kwacha
MT
Metric Tonnes
MV
Millennium Village
MVs
Millennium Villages
MVP
Millennium Village Project
NCPB
National Cereals and Produce Board
NFRA
National Food Reserve Agency
sp.
Species
spp.
Species (plural)
TN
Teretrius nigrescens
TOT
Training of Trainers
TPRI
Tropical Pesticide Research Institute
TSh
Tanzanian Shilling
UNDP
United Nations Development Programme
7
1. Executive Summary
The Millennium Villages Project (MVP) is the product of a partnership between the Earth Institute at Columbia
University, United Nations Development Programme (UNDP) and the Millennium Promise, to help African
communities lift themselves out of poverty. The project aims to establish rigorous proof of concept for implementing
the practical interventions needed to achieve the Millennium Development Goals (MDGs) in rural Africa over a five
year time frame. Millennium Villages are units of 1,000 households, reaching roughly 5,000 people. The Millennium
Development Goals Centre for East and Southern Africa has been supporting implementation of the MVP in
countries of East and Southern Africa, through which inputs are provided to increase farmers’ food security. The
support to farmers living in Millennium Villages (MVs) has resulted in huge increases in production to the magnitude
of more than 12 times than that of the national maize production levels. However, these huge leaps in maize
productivity came with challenges which led to substantial maize losses to storage pests each year, especially since
farmers did not seem to adequately prepare for storing extra maize grain. It is in view of the aforementioned that the
MDGC’s East and Southern Africa Regional Office approached CABI Africa to carry out a study in order to document
the status of the maize loss in storage due to pests and make recommendations for alleviating losses.
The study was carried out in Malawi’s Mwandama and Gumulira Clusters, Tanzania’s Mbola Cluster, and Kenya’s
Sauri Cluster from end of April to mid June 2008. The study was conducted through farmer focus group discussions,
assessments of storage structures and pest status in selected households, and discussions with key informants in
all the three participating countries. A maize chain analysis and assessment of maize storage losses along the chain
was conducted but mainly carried out in Malawi and Kenya due to low rainfall in Tanzania and subsequent reduction
in maize productivity.
Maize losses occur primarily at the following sites:
1. Household
2. Receiving and storage sites for payback maize
3. Community Cereal/Grain Storage facilities, and
4. Schools which are used as temporary storage facilities for MVP payback maize some of which is for the school
feeding programme.
Maize losses due to pests and LGB:
As for pests, the Larger grain borer (LGB) causes the highest maize storage losses followed by the Maize weevil,
Maize flour beetle and Angoumois grain moth. According to national maize experts, maize losses due to storage
pests range from 30% – 60% in Malawi, Tanzania and Kenya, much of which is attributed to the presence of LGB and
these figures far exceed what is currently recorded in the literature. Maize losses experienced by farmers are variable,
but farmers in all countries of the study confirmed experiencing losses even if they used inorganic or organic storage
insecticides and all confirmed that losses can be up to 100% if maize is not protected with insecticides before storing.
Key factors influencing maize losses due to storage pests:
• Improper harvesting methods which result in overexposing maize to storage pests in the field
• Varietal susceptibility
• Inappropriate use of storage structures and improper application of insecticides
• Under dosing of insecticides and improper timing for applying insecticides leading to maize loss from pretreatment infestation of pests
• Use of expired and adulterated insecticides
• Treating maize with insecticides at incorrect moisture content (MC) levels
• S
hort effectiveness of insecticides - some are only effective in protecting treated maize from pest infestation in
storage for only three months
• Storing untreated maize for long periods such as the maize in the maize payback receiving centres
• Lack of experience in storing maize by school teachers and administrators who are often responsible for
caring for the MVP maize
• Lack of adequate storage facilities at Community Cereal/Grain Banks
8
National maize storage experts in all three countries recommended the following:
• Early harvesting
• Use of new or treated bags for storage and store hygiene
• Treating maize with insecticides
• Use of botanicals and diatomaceous earths (DEs)
• Use of modern structures such as improved granaries and mini silos
• Frequent inspection of maize while in storage and re-drying and retreating if infested
Discrepancies between national recommendations and farmers actions:
Despite these national level recommendations, the study revealed that many farmers are not using all or any of
the above recommendations. For example, apart from farmers in two MVs in Mwandama Cluster, Malawi, very few
farmers are using inorganic or modern insecticides; farmers are still using traditional granaries, even those living
close to modern granaries that were built for demonstration. The closest structure resembling silos was the 200 litre
drums, which were found in Kenyan MVP, but used by very few farmers in Kenya. Farmers suggested a number
of reasons as to why they have not adopted national storage recommendations and/or more modern storage
management technologies such as limited financial resources and lack of awareness of the recommendations.
It is apparent that maize storage is a crucial component of ensuring greater food security and should be included in
efforts by national governments, development partners such as MVP, FAO, the World Bank, the African Development
Bank, bi-lateral donors and other development partners, especially in countries where such efforts have yielded
substantial returns in maize or other food crop productivity. Due to lack of awareness and proper technologies,
farmers end up selling their maize soon after harvest, only to buy it back from the same people at more that twice the
price they sold the maize for just a few months after harvest, resulting in a continual poverty trap. If efforts to increase
food security included storage, and farmers were able to store their maize properly, they would save between US$10
to US$20 per bag of maize needed for household consumption throughout the year. These may appear like small
savings, but an analysis of family sizes in rural Sub-Saharan Africa and the corresponding maize required to feed
such big families, these translate into huge savings per family. Furthermore, storage pests, in particular LGB and in
combination with other pests such as Maize weevils cause substantial losses at national levels, which translates,
approximately, to between US$ 150 and $300 Million, money which could be used to provide other essential incountry services.
In order to address these factors a range of country specific short term recommendations have been presented, a
summary table of recommendations can be found below. The short term recommendations can be implemented
immediately in order to start alleviating losses from storage pests. Long term recommendations are also included in
the report, but will need to be implemented through a longer term project of between three and five years in order to
sustainably manage storage pests.
Summary of short term recommendations:
RECOMMENDATIONS
1. The MVP to facilitate availability of insecticides to farmers
2. Training of agriculture staff and farmers in proper maize storage systems
3. Use of maize cribs – the period of drying maize in the cribs should be
shortened to a maximum of 4 weeks
4. Awareness creation in maize harvesting and handling, storage pests,
insecticide rates and proper use
5. Payback maize in receiving centres and the maize in Cereal/Grain Banks
should be fumigated before treating with contact insecticides
6. Diatomaceous Earths (DEs) should be tried at a pilot level in Millennium
Research Villages
7. An inventory of farmers who use ash of different types should be
developed, and they should be supported and followed up to make sure
their maize is safe from storage pests
9
MALAWI
KENYA
TANZANIA
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
8. Institute LGB reporting system
9. Farmers using wild tubers and other botanicals should be followed up,
and the effectiveness of the botanicals verified
✓
✓
✓
✓
10. Carry out campaigns for spraying houses and storage structures
against LGB in the Zomba MVs where there are high populations of LGB
✓
11. Introduce dipping of maize in water before milling at all maize mills
in MVP to drown storage pests as part of an integrated storage pest
management
✓
✓
✓
12. MVP to devise a way of measuring maize quantities for treating with
insecticides e.g. develop a measuring container with 10 kg capacity
which could be used to measure 50 kg (5 containers equals 50 kg in
Malawi) or 90 kg (9 containers equal 90 kg in Kenya and Tanzania)
✓
✓
✓
13. Where not available maize stores should be built for storing maize at
each MV
✓
✓
✓
1. Introduction
Maize is a staple food for many countries in sub-Saharan Africa, and in Kenya, Malawi and Tanzania it is mainly
produced by resource poor farmers. With the withdrawal of input subsidies in African countries, the production of
maize has been adversely affected as well as other smallholder crops that depend on inorganic fertilizer. As result,
many African countries have become food-insecure since most smallholder farmers cannot afford to buy inputs.
However, a number of countries, such as Malawi, have worked with development partners and international NGOs to
overcome this problem by providing targeted free inputs to the poorest of the poor.
The Millennium Development Goals (MDG) Centre has been supporting implementation of the Millennium Villages
Project (MVP) in Malawi, Tanzania and Kenya by providing inputs to increase farmers’ food security. Most resource
poor farmers in the Millennium Villages (MV) live on less than a dollar per day, but the provision of agricultural inputs
has led to “revolutionary” leaps in maize production. At a national level in Malawi for example, a targeted input
programme provided free seed and fertilisers to 70% of all smallholder farmers nearly trebling maize yields (maize
production increased from 1.2 MT in 2004 to 5.6 MT in 2007 in Malawi). These dramatic increases in yield have
required farmers to put large quantities of maize in storage for use throughout the year but the increase in maize
production and subsequent storing has created new challenges, in particular the protection of stored maize from
storage pests. There is a risk that much of the production gains will be lost through inadequate or inappropriate
storage of maize.
A six week study was carried out in Millennium Villages in Malawi, Tanzania and Kenya to assess the extent of
maize damage due to storage pests as well as other challenges related to the storage of maize. Millennium Villages
are grouped into Millennium Research Villages (MRV) and Scaling up Villages (SuMV), the two are also referred
to as MV1 and MV2, respectively. The objective of MRV is to establish the evidence base for implementing proven
and practical interventions needed to achieve, or set the path to achieving the MDGs over a five year time frame.
On the other hand, SuMVs’ aim is to replicate the interventions that have been proven effective in the MRV. This
study covered both the MRVs and SuMVs in each country and discussions were held with farmers from the MVs.
In Malawi two discussion groups were held in Mwandama Cluster; one in the Mwandama MRV, and another at
Nambande SuMV, both in Zomba District. In addition, one discussion group was held at Gumulira MRV, a more
recently established MV in Mchinji District. In Tanzania, discussions were held in Mbola Cluster, specifically at
Mbola MRV, and Inonelwa SuMV, with a brief visit to Migumgumelo in Msimba Cluster (SuMV) in Tabola, while in
Kenya, the discussions were held in Sauri Cluster, specifically with Sauri MRV, and with farmer representatives from
Anyiko, Nyamninia, Jina, Nyawara, Nyandiwa, Gongo, Ramula, Uranga, and Lihanda SuMVs. Apart from Sauri, the
rest of the clusters were met in three venues, Gem Hall, Yala Guesthouse, and Bar-Kalare all in Siaya District. In all
the MVs in the three countries, selected households were visited to assess their storage facilities and the storage
pest status and to discuss their maize storage challenges and opportunities. Key informant discussions were held
with government national maize storage experts, maize marketing institutions, storage insecticide providers, and
government officials in Malawi, Tanzania and Kenya.
This report outlines key activities which were carried out during the consultancy, the findings, analysis and
recommendations. However, discussions were mainly held with farmers who are being supported by MVP, but
findings can be applied to the rest of the countries. The report outlines/includes the following:
10
• Major pests and estimated maize losses due to storage pests
• Losses according to national key informants as well as farmers
• Recommendations from national maize experts are presented in relation to what farmers are actually doing
and any knowledge gaps and/or discrepancies are discussed
• A
nalyses of possible factors that are influencing maize losses to storage pests in all three countries as well as
MV specific factors
• A
set of short term country specific recommendations as well as some MV specific recommendations that can
be implemented immediately to help alleviate or reduce further losses to maize in storage
• L
ong term recommendations, however, these form the basis for a long term project aimed at addressing
maize storage pests at national and village levels and will involve more stakeholders in addition to MVPs
3. General flow of maize from the producer
The movement of maize throughout Malawi, Tanzania and Kenya takes several routes and consists of various stages,
each posing a potential risk for maize to be lost or damaged due to storage pests. In addition to pest challenges,
maize growers who do not have adequate storage facilities sell their surplus maize to those equipped with such
facilities and in doing so incur additional costs when purchasing maize at a later stage. Thus the importance of
analysing maize storage and storage facilities at the farm level is essential. The movement of maize analysed in this
study is unique considering the consultancy targeted Millennium Project areas, which are quite different from other
maize producing areas and the normal movement of maize. And this will become particularly clear in the case of
Malawi and Kenya where the study includes the main maize marketing institutions.
Since maize harvests in Tanzania were quite low this past season, the study mainly concentrates on Kenya and
Malawi however Tanzania will have much higher yields this season enabling farmers to harvest, and pay back maize.
The flow of maize in Kenya and Malawi is presented in Figs. 1 and 2 below.
3.1
Stages where maize is stored
3.1.1
Home/household
Participating farmers of the MVP contributed two bags of maize in Malawi and Kenya, 50kg and 90kg bags
respectively, while Tanzania is expected to contribute a similar amount this coming year. This contribution is
approximately 7% of the maize these farmers produce annually leaving approximately 90% to be stored and sold.
This proportion appears low due to smallholder farmer’s maize production levels, but maize productivity in the
Millennium Villages has increased from almost nothing to an average 6.5 tonnes per ha, which is far above the
national average of 1.5 tonnes in Malawi for example. Such increased production brings new challenges to farmers
and how maize is stored, which will be discussed in greater detail in section 6.
3.1.2Community Grain banks/Community Cereal banks
Fig. 1. A large scale community grain bank at
Mwandama Millennium Village
In Malawi and Kenya, substantial maize is received through the
MVP pay back scheme; however, Kenya has progressed and some
farmers in the Millennium Villages have “weaned off” the scheme
and have started buying their own inputs as well as jointly forming
Cereal Banks. In Kenya, farmers contribute 90kg bags therefore maize
contributions are higher than that of Malawi or Tanzania. The Cereal
Banks purchase maize, store it and then sell it at a higher price but
Cereal Banks in Kenya, such as the Marenyo Community Cereal Bank,
face serious challenges when it comes to storing their maize and lack
adequate storage facilities. The Marenyo Community Cereal Bank
and other cereal banks have to store their maize at the Cereals and
Produce Board storage facilities in Yala at a cost of KSh 5 per 90 kg
bag per month and have to pay additional fees for fumigation.
11
In Mwandama Malawi, Community Grain Banks are taking a different approach and the MVP is currently constructing
a large storage facility (Fig. 1), which will substantially reduce the problem of maize storage at the community level.
The facility is hopefully large enough for neighbouring Millennium Villages to use the space to store their contributed
maize and in fact farmers in nearby Nambande MV already requested, during the study, the use of the facility.
3.1.3
School storage facilities
Due to lack of adequate storage facilities, a number of schools are used to store maize (mainly untreated) supplied
by the community contribution programme. Approximately 2,000 90kg bags of maize are stored across a number of
schools with individual schools storing up to 300 bags each. Some of the maize stored at the schools will be used
for the school feeding component of the MVP but the maize is not used immediately by the schools, it is stored at
the school by teachers who are not trained in maize storage until the MVP is ready to move it to the National Cereals
and Produce Board (NCPB). As a result, this interim or “transit” storage arrangement, often lasting for more than
two months, lacks proper care and monitoring and leaves maize susceptible to damage. In some cases, maize
harvested in September is still being kept at the school awaiting transportation to the NCPB. Once the maize is
received at the NCPB, the MVP allocates maize to the school feeding program and delivers the school feeding
portion back to the schools where it often sits for another 3 months or full school term. Both before and after the
maize reaches the NCPB, it is kept at the school by those who lack experience in storing maize and in some cases,
the schools resort to storing maize in the classrooms, often on the floor, which results in the maize being exposed
to a number of storage pests. Furthermore, in many schools maize is stored for the whole community in addition
to the maize stored for the school feeding programme and since they do not treat maize, the losses are potentially
very high. For example, at the time of writing this report, pay back maize was still being stored at Muhanda and Luri
Primary Schools, from the September 2007 harvests, and it is suffering huge storage losses.
3.1.4
Vendors and maize traders
Due to time limitations, the study did not include the vendors, hence not much information in the case of possible
quantities of maize stored by this group or stage, even though substantial amount of maize is sold to this group, for
example most farmers indicated that they sold more than 50% of their harvested maize, in some cases up to as high
as 70%.
3.1.5The Cereal Boards – the National Food Reserve Agency
(Malawi) and the Cereals and Produce Board (Kenya),
Agriculture Development and Marketing Corporation
(ADMARC) (Malawi)
Even though a substantial amount of maize is stored by these
organisations, they are very capable of protecting it from storage
pests. In both Malawi and Kenya, they offer maize treating services
to smallholder farmers and in Kenya, for a reasonable fee, they offer
maize storing and treating services. An example of a fumigated stalk
of maize at the ADMARC depot in Malawi is shown in Fig. 2.
Fig. 2. Maize being fumigated in a mass storage
facility at ADMARC Depot in Limbe, Malawi
12
Movement of Maize from the Farm under Millennium Village Arrangement in Kenya
Fig. 3. The flow of maize in Kenya
13
Movement of Maize from the Farm under Millennium Village Arrangement in Malawi
Fig. 4. The flow of maize in Malawi
14
4. Major Pests and their related losses
4.1
Major pests
One of the main causes of food insecurity in Africa is the high prevalence of storage pests and although maize is an
excellent food source for humans, it is also an excellent food source, and an ideal breeding site for storage pests.
Pests can be defined as those organisms that cause damage resulting in economic loss to maize and other plants
be it in the field or in storage (Haines, 1991). Below are a number of storage pests which were encountered or are
present in Malawi, Kenya and Tanzania.
4.1.1
Larger grain borer (Prostephanus truncatus (Horn))
The Larger grain borer (LGB), which is sometimes referred to as the Greater Grain Borer (GGB), and given names
like “scannia”, and “Osama” is the single most serious pest of stored maize and dried cassava roots (chips), and will
attack maize in the field just before harvest. The primary host is maize, in particular maize on the cob both before
and after harvest. Larger grain borer also bores into non-food substances such as wood, bamboo, and even plastic,
which poses a challenge to controlling the pest.
Infestations in maize may start on the mature crop in the field, i.e. when moisture content is at or below 18%. Weight
losses of up to 40% have been recorded from maize cobs stored for 6 months (Giles and Leon, 1975). In Tanzania,
losses of up to 34% have been observed after 3 months storage of maize on the farm, with an average loss of 8.7%
(Hodges et al., 1983). Larger grain borer is a much more damaging pest than other storage insects including Rice
weevil, Maize weevil and Angoumois grain moth, under similar conditions. Losses caused by LGB in dried cassava
roots can be very high; the dried roots are readily reduced to dust by boring adults and a loss of 70% has been
recorded after only 4 months of farm storage (Hodges et al., 1985). Larger grain borer is present in West, East and
Southern Africa.
4.1.2
Maize weevil (Sitophilus zeamais Motschulsky)
Maize weevil, also called greater grain weevil is the most common pest of stored maize in most African countries.
Maize weevil prefers maize, but has also been reported as a pest of cassava, rice, sorghum, and wheat. Minor hosts
include taro, soybean, common beans, wheat, adzuki bean and cowpea.
Maize weevil causes substantial losses in maize or sorghum. Attack may start in the mature crop when the moisture
content of the grain has fallen to 18-20%. Subsequent infestations in store result from the transfer of infested grain
into store or from the pest flying into storage facilities, probably attracted by the odour of the stored grain. Re-use
of sacks borrowed from neighbours or traders is a source of Maize weevil. In stored maize heavy infestations may
cause weight losses of as much as 30-40%, although losses are commonly 4-5%. The Maize weevil is found in all
warm and tropical parts of the world. In Africa it occurs in all sub-regions.
4.1.3
Angoumois grain moth (Sitotroga cerealella (Olivier))
The grain moth is a pest of various stored products. Grains affected are maize, oats, barley, rice, pearl millet,
rye, sorghum, and wheat. However, the grain moth is often found alongside other pests, with which it may act
synergistically. The complex with other storage pests resulted in grain losses of up to 90% in Malawi in varieties of
soft grains (Schulten, 1975). In Malawi infestation was found to be caused by a combination of Angoumois grain
moth, Maize weevil, and Rice weevil. However, in Zimbabwe, losses in storage were mainly caused by Angoumois
grain moth and Maize weevil with losses of 70% in untreated maize.
Angoumois grain moth is found in all sub-Saharan regions of Africa.
4.1.4
Lesser grain weevil (Sitophilus oryzae (Linnaeus))
The Lesser grain weevil, which is also called the Rice weevil, is an important pest of stored maize, rice, cassava,
sorghum, and wheat. It also infests pearl millet, barley, lentil, millets, peas, rye, broad bean, and cowpea.
The Lesser grain weevil is regarded as one of the most destructive primary pests of stored cereals, its voracious
feeding on whole grains results in weight loss, fungal growth, and quality loss through an increase in free fatty acids.
Its invasion may cause grain heating and may facilitate the establishment of fungal colonies, secondary insect pests,
and mites. In maize or sorghum, attack by the Lesser grain weevil may start in the mature crop when the moisture
content of the grain has fallen to 18-20%. Subsequent infestations in storage result from the transfer of infested grain
into the stores or from the pest flying into storage facilities. In stored maize heavy infestations by the Lesser grain
weevil may cause weight losses of up to 30-40%. The Lesser grain weevil, like the maize weevil, is found in all warm
and tropical parts of the world, and may also be found in temperate climates.
15
4.1.5
Aflatoxin contamination (Aspergillus flavus Link)
Aflatoxin contamination results from storage rots in maize, groundnut and rice, caused by Aspergillus flavus and A.
parasiticus, closely related fungi that contaminate seeds and plant debris of many crops in the field and in storage.
Aspergillus flavus produces aflatoxin B1 and B2, whereas A. parasiticus produces G1, G2, and M1. Aflatoxins have
been associated with various diseases in livestock, domestic animals and humans throughout the world. The
occurrence of aflatoxins is influenced by certain environmental factors; hence the extent of contamination will vary
with geographic location, agricultural and agronomic practices, and the susceptibility of commodities to fungal
invasion during pre-harvest, storage, and/or processing periods. Aflatoxins have received greater attention than other
mycotoxins because of their potent carcinogenic effect in animals and their acute toxicological effects in humans.
Aflatoxin contamination also results in export losses since aflatoxin contaminated produce are rejected by importing
countries, as has occurred with groundnuts from Malawi.
4.2
Losses caused by major pests
In most cases, different types of storage pests group together making it virtually impossible to accurately
apportion losses from one specific pest to another. Losses are therefore grouped according to information found
in the literature (Tables 1a-e), and according to information collected throughout the fieldwork component of the
consultancy in Kenya, Malawi and Tanzania. These particular losses are grouped according to information from
agricultural experts in each respective country (Tables 2-4) and farmers’ own experience (Tables 5 and 6). Farmers’
experiences were collected during discussions in farmer groups at each MV focus group meeting.
4.2.1
Losses from literature
Even though most losses caused by storage pests are difficult to separate, the below are some of the documented
losses for different storage pests (Tables 1a-e). These can be compared to actual losses which are experienced and
reported by farmers (Tables 5 and 6).
Table 1a. Larger grain borer (Prostephanus truncatus (Horn))
LOSS
SOURCE OF INFORMATION
1. Up to 40% recorded in Nicaragua from maize cobs stored on the farm for 6
months
1. Giles and Leon, 1975
2. In Tanzania, up to 34% losses have been observed after 3 months storage on
the farm, with an average loss of 8.7%
2. Hodges et al., 1983
3. In the early days after the arrival of P. truncatus in East Africa, countries with the
pest found their maize exports banned. For example in 1987-88, it is estimated
that Tanzania lost US$634,000 in export earning. This situation improved
following efforts to upgrade phytosanitary procedures in the region but such
procedures, involving fumigation, have their own continuing costs
3. Boxall, 2002
Table 1b. Maize weevil (Sitophilus zeamais Motschulsky) and Lesser grain weevil (Sitophilus oryzae (Linnaeus))
LOSS
SOURCE OF INFORMATION
Heavy infestations of Sitophilus spp. may cause weight losses of as much as 3040%, although losses are commonly 4-5%.
Arbogast and Throne, 1997
Table 1c. Angoumois grain moth (Sitotraga cerealella (Olivier))
LOSS
SOURCE OF INFORMATION
1. Up to 30%
1. Singh and benazet, 1975
2. In Tanzania, a complex of pests was responsible for dry weight loss of 31.8% for
maize cobs and 7.85% for grains after 9 months of storage
2. Henckes, 1992
3. After 8 months, damage to untreated grain and grain treated with malathion,
pirimiphos-methyl and methacrifos was 76, 36, 17 and 10%, respectively, and
the weight losses estimated were approximately 13, 6, 4 and 2%.
3. Giga et al. (1991)
16
Table 1d. The Maize flour beetle (Tribolium sp)
LOSS
SOURCE OF INFORMATION
1. They cause extensive damage to grains already damaged as a result of
handling during harvest, holed grains, and those damaged by other pests
1. Atanasov, 1977; white, 1982
2. In Nigeria, weight losses of 29.5 and 39.2% were reported in 4.5 months for
dried yam chips that had already been in storage for 6 months
2. Adesuyi, 1980
Table 1e. Aflatoxin contamination
LOSS
SOURCE OF INFORMATION
1. The incidence of Aflatocin in America in 1976 was 44% for maize from the south- 1. Stoloff, 1976
east, and 2.5% for maize from the mid-west
2. During 1977 and 1980, losses to individuals, firms and public expenditures
due to aflatoxin contamination of maize in the South-Eastern USA amounted to
approximately US$ 200 million and US$ 238 million, respectively
2. Nichols, 1983
3. In Malawi, export losses due to aflatoxins ranged from K 0.16 million in 1988/89
to K 1.58 million in 1985/86 with a mean of K 0.943 million. The export losses in
groundnut as a percentage of the trade balance ranged from 0.01% in 1988/89
to 1.77% in 1981/82
3. Babu et al., 1994.
4.2.2
Maize storage losses to pests – information from maize experts and agriculture staff
Losses are also presented as per the experience of national maize storage experts (Table 2).
4.2.2.1 Malawi
Table 2. Maize losses to pests as given by maize experts and agriculture staff in Malawi
PEST
LOSS
SOURCE OF INFORMATION
Larger grain borer
(Prostephanus truncatus
(Horn))
1. Up to 40% if maize is treated
1. Extension personnel in Millennium
Villages in Zomba, Malawi
2. 80 to 100% if maize is not treated
3. Up to 45% - but no proper
estimates done
4. Over 40% nationally
5. In 2007 national loss was at
60%, but losses of up to 100%
were experienced
2. Extension personnel in Millennium
Villages in Zomba, Malawi
3. The Director of Crops, Ministry of
Agriculture and Food Security
4. Crop Storage Research Officer, Bvumbwe
Agriculture Research Station (now
transferred to Chitedze R. S.), Malawi –
2005 survey results (unpublished)
5. Deputy Pesticide Registrar, formally a
Crop Storage Scientist
1. Maize weevil (Sitophilus
zeamais Motschulsky)
2. Lesser grain weevil
(Sitophilus oryzae
(Linnaeus))
3. Angoumois grain moth
(Sitotraga cerealella (Olivier))
Losses from LGB seem to mask losses from the other pests, which according to
the government officials are far lower than those of LGB
4. The maize flour beetle
(Tribolium spp.)
Rats
Up to 20% at national level
17
Crop Storage Research Officer, Bvumbwe
Agriculture Research Station (now
transferred to Chitedze R. S.), Malawi – 2005
survey results (unpublished)
4.2.2.2 Tanzania
Table 3. Maize losses to pests as given by maize experts and agriculture staff in Tanzania
PEST
LOSS
SOURCE OF INFORMATION
Larger grain borer
(Prostephanus truncatus
(Horn))
1. 30-40% (national) but need to
update according to the source
1. Assistant Director, Post – Harvest
Management Services, National Food
Security Division, Ministry of Agriculture,
Food and Cooperatives
2. 30% (in Tabora)
3. Up to 60% in areas of high LGB
infestation
2. District Plant Protection Officer and
District Agriculture and Livestock Officer,
Tabora District, Ministry of Agriculture,
Food and Cooperatives
3. The Principal Research Officer, Post
Harvest Entomologist, Tropical Pesticide
Research Institute, Arusha, Tanzania
1. Maize weevil (Sitophilus
zeamais Motschulsky)
2. Lesser grain weevil
(Sitophilus oryzae
(Linnaeus))
3. Angoumois grain moth
(Sitotroga cerealella (Olivier))
Losses from LGB seem to mask losses from the other pests, which according to
the government officials are far lower than those of LGB
4. The Maize grain beetle
(Tribolium spp.)
4.2.2.3 Kenya
Table 4. Maize losses to pests as given by maize experts and agriculture staff in Kenya
PEST
LOSS
SOURCE OF INFORMATION
Larger grain borer
(Prostephanus truncatus
(Horn))
1.Up to 100% if maize is not
treated
1.The Crop Storage Scientist, Kenya
Agriculture Research Institute, National
Agriculture Research Laboratories,
Nairobi, Kenya
2.Up to 30% if produce is not
stored for a long time
3.about 30% from all storage pests
4.20 to 25% when treated; and
100% when untreated the first 3
to 4 months
2.Provincial Agriculture Officer, Kisumu,
Kenya
3.The District Agriculture Officer, Siaya
District, Kenya
4.The Agriculture Coordinator, MVP,
Kisumu, Kenya
1. Maize weevil (Sitophilus
zeamais Motschulsky)
The rest of the pests cause up to
20% if stored for 6 months, and
30% if LGB is present – figures
from experiments (2002 to 2003),
3. Angoumois grain moth
but detailed loss studies are
(Sitotroga cerealella (Olivier)) needed
4. The Maize grain beetle
(Tribolium spp.)
2. Lesser grain weevil
(Sitophilus oryzae
(Linnaeus))
18
The Crop Storage Scientist, Kenya
Agriculture Research Institute, National
Agriculture Research Laboratories, Nairobi,
Kenya
Maize storage losses as experienced by farmers
Farmer’s quantified maize losses in relation to 10 bags of maize, whether they were treated or untreated and length
of time stored i.e. 3, 6, and 12 months. In Kenya where a larger proportion of farmers were using ash from different
sources, the exercise included loss to ash treated maize as well. The exercise was done in groups ranging from three
to six at each site. Results are presented as percent of 10 bags, but were originally given in terms of a fraction of a
bag or whole bags. In Tabora, Tanzania, a group of farmers included what they have been experiencing in relation to
two different varietal types, local and hybrids, and in relation to treating maize with modern insecticides, ash and not
treating the maize. Results are presented in Tables 5 and 6.
Table 5. Maize losses in storage due to storage pests as per the farmers’ experiences with losses from storage
insect pests.
COUNTRY
MILLENNIUM
VILLAGE
Malawi
Mwandama
Nambande
Tanzania
Inonelwa
Mbola
Kenya
Nyawara,
Nyandiwa, and
Gongo (at Gem
Hall)
PERIOD OF
STORING
10 BAGS
(MONTHS)
PROPORTION OF MAIZETHAT
COULD BE LOST DURING
STORAGE (% OF 10 BAGS)
Treated
Untreated
3 months
2.0
38.0
6 months
7.0
54.0
12 months
32.0
100.0
3 months
12.0
26.0
6 months
28.0
61.0
12 months
54.0
97.0
3 months
3.3
17.3
6 months
11.7
36.7
12 months
20.0
83.3
3 months
3.8
17.3
6 months
11.3
36.7
12 months
23.8
83.3
3 months
0.3 (0)
16.3
6 months
5.1 (4.4)
47.2
12 months
10.3 (16.0)
77.8
COMMENTS
Figures in
brackets under
treated represent
loss if maize was
treated with ash
Table 6. Additional information for Tanzania on Maize losses in storage due to storage pests as per the farmers’
experiences with losses from storage insect pests.
Millennium
Village in
Tanzania
Period of
storage
(months)
% (Out Of Ten Bags) loss if maize if Treated with
Ash
Actellic
if Untreated (% Loss Out
Of Ten Bags)
Local maize
Hybrid
maize
Local maize
Hybrid
maize
Local maize
Hybrid
maize
Migungumelo 3
0
30
0
30
30
60
Tabora
6
20
60
20
60
70
100
Tanzania
12
100
100
100
100
100
100
19
5. Official recommendations and current strategies for
management of pests
Recommendations and management strategies formed an integrated approach to the management of storage pests
in all the three countries, Kenya, Malawi, and Tanzania. The recommendations and management strategies included:
5.1
General recommendations and management strategies
• Early maize harvesting (at physiological maturity) to limit field infestation
• Use of new bags or spraying bags with Actellic 50EC to kill LGB and other storage pests and their eggs
• S
tore hygiene, i.e. getting rid of old maize before storing the new maize in the stores, and spraying the walls of
maize stores with Actellic 50EC
• Treating maize with storage insecticides. There was a small variation in types and rates among the three
countries, but most of the insecticides were common. Method of mixing was also similar. These will be
outlined below
• Use of botanicals – only Tanzania had a list of recommended botanicals
• U
se of diatomaceous earth (DE) – DEs only form part of the control strategy in Tanzania. They were not
mentioned in Malawi and Kenya although DEs are available in Kenya
• Proper storage structures
• Frequent inspection of the grain, re-drying and re-treating if infested
• U
se of biological control - involves use of live natural enemies or antagonists of the pest, for example
Teretrius nigrescens (TN) used for the control of LGB as part of an integrated control strategy.
These recommendations and management strategies will be presented in detail below.
5.1.1
Early maize harvesting and drying
5.1.1.1 Harvesting
Maize should be harvested at physiological maturity to limit infestation by storage pests in the field. If maize is infested in
the field, it is difficult to control pests in storage because the eggs and the insect pests are already buried inside the grain
and cannot be killed by all dust insecticides, which act on contact. Only fumigants can control such infestations.
5.1.1.2 Drying Techniques
Maize should be properly dried to 13% moisture content (MC) in order for dust insecticides to work properly. Even
though farmers do not have moisture metres, they can determine if maize is dry by biting it (if hard then it is dry)
or using the salt test. This works by putting maize grains in a bottle, adding table salt and closing the lid tightly on
the bottle. If the maize is fully dry, the salt will remain free flowing, however, if the maize is not dry, then the salt will
absorb moisture and stick to the wall of the bottle.
5.1.1.3 Drying Cribs
In Malawi, after harvesting maize at physiological maturity, the use of drying cribs (Fig.5a and b) was recommended
for drying maize. However, this method was not emphasised in Tanzania and Kenya. Proper drying on plastic, tent
material, mats and smeared drying grounds were also mentioned. Cribs come in different variations, but the one in
Fig. 5(a), is the one currently recommended in Malawi.
Fig. 5. Drying cribs – (a)
Recommended but need to be
thatched to prevent spoilage
of maize from rain water); (b) a
different variation of a drying crib
20
5.1.1.4 Maize treatment for storing
Government officials in all three countries recommended that chemical based insecticides must be: 1) thoroughly
mixed and 2) applied to properly dried maize under shaded conditions. Rates of mixing the maize are presented
below (Tables 7a to 9). Information on available insecticides and management strategies were also collected from
pesticide dealers.
5.2
Insecticides recommended for treating maize for storage:
5.2.1
Kenya
5.2.1.1 From Maize Storage Research Team
Table 7a. Storage insecticides recommended by the national maize storage experts in Kenya
INSECTICIDE
RATE AND METHOD OF
APPLICATION
COMMENTS
Actellic Super
50g mixed with 90kg of maize
No infestation for 6 months if treated properly,
e.g. though mixing of dried maize under shade
Spintor Dust
50g mixed with 90kg of maize
Complaints from farmers of infestation even after
1-2 months
Scanner Super
50g mixed with 90kg of maize
Malpa Dust
50g mixed with 90kg of maize
5.2.1.2 From Agro dealers
Table 7b. Storage insecticides being sold by Farm Choice Agro-Vet, Kisumu
INSECTICIDE
RATE AND METHOD PRICE
OF APPLICATION
(KSH)
COMMENTS
Actellic Super Dust
50g mixed with 90kg
of maize
500 per Kg
• Applied after every 3 months.
50g mixed with 90kg
of maize
1200 per
Kg
• Applied every 6 months of storage
50g mixed with 90kg
of maize
370 per kg
• Applied after every 3 months
Spintor Dust
Scanner Super
Gastoxin (store fumigant)
• To be applied before kernels are internally
infested
• To be applied before kernels are internally
infested
• Can be applied when there is serious internal
kernel infestation
1 tablet per tonne of
maize
• Fumigant to be used in the maize store
• Repeat dose after 3 months of storage
• Store should be air tight, away from main
house
21
Table 7c. Storage insecticides being sold by Mwanga agro-Vet, Kisumu
INSECTICIDE
RATE AND METHOD PRICE (KSH)
OF APPLICATION
COMMENTS
Actellic Super
50g mixed with 90kg
of maize
• Reapplied after 1 month of storage
• 200g for treating only
4 bags selling at
KSh130
• 500g is going at
KSh240
• 1kg sells at KSh340
Sumi combi
Super Grain
Dust
50g mixed with 90kg
of maize
50g mixed with 90kg
of maize
• Reapplied after 1 month of storage
• To be applied before kernels are internally
infested
• 370 per kg
• Reapplied 6 months of storage
• Wholesale price at
Juanco Chemicals
is KSh275 (Juanco
Chemicals are
the source of the
insecticide)
• Advice from Juanco Chemicals
• effective for over 6 months
• scout and retreat if infested
• Mostly used to disinfect storage bags, stores
and at times sprayed direct to maize
Actellic
Emulsifiable
Concentrate
(EC)
5.2.2
• grain should not be used until after 2-3
months from time of treating the maize
Malawi
5.2.2.1 From research experts and the Pesticide Control Board
Table 8a. Storage insecticides recommended by the national maize storage experts in Malawi
NSECTICIDE
RATE AND METHOD OF
APPLICATION
COMMENTS
Actellic Super Dust
25g for 50 kg of maize
To be thoroughly mixed with shelled maize
Actellic Super EC
25 ml in 10 l of water for spraying
10 to 20 bags of 50 kg each
Super Guard Dust
25g for 50 kg of maize
Super Guard EC
25 ml in 10 l of water for spraying
10 to 20 bags of 50 kg each
Shumba Super Dust
25 g for 50 kg of maize
To be thoroughly mixed with shelled maize
Chikala Super Dust
25 g for 50 kg of maize
To be thoroughly mixed with shelled maize
Novartellic EC
25 ml in 10 l of water for spraying
10 to 20 bags of 50 kg each
Spintor Dust
75 g for 50 kg maize
To be thoroughly mixed with shelled maize
Delta Force Dust
25 g for 50 kg of maize
To be thoroughly mixed with shelled maize
Fumigant (Fostoxin)
For fumigating maize in mudded
granaries, metal bins and silos,
and cemented granaries
To be thoroughly mixed with shelled maize
22
5.2.2.2 From Agro dealers
Table 8b. Storage insecticides being sold by Farmers World in Blantyre
INSECTICIDE
COMMON NAME RATE AND
METHOD OF
APPLICATION
PRICE (MALAWI COMMENTS
KWACHA)
Target Actellic
Supper
Pirimiphos mythyl 25 g per 50 kg K182 per 200g
+ Pemithrin
maize or beans (US$1.28 per
or pigeon peas 200g)
To be properly mixed with shelled maize
Spintor Dust
37.5g per 50kg
of maize
K410 per 300g
To be properly mixed with shelled maize
Noveltellic
Super EC
20 ml to 1 l of
water to 500 kg
of maize
K2800 per l
• Spraying with a proper sprayer should
be done under shade
• No drying in the sun (only under
shade) after spraying
Or 40 ml to 2
litres of water to
spray 1 tonne
of maize
Shumba Dust
• Provides 6-9 month of protection to
maize against all storage pests
25 g per 50 kg K320 per 200 g
maize or beans
or pigeon peas.
This translates
to 200g for 8
bags (50kg)
• To be properly mixed with shelled
maize
• Rated as the best by the company
Table 8c. Storage insecticides being sold by Chemicals and Marketing in Lilongwe
INSECTICIDE
COMMON NAME RATE AND
METHOD OF
APPLICATION
PRICE (MALAWI COMMENTS
KWACHA)
Super Guard
Dust
Pirimiphos mythyl 25 g per 50 kg
+ Pemithrin
maize or beans
or pigeon peas
K305 per 200g
wholesale price
Super Guard
EC
K355 per 200g
retail price
Pirimiphos mythyl 200ml for 10
K1330 per
+ Pemithrin
tonnes of maize 200ml
wholesale price
K1600 per
200ml retail
price
Fumaphose,
Quickphose,
Phostoxin
Aluminium
Phosphite
6 tablets for 1
tonne of maize
under tarpaulin
K1900 for
330 tablets
wholesale price
• Can control eggs and larvae of LGB
especially when maize is infested in
the field
K2295 for 330
tablets retail
price
• Fumigant
• Very toxic
• The company is not sure regarding
government policy whether smallscale farmers can use it
• Allowed to use by grain traders and
large scale producers who can use
trained applicators
• No residual protection
23
Table 8d. Other storage products being sold by Chemicals and Marketing in Lilongwe
PRODUCT
ESTIMATED PRICE
Super Grain Bag
US$3 per bag
PHOTO
DESCRIPTION
• A special bag for storing 50 kg maize and
is capable of suffocating any storage
pests during storage – no need for
treating the maize
• The effectiveness has not been tested in
Malawi, but it is being introduced into the
country and was originally tested by the
International Rice Research Institute (IRRI)
for storing rice
Cocoon
US$3000 for 300 t
• Not sure of the price
• Can be used for large scale storage
• Works like super grain bag
5.2.3
Tanzania
5.2.3.1 From national research (TPRI) and government maize storage experts
Table 9. Storage insecticides recommended by the national maize storage experts in Tanzania
INSECTICIDE
COMMON NAME
RATE AND METHOD COMMENTS
OF APPLICATION
Actellic Super Dust
Pirimiphos Methyl
1.6% + Permethrin
0.3%
100g per 90kg
LGB , maize weevils, storage moths, red
Flour Beetle, Bean Bruchid
Shumba Super Dust
Deltamethrin 0.13%
+ Fenitrothion 1.0%
50g per 90kg
LGB , maize weevils, storage moths, red
Flour Beetle, Bean Bruchid
Actellic EC
Primiphos – methyl
and Permethrin
Super Grain Dust
Bifenthrin
100g per 90kg
LGB , maize weevils, storage moths, red
Flour Beetle, Bean Bruchid
Stocal Super Dust
Pirimiphos Methyl
1.6% + Permethrin
0.3%
100g per 90kg
LGB , maize weevils, storage moths, red
Flour Beetle, Bean Bruchid
Nafaka Super Dust
Fenitrothion 1.7% +
Permethrin 0.3%
50g per 90kg maize
LGB , maize weevils, storage moths, red
Flour Beetle, Bean Bruchid
Sprintol Dust
Pyrethrin 0.1%
100/90kg
LGB , maize weevils, storage moths, red
Flour Beetle, Bean Bruchid
Diatomaceous Earth
(DE)
Silica
250g per 90kg maize
5.3
Maize storage structures
5.3.1
Bags
For treating the stores only
Bags or sacks are generally the most common method of storing maize and in Malawi; bags have a capacity of 50
kg while in Kenya and Tanzania bags have a capacity of 90 kg. Synthetic poly bags are currently the most popular
while gunny bags are both rare and more expensive. The following is a summary of recommendations regarding the
use of bags or sacks in order to reduce the amount of storage pests (Table 10):
24
Table 10. Summary of recommendations regarding use of bags in all the three countries
COUNTRY
RECOMMENDATION ON BAGS
Kenya
Use new bags, and spray in and outside the Store maize filled bags on a raised platform
used bags with Actellic Super EC
e.g. made of wood or poles, and should be
kept away from the wall
Tanzania
Spray used bags with Actellic Super
Malawi
Boil the used sacks in hot water and dry
properly before re-use
5.3.2
GENERAL FOR ALL
Stores
Brick constructed stores are also used for storing bags of maize and are ideal for fumigating maize since they are
situated far from the household but stores are uncommon since they are costly and susceptible to break-ins and
theft. Bricks can be removed from the stores giving thieves easy access to the stored maize. Stores were observed
in Tanzania and Kenya, but none were observed in Malawi. The use of the storage facilities will be discussed further
under the “what farmers are actually doing” section below.
5.3.3
Traditional Granaries
Granaries are normally made of sticks and are common storage structures in most African countries. Stores should
be: 1) smeared with mud inside and out in order to prevent damage from LGB, 2) covered with a roof in order to keep
rain water off and 3) built well off the ground with rat guards attached to the poles supporting the platform (Figs. 6a
and b). Granaries are normally built outside the house but due to security concerns, many are built inside the house
as was in some homes in the Millennium Villages in Tanzania and Kenya.
Fig. 6. Non mudded
(a) and mudded (b)
granaries (right)
5.3.4
Improved granaries/cribs
Improved granaries or cribs are a major improvement over the traditional granaries. The platform is made of a brick
structure, and cement is used for plastering inside and outside, instead of mud, giving the twig/stick woven structure
(some improved granaries are made from brick) increased durability (Fig 7). The improved structure also has a
door for removing maize grain and a better ventilation system due to the insertion of a plastic pipe and an improved
granary can also support fumigation of grains under supervision of trained personnel. Even though improved
granaries were recommended in Malawi adoption is almost zero and none were observed in Kenya or Tanzania.
One granary was constructed at Mwandama Millennium Research Village, and one was seen in rural Lilongwe built
under the Sasakawa 2000 project.
Fig.7. Improved
granaries/cribs
(cemented types)
25
5.3.5Small Metal silos/drums
Small metal silos are ideal for storing maize at smallholder farmer
level (Fig. 8). Small silos have different capacities, the lowest holding
5 bags, and can be sealed after loading thus suffocating any insect
pests in the grain. Silos can also be kept inside the house, which
can mitigate theft. The following recommendations apply when using
metal silos:
• Off the Ground - keep silos off the ground and away from the wall
• Dried Before Stored - maize should be dried and tested before
stored
Fig. 8. Small scale metal silos - standard (left), and
collapsible (right)
• Kept away from the Roof - to avoid overheating of grain
• Stored for 2 Months - maize should be stored for a minimum of 2
months
• Remove and Reseal - maize should be removed quickly, and the silo re-sealed to prevent excess air getting
in when removing part of the maize
• Remove from Outlet - grain should be removed from the outlet section only – not the top in order to create a
vacuum
Examples of small metal silos are those developed by the Tropical Pesticide Research Institute (TPRI) in Arusha,
Tanzania are presented in Fig. 8.
5.3.6Community metal silos
Large silos (Fig. 9) are ideal for community storage because of their
capacity, ranging from 500kg to 1800kg, to store larger amounts
of grain. Large silos work on the same principle as the small metal
silos; both are made from flat metal sheets, and should be air tight
and shaded in order to prevent overheating of the grain and sudden
temperature fluctuation. National scale silos are not discussed
because they are beyond the scope of this study – the study targeted
small scale farmers and community maize storage in order to help
farmers save their maize from storage pests.
Fig. 9. Community metal silos
5.3.7
Community Grain Stores
Community grain stores (Fig. 10) are large storage buildings with the capacity for fumigating and storing tonnes of
maize as such as those used by grain marketing organizations. Examples of brick and iron sheeted community grain
stores are shown in Fig. 10.
Fig. 10. Some
large scale storage
buildings (left = brick
type, and right = one
constructed from iron
sheets)
which can be used
for community grain
storage
5.3.8
Costs of the different storage structures (where available)
A summary of costs of different storage structures are presented in Table 11.
26
Table 11. Costs of different storage structures
STORAGE STRUCTURE
COST
Bags
• US$0.65 for synthetic poly bags
• US$1.6 for jute bags
Stores
• Not known
Traditional Granaries
• About US$10
Improved granaries/cribs
• US$250 for 2 tonne capacity
• US$500 for a 5 tonne capacity
Small Metal silos
• US$110
Community metal silos
• US$250 for 0.5 tonne capacity
• US$400 for 1.8 tonne capacity
Community Grain Stores
• Cost not known
27
6. Knowledge Gaps: Discrepancies between Experts,
Farmers and Millennium Villages
This section presents what farmers are doing in the field in relation to the production and storage of maize and will
reveal the knowledge gaps between: 1) experts/officials and farmers, 2) different Millennium Villages and 3) sources
of information on storage technologies. This section starts with the varieties farmers are planting to their preferred
and actual maize storage facilities.
6.1
Maize varieties and storage pests
A large number of maize varieties, whose seed is mainly provided by MVP staff, are being grown in the Millennium
Villages in Malawi, Tanzania, and Kenya but participating farmers, after growing the varieties, would like a stronger
say in the varieties provided by the MVP. In Malawi for example, farmers did not want to grow variety DK8073 since it
was getting infested by storage pests right in the field.
Maize varieties fall into two categories: 1) hybrids (mostly dent types) and 2) local (open pollinated) which are flint. In
discussion with farmers, many stated that some of the hybrids, particularly the more flint types which are poundable,
are also more tolerant to storage pests. It was also found that “local” varieties are more tolerant than hybrids and in
some cases farmers sold most of their harvests from hybrid growing, but kept the “local” maize.
The range of varieties grown by the visited Millennium Villages is presented in the Table 11 below. Some preference
of the different maize types given and reasons for their preference are also given in the Table 12.
Table 12. A list of varieties grown by farmers in the different Millennium Villages and their preferred varieties and
reasons for preference
MILLENNIUM
VILLAGES
(VILLAGES MET)
VARIETIES GROWN
IN MILLENNIUM
VILLAGES
VARIETIES
PREFERRED
COMMENTS
Mwandama
Research Village,
Zomba Malawi
• SC627 (Hybrid)
SC627
• Tolerant to storage pests
Nambande
Millennium Village,
Zomba, Malawi
• DK 8033 (Hybrid)
• SC403 (Hybrid)
• Poundable
• SC407 (Hybrid)
1. DK 8073
DK 8073
• DK 8051 (Hybrid)
• DK 8031 (Hybrid)
2. Pan 67
• DK 8073 (Hybrid)
• Pan 67(Hybrid)
• Local
3. Local
Gumulira Research
Village, Mchinji,
Malawi
• DK 8033 (Hybrid)
• DK 8033 (Hybrid)
It is not affected by weevils in the field
Inonelwa Millennium
Village, Ibiri Cluster,
Tabora, Tanzania
• Pannar
DK (hybrid)
• Due to high yields
• DK 8031 (Hybrid)
• Local
• DK
• Wind resistant
• SeedCo
• Good taste
• Ukiriguru
• Early maturing
• Ironga
• Katumani
• Katumbiri – Local
• Kiluna
• Shituka
• Quality Protein
Maize
28
Mbola Research
Village, Tabora,
Tanzania
• Katumbiri
• Pannar
• DK
• SeedCo
• Ukiriguru
• Ironga
• Katumani
• Katumbiri – Local
• Kilima
• Kaguha
• Yanga – Yellow
maize
• Gembe- Red
Maize
• Kilima (OPV) –
grown by 12 out of
32 people
• Ituka – grown by 7
out of 32 people
• Reasons include availability of seed
• High yielding
• Early maturing
• Drought resistant
• Katumbiri (Local)- • Easier to mill
early maturing
• Little flour produces big “Ugali”
grown by 30 out of
32 people
• Ukiriguru – grown
by 2 out of 32
people
• DK – grown by all
32 farmers
• Panner – grown by
6 out of 32 people
• Shituka
• Quality Protein
Maize
Nyawara, Nyandiwa,
and Gongo (at Gem
Hall), Siaya, Kenya
Western 403, 502
and 505
Western 502, and
505
Duma
• Western 403 – 15 out of 27 people
indicated it was more tolerant to storage
pests
• 505 - 7 out of 27 people indicated it is
more tolerant
Pannar
Pioneer
• Hybrid 614 – all 6 people who grew it
before stated that it is more tolerant
Local white
Local yellow
• 505 is sweet when roasted, double cobber
– high yielding
Local spotted
Kenya Seed 513
Ramula, Uranga,
and Lihanda (at BarKalare), Siaya, Kenya
Western 403, 502,
and 505
Western seeds 403
and 502
• They give big cobs, high yield, mature
early
Duma
• 403 does not rot easily
DK Monsanto
• 502 is not eaten by monkeys, and it is
tolerant to striga
Pannar
• 403 is tolerant to storage pests
Nyamula – local
yellow
Local white
Pioneer
Maseno double
cobber
29
Sauri
Western 403, 502,
and 505
Duma
Western 505
Western 505:
Ababari, Duma, and
local yellow
• It is tolerant to storage pests among the
hybrids, but only for a month
Monsanto
• Has enclosed cob
Ababari – local
• Big cob
Local yellow
• Sparkling while colour
Local white
• High yielding
Pioneer
• Wind resistant
Local Yellow maize is most tolerant
Ababari is second most tolerant
6.2 Maize harvesting processes
Harvesting processes include direct harvesting in farm, by shelling
and removing the cob only while leaving the maize sheath on the
maize plant which would be cut later, cutting the maize plants and
stooking (Fig.11) them so that the cobs are removed at a later date
(after some drying of the maize in the field). Even though this is a
common practice in Tanzania, farmers confirmed presence of storage
pests on maize while still stooked in the field. Common maize
harvesting practices have been summarised (Table 13).
Fig.11. Stoked maize before harvesting – a common
practice in Inonelwa Millennium Village, Tabora,
Tanzania
Table13 . Summary of maize harvesting practices
MILLENNIUM VILLAGE
HARVESTING METHOD
REMARKS
Mwandama Research
Village, Zomba, Malawi
Stooking and Direct
harvesting
The maize is stooked in the field after cutting the stems near
the ground level, and direct harvesting is carried out by
removing the inside cob (without the sheath) from a maize
plant. The remaining maize plant is removed later. The
stooked maize is harvested the same day to avoid theft and
damage by termites
Nambande Millennium
Village, Zomba, Malawi
Maize is shelled the
same day it is harvested
from the garden
Direct harvesting of the cob – dehusked and carried home
for drying for at least two weeks on the floor, mat, plastic
papers. Some farmers stook just to make sure all the maize
is harvested, and remove the cobs right away – same day.
Gumulira Research
Village, Mchinji, Malawi
Stooking
Temporary stooking, just to make sure all the maize is
harvested. Cobs are removed the same day without husks
Inonelwa Millennium
Village, Ibiri Cluster,
Tabora, Tanzania
• Stooking (63%)
Maize stays in the field after stooking for two months before
shelling it. By the end of the two months the maize is dry.
Mbola Research Village,
Tabora, Tanzania
• Stooking (47%)
• Shells direct and dries
at home (37%)
Those who shell direct from the maize plant in the field dry
the maize at home.
Stooking takes one to two months in the field
• Direct harvesting (53%)
30
Nyawara, Nyandiwa,
and Gongo (at Gem
Hall)
Cut and stook (35 out
of 40)
Direct farm harvesting (5
out of 40)
When the stovers have turned brownish, they are cut and
stoked for 1week on the farm then transported home. Cobs
are removed, dehusked then dried at home until the kernels
begin to separate from each other then hand shelled. The
shelled grains are then dried further for another 1week and
dryness is confirmed by hand tossing the grains and when
they make a ringing metallic sound then they are dry for
treatment and storage.
For direct harvesting the farmers wait until the cobs begin
to droop downwards as a sign of being dry then harvest by
dehusking, take home, dry for 1week. Maize are then sorted
according to size and presence/absence of pests on them.
Big grains shelled by hand while smaller ones are shelled by
beating the cobs in a bag with stick.
Anyiko, Nyamninia,
and Jina.(at Yala Guest
House)
Cut and stook
Cut and carry home(1)
Cut and dehusk at
home(21)
Direct harvest(3)
Stooking for 2-3 days, dehusk and carry home. Cobs dried
for 2-3 days, shelled then dried further for 4 days.
After reaching physiological maturity, the stovers ate cut,
transported home, dehusked and cobs laid in rakes within
the house where they dry for 4-5 days. Sorts according to
size and presence of pests on cobs. Shell then dries for 3-4
days; keep in the open for 2 days before storing.
Dehusk while the stover is left standing,dry the cob for 4
days at home,sort the cobs according to their grades and
size.
Ramula, Uranga, and
Lihanda (at Bar-Kalare)
Cut and stook
Cut halfway, stooked at home for 1-2 weeks, dehusked and
dry for 1week.Hand shelled then dry for4days to 1week
depending on the sun intensity. Treated then stored.
Sauri
Direct harvesting
Cobs detached from the stovers, dehusk then transported
home where they are dried till the kernels begin to separate
from each other. Shelled and dried for 1week, treated then
stored.
Cuts and stooks
Stooking and Direct
harvesting
The cut stovers are stooked in the farm for 1week, cobs
dried for 2-3 days, shelled and dried further for about 1week.
If a farmer has enough labour then harvests directly other
will always stook.The drying period is normally 3-4 days if
there is enough sunshine otherwise it rakes 1½-2weeks in
chilly weather for both cobbed and shelled maize.
6.3
Pre-storage structures
The most common pre-storage structures are drying cribs (Fig. 12), which come in a variety of shapes and sizes.
They are mainly used for drying maize and are particularly common in the tropics where temperatures are high
during the harvesting periods. Drying cribs are designed to let air in and facilitate drying of maize before shelling,
which on average takes up to two moths. Maize is kept in the drying cribs on the cob with husks removed.
In spite of the importance of drying cribs, they were rare among farmers visited throughout the study other than a
few villages in Malawi such as Mwandama and Nambande where a number of households had built drying cribs.
Interestingly, drying cribs were rare among the farmers visited in Gumulira. The farmers’ explanation was that their
maize was eaten by goats while drying in the cribs but this was due to the way the cribs were constructed. Fig. 13
below shows a drying crib constructed under a tobacco drying shed, which limits the height of the crib exposing it to
grazing goats.
In Tanzania one farmer in Mbola constructed his own maize drying structure which is a hybrid model between cribs
and platforms (Fig13).
31
Fig. 12. A non thatched drying crib
6.4
Fig.13. A version of a drying crib which was constructed under a tobacco shade in Gumulira Village
(left), and a drying structure constructed by a farmer in Mbola Millennium Research Village (right)
Storage structures
6.4.1Use of bags (sacks)
Bags are the most common maize storage facility in all Millennium
Villages in Malawi, Tanzania and Kenya and they are preferred over all
other storage structures because maize in bags can be stored inside the
house making them less susceptible to theft. Some farmers in Inonelwa,
Ibiri Cluster, Tabora, Tanzania, used stores which are built near the main
house. The most common bags in all Millennium Villages were synthetic,
and in Kenya farmers preferred jute bags (Fig. 14, right) which may not be
punctured and damaged by LGB unlike synthetic bags.
Fig. 14. Super grain bag (left) and a Hessian bag (right)
6.4.2
An Agro dealer in Malawi, Chemicals and Marketing, introduced
“Super Grain Bags” (Fig. 14, left) which apparently can suffocate
pests in storage but whether or not the bag can be punctured by
LGB has yet to be determined
Traditional cribs/granaries
Traditional granaries, residing outside the house, are very common in the Millennium Villages in Malawi (Fig. 15a).
In Tanzania, granaries were often found inside the house as a way to prevent theft (Fig. 15b). Common storage
structures were fist bags followed by woven baskets then drums, which were mainly found in Kenya.
Fig. 15. (a) Traditional granaries in Malawi (first two) and (b) inside a house in Tanzania (far right)
6.4.3Improved granaries
Fig. 16. An improved granary
Improved granaries have a capacity of up to 5 tonnes and are ideal for
storing large quantities of maize; especially by medium scale farmers
and/or close family members (Fig. 16 ). In the Millennium Villages of
Malawi, a number of farmers were able to harvest more than 2 tonnes
of maize, and could therefore easily utilise the smaller versions of the
improved granaries. Even though improved granaries were constructed in
Mwandama in Malawi they have yet to be fully embraced because farmers
stated they were too expensive to construct. But farmers have expressed
interest in building improved granaries if the MVP contributes cement and
the farmers all other building materials. No improved granaries were built
in the Millennium Villages of Kenya and Tanzania.
32
6.4.4Small Metal silos/Drums
Small Metal silos which carry about half a tonne of maize, though ideal
for storing maize even without treating with insecticides are not used
in all the Millennium Villages in the three countries visited. They are
however available at the TPRI in Arusha, Tanzania, and the team at the
institute indicated that they are used in Kilimanjaro Region of Tanzania.
The small metal silos were introduced in Kenya, but were not adopted.
Interestingly, two farmers, a lady in Nyandiwa Millennium Village,
and a man in Sauri MRV are using drums for storing their maize (Fig.
17). They both claimed they store maize for as long as two years. No
large scale community metal silos are being used in the MVs. The
community metal silos were launched this year in Malawi.
Fig. 17. A type of a two hundred litre drum being used
for storing maize in Kenya
6.4.5
Summary of storage structures in the different Millennium Villages
Below (Table 14) is a summary of storage structures being used in the MVs which were visited in Malawi, Tanzania
and Kenya. Of particularly interest is the fact that most people use synthetic bags.
Table 14. Number and proportion of farmers using the different storage structures in the respective Millennium
Villages
COUNTRY
MILLENNIUM
VILLAGE
COMMON
MAIZE
STORAGE
STRUCTURES
N0. USING
EACH
STORAGE
STRUCTURE
TOTAL NO.
FARMERS
WHO
ATTENDED
THE MEETING
PERCENT
(%) USING
EACH TYPE
OF STORAGE
STRUCTURE
Malawi
Mwandama
Synthetic
bags
27
27
100
Traditional
granary
8
27
30
Synthetic
bags
45
45
100
Traditional
granary
45
45
100
Synthetic
bags
34
43
80
Traditional
granary
39
43
90
Platform
6
43
14
Pot
4
43
9
Synthetic
bags
19
19
100
Granary
1
19
5
Tree bark1
1
19
5
Synthetic
bags
31
31
100
6
43
14
Gumulira
Nambande
COMMENTS
Treating with
tobacco stems
or tephrosia
leaves
Tanzania
Inonelwa
Mbola
Kenya
Nyawara,
Drums
Nyandiwa,
and Gongo (at
Gem Hall)
33
Kept in the
house
Anyiko,
Nyamninia,
and Jina.(at
Yala Guest
House)
Ramula,
Uranga, and
Lihanda (at
Bar-Kalare)
Sauri
Synthetic
bags
30
43
70
Traditional
granary
1
43
2.3
Clay pots
1
43
2.3
Synthetic
bags
28
39
71.8
Metallic drums 3
39
7.9
Woven
baskets
1
39
2.6
Drums
4
12
33
Synthetic
bags
7
12
58
Traditional
granary
1
12
8
Synthetic
bags
8
13
62
Drums
2
13
15
Granary
1
13
8
Pot
1
13
8
Kept in the
house
Note:
1 A type of a tree bark maize storing
structure kept inside the house (left),
and the type of tree the bark is taken
from (second and far left)
6.5
Treatment of grain by farmers
Treating maize grain with insecticides is a crucial method for controlling storage pests and fortunately, all the farmers
who attended study discussions in Mwandama, Nambande and Mbola MV’s said they were using insecticides. But
this was not the case in all villages where the proportion was much lower and in Gumulira for example, insecticide
use was as low as 21%. Apart from Gumulira, most villages used traditional methods such as ash and wild plants
rather than insecticides (Table15).
34
Table 15. Number and proportion of farmers using the different maize treatment insecticides in the respective
Millennium Villages
COUNTRY
MILLENNIUM INSECTICIDE
VILLAGE
USED
NUMBER
OF PEOPLE
USING EACH
INSECTICIDE
NUMBER OF
PEOPLE WHO
ATTENDED
THE FOCUS
GROUP
DISCUSSION
PERCENTAGE REMARKS
OF FARMERS
USING EACH
INSECTICIDE
OR
TREATMENT
(%)
Malawi
Mwandama
Modern
insecticides
(e.g. Actellic
super)
27
27
100
The farmers
indicated that
they all use
insecticides
even though it
might not be the
right doses
Nambande
Modern
insecticides (
45
45
100
The farmers
indicated that
they all use
insecticides
even though it
might not be the
right doses
Gumulira
Research
Village,
Mchinji,
Malawi
Modern
insecticides
9
43
21
79% did not use
any insecticides,
giving financial
shortage as one
of the reasons.
They instead
mill their maize
(to remove the
seed coat) and
store
Inonelwa
Modern
insecticides
16
18
89
Traditional
insecticides
2
18
11
Actellic super
dust
10
32
31
Actellic E C
3
32
9
Local remedies 32
(e.g. a local
wild tuber
(Mavumangizo))
– see
photograph
under
comments
32
100
Fumigant
tablets
2
32
6
Actellic super
dust
12
43
27.9
Scanar super
dust
1
43
2.3
Ash
26
43
60.5
Tanzania
Mbola
Kenya
Nyawara,
Nyandiwa,
and Gongo
(at Gem Hall)
35
Anyiko,
Nyamninia,
and Jina.(at
Yala Guest
House)
Ramula,
Uranga, and
Lihanda (at
Bar-Kalare)
Sauri
Actellic super
dust
8
39
20.5
Cow dung ash
11
39
28.2
Bean plant ash
2
39
5.1
Maize cob +
Cow dung ash
2
39
85.1
Tephrosia
candida
1
39
2.6
Not treating
15
39
38.5
Actellic Super
Dust – using
sachet, one for
4 bags costing
Ksh120
3
12
25
Ash – one big
8
cup for one bag
of maize
12
66.7
Insecticides
5
13
38.5
Ash
7
13
56.8
Ash +
Insecticide
2
13
15.4
36
7.
ANALYSIS
7.1
Importance of maize storage in Malawi, Tanzania and Kenya
Maize is harvested once a year in Tanzania and Malawi and even though Kenya has a bimodal rainfall system;
maize produced during the minor rainfall season is insignificant. With harvesting mainly occurring once a year,
large quantities of maize need to be stored in order to meet the maize demand throughout the year. Most farmers
however, are unable to store all of their subsistence maize due to lack of storage facilities and fear of losing their
maize to storage pests therefore they sell most of their maize only to have to buy back the maize at a later date and
at a much higher price than they sold it for. In most cases the price differential between the selling and buying prices
could easily offset storage costs, particularly if they were to use insecticides and treated or new bags (Table 16).
Table 16. Amount of money farmers would save if they treated their maize with insecticides and store in the different
Millennium Villages – assuming losses would be negligible if the maize is properly treated and stored
COUNTRY
MILLENNIUM MAIZE
VILLAGE
BUYING
PRICE
(ABOUT SIX
MONTHS
AFTER
HARVEST)
(PRICE PER
BAG)
MAIZE
SELLING
PRICE AT
HARVEST
(PRICE
PER BAG)
PRICE
DIFFERENTIAL
(PRICE PER
BAG)
(A-B)
COST OF
INSECTICIDES
PLUS LABOUR
FOR TREATING
ONE BAG
COST
OF A
NEW
EMPTY
BAG
C
D
B
MONEY
SAVED
PER BAG
IF THEY
STORED
THEIR
MAIZE
[(A-B)–
(C+D)]
A
Malawi
Tanzania
Kenya
Mwandama
K2,250
K500
K1,750
K91
K70
K1,589
Nambande
K2,250
K500
K1,750
K91
K70
K1,589
Gumulira
K2,250
K900
K1,350
K70
K70
K1,210
Inonelwa
TSh42,000
TSh18,000
TSh24,000
TSh3,000
TSh600
TSh20,400
Mbola
TSh42,000
TSh18,000
TSh24,000
TSh2,500
TSh700
TSh20,800
Nyawara,
Nyandiwa,
and Gongo
KSh2,400
KSh1,000
KSh1,400
KSh70
KSh50
KSh1,280
Anyiko,
Nyamninia,
and Jina
KSh2,400
KSh800
KSh1,600
KSh50
KSh50
KSh1,500
Ramula,
Uranga, and
Lihanda
KSh2,400
KSh1,000
KSh1,400
KSh50
KSh50
KSh1,300
Sauri
KSh2,400
KSh1,000
KSh1,400
KSh95
KSh50
KSh1,255
37
Exchange rates:
1. Malawi Kwacha: K141 = US$1
2. Tanzanian Shilling: TSh1200 = US$1
3. Kenyan Shilling: KSh64 = US$1
7.2
Importance of storage pests in the Millennium Villages
Storage pests are apparently a serious problem in all MVs where the study was undertaken in Malawi, Tanzania and
Kenya. They are causing substantial losses even when maize is treated by insecticides. according to the interviews
and observations, where LGB is present, the effect of the other pests is masked greatly due to the destruction
caused by the LGB. A summary of the importance of LGB and the other storage pests is presented below (Table 17)
Table 17. Relative importance of storage pests in the different Millennium Villages
COUNTRY
Malawi
MILLENNIUM VILLAGE
IMPORTANCE OF
PEST
IMPORTANCE OF
PESTS
Larger Grain Borer
Maize Weevil, Flour
Beetle, and other
pests
Mwandama
Nambande
Gumulira Research Village, Mchinji, Malawi
Tanzania
Inonelwa
Mbola
Kenya
Nyawara, Nyandiwa, and Gongo (at Gem
Hall)
Anyiko, Nyamninia, and Jina.(at Yala Guest
House)
Ramula, Uranga, and Lihanda (at BarKalare)
Sauri
Key to symbols:
The pest is less important
The pest is more important (please note that where LGB is present, the importance of the other storage
pests is masked)
38
7.3 Maize loss to storage pests and the corresponding monetary loss in the
different countries
Substantial amounts of maize are lost due to storage pests in Malawi, Tanzania and Kenya. Using the national loss
percentages, losses to national maize production translate to as high as 1.548 million MT in Malawi (Table 18) using
the 2006/07 maize production figures, which is equivalent to losing millions of US Dollars (USD). In Malawi, it is
equivalent to roughly 309.6 million USD per annum despite the countries’ current efforts to manage pests. Losses
could be even higher if management strategies for storage pests were not employed, as was experienced by some
farmers who lost up to 100% of their maize if they did not apply any pest control strategies. Despite concerted efforts
by governments and international development partners in all three countries; efforts to improve food security are
being drastically undermined by storage pests.
Table 18. Monetary loss to storage pests at national level in Malawi, Tanzania and Kenya
COUNTRY
NATIONAL
MAIZE
PRODUCTION
(MOST RECENT
ESTIMATES)
(MT)
PERCENT (%)
NATIONAL
LOSS DUE
TO STORAGE
PESTS
AMOUNT OF
LOSS DUE
TO STORAGE
PESTS (MT)
PRICE OF MAIZE LOSS IN
US$/MT
MONETARY
VALUE
(US$)
Malawi
3.44 million MT*
45
1.548 million MT
200
309.6 million
Tanzania
3.7 million MTx
40
1.48 million MT
170x
251.6 million
Kenya
2.5 million MT+
30
0.75 million MT
200x
150 million
Source:
• 2006/07 Agricultural Malawi Production (http://www.fews.net/docs/Publications/Malawi_200707en.pdf.).
• Regional Agricultural Trade Intelligence Network (RATIN); East Africa Food & Trade Bulletin, Oct ‘07 (No. 45)
Crop Production and Harvest Outlook (http://www.uce.co.ug/Ratin%20bulletin_Oct%2007.pdf.).
• Kibaara, W B (2005), Technical Efficiency in Kenyan’s Maize Production: An Application of the Stochastic
Frontier Approach, MSc Thesis, Colorado State University. 51 pp. (http://www.aec.msu.edu/fs2/kenya/o_
papers/tech_eff_maize.pdf.).
7.4 Factors influencing maize losses to storage pests at each level of maize
storage
An analysis of losses at each level in the maize chain – from the producer to the end user, reveals a number of
factors which come to play in the maize storing systems. These factors will be dealt with under each stage of the
chain/maize flow and will lead to developing stage specific recommendations. The stages which will be dealt with
in detail are: 1) the household level, 2) the maize holding stage for contributed maize, 3) the community cereal/grain
banks, and 4) the other stages.
7.4.1
Factors influencing losses at household level
The household level is the primary and most crucial level in the maize chain since maize losses at the household
storage level impact storage losses at subsequent stages in the chain. These factors will be discussed in relation to
each MV that was visited throughout the study.
7.4.1.1
Malawi
A general factor affecting losses from storage pests a part from
those outlined below is the use of the traditional granary locally
known as “Nkhokwe”. In spite of advice from local experts that the
local granaries should be mudded in and out side due to LGB which
can survive on the wood or twigs or bamboo used to construct the
granary, no mudded granary was observed in all the villages visited.
An example of the local granary is presented in Fig. 18.
Malawi has the largest number of maize storage insecticides. Unless
farmers are properly guided, choosing the right insecticide can be a
daunting task especially that not all insecticides are effective.
Fig. 18. A traditional non-mudded granary in Malawi
39
Drying cribs are ideal for controlling maize weevils because maize is often dried ushelled on the cob, which makes
it less susceptible to maize weevils than shelled maize. However in Malawi, they dry shelled maize on the cob
in drying cribs, which is more susceptible to the grain moth (S. cerealella). What is particularly problematic is that
LGB, one of the most prevalent and destructive pests, attacks maize stored on the cob regardless of the presence
or absence of the sheath. This may explain why there is increased maize loss in storage due to LGB; especially in
Millennium Villages in Zomba where LGB is a serious problem.
7.4.1.1.1Mwandama Millennium Village
Mwandama, one of the leading Millennium Villages in Malawi, has experienced rapid increases in maize productivity,
with a mean of 6.5 MT per ha. But despite these impressive figures, strategies to increase productivity did not
adequately consider the importance of proper maize storage thus substantial losses have resulted from storage
pests. Other factors influencing maize loss to storage pests are outlined below:
1. LGB is in abundance
LGB is abundant in Mwandama and observations of last season’s maize confirm that LGB is the determining factor
accounting for maize losses in storage. While in the field, farmer John Nickson Nkhoma, demonstrated the presence
LGB by showing a cob of local maize infested with up to 60 LGB, maize weevil and Flour beetles. Mr. Nkhoma and
his wife confirmed that the presence of LGB often results in the total destruction of their maize. Even though other
storage pests are present in the village, LGB exacerbates the situation and leads to increasing losses of maize during
storage. Furthermore, farmers witnessed LGB even boring into their plastic plates, clothes, and curtains.
2. Maize varieties
Fig. 19. Soft (left) and hard (right) grain hybrids grown in
Mwandama Research Village,
Farmers are growing hybrids which are mostly dent (soft) types,
hence are more susceptible to storage pests. Even though hybrids
are susceptible to storage pests, their yield potential is very high.
However, other types of hybrids being grown in Mwandama are more
susceptible than others. For example, the group stated that some
varieties get infested right in the field. This is therefore a contributing
factor to difficulties farmers have in controlling LGB and other pests,
and it is part of the cause of the increase in maize losses to storage
pests because most insecticides being used in Mwandama and
Malawi as a whole can not be effective to storage insect pests when
they have bored or laid their eggs on the maize grain. Differences in
maize hardness between two newly harvested hybrids was evident
(Fig. 19). Farmers indicated that the one on the right is more tolerant
and close to their local varieties in a number of characteristics
including tolerance to storage pests and poundability
3. Factors influencing the effectiveness of maize storage insecticides
Farmers indicated that the insecticides being used in the village were not effective; many still experienced losses to
their stored maize even two months after treating it with common insecticides. However, investigations showed that:
• From farmers’ responses, at least all farmers try to apply some modern insecticides – but may have limitations
in the way they apply, and types and effectiveness of the insecticides.
• D
ue to financial limitations farmers mostly purchase insecticides in sachets since they are much cheaper.
Unfortunately sachets were being sold at roadside markets where vendors were exposing the insecticides to
the sun’s heat, which reduces the effectiveness of insecticides.
• T
hrough discussions with farmers and Malawian professionals, it was discovered that vendors often sell
adulterated insecticides to farmers without their knowledge. They mix the insecticides with flour from ground
legumes which in the end looks very similar to the actual insecticides making it very difficult to tell the
difference between the two.
• There is also a tendency, particularly for vendors, to sell expired insecticides from across the border in Mozambique.
• A
pplication rate – there were apparent discrepancies regarding the application rate. For example the pesticide
manufacturing companies or wholesalers and researchers were stating that 200g of insecticides in dust form
can be admixed with 8 bags (i.e. 50g per 50kg maize). The instructions are actually written on the container for
the insecticides. However, the agrochemical trader in Zomba City stated that the 200g of insecticide should
be applied to only 4 to 5 bags or 200 to 250 kg of maize. He actually stated that if one followed the instructions
on the bottle his or her maize would be destroyed by storage pests.
40
• If using insecticide in dust form, the moisture content (MC) of maize is crucial at the time of treating for maize
must be dried to 13% MC for the insecticides to be effective. Maize is harvested at physiological maturity in
Mwandama MRV and dried in drying cribs before it is shelled, treated and put in bags. If maize is kept in the
drying cribs up to 2 months and dried properly to the right moisture content then insecticides will generally
be effective. However, the long drying period could expose the maize to storage pests such as LGB thus
rendering insecticides ineffective. In light of this complexity and the severity of damage of LGB, a more
detailed study is recommended.
• E
ffectiveness of some insecticides is questionable. There was a case of purportedly effective insecticide
which was bought direct from the importing company. It was even demonstrated by one of the company’s
experienced sales representative, but all the farmers treated maize and the maize treated for demonstration
by the representative was destroyed by LGB. The company was given feedback and as a result increased the
dosage of the insecticide. This is not the only case of insecticides being ineffective, commercial maize seed
treated with insecticide that was purchased in September 2007 for winter cropping was destroyed to almost
flour by LGB by May 2008 (Fig. 20).
Fig. 20. Insecticide treated maize seed reduced to flour (left) by Larger grain borer (being shown to farmers in the middle), and a comparison of the
destroyed seed with the non infested seed (far right)
There is a possibility that LGB has developed resistance to the main dust based insecticides and farmers seem to
believe that the EC formulations are more effective. However, it is important to investigate this further.
• Method for applying EC formulation - EC formulated storage insecticides ought to be applied with a sprayer
but not all farmers have sprayers and tend to improvise by using a bloom or leaves on twigs. It has been
found that use of alternative application methods results in uneven distribution of insecticides among the
grains, thus some maize grains remain unprotected. In addition, farmers may tend to dry their maize in the sun
after spraying the maize, thus destroying the effectiveness of the insecticide.
• U
nder dosing of insecticides can lead to their ineffectiveness. For example farmers may try to apply the
recommended insecticides dose for 8 bags to all their bags due to economic reasons.
• T
iming of insecticide application is crucial and insecticides should be applied before maize is infested but
farmers often try to treat their maize after infestation has occurred. But the eggs laid by the insect pests and
the insects already inside the grains cannot be killed by the insecticides and the eggs may hatch when the
effectiveness of the insecticides is reduced.
• T
he time of day is important when applying dust formulations. It is important to treat maize in the morning or in
the late afternoon when temperatures are cooler. The mixing of insecticides would also need to be carried out
under shade because heat reduces the effectiveness of the insecticide. It was apparent that farmers did not
know such details.
4. Proper storage is a major problem in Mwandama, Namande and Gumulira Millennium Villages. Even though the
project built an improved granary, which is very effective in protecting maize from re-infestation, farmers are not
adopting the storage facility. The main reason for non adoption was due to limited financial resources.
5. As a coping strategy farmers try to mill (remove the seed coat) and store their maize but this does not help
considering milled maize is also destroyed by maize weevils and LGB (Fig. 21).
41
Fig. 21. Milled maize reduced to
flour by Larger grain borer and
Maize weevil
7.4.1.1.2 Nambande Millennium Village
As with Mwandama, farmers from Nambade (from several clusters) indicated that insecticides do not work very well.
In fact one farmer was so desperate he used Marathion, which could kill that attempted to infest the maize. He was
advised on the spot of the dangers of toxic insecticides which are not recommended by the extensionists or the MVP
staff.
1. There is an urgent need to train farmers regarding the use of insecticides in all villages. In fact some traders are
selling fumigants such as fostoxin tablets which many farmers stated were very effective. Fortunately one farmer who
used fumigants slept outside of the house for five days while treating his maize but tragically, two children of the
same family died in Kasungu District in Central Region of Malawi from inappropriate application of fostoxin.
2. Unlike at Mwandama, fewer farmers use drying cribs at Nambande. One possible reason for this is that they
harvest their maize until it is dry in the field, thus exposing it to insect pests that infest maize while in the field such as
LGB and Maize weevil.
3. Just like at Mwandama, MC, effectiveness, application methods and rates of insecticides are applicable to
Nambande,
7.4.1.1.3 Gumulira Millennium Village
Gumulira did not seem to have as much storage maize losses as in Mwandama and Nambande. All farmers agreed
that if they used Actellic Super Dust their maize would be protected. However, the following observations can
account for losses from storage pests:
• •According to the farmers who attended the focus group discussions, most farmers did not apply
insecticides. For example, only 9 out of 42 farmers (or 21%) who attended were using modern insecticides
in spite of the fact that they all agreed insecticides can protect their maize. The reason is that farmers cannot
afford to purchase insecticides even though they are sold within walking distance.
• •The main insect pests observed were maize weevil and the Flour beetle and one farmer described an insect
close to LGB. Surprisingly government researchers indicated that LGB is present in Mchinji District where
Gumulira is situated.
• •As a coping strategy farmers mill (to remove the seed coat) their maize twice a year and store what is locally
referred to as “Mphale”, and farmers claim this method protects against storage pests.
7.4.1.2 Tanzania
Millennium Villages in Tanzania seemed to have low maize yields during the last two harvesting seasons; however,
this particular harvesting season is a bumper harvest and farmers are experiencing substantial maize losses due
to storage pests. Maize weevil, locally called “Tembo” or elephant and LGB are the main pests destroying maize in
storage. Even though Actellic Super and Shumba Dusts are used, farmers reported that the former is working well
while the latter is ineffective. Some of the factors influencing losses to storage pests are therefore outlined below for
all MVs which were visited:
7.4.1.2.1 Inonelwa, Migungumelo, and Mbola Millennium Villages
1. Varietal susceptibility
Some varieties get infested right in the field thus making it more difficult to manage storage pests in storage.
42
2. Harvesting system
Most farmers visited in the MV’s employ traditional systems for harvesting maize such as cutting maize stalks with
cobs still attached and then stooking. Maize then remains on the stook for at least 2 months or until dry in the field,
which can expose maize to storage pests (especially maize outside the stook) and farmers actually confirmed they
observed storage pests on their maize while still on the stook. Furthermore, infested maize is difficult to treat with
dust insecticides.
3. Use of insecticides
• For those who use insecticides, Shumba Dust works well and better than Actellic Super Dust, however many
found the smell of Shumba Dust more offensive compared to that of Actellic Super Dust.
• Those who use insecticides and granaries strongly believe that insecticides work better in granaries.
• A
part from Inonelwa, the proportion of farmers using modern insecticides was extremely low as was the use
of traditional remedies, which would account for maize losses.
• A
ll farmers from Mbola used a traditional insecticide, a tuber, which grows in the wild. They claimed it works
very well but further investigation would be needed to asses the efficacy of this technology.
• F
inancial resources are often limited, therefore some farmers could not afford insecticides but some also
stated that they would not use modern insecticides because their harvests were too low to warrant long
storage – this may not be common in this year’s harvesting season.
• A
vailability of insecticides is one of the major problems in the villages. They depend to a large extent on
vendors who peddle purportedly effective maize storage insecticides, some of which are not recommended in
Tanzania.
• S
ome farmers were using Actellic Emulsifiable Concentrate (EC) which is only recommended, by the
Tanzanian Authorities, for applying in storage areas and on used bags, thus showing a definite knowledge
gap.
4. Some farmers were using fumigants without proper training, which goes against government recommendations,
implying breakdown in information flow.
5. A DFID funded project previously supported and recommended the use of Diatomaceous Earths (DEs) in Kagera
and Central Tanzania but they are currently not used in any of the MV’s. The MVP could explore using DEs and
making them available to farmers.
6. Coping strategy - Milling and storing milled maize is the main coping strategy in the area as long as the milled
maize is dried properly.
7. Use of granaries, “Vihenge” - Most farmers do not mud their granaries inside and out as recommended by the
Tanzania authorities, this may have a serious baring on LGB.
8. Even though small maize silos are very effective in controlling storage pests; farmers do not use them and did not
mention them in the MVs.
7.4.1.3 Kenya
7.4.1.3.1 Nyawara, Nyandiwa, and Gongo; Anyiko, Nyamninia, and Jina; Ramula, Uranga, and Lihanda; and
Sauri Millennium Villages
Due to similarities in the pre-storage treatment of maize and storage methods, factors that could influence maize
storage losses will be discussed for all MVs in Kenya. Nyawara, Nyandiwa and Gongo were met as one group,
Anyiko, Nyamninia, and Jina in one group, Ramula, Uranga, and Lihanda in one group, and Sauri Millennium
Research Village was met separately. However the findings in all the groups of villages were similar. Factors which
could be influencing maize losses to pests in the villages are therefore outlined below:
1. Maize varieties
According to the farmers, some maize varieties are more susceptible to storage pests than others, which could
worsen the pest situation.
2. Maize harvesting method
The common maize harvesting method of leaving maize in the field until the cob droops or faces down suggests
that many farmers are not practicing early maize harvesting techniques. Leaving maize to dry this long in the field
43
is one way of exposing maize to storage pests such as LGB which starts infesting maize while still in the field. In
fact the maize is harvested when it is so dry that farmers only dry the maize for a maximum of a week at home after
harvesting.
3. Presence of Larger grain borer
All farmers acknowledged that LGB is the worst storage pest in their villages and is the main reason why farmers lose
maize even after treatment.
4. Use of maize storage insecticides
• A
large proportion of farmers in Kenyan MVs are using alternatives to modern grain treatment methods in
order to preserve and store their maize. In fact the highest proportion of farmers who used synthetic/modern
insecticides was 38.5% at Sauri MRV while over 85% of farmers in Anykio, Nyamninia and Jina MV’s were
using various types of ash as a treatment method. The most common ash come from cattle dung, tephrosia,
maize cobs, bean haulms or a combination of such. One farmer’s ash treated maize was apparently clean
after almost a year’s storage (some even claimed it could be stored up to two years) but even though farmers
claim ash is effective, it would be useful to carry out further experiments to establish the effectiveness of
ashes from different sources.
• The fact that very few farmers use synthetic insecticides leads to the build up of storage insect pests.
• A
ll agro-dealers and insecticide manufacturers recommended that maize should be inspected frequently,
at least weekly, and that it should be re-treated after observing re-infestation but it is difficult for farmers to
carry out frequent inspections when they are attending to other duties. Furthermore, it is difficult for farmers
to purchase insecticides to retreat their stored maize since most farmers have limited funds for purchasing
insecticides.
• Longevity of insecticides
The local research maize storage expert stated that Actellic Super dust is effective for 6 months; however, the agrodealers stated that it, along with fumigants, should be reapplied after every 3 months. This is costly for farmers
especially since they need to store their maize for more than 6 months before the next harvest.
• Time of application and the effectiveness of insecticides
Apart from fumigants, most dust insecticides are the contact type meaning that maize should be treated before it is
infested otherwise the insecticides will not work. With the practice of delayed harvesting, farmers actually treat their
maize after it has been infested explaining why some farmers who use insecticides actually experience infestation
shortly after treating their maize.
• Efficacy of insecticides
Farmers generally agreed that insecticides were effective, albeit for a short time, yet group discussions revealed that
insecticides may actually be ineffective in controlling storage pests. This came out strongly in group discussions and
some famers felt that this may be due to LGB developing resistance to the insecticides, which is possible since the
active ingredient in most insecticides has been used over a long period of time.
5. Storage structures
• Use of bags
Synthetic bags are the most common storage structure used by farmers but farmers claimed that LGB bores through
synthetic bags and that the jute bags are better for storing maize. LGB does in fact bore through synthetic bags, and
may even enhance maize losses to storage pests.
• Use of used bags
Used bags are one of the major sources of storage pests. National experts recommend spraying storage
bags previously used for storing maize before they are re-used but this is not feasible since: 1) not all farmers
have sprayers and 2) it would require purchasing additional insecticides just for the treatment of bags. The EC
formulations are recommended for the treatment of bags in Kenya and Tanzania yet in Malawi, EC formulations can
be diluted to spray grain and bags, even though boiling bags is recommended, boiling was not considered feasible
in Kenya due to shortages of firewood.
• Use of drums
Farmers who used drums were pleased with their level of protection; however drums require proper drying in order to
prevent maize infestation by Aflatoxin producing fungi.
44
6. Adulterated and unavailable insecticides
• Farmers living in remote villages are often susceptible to being sold fake insecticide. It has been reported that
some vendors travel to villages situated far from main trading centres and sell farmers adulterated or expired
storage insecticides.
7. Farmers reasons for the increase in pest storage problems
• Lack of knowledge, by farmers, in maize storage as being responsible for increased storage losses
• Inability to manage bumper harvests by farmers and sharp increases in yields.
• Lack of financial resources to purchase insecticides
• Inadequate maize storage capacity
• Low adoption of insecticides resulting in pest build-up
• Deforestation and/or removal of trees, which are considered alternative hosts.
7.4.2 Causes of losses at maize collection level
The challenges at this level of maize storage are enormous. Farmers who receive input support from the MVP are
required to pay back two bags of maize, which is cared for and stored by the agriculture committee at the MV level
with the support of the Agriculture coordinator. The time period in which maize is stored by agricultural committees
varies from country to country. Since maize yields were low the past two years in Tanzania farmers were excused
from contributing, therefore the discussion on Tanzania will be limited.
7.4.2.1 Malawi
Maize is received by the agriculture committee at each village and is stored at the centre of the MV, in most cases
it’s stored at the house of the Group Village Headman. The following are factors which could influence maize’s
vulnerability to storage pests:
1. Lack of appropriate storage facilities
Approximately 1000 farmers contributed 2000 bags (50 kg each) of maize and it was apparent that collecting points
lacked appropriate storage facilities. For example at Nambande MV a makeshift shelter made of sticks and grass
was constructed and used to store maize which resulted in substantial losses to storage pests and LGB, in particular.
2. School feeding program
The schools are required to store maize for the school feeding contribution even though school teachers and/or
administrators may not be knowledgeable in maize storing techniques, which have resulted in excessive losses.
3. Unprotected maize
Mainly due to financial constraints, farmers are unable to treat the maize they contribute to the MVP even though the
maize is consumed in their own communities. The contributed maize is therefore extremely vulnerable to storage
pest attack as was experienced by a number of receiving centres. Storing untreated maize could have contributed
to the failure of insecticides to protect the maize at a later date because it was infested from the outset. Fumigation is
often the only option after substantial amounts of maize are destroyed.
4. Large budget for treating maize
Maize is contributed to the school feeding programme and donated to vulnerable members of the community. Only
a small proportion is sold, sometimes to prevent further storage losses therefore it may not be sustainable for the
project to invest heavily in treating and storing the maize.
7.4.2.2 Tanzania
Due to low maize harvests over the past two years, the MVs in Tanzania have not been paying back as much maize
yet the current harvesting season is looking more promising. Some challenges therefore exist which could influence
maize losses to storage pests at this level in the maize chain. Below are some of the factors:
1. Lack of storage facilities
• Tanzanian MVs did not seem to have adequate storage facilities for storing pay back maize and this will
45
become even more challenging if Tanzania’s maize yields increase over the coming season.
• S
chools have small storage spaces, and in most cases classrooms are used for storing maize. This is likely to
result in huge losses to storage pests unless provisions are made for proper storage facilities.
2. Limited knowledge of maize treatment and storage
• School teachers and administrators may find it challenging to look after the school maize for feeding their
pupils. Unfortunately the agriculture team of the MVP may not be at all the schools in the MVs all the time.
7.4.2.3 Kenya
Just like in the Malawi, Kenyan MV’s experience major challenges when it comes to storing maize; especially at the
payback level in the maize chain. Maize is received through a payback system and collected at central points, which
in Kenya are generally primary schools where maize is often kept for lengthy periods of time before it is taken to the
NCPB. Due to various factors outlined below, substantial quantities of maize are lost to pests in storage because
maize is stored at schools before it is transported to the NCPB.. A study by Otieno (2008, unpublished) indicated
that 25 out of 127 bags of maize stored at a school in Yala Township and 28 out of 137 bags stored at a school in
Muhanda, from September 2007 to March 2008, suffered substantial losses. Below are several factors that could be
influencing maize losses at this level:
1. Maize contributed by farmers is untreated
Farmers confirmed that all the maize they contribute through the pay back system is not treated with insecticides,
thus making it extremely vulnerable to infestation by storage pests such as LGB, moths and weevils. Maize is also
not treated upon arrival at the collection centre resulting in excessive losses. Unfortunately this untreated maize is
sometimes kept for long periods before it is taken to the NCPB storage facilities.
2. Lack of proper maize storage facilities
Maize contributions are kept in schools as alternative storage facilities. At this stage the maize is not in the hands
of the school even though some of it will be brought back to the schools at a later date through the school feeding
programme, but this is after the maize has been taken to the NCPB for further storage. Although some schools have
warehouses where maize is kept such as at Yala Township School, still substantial losses occur.
3. Lack of proper care of maize by schools
Before maize is transported to the NCPB, there is lack of ownership by the school since not all the maize will be
coming back to the school as part of the school feeding programme. Furthermore, teachers and administrators are
not properly trained to store maize.
7.4.3 Causes of losses at Community Cereal/Grain Banks
• K
enyan Community Cereal Banks lack storage facilities, and can only store limited amounts of maize. For
example Marenyo Community Cereal Bank was temporarily storing only a few bags of maize, incidentally
infested with weevils, in a small building which was also housing a private maize mill. However, most of the
banks’ maize is stored at NCPB where it is treated and stored at a fee.
• M
alawi’s Grain Bank has no storage facility but one large storage structure is being built at Mwandama, which
will substantially ease the storage of maize for the grain bank. The storage facility being built at Gumulira
on the other hand, seems much smaller and may be limited in storage capacity. It is not certain whether
the system of grain banking in Malawi has started operating at the level of Kenya, where farmers own and
contribute to the cereal bank, with proceeds from their maize sales distributed back to the cereal bank
members.
• In Malawi, community storage outside MVP areas has taken off with the government providing metal silos for
community maize storage. The metal silos have a large capacity; which may ease maize storage losses at
community level.
• T
anzania’s cereal banks may not be operational due to low maize harvests - this may change in the near
future - but storage space could be very limited.
7.4.4 Losses at other levels (ADMARC, NFRA, NCPB, Traders)
• A
DMARC, the main maize marketing institution in Malawi, is capable of storing and fumigating maize and they
offer their services to farmers at a fee.
46
• M
alawi’s National Food Reserve Agency (NFRA), equivalent to Kenya’s National Cereals and Produce Board
(NCPB), has a huge capacity for storing maize at the national level and has silos in all regions of Malawi.
Unlike ADMARC, which buys and sells maize to people in the country, NFRA is responsible for food security
at a national level. They have the capacity to fumigate maize, and a programme to assist farmers in maize
storage and handling.
• N
CPB in Kenya also has a huge capacity to handle and store maize, their losses are limited, and they also
offer treatment services at a fee.
• •Information on national level maize storage facilities were not collected in Tanzania but the Post Harvest
Management Services of the National Food Security Division of the Ministry of Agriculture, Food and
Cooperatives have a programme to train grassroots government staff on grain storage technologies.
47
8. RECOMMENDATIONS
Recommendations have been split into short term and long term recommendations. The short term recommendations
are for immediate implementations in order to reduce loss of the recently harvested maize in MVPs in Malawi
and Tanzania, and the maize which will be harvested in September in Kenya. On the other hand long term
recommendations will form the basis for a project proposal which will be implemented over a three to five year period.
8.1
Short term recommendations
Short term recommendations are presented below for each MVP are presented in sections 8.1.1 to 8.1.3. A summary
of the short term recommendations are presented in section 8.1.4, specifically in Table 24.
8.1.1
Short term recommendations for Millennium Village Project in Malawi
Short term recommendations for the MVP in Malawi are presented in Table 19. In addition short term
recommendations specific to Mwandama MRV and Nambande MV are presented in Table 20 below.
Table 19. Short term recommendations for all Millennium Villages in Malawi
RECOMMENDATIONS STRATEGY
1. Provision of
Insecticides - the
MVP to facilitate
the availability of
insecticides to
farmers
• The MVP should purchase insecticides from reliable sources in Blantyre or Lilongwe to
provide to all eligible farmers so that it becomes part of the input support scheme. This
will prevent farmers from buying and using ineffective, even expired insecticides.
• Repayment arrangements could be organized by the project. Where possible farmers
should be encouraged to pay for the insecticides on receipt. Arrangements could be
made for farmers to pay with maize contributions which could be sold to recoup the
money.
• Insecticides with the following Active Ingredients (AI); Pirimiphos Methyl +
Permethrin, Bifenthrin, Fenitrothion + Permethrin, and Deltamethrin +
Fenitrothion should be used for treating maize as protectants.
• Fumigants with Aluminium Phosphite AI should be used for fumigating maize by a
trained fumigator particularly for MVs in Zomba.
48
2. Training on Maize
Storage - there
must be urgent
training on maize
treatment and
storage
• Training of trainers (TOT) should be conducted immediately so farmers can be trained
in the following:
i. Insecticide use - which insecticides to use for treating maize
ii. Maize drying – before treating maize with insecticides a simple Table salt test in a
closed bottle should be conducted to determine maize dryness. If not dry, the maize
will cause condensation and the salt will absorb moisture and stick to the inside of the
bottle
iii. Storage hygiene and treatment - for the used storage bags before storing in grain
iv. Treating maize - proper ways of treating maize using dust and EC formulations of
insecticides
v. Maize inspection and re-treating
vi. Fumigants - dangers and proper use of fumigants
vii. Food budgeting – so that farmers know how many bags of maize to store
• Trainees should include MVP and government agriculture staff who are working in MVs,
maize traders, and teachers from schools involved in school feeding programme.
3. Drying Cribs
– the period of
drying maize in
cribs should be
shortened to a
maximum of 4
weeks
• This is to reduce the time that maize may be exposed to infestation. However, farmers
should make sure their maize is dry by using the Table salt test (see 2 above) before
treating with insecticides and storing.
4. Awareness
Creation
• Posters and leaflets should be produced, in Chichewa, and disseminated as soon as
possible to sensitise farmers on proper storage and storage pest control. The following
areas should be included in campaigns:
i. Mud granaries - traditional granaries should be mudded in order to reduce
infestation from LGB, which can survive on the wooden components of the granary
ii. Store in grain form - farmers should store maize in grain form as opposed to
storage of maize in cob form. Cob form is more susceptible to LGB
iii. No sprayers no EC - farmers without sprayers or who can not access sprayers
should be discouraged from using EC formulated insecticides
iv. Dangers of fumigants - farmers should be informed about the dangers of
fumigants in tablet form – for example there was death of two children of a family
which used Phostoxin tables to fumigate the house in Kasungu District, Malawi
v. Maize drying and the Salt Test - maize drying and the table salt test
vi. Safety and dust formulations - safe use of dust formulations, time, methods and
rates of application
vii. Avoid mixing hard and soft maize - avoid mixing of dent (soft) and flint (hard)
grain maize types in one storage container
viii. Trash removal from maize - proper removal of trash from maize through
winnowing before treating with insecticides to facilitate protection of grain by contact
insecticides
5. Develop a System
for Measuring
Maize - MVP to
come up with a
way of measuring
50 kg to be used
when mixing with
insecticides
• Overfilling bags could contribute to under dosing insecticides but this can be solved by
providing maize measuring containers. For example containers could be developed
with the capacity to hold 10 kg of maize so that all maize treatment recommendations
to the farmers can be in form of numbers of containers, e.g. one 50kg bag equals 5
scoops from the maize measuring container.
• Similar arrangement has been done for insecticides, recommendations for farmers are
in form of a number of match box full
49
6. Build Storage
• Provide funds to permit each MV to build brick storage facilities where maize received
Facilities - where
from the pay back system can be immediately fumigated. Maize currently contributed
not available
through the pay back system is not fumigated. The store system would allow maize
receiving stores
to be held for longer periods (as is the case now) without losing much of the maize to
should be built
storage pests.
to store maize
received through
the payback system
Table 20. Specific short term recommendations for Mwandama and Nambande Millennium Villages in Zomba
RECOMMENDATIONS STRATEGY
1. Community Based • NFRA offered free fumigation services to farmers, but the project could contribute
Fumigation - if
transportation costs. The project could explore this further – contact The Chief
maize is already
Executive Officer of NFRA
infested with
• ADMARC also offered their services, but may be too expensive
storage pests, then
• Farmers should be responsible for transporting their maize, providing necessary
community based
assistance when setting up the fumigation process, and looking after the maize during
fumigation must be
fumigation
provided
• A nominal fee could be charged such as K5 per bag just to prevent development of
dependency syndrome
2. Dipping Maize in
Water - introduce
dipping of maize in
water before milling
at all maize mills
• This would help in drowning LGB and other pests in order to slow down spread of the
pests
3. Spraying
Campaigns - carry
out campaigns for
spraying farmers’
houses and storage
structures against
LGB
• Due to the high levels of LGB, all storage structures (houses, cribs, granaries
(nkhokwes), stores) in the MVs should be sprayed with an EC formulation of Actellic
Super or any other similar insecticide
• Currently, dipping is only carried out in maize for processing into mphale, the seed coat
is removed, but to include all types of milling of maize into flour
• A drum cut in half can be filled with water where maize can be dipped using a
perforated container
• This campaign should be led by the MVP with farmers providing labour for spraying.
This will be similar to the malaria control campaign which involves spraying houses with
insecticides to kill malaria vectors, mosquitoes, and is aimed at reducing the population
pressure of LGB in the villages
• Sprayers and protective material will need to be bought for each MV and can be used
for future operations.
4. Fumigate Before
• This should be done far away from people. If fumigating near a school (this may need
Treating with Dust
to be done while community storage facilities are being built) then it should be done at
- payback maize in
the far end of a football ground for example. This should be carried out by agriculture
receiving centres
staff of MVP who can seek extra guidance from the national storage experts.
and the cereal/grain
banks should be
fumigated before
treating with dust
8.1.2
Short term recommendation for Millennium Villages in Tanzania
Short term recommendations for MVP in Tanzania are presented in Table 21, and Table 22 for those specific to the
Mbola MRV.
50
Table 21. Short term recommendations for all Millennium Villages in Tanzania
RECOMMENDATIONS STRATEGY
1. The MVP to facilitate • The MVP should purchase insecticides from reliable sources in Dar es Salaam and
availability of
provide to all eligible farmers so that it becomes part of the input support scheme. This
insecticides to
will prevent farmers from buying and using ineffective, non recommended, even expired
farmers
insecticides sold around by vendors. Some farmers are very far from trading centres
and depend only on vendors who may sell fake or expired insecticides
• Repayment arrangements could be worked out by the project, but direct repayment by
cash should be encouraged. Arrangements could also be made for farmers to pay with
maize contributions which could be sold to recoup the money
• Insecticides with Pirimiphos Methyl + Permethrin, Bifenthrin, Fenitrothion + Permethrin,
Deltamethrin + Fenitrothion, and Pyrethrin AI should be used in treating maize as
protectants
• Fumigants with Aluminium Phosphite AI should be used for fumigating maize by trained
fumigators particularly for Mbola MV and other centres where LGB is more prevalent.
• Only purchase insecticides with the Tanzanian flag on the bottle – symbol of authenticity
- and from reliable dealers who cannot adulterate the insecticides
2. Awareness creation
• Posters and leaflets should be produced in Kiswahili and disseminated as soon as
possible to sensitise farmers on proper storage and storage pest control. The following
areas should be included in dissemination campaigns:
i. Mud granaries - traditional granaries, Vihenge should be mudded in order to reduce
infestation from LGB which can survive on the wooden components of the granary
ii. Store in grain form not on cob - Farmers should store maize in grain form as opposed
to storage of maize in cob form. Cob form is more susceptible to LGB
iii. Use of EC formulations - EC formulated insecticides should be used for spraying
maize stores, houses used for storing maize, used bags, and drums. Sprayers should
iv. Dangers of fumigants - Farmers should be informed about the dangers of fumigants
in tablet form
v. Maize drying and the salt test - before treating maize with insecticides a simple Table
salt test in a closed bottle should be conducted to determine maize dryness. If not
dry, the maize will cause condensation and the salt will absorb moisture and stick to
the inside of the bottle
vi. Safety and dust formulations - safe use of dust formulations, time and rates of
application
vii. Avoid mixing hard and soft maize - Avoid mixing of dent (soft) and flint (hard) grain
maize types in one storage container
viii. Trash removal from maize - proper removal of trash from maize through winnowing
before treating with insecticides to facilitate protection of grain by contact insecticides
51
3. Extensionists and
farmers should be
trained
• Training of trainers (TOT) should be conducted immediately so farmers can be trained in
the following:
i. Insecticide use - which insecticides to use for treating maize
ii. Maize drying - before treating with insecticides – to include a simple test for
determining maize dryness using the Table salt test in a closed bottle. Maize which is
not dry will cause condensation and salt will absorb moisture and stick to the inside
surface of the bottle
iii. Storage hygiene and treatment - for the used storage bags and stores before
storing in maize again
iv. Treating maize - proper ways of treating maize using insecticides in dust form
v. Food budgeting – so that farmers know how many bags of maize to store for their
consumption
vi. Maize inspection and re-treating
vii. Danger of fumigants - dangers and proper use of fumigants
viii. Trainees should include - MVP and government agriculture staff who are
working in MVs, and maize traders. teachers who are responsible for school feeding
programme should also be included in the training programme
ix. Use insecticide with Tanzanian flag - only purchase insecticides with the
Tanzanian flag on the bottle – symbol of authenticity
4. Stores should be
built for receiving
and storing maize
from the payback
scheme
• The MVP should build brick structures as stores for each MV where fumigation of maize
can be carried out at the point of receiving maize from the pay back system, and for
storage. Maize coming in from the pay back system is not treated by farmers. The store
system can allow holding of maize for longer periods without losing much of the maize
to storage pests before it is given to schools and vulnerable members of the community
5. All maize mills
sites should have
a tank of water
where maize should
be dipped before
milling
• This technique drowns storage pests in the maize, which can prevent spreading. It was
already recommended in Tanzania, although its adoption may be limited
6. MVP to come
up with a way of
measuring 90
kg to be used
when mixing with
insecticides
• Overfilling of bags could be contributing to under dosing of insecticides, this can be
solved by making containers available for example ones that can take 10 kg of maize so
that all maize treatment recommendations to the farmers can be in form of numbers of
containers, e.g. for 90kg it would be 9 containers.
• Water tanks can be in a form of a cut 200 litre drum which can be filled with water or a
concrete water rectangular water tank made from bricks and cement. Maize can be put
in a perforated container and dipped in the water for about 5 minutes
Table 22. Short term recommendations for Mbola Millennium Research Village
RECOMMENDATIONS STRATEGY
1. Diatomaceous
Earths (DEs) should
be tried at a pilot
level
• DE from Bukoba, Kagera Region or from Central Tanzania, should be tried with selected
farmers who are keen to test Des in the research village. The technology is bulky,
therefore arrangements should be made for transporting the soil
2. Use of a wild tuber,
locally called
“Mavumangizo” and
other botanicals
should be
followed up, and
its effectiveness
verified
• Almost all farmers in Mbola use this wild tuber, Mavumangizo – an inventory of
farmers using this tuber and other botanicals should be collected and kept, and
the Mavumangizo and or any other botanical treated maize should be monitored
periodically to ascertain the effectiveness of the tuber and other botanicals
52
8.1.3
Short term recommendations for Millennium Villages in Kenya
Short term recommendations for the MVP in Kenya are presented in Table 23, and Table 24 for those specific to Sauri
MRV.
Table 23. Short term recommendations for Millennium Villages in Kenya
RECOMMENDATIONS
STRATEGY
1. Maize should be
harvest timely in all
the MVP
• Farmers will need to be trained so that they harvest their maize at physiological
maturity. The current method of harvesting after the maize cob has drooped or has
dried completely exposes maize to pest infestation while it is still in the field
• Maize will be harvested from September in Kenya
• This information could also be included in dissemination materials
2. The MVP to
facilitate availability
of insecticides to
farmers
• The MVP should purchase insecticides from reliable sources in Kisumu or Nairobi to
provide to all eligible farmers so that it becomes part of the input support scheme. This
will prevent farmers from buying and using ineffective, even expired insecticides. This
is crucial because most farmers in Kenyan MVs do not apply synthetic insecticides,
mainly due to lack of finances.
• Repayment arrangements could be worked out by the project. Where possible farmers
should be encouraged to pay for the insecticides on receipt. Arrangements could be
made for farmers to pay with maize contributions, which could be sold to recoup the
money.
• MVP should obtain insecticides from reputable companies. One Agrovet in Kisumu
indicated, when queried about the insecticides which were about to expire, that even if
you take the expired insecticides to the dealer, the dealer will just remove the label and
replace a new one with a new expiry date – this component will be addressed further in
a long term recommendations
• Insecticides with Pirimiphos Methyl + Permethrin, Bifenthrin, and Pyrethrin AI
should be used in treating maize as protectants
• Fumigants with Aluminium Phosphite AI should be used for fumigating maize by
trained fumigators, possibly from NCPB
3. Extensionists and
farmers should be
trained
• Training of trainers (TOT) should be conducted immediately so farmers can be trained.
TOT training should target agriculture facilitators and other MVP agriculture staff so that
they in turn train farmers in the following:
x. Insecticide use - which insecticides to use for treating maize
xi. Maize drying - before treating with insecticides – to include a simple test for
determining maize dryness using the Table salt test in a closed bottle. Maize which is
not dry will cause condensation and salt will absorb moisture and stick to the inside
surface of the bottle
xii. Storage hygiene and treatment - for the used storage bags and stores before storing
in maize again
xiii. Treating maize - proper ways of treating maize using insecticides in dust form
xiv. Food budgeting – so that farmers know how many bags of maize to store for their
subsistence
xv. Maize inspection and re-treating
xvi. Dangers of fumigants - dangers and proper use of fumigants
xvii. Trainees should include - MVP and government agriculture staff who are working in
MVs, and maize traders. Teachers and school administrators who are responsible for
school feeding programme should also be included in the training programme
xviii. Only purchase insecticides from reliable pesticide traders
53
4. Awareness creation
Posters and leaflets should be produced in Kiswahili, Kiluya and Kijaluo, and
disseminated as soon as possible to sensitise farmers on proper storage and storage
pest control. The following areas should be included in dissemination campaigns:
• Mud granaries - traditional granaries and woven baskets should be mudded in order to
reduce infestation from LGB which can survive on wood
• Store in grain form not on the cob - Farmers should store maize in grain form as
opposed to storage of maize in cob form. Cob form is more susceptible to LGB
• Use of EC formulated insecticides - EC formulated insecticides should be used for
spraying maize stores, houses used for storing maize, used bags, granaries, woven
baskets and drums
• Dangers of fumigants - Farmers should be informed about the dangers of fumigants in
tablet form
• Maize drying and the salt test - the Table salt test should be used to confirm that maize
has dried adequately before treating with insecticides and storing it
• Safety and dust formulations - safe use of dust formulations, types of insecticides to
use, time and rates of application
• Avoid mixing hard and soft maize types - Avoid mixing of dent (soft) and flint (hard)
grain maize types in one storage container since the two have different levels of
tolerating storage pest infestation, and can therefore bring problems in protecting the
two types when mixed
• Trash removal from maize - proper removal of trash from maize through winnowing
before treating with insecticides to facilitate protection of grain by contact insecticides
5. Institute LGB
reporting system
• After farmers have been trained in proper identification of storage pests, they should be
reporting the presence of LGB in their storage to their local agriculture facilitator so that
they can be advised on appropriate insecticides use
6. Farmers who use
ash of different
types should be
supported to make
sure their maize is
safe from storage
pests
• The majority of farmers in Kenyan MV’s use ash and they seem to be pleased with the
ash’s effectiveness in keeping insects away
• However, it would be useful to have an inventory of all farmers who use ash and to
conduct follow-up visits to make sure ash is an effective technique for preventing
damage and/or infestation
7. Payback maize in
• This should be done far away from people. If fumigating near a school (this may need
receiving centres
to be done while community storage facilities are being built) then it should be done at
and the maize
the far end of a football ground for example. This should be carried out by agriculture
in Cereal banks
staff of MVP who can seek extra guidance from the national storage experts
should be fumigated
before treating with
dust formulated
insecticides
8. All maize mills
sites should have
a tank of water
where maize should
be dipped before
milling
• This technique drowns storage pests in the maize, which can prevent spreading. It was
already recommended in Tanzania, although its adoption may be limited
9. Stores should be
built to be used
for receiving and
storing maize
received through
the payback system
at each MV, and for
each Cereal Bank
• Provide funds to permit each MV to build storage facilities where maize can be
fumigated, treated and stored. In addition, each Cereal Bank should have a maize
store that can be managed by the members of the Cereal Bank. The Cereal Bank and
the agriculture committee members should undergo training in proper maize storage
systems.
• Water tanks can be in a form of a cut 200 litre drum which can be filled with water or a
concrete water rectangular water tank made from bricks and cement. Maize can be put
in a perforated container and dipped in the water for about 5 minutes
54
Table 24. Short term recommendation for the Sauri Millennium Research Village
RECOMMENDATIONS STRATEGY
1. Diatomaceous
• DE from Gilgil should be tested with selected farmers who are keen to test the DE
Earths (DEs) should
technology mainly in the Millennium Research Village
be tried at a pilot
level
8.1.4 Summary of recommendations (all countries)
A summary of recommendations for all the three countries is presented in Table 25.
Table 25. Summary of recommendations for Malawi, Kenya and Tanzania
RECOMMENDATIONS
1. The MVP to facilitate availability of insecticides to farmers
2. Training of agriculture staff and farmers in proper maize storage
systems
3. Use of maize cribs – the period of drying maize in the cribs should be
shortened, probably to a maximum of 4 weeks
4. Awareness creation in maize harvesting and handling, storage pests,
insecticide rates and proper use
5. Payback maize in receiving centres and the maize in Cereal/Grain
Banks should be fumigated before treating with contact insecticides
MALAWI
KENYA
TANZANIA
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
✓
6. Diatomaceous Earths (DEs) should be tried at a pilot level in
Millennium Research Villages
7. An inventory of farmers who use ash of different types should be
developed, and they should be supported and followed up to make
sure their maize is safe from storage pests
8. Institute LGB reporting system
✓
9. Farmers using wild tubers and other botanicals should be followed up,
and the effectiveness of the botanicals verified
10. Carry out campaigns for spraying houses and storage structures
against LGB in the Zomba MVs where there are high populations of
LGB
✓
11. Introduce dipping of maize in water before milling at all maize mills
in MVP to drown storage pests as part of an integrated storage pest
management
✓
✓
✓
12. MVP to devise a way of measuring maize quantities for treating with
insecticides e.g. develop a measuring container with 10 kg capacity
which could be used to measure 50 kg (5 containers equals 50 kg in
Malawi) or 90 kg (9 containers equal 90 kg in Kenya and Tanzania)
✓
✓
✓
55
13. Where not available maize stores should be built for storing maize at
each MV
8.2
✓
✓
✓
Long term recommendations for Malawi, Kenya and Tanzania
Long term recommendations for all countries are presented in Table 26 below. In addition long term
recommendations specific to Malawi have been presented in Table 27. The long term recommendations form a basis
for a project proposal which will be submitted separately.
Table 26. Long term recommendations for Malawi, Kenya and Tanzania
RECOMMENDATIONS/
POSSIBLE OUTPUTS
STRATEGY/ACTIVITIES
1. Socioeconomic analysis
to determine the feasibility
and economic viability
of different grain storage
practices at household,
community and district or
national levels
• Socioeconomic surveys to analyse impact on farmers of maize losses to storage
pests
2. Evaluation of existing
hybrid maize varieties for
tolerance to storage pests
• Farmer participatory evaluation of existing and upcoming maize varieties for
tolerance to maize storage pests
56
3. Training of agriculture
facilitators and farmers
• Training of Trainers (TOT) courses for agriculture staff who will in turn train
farmers
• Farmer field school (FFS) approach to be used in hands-on training of farmers by
agriculture facilitators
• Maintenance of FFSs
• Topics to include:
1. Insecticide use - which insecticides to use for treating maize
2. Maize drying - before treating with insecticides – to include a simple test for
determining maize dryness using the Table salt test in a bottle. Maize which is
not dry will cause condensation and salt will absorb moisture from the maize
and stick to the inside surface of the closed bottle
3. Storage hygiene and treatment - for the used storage bags and stores
before storing in maize again. Proper use of EC formulated insecticides in
storage hygiene and removal of residual maize
4. Treating maize - proper ways of treating maize using insecticides in dust
form. This will also cover types of insecticides in each country
5. Food budgeting – so that farmers know how many bags of maize to store for
their subsistence
6. Maize inspection and re-treating
7. Danger of fumigants - dangers and proper use of fumigants
8. Trainees should include - MVP and government agriculture staff who are
working in MVs, and maize traders. Teachers and school administrators who
are responsible for school feeding programme should also be included in the
training programme
9. Only purchase insecticides from reliable pesticide traders
10. Improved traditional granaries and their adoption strategies
11. Storing maize in grain vs. cob form
12. Use of drying cribs – if found effective in preventing infestation by storage
pests
4. Carry out research and
development activities on
biological control of LGB
• Support mass rearing and release of biocontrol agent, TN
5. Evaluation of existing and
new insecticides for their
efficacy to most important
storage pests
• On-farm farmer participatory evaluation of the existing and new insecticides
6. Evaluation of botanical
pesticides such as Neem,
ashes, wild tubers, and
other existing botanicals
with putative insecticidal
properties for their efficacy
against maize storage
pests
• On-farm farmer participatory evaluation
7. Detailed assessment of
maize losses from storage
pests
• National surveys to determine national losses to storage pests, especially LGB.
This will include follow up periodic surveys in selected households to determine
loss progression over time
• Monitoring the establishment and efficacy of TN on LGB
• Search for new biocontrol agents by incubating dead insect pests from untreated
maize, and evaluating what is found against LGB
• On-station evaluation to determine or confirm efficacy and exclude insecticides
which are no longer effective
• On-station research based evaluation of the materials
• Evaluation of sources of ash
• Determination of rates of application for botanicals and ash
• Controlled experiments to supplement survey data
57
8. LGB surveys to
• Biological surveys in maize and cassava growing, and forests areas. The survey
determine populations
will also include assessment of TN where it was released to determine whether it
and distribution of the
is established and its relative effect
pest in each country in
order to carry out area
specific LGB management
strategies
9. validation of small metal
silos and drums as a
possible component of an
integrated maize storage
pest control strategy
• Small farmer evaluation trials with metal silos and drums as a possible strategy
for long term grain storage system for farmers
10. Evaluation of “Super
Grain Bags” for maize
storage by smallholder
farmers
• Farmer participatory evaluation of the “Super Grain Bags” as a technology for
controlling storage pests without using insecticides. They will be evaluated in
relation to synthetic and jute bags
• Facilitation of farmers who are interested in adopting the technology
• Exploring possibilities of importing the bags cheaply since US$3 may be on the
higher side for smallholder farmers
• Scientific evaluation of the bags in order to determine their efficacy and durability
against LGB which bores through plastic
11. Verification of drying
cribs for preventing maize
infestation by storage
pests
• Survey of LGB and other storage pests in drying cribs at two weekly intervals
during the maize drying period in order to determine the optimum period for
drying maize in cribs before it is infested
• Determine the optimum maize drying time to 13% MC in order to come up with
area specific periods for drying maize in drying cribs
• A re-design of the distance from the ground for the crib platform in areas where
goats are a problem
12. Dissemination of
technologies on maize
storage and storage pest
management
• Production and dissemination of:
1. Posters
2. leaflets
3. Radio and TV programmes
• Topics to include:
1. Improving traditional granaries
2. Storing grains in grain form instead of cobs
3. Promotion of cribs – if found safe from overexposing maize to storage pests
4. No sprayers no EC - EC formulated insecticides should be used for spraying
maize stores, houses used for storing maize, used bags, and drums,
and grain where recommended. Proper application techniques will be
emphasised
5. Dangers of fumigants - Farmers should be informed about the dangers of
fumigants in tablet form
6. Maize drying and the salt test - maize drying and the Table salt test (see
recommendation number 3 above)
7. Safety and dust formulations - safe use of dust formulations, types of
insecticides to use, time and rates of application
8. Avoid mixing hard and soft maize - Avoid mixing of dent (soft) and flint
(hard) grain maize types in one storage container
9. Trash removal from maize - proper removal of trash from maize through
winnowing before treating with insecticides to facilitate protection of grain by
contact insecticides
10. Proper use of metal silos and drums
58
13. Validating and promoting
use of Diatomaceous
Earths (Des)
• Feasibility study on availability to farmers of DEs
14. Facilitating the adoption
of improved granaries
• Through developing cost effective granaries to improve adoption of the granaries
• On-farm farmer participatory validation of DEs as a maize treatment substance
• Is DE available in Malawi?
• Explore the feasibility of fumigating maize in-situ
15. Development of
recommendations for
storage pest management
at the different levels
• Recommendations developed from activities outlined above packaged into
maize storage pest control strategies
16. Promotion of the maize
storage pest management
strategy among policy
makers, extensionists,
farmers and other key
stakeholders
• Promotional activities – workshops for the key stakeholders in each country - also will act as an exit strategy for the project so that governments can take over
remaining promotional and support activities
Table 27. Long term recommendations specific for Malawi only
RECOMMENDATIONS/POSSIBLE OUTPUTS
STRATEGY/ACTIVITIES
1. Feasibility study/validation of large metal silos
• Farmer participatory validation and utilisation of metal silos
• Feasibility studies on carrying out in-situ fumigation of the
stored maize
59
9. References
Adesuyi SA, 1980. The problems of insect infestation of stored yam chips in Nigeria. Review of Applied Entomology,
68:abst. no.3650.
Atanasov H, 1977. Causes of the increase in the population density and economic importance of the red flour beetle
in storehouses and silos. Rasteniev”dni Nauka, 14(9):124-132.
Arbogast RT, Throne JE, 1997. Insect infestation of farm-stored maize in South Carolina: towards characterization of a
habitat. Journal of Stored Products Research, 33(3):187-198.
Babu SC, Subrahmanyam P, Chiyembekeza AJ, Ng’ongola D, 1994. Impact of aflatoxin contamination on groundnut
exports in Malawi. African Crop Science Journal, 2(2):215-220.
Boxall RA, 2002. Damage and loss caused by the Larger Grain Borer, Prostephanus truncatus (Horn) (Coleoptera:
Bostrichidae. Integrated Pest management Reviews, 7:105-121.
Braunschweig (Heft) I, Henckes C, 1992. Investigations into insect population dynamics, damage and loss of stored
maize: an approach to IPM on small farms in Tanzania with special reference to Prostephanus truncatus (Horn). Xiv
+ 124 pp. CABI Abstracts, CAB International 2007.
CAB International, 2007. Crop Protection Compendium, http://www.cabicompendium.org/cpc/home.asp
Compton JAF, Sherington J, 1999. Rapid assessment methods for stored maize cobs: weight losses due to insect
pests. Journal of Stored Products Research, 35(1):77-87.
Giga DP, Mutemerewa S, Moyo G, Neeley D, 1991. Assessment and control of losses caused by insect pests in small
farmers’ stores in Zimbabwe. Crop Protection, 10(4):287-292.
Giles PH, Leon O, 1975. Infestation problems in farm-stored maize in Nicaragua. In: Proceedings of the 1st
International Working Conference on Stored Products Entomology, Savannah, Georgia, USA, 1974: 68-76.
Hodges RJ, Dunstan WR, Magazini I, Golob P, 1983. An outbreak of Prostephanus truncatus (Horn) (Coleoptera:
Bostrichidae) in East Africa. Protection Ecology, 5(2):183-194.
Nichols TE, Jr., 1983. Economic impact of aflatoxin in corn. In: Diener UL, Asquith RL, Dickens JW, eds. Aflatoxin and
Aspergillus flavus in corn. Auburn, USA: Alabama Agricultural Experiment Station, 67-71.
Singh SR, Benazet J, 1975. Chemical intervention on all stages and on all scales of tropical storage practice.
Brady, E. U.; Brower, J. H.; Hunter, P. E.; Jay, E. G.; Lum, P. T. M.; Lund, H. O.; Mullen, M. A.; Davis, R. (Organisers):
Proceedings of the First International Working Conference on Stored-Product Entomology, Savannah, Georgia, USA,
October 7-11, 1974, 41-46.
Stoloff L, 1976. Incidence, distribution, and disposition of products containing aflatoxins. Proc. American
Phytopatholgical Society, 3:156-172.
White GG, 1982. The effect of grain damage on development in wheat of Tribolium castaneum (Herbst) (Coleoptera:
Tenebrionidae). Journal of Stored Products Research, 18(3):115-119.
60
ANNEXES
ANNEX
PAGE
ANNEX 1. Itinerary for the consultancy related travels and activities
61
ANNEX 2. Checklist used in facilitating discussions with farmers and key informants in the
Kenya, Malawi and Tanzania
63
ANNEX 3. A chart of common storage pests which was used to record the major storage insect
pests which are destroying farmers’ maize in storage (used during discussions with farmers)
67
ANNEX 4. The consultancy activities – Purpose and objectives, and description of consultancy
activities (from consultancy proposal)
69
ANNEX 5. Farmers’ suggestions on what should be done to improve the storage pest situation
72
ANNEX 6. Farmers’ views on whether the storage pest situation has worsened or improved
in the past three years, and their reasons.
73
ANNEX 7. – Detailed information for various storage pests of maize
76
ANNEX 1. Itinerary for the consultancy related travels and activities
DATE
ACTIVITY
21st to 25th April
Working in Nairobi
27th April 2008
Fly to Lilongwe, Malawi and travel to Zomba by road
28th April 2008
1. Meeting with the MVP Science Coordinator (Team Leader) and the Agriculture Coordinator in
Zomba, Malawi
2. Discussions with farmers and visits to selected households in Mwandama Millennium
Research Village, Zomba, Malawi
29th April 2008
Discussions with farmers and visits to selected households in Nambande Millennium Village,
Zomba, Malawi
30th April 2008
1. Discussions with Agriculture Extensions working in the Millennium Villages – meeting held at
Thondwe Extension Planning Area, Zomba, Malawi
2. Meeting with the crop storage team and the Pesticide Control Board at Bvumbwe Agriculture
Research Station, Thyolo, Malawi
3. Visit to Farmers World, Blantyre, Malawi
4. Visit to ADMARC Headquarters, Limbe, Malawi
1st May 2008
1. Visit to Thunga, Thyolo District to see the Community Metal Silos which were launched by His
Excellency, Dr Bingu Wa Mutharika, President of Malawi
2. Travel to Lilongwe, Malawi
2nd May 2008
Visiting selected households in Gumulira MVP, Mchinji, Malawi
3rd May 2008
Discussions with farmers at Gumulira MRV, but they came from several clusters, and more
visits to households in the other MVs
5th May 2008
1. Discussions with the Director of Crops, Ministry of Agriculture and Food Security
Headquarters, Malawi
2. Visit to Bunda College of Agriculture, University of Malawi
6th May 2008
1. Discussions with the Principal Secretary, Ministry of Agriculture and Food Security, Malawi
2. Discussions with the Director of Agriculture Research, Ministry of Agriculture and Food
Security, Malawi
3. Discussions with the Chief Executive Offer and the Finance and Administration Manager,
National Food Reserve Agency, Lilongwe, Malawi
4. Visit to Chemicals and Marketing Company, Lilongwe, Malawi
61
7th May 2008
Fly back to Nairobi
8th May 2008
Fly to Dar es Salaam
9th May 2008
Fly to Tabora
10th May 2008
1. Discussions with farmer in Inonelwa MV
2. Brief visit to and discussions with some farmers of Migungumalo Village, Msimba Cluster
11th May 2008
Discussions with farmers and visits to households in Mbola MRV
12th May 2008
1. Discussions with the District Agriculture Officer and District Crop Protection Officer for Tabora
2. A brief visit to the Provincial Agriculture Officer in Tabora
3. Travel from Tabora to Dar es Salaam
4. Discussions with the Assistant Director, Post-Harvest Management Services in the Food
Security Division at the Ministry of Agriculture Food and Cooperatives Headquarters
13th May 2008
Fly back to Nairobi
14th to 16th May
2008
Report writing
18th May 2008
Fly to Kisumu, Kenya
19th May 2008
1. Meeting the Team Leader (Science Head) and Agriculture Coordinator at the MVP office in
Kisumu, Kenya
2. Discussions with the Provincial Agriculture Officer, Kisumu, Kenya
3. Visits to agrovet shops in Kisumu, Kenya
20th May 2008
1. Discussions with the District Agriculture Officer, Siaya District, Kenya
2. Visit to Marenyo Community Cereal Bank, Sauri MVP, Siaya District, Kenya
3. Farmer discussions at Bar-Kalare, Sauri MVP, Siaya District, Kenya
21st May 2008
1. Visit to Yala National Cereals and Produce Board (NCPB), Yala, Siaya District, Kenya. The
Yala NCPB is also used for storing MVP maize from the area
2. Discussions with farmers at Germ Hall, Sauri MVP, Siaya District, Kenya
3. Discussions with farmers at Sauri MRV, Siaya District, Kenya
22nd May 2008
1. Discussions with the Agriculture Facilitators at Yala Guest House, Sauri MVP, Siaya District,
Kenya
2. Discussions with farmers at Yala Guest House
3. Visits to selected households in Sauri MVP
23rd May 2008
Trip from Kisumu to Nairobi
29th May 2008
Trip to Arusha, Tanzania by road
30th May 2008
1. Discussions with the Director and Crop Storage Scientist at the Tropical Pesticides Research
Institute, Arusha, Tanzania
2. Trip back to Nairobi
2nd to 25th June
Report writing
62
ANNEX 2.
Checklist used in facilitating discussions with farmers and key informants in the Kenya, Malawi and Tanzania
DISCUSSIONS WITH FARMERS
Name of Millennium Village……………………..................................... Number of farmers attending the discussion ………
Date ………………….
1.
Information on groups
1. Location of MV (District)……………..
2. A. Maize production
1.
List the main varieties grown in your villages
2.
Which is the most preferred, why
3.
List most resistant varieties to maize storage pests
4.
Quantity of maize produced per hectare (Ha.). Obtain the average from the group
5.
What are the reasons for choosing a particular variety if you choose?
B. Harvesting practices
1.
How is maize harvested?
2.
Do you carry out any drying in the field?
3.
How long do you dry your maize before you put your maize in storage?
4.
How do you know that the maize has dried enough? How do you dry your maize?
5.
Who is responsible for drying and storing maize?
C. Maize use
1.
Sold, shared, saved as seed, stored at home, stored centrally; given away);
2.
Quantity which is sold at different times of the year and to whom it is sold
3.
Do you store your maize in grain form or on the cob?
4.
Do you sell any of your maize? Yes/no. How much do you sell, to who?
5.
How much of the maize do you store?
D. Marketing patterns
1.
How is maize sold, at home, at a local market, special market such as ADMARC?
2.
When do you normally sell your maize; soon after harvest, six months after harvest, or just before the next
harvest?
3.
What are the common reasons for selling the maize?
E. Pre-storage management and treatment
1.
How do you handle your maize after harvesting?
2.
Do you treat your maize with any pesticides or any form of treatments before storing, mention the treatment?
What is the rate?
F. Relative importance of maize storage pests to farmers
1.
List five major pests of maize in the field?
2.
Do you experience any pest damage to your maize in storage? Yes/No
3.
Carry out matrix ranking of pests of maize especially in storage to gauge relative importance of storage pests
affecting maize quantity in storage, livelihoods, household incomes etc.
63
G. Awareness, incidence and loss from maize storage pests
1.
Farmers knowledge of storage pest losses; losses due to maize storage pests
2.
List five major pests of maize in storage? (after listing NP to circulate the photos of common storage pests to see
if they are same as they experience
3.
According to you how much maize in terms of bags is lost to pests eg out of ten bags stored, how much would
be lost to pests after:
i.
3 months?
ii.
6 months?
iii. 1 year?
4.
Do they recognize the different storage pests and their effects on stored maize
5.
Has incidence of maize storage pests decreases or increase in the past three years? Ask farmers to provide
reasons for the decrease or increase.
6.
Estimate the maize loss in storage from pests
H. Control of storage maize pests and coping strategies
1.
List the four major control methods for maize storage pests
2.
number of members controlling maize storage pests
3.
For the methods of control used; carry out matrix scoring of these methods to establish the farmer rating these
methods
4.
Problems encountered while trying to control the pests
5.
Are the control methods successful? If not why not?
6.
If the use materials such as insecticide – where do you source materials – if source is far how do they go to
collect the materials and what does it cost
7.
what do you do when your maize has been destroyed in storage by storage pests
8.
List other causes of losses, such as weather, rodents, fungi, theft – in order of priority
9.
Suggestions on how to improve control of storage pests
I. Storage structures; management during storage
1.
List five major storage methods/structures you use; e.g. bags (Hessian, sisal, plastic, drums, cribs, big earthen
pots, platforms or grain stores etc
2.
In your view which is the most ideal method in controlling storage pests, why?
3.
How maize is harvested and stored?
4.
Do you store everything together or separate particular grain for storage and immediate use?
5.
Do they have facilities to store as much maize as they want – or are they forced to sell some immediately
because of lack of space
L. Costs of storage
1.
Pre-storage treatments – cost of pesticides, transport, cost of applying pesticides, cost of storage structures,
e.g. bags, tins, cribs (construction and maintenance), pots, grain stores
2.
Quantify costs associated with the different control methods
3.
How much maize would you lose if you did not treat your maize?
M. Constraints and opportunities
1.
How would you treat and store your maize if you had adequate resources
2.
What would you like Millennium Village Project to do in the area of maize storage in order to reduce maize
storage losses?
3.
What areas would you require more information/investigated further?
4.
Are there materials (e.g., insecticides) that you know would be useful but can’t source them – if so what are
these and do you know where they are
64
DISCUSSIONS WITH MILLENNIUM VILLAGE PROJECT STAFF AND GOVERNMENT AGRICULTURE
EXTENTIONISTS
1.
What maize treatment methods do you recommend to farmers before and during storage?
What rates if insecticides?
2.
Are farmers following the recommendations? Yes/no
3.
If no why
4.
In your view, which recommended maize treatment methods are used by farmers?
5.
What are the routes the maize takes after it is harvested by farmers?
6.
What proportions is stored by:
a.
Farmers?
b.
At community level storage facilities? What proportion is sold?
c.
How is it sold? What community based/bulk storage facilities are available? Who is in charge?
7.
Where does maize go to from community based storage facilities? In what proportions?
8.
What are the main maize storage structures at the central storage centres?
9.
What are the main storage pests experienced in the bulk storage facilities?
10. What proportion of the maize is damaged by storage pests?
11. What is being done to control the pests?
12. Are any insecticides applied? Which ones? What are their costs?
13. Which insecticides are most effective? How are they applied?
14. How much/what proportions of maize do farmers actually lose in storage?
a.
If they do not apply any insecticides?
b.
If they apply insecticides?
c.
In each storage type? Storage type and loses:
15. What storage methods do you recommend to farmers?
16. In your view which are the common storage facilities which are used by farmers:
17. What are the maize varieties which you recommend?
18. Which varieties are tolerant to storage pests?
19. Which varieties are mostly grown by farmers in MVP areas?
20. How much would farmers get per bag if they sold their maize soon after harvest?
a.
After storage?
21. How much does maize cost from traders?
a.
At harvest
b.
Just before next harvest
22. How much does maize cost from semi government maize marketing institutions?
23. What areas of maize storage would you like investigated further?
MEETINGS WITH MAIZE STORAGE RESEARCHERS
1.
The recommended maize storage facilities in the country:
2.
What are the recommended pre-storage maize treatment methods for the country?
3.
What are the most important storage pests in the country?
4.
What loses are expected if maize is not treated?
5.
What is the cost of insecticides used in treating maize before storage?
6.
What are the costs of the different recommended storage facilities?
65
7.
What proportion of maize would be saved if the farmer followed the recommended maize treatment and storage
facilities?
8.
What are the main areas of research in maize storage you feel should be investigated further?
MEETING WITH GOVERNMENT MAIZE AUTHORITIES (DEPARTMENT HEAD(S))
1.
What is the government policy on maize in relation to food security, curbing storage losses, etc?
2.
What are the main maize varieties which are recommended in the country?
3.
In your view what are the major constraints to maize production?
4.
What are major maize storage constraints?
5.
What is the ministry/department doing to manage the constraints?
6.
What is the department’s priorities in maize storage?
7.
What are the losses due to pests in storage at:
a.
Household level?
b.
At national level?
NATIONAL SILOS
1.
What is the proportion of the annual production which comes to the silos?
2.
What route does the maize follow from harvesting to the silos?
3.
What are expected losses a long the chain? (sources of maize which is stored in the national maize silos)
4.
What are the main pests in storage in the silos, and how are they managed?
5.
What do you think could be possible areas of improvement as far as curbing losses in storing in the silos,
funds permitting?
GOVERNMENT MAIZE MARKETING ORGANISATIONS (EG ADMARC IN MALAWI) /CEREAL BOARDS
1.
Roughly what proportion of maize do you buy from farmers’ annual production?
2.
How do you store maize soon after purchasing the maize at your satellite and area markets?
3.
How long is maize kept at the primary buying depots?
4.
How long is maize kept at the area depots?
5.
What are the maize storage pests you encounter at each level/depot type?
6.
What do you do to control the pests?
7.
What insecticides do you sell to farmers for controlling storage pests?, what are the costs?
How are they applied, at what rate?
8.
What are the potential losses if you do not carry out the necessary treatments?
9.
What proportion of the stored maize is still lost even when you apply the necessary treatment and storage?
a.
At primary maize buying depots?
b.
At area depots?
c.
At regional or central depots?
10. What proportion of the maize goes to the national maize silos?
11. What proportion is sold at the organisation’s depots?
66
ANNEX 3. A chart of common storage pests which was used to record the major storage insect pests which are
destroying farmers’ maize in storage (used during discussions with farmers
Do you know your enemy - Common pests of stored maize
1
2
3
4
5
6
67
7
8
9
10
11
12
13
68
Key to pests
Number
Name of pest
1
Maize weevil
2
Rice weevil
3
Rice weevil
4
Granary weevil
5
Confused flour beetle
6
Rust Red Flour beetle
7
Larger grain borer
8
Larger grain borer
9
Confused flour beetle
10
Confused flour beetle
11
Lesser grain borer
12
Angoumois Grain Moth
13
Fungal (mycotoxin) contamination
ANNEX 4. The consultancy activities – Purpose and objectives, and description of consultancy activities (from
consultancy proposal)
1. Purpose and Objectives
The purpose of the proposed consultancy is therefore to reduce post-harvest losses of maize in the Millennium
Villages of Kenya, Malawi and Tanzania, and by extension across the region, through improved management.
The specific objectives are:
• To make a rapid assessment of maize storage practices and losses in Malawi, Kenya and Tanzania
• To provide interim recommendations (best practice) for managing maize storage pests in these countries
• To prepare a full CABI-MDG Centre joint proposal for submission to donors.
2. Description of activities
The following activities will be carried out:
Activity 1: Literature review
A literature review of the latest maize storage and pest management methods, with a view of choosing the most
appropriate management practices for stored pests for use by farmers in the Millennium Villages, other farmers
surrounding the Millennium Villages, and the country as a whole. Literature review will form the first component of the
study.
Activity 2: Consultation
In the Millennium Villages of Kenya, Tanzania and Malawi, discussions with members of staff and participating
farmers will determine the varieties of maize being grown, storage methods, and methods currently used to manage
pests of maize. Grain storage experts from the national programmes, as well as government officials responsible
for maize production, will also be consulted, to determine available storage methods in each country and their
perceptions regarding maize storage pests. In addition, the most common maize storage structures and pests will
be physically examined, to validate the information acquired through discussions. Stored grain will be randomly
sampled using a spear sampler to determine the most common maize storage pests particularly under smallholder
conditions.
Activity 3: Development of interim recommendations
The findings of Activities 1 and 2 will inform the development of interim recommendations on best practice for the
management of maize storage pests within the context of the current state of knowledge.
69
Activity 4: Development of a comprehensive proposal for an integrated and sustainable management
system for maize storage pests
There is a need for further research and development activities to build upon current knowledge to expand the
range of options available for effective management of stored maize in the region. The consultancy will include the
development of a full project proposal which will include the following areas:
• Review and validate, using farmer participatory methods, the technical efficacy of managing maize storage
pests
• R
eview of the available maize varieties and documentation of tolerant (hard grain) varieties. This will include
short term storage experiments in liaison with the national teams. The review will also include the use of
hybrids vs. open pollinated varieties and their associated socio-economics of storage
• D
evelop storage pest management recommendations which can be taken up at household, community and
large scale levels
3. Methodology
Different methods will be used in carrying out the different activities. A summary of the methodologies which will be
used are presented below:
Activity
Methodology
Activity 1: Literature review
A desk study.
Activity 2: Consultation
1. Discussions with Millennium Village staff and at least 10 farmers;
discussions will aim at answering the following questions:
• Are there pest problems in maize production?
• Which are most important pests during pre- and post-harvest of maize
(ranking of 1-5 in level of importance)?
• What are the farmer/staff doing about the pests?
• What control measures are they using if carrying out any control measures?
• How successful are the methods in controlling the pests?
• What are their sources of information on maize production, storage, and
pest control?
• Which are the main storage methods farmers are using?
• What maize varieties are farmers growing in Millennium Villages?
• What aspects of maize storage (including pest management) would they
like research to investigate further?
2. Discussions with government
agriculture extension and crop
storage staff to find answers to
the following questions:
• Which are the most common maize varieties being grown in the country?
3. Physical assessment storage
structures and the pest status.
• Maize in storage will be randomly sampled for presence/absence of the
main storage pests. This will not be a detailed study due to limited time
available. More details will be carried out in the main project if the main
proposal is funded.
Activity 3: Development of interim
recommendations
Desk study. Recommendations will be given on predominant storage pests
and structures found during visits to the different countries and Millennium
Villages in the respective countries, and will be based on findings from
literature review.
Activity 4: Development of a
comprehensive proposal for
an integrated and sustainable
management system for maize
storage pests
Desk study which will utilize findings from the field visits and literature review.
• What are the most common storage problems/pests in the country?
• What are they doing about it?
70
4. Expected outputs
1. A report outlining:
a. The main methods for storing maize in participating countries
b. The main maize storage pests in each of the Millennium Villages in Malawi, Kenya and Tanzania
c. The main methods being used in managing the main storage pests by farmers in the Millennium Villages of
the three countries
d. Recommendations on the best interim methods for managing the maize storage pests
2. A full project proposal on integrated management of the main maize storage pests in the Millennium Villages, to
be co-hosted by CABI and the MDG East and Southern Africa Centre.
5. Schedule of activities:
Activity
Week 1
Week2
Activity 1: Literature Review
Activity 2: Consultation
• Visit to Malawi
• Visit to Tanzania
• Visit to Western Kenya
• Report writing
Activity 3: Development of interim
recommendation
Activity 4: Develop a full proposal
71
Week 3
Week 4
Week 5
Week 6
ANNEX 5. Farmers’ suggestions on what should be done to improve the storage pest situation
Millennium Village
Suggestions
Mwandama Research
Village, Zomba Malawi
• The project to provide cement while the farmers to provide labour and the rest.
• Grain banks to be used by the community members who don’t have granaries.
• The project to assist in sourcing for good storage pesticides.
• Farmers to be trained on the chemical applications and the right type of
chemicals to be used.
Nambande Millennium
Village, Zomba, Malawi
• Provide farmers with good seed varieties.
• Construct Granaries in every house hold as the farmer provides labour, sand and
bricks.
• Sprayers to provide chemicals and technical advice.
• MVP to come up with formulations to control LGB.
Gumulira Research Village,
Mchinji, Malawi
• The project to provide storage pesticides and a technical person to advice the
farmers on their application and storage.
• Construct a grain bank.
Inonelwa Millennium
Village, Ibiri Cluster, Tabora,
Tanzania
• The project to help with storage pesticides which are effective.
Mbola Research Village,
Tabora, Tanzania
• To provide sisal bags which are mare durable.
• To provide durable storage bags.
• Should assist them to make cribs or granaries.
• Provide stores/granaries.
• Set up dome granaries.
Ramula, Uranga, and
Lihanda (at Bar-Kalare)
• Provision of safe storage structures.
• Community Silos.
• Improvement on cereal banking where their maize is stored at a small fee.
Anyiko, Nyamninia, and Jina. • Construction of a community to be maintained by them.
(at Yala Guest House)
• Should be taught on how store their produce and to construct modern granaries
e.g. metallic silos.
• Should be provided with sisal gunny bags.
• To be advised on the recommended pesticides or supplied with.
Nyawara, Nyandiwa, and
Gongo (at Gem Hall)
• Construct a storage facility like the NCPB one at Yala.They are willing to pay a
small fee.
• The community store could be paid in of the produce harvested.
• Transport should also be organised in the form of a community van.
• MVP to open an enterprise where they can sell their maize.
• Trained personnel to advice on the proper storage operations.
Sauri
• They should be supported through construction of mini silos at household level.
• Construction of improved cribs.
• Build bigger rooms for them so as to have store room within.
72
ANNEX 6. Farmers’ views on whether the storage pest situation has worsened or improved in the past three years,
and their reasons.
MILLENNIUM VILLAGE
PEST PROBLEM
INCREASED OR
DECREASED
REASONS
Mwandama Research
Village, Zomba Malawi
Increased (All
groups)
• Insufficient storage structures to store maize
• Most of farmers do not have enough money to buy
chemicals(insecticides)results into high multiplication of
storage pests
• Most of storage pests enter our village through maize
assistance from government to the past three years the
multiplication of insect is faster
• The hybrid maize is soft
• Food aid came with storage pests
• Because of delays in harvesting
• Not applying insecticides on time
• Due to coming of different maize types in the Grain Bank
• Lack of applying the correct insecticides
• Increase in amount of hybrids maize
• The insecticides which are being bought are ineffective
• Lack of proper care from harvesting such as not putting in
sacks
• Coming of maize/food which came with weevil storage pests
especially LGB
• This happened in 2004/2005 when there was a lot of structure
• Some maize mature early and become infected in the field e.g.
DK 8031- it is open tipped hybrid by Monsanto
• Most hybrids do not close properly
Nambande Millennium
Village, Zomba, Malawi
Increased
• Due to ineffective insecticides
• Due to destruction of trees which are alternative hosts
• Due to susceptible varieties
Gumulira Research Village,
Mchinji, Malawi
Increased
• Only few people use insecticides, thus pest population
build up Maize is not fully mature due to shortage of rains, it
becomes very susceptible
• Due to proliferation of susceptible varieties
• Scarcity of insecticides and money
Inonelwa Millennium
Village, Ibiri Cluster, Tabora,
Tanzania.
Increased (All
groups)
• Lack of money to buy pesticides
• Insufficient storage structures to store maize
• Most of storage pests enter our village through maize
assistance from government to the past three years the
multiplication of insect is faster
• when mixing the insecticides we get cough and flu
• Low chemical strength to kill storage insects
73
Mbola Research Village,
Tabora, Tanzania
Increased
• Type of seeds-Varieties grown susceptible to insect
• Stored grains are not treated
• Unavailability of chemicals to control storage pests
• Lack of money to buy chemicals
Nyawara, Nyandiwa, and
Gongo (at Gem Hall)
Decreased (2
out of 6 groups)
• When I found them being destroyed I bought the chemical
which decreased the pests
• After realizing that the particular bags increased pests, I
started using the granary and sisal bags
• Airing for sometimes especially after 2 month
Increased (4 out
of 6 groups)
• Lack of money/income
• Bad weather i.e. rainy season
• Poor storage facility
• HIV pandemic has reduced manpower
• Chemical side effects have hamper people from using
chemicals
• Mixing of new harvest with old stock
• Poor storage
• Stick beating of cobs while shelling
• Lack of dusting materials
• Lack of effective pesticide
• Lack of funds to buy these pesticides
• Lack of good storage facilities
• Type of seeds-Different seeds, recently introduced seeds
encourages these pests
• The chemicals are expensive to the farmers
• Lack of knowledge on the chemical use
Anyiko, Nyamninia, and Jina. Increased (4 out
(atYala Guest House)
of the 5 groups)
• Inadequate treatment
• Increase in yields
• Poor management of maize yield practices
• Weather problems in drying maize
• Lack of storage facilities
• Different varieties of chemicals
• Lack of knowledge on storage management
• Pests multiply
• Poor storage
• Poor dusting
• Some drugs are not powerful
• Poor drying
• Rapid multiplication of pests
• Inadequate chemical application due to bumper harvest
74
Ramula, Uranga, and
Lihanda (at Bar-Kalare)
Decreased (1
out of the 5
groups)
• Use of insecticides
Increased(All)
• Developed resistance
• Well ventilated stores
• Use of sisal sacks
• Lack of proper knowledge on drying and pest control
• Maize varieties planted now are easily affected by pests
compared to local varieties
• Lack of proper storage facilities
• Lack of storage skills
• Increase in yields
• Insufficient funds to buy pesticides
• Lack of market
• The strength of the pesticide/chemical has reduced
• Use of less amount of the pesticide due to lack of money
• Poor drying method
Sauri
Decreased (1
out of the 3
groups)
• Application of chemicals
Increased (2 out
of the 3 groups)
• Lack of storage knowledge
• Improved storage
• Technical know-how over the pests
• Financial disability to buy the pesticides
• Bumper harvest
• Capacity of storage inadequate
75
ANNEX 7. Descriptions of various storage pests of maize
PEST TYPE
DESCRIPTION
The Larger
Grain Borer
(Prostephanus
truncates (H).
The Larger Grain Borer (LGB) belongs to the order Coleoptera and family Bostrichidae. It’s a
polyphagous insect with a wide range of hosts e.g. maize, cassava, bulrush millet, sorghum,
yam, wheat, and structural wood (Nansen et al., 2004).The first reported African outbreak of the
LGB occurred in western Tanzania in the late 1970s and Togo in West Africa in the early 1980s
(Dunstan and Magazini, 1981) where, due to lack of natural enemies and with a favourable
climate and food sources, the pest caused serious damage to farm-stored maize. The pest has
now spread to many African countries where it has become a serious pest of both stored maize
and dried cassava ((Meikle et al., 1998). Females lay about 30-50 eggs in tunnels they bore
as they feed in the food source which hatches after 3-7 days to larvae which are white, fleshy,
partly covered with hairs and have three pairs of legs. After 4-7 days, pupation occurs inside
the grains from where the adult beetles which are cylindrical, 3-4.5 mm long and dark-brown
in colour emerge through round exit holes. The life cycle is completed within 25-26 days at
optimum conditions of temperatures of 30ºC, humidity of 70% and grain moisture content of13%
but takes longer under cooler and drier conditions (Nan’gayo et al., 1993, 2002, Nansen et al.,
2004). The pest attacks maize on the cob both before and after harvest with the adults boring
holes into the maize husks, cobs, or grains making round holes and producing large quantities
of grain dust as it tunnels (Nansen , 2003). Adult beetles display most flight activity around dusk
with a small peak around dawn. This flight activity together with the importation and exportation
of infested grains helps in the spread of the beetle over long distances to new and uninfested
areas (Nansen et al., 2001).They cause losses as high as 35% after only 3- 6-month maize
storage period in East Africa with a mean loss of 9% in farm stores (Meikle et al., 2002).
76
Biology and Ecology
Prostephanus truncatus may be attracted to maize grain and dried cassava over short
distances. However, field studies in both Mexico and Togo suggest that there is no long-range
attraction of adult P. truncatus to maize grain or cobs, or dried cassava; this is not surprising
because wood is the major host of this beetle. It has been shown in laboratory tests that
upwind flight is mediated by a male-released aggregation pheromone and not by host volatiles
(Fadamiro et al., 1998) and field studies provide strong evidence that host selection, in the case
of maize and cassava, occurs by chance (Birkinshaw et al., 2002). Details of host selection can
be found in Hodges (1994), Scholl et al. (1997) and Hodges et al. (1998).
Adults frequently initiate their attack on stored maize cobs with intact sheaths by boring into the
base of the maize cob cores, although they eventually gain access to the grain via the apex of
the cob by crawling between the sheathing leaves (Hodges and Meik, 1984). Adults bore into
the maize grains, making neat round holes, and as they tunnel from grain to grain they generate
large quantities of maize dust. Adult females lay eggs in chambers bored at right angles to
the main tunnels. Egg-laying on stabilized grain, like that on the maize cob, is more productive
than on loose-shelled grain as the oviposition period is longer, equal in length to the life of the
female, and the eggs are laid at a greater rate.
Larvae hatch from the eggs after about three days at 27°C and seem to thrive on the dust
produced by boring adults. For example, large numbers of larvae develop and pupate in dust at
the base of dense laboratory cultures.
The life cycle of P. truncatus has been investigated at a range of temperatures and humidities
and according to the work done by Shires, 1979, 1980; Bell and Watters, 1982; Hodges and Mei,
1984), development of the larva through to the adult stage at the optimum conditions of 32°C
and 80% RH takes 27 days on a diet of maize grain. They observed that humidity within the
range 50-80% RH does not greatly affect the development period or mortality; at 32°C, a drop in
RH from 80 to 50% (giving maize with an equilibrium moisture content of about 10.5%) extended
the mean development period by just 6 days and increased the mean mortality by only 13.3%.
This tolerance of dry conditions was confirmed during field studies in Nicaragua and Tanzania in
which maize at 10.6 and 9% moisture content, respectively, was heavily infested.
The success of this pest may be partly due to its ability to develop in grain at low moisture.
Many other storage pests are unable to increase in number under low moisture conditions.
For example, Sitophilus oryzae, a species occurring in the same ecological niche, needs a
grain moisture content of at least 10.5% for development. Thus, in dry conditions, P. truncatus
probably benefits from the absence of any significant competition from other storage pests.
P. truncatus develops more rapidly on maize grain than on cassava; at 27°C and 70% RH,
the respective development periods on maize grain and cassava were 32.5 and 40 days,
respectively. Under ideal conditions of temperature and humidity on maize cobs or stabilized
maize grain, estimates for the intrinsic rate of increase (r) of P. truncatus are in the order of
0.7-0.8 per week; this is similar to the rate of increase reported for Tribolium castaneum under
comparable climatic conditions (Hodges et al 1984).
Details of flight performance and factors affecting flight and distribution behaviour have been
investigated in the laboratory (Fadamiro and Wyatt, 1955, 1996; Fadamiro, 1997). A field study
in Honduras showed flight activity of P. truncatus following a daily bimodal pattern with a major
peak at 06.00-08.00 h and a minor peak at 18.00-20.00 h (Novillo, 1991). A similar pattern was
observed by Tigar et al. (1993) in Central Mexico and Birkinshaw et al. (2004) in Ghana, but in
both these cases the major peak was associated with dusk.
Adults may be sexed using a method described by Shires and McCarthy (1976).
For further detailed information on biology and ecology, consult reviews by Hodges (1986),
Markham et al. (1991), Hodges (1994), Nansen and Meikle (2002) and Hill et al. (2002).
77
Maize weevil
(Sitophilus
zeamais
Motschulsky)
and Lesser
grain weevil
(Sitophilus
oryzae
(Linnaeus))
Maize weevil, also called greater grain weevil is the most common pest of stored maize in most
African countries. Maize weevil mainly prefers maize, but has also been reported as a pest of
dried cassava. Its preferred host include maize, cassava, rice, sorghum, and wheat. Minor hosts
include taro, soybean, common beans, wheat, adzuki bean and cowpea.
Biology and ecology
The earlier confusion over the identity of S. zeamais and S. oryzae, and the fact that most of
the major basic studies were made before the confusion was resolved, means we cannot
be sure to which of the species many of the observations refer. The development of the two
species is clearly very similar, but there are probably a number of differences in the effects of
environmental factors. Thus, the information given below may be taken as generally applicable
to both species, but it should be remembered that there may be specific differences in details.
The biology of S. zeamais and S. oryzae has been reviewed in detail by Longstaff (1981). The
adults are long-lived (several months to one year). Eggs are laid throughout most of the adult
life, although 50% may be laid in the first 4-5 weeks; each female may lay up to 150 eggs. The
eggs are laid individually in small cavities chewed into cereal grains by the female; each cavity
is sealed, thus protecting the egg, by a waxy secretion (usually referred to as an ‘egg-plug’)
produced by the female. The incubation period of the egg is about 6 days at 25°C (Howe, 1952).
Eggs are laid at temperatures between 15 and 35°C (with an optimum around 25°C) and at grain
moisture contents over 10%; however, rates of oviposition are very low below 20°C or above
32°C, and below about 12% moisture content (Birch, 1944).
Upon hatching, the larva begins to feed inside the grain, excavating a tunnel as it develops.
There are four larval instars: in English wheat at 25°C and 70% RH, pupation occurs after about
25 days, although development periods are extremely protracted at low temperatures (e.g.
98 days at 18°C and 70% RH). Pupation takes place within the grain; the newly developed
adult chews its way out, leaving a large, characteristic emergence hole. Total development
periods range from about 35 days under optimal conditions to over 110 days in unfavorable
conditions (Birch, 1944; Howe, 1952). The actual length of the life cycle also depends upon
the type and quality of grain being infested: for example, in different varieties of maize, mean
development periods of S. zeamais at 27°C and 70% RH have been shown to vary from 31 to 37
days. The development of S. zeamais on different wheats (Triticum spelta, T. dicoccum and T.
monococcum spikelets and kernels) has also been studied (Suss et al., 1999). A demographic
population simulation model of S. zeamais in grain stores in West Africa has been devised
(Meikle et al., 1999).
Although both species are capable of flight, S. zeamais has a greater ability and tendency to fly
(Giles, 1969). Where grain is stored on small farms, S. zeamais is thus more likely than S. oryzae
to fly to the ripening crop in the field and establish an infestation in the grain before harvest.
Trematerra et al. (1996) developed a method for analysis and comparison of the development
rate of S. oryzae on different cereals (Triticum aestivum, T. dicoccum, T. durum, T. monococcum
and T. spelta). Yoon et al. (1997) constructed a matrix model of S. oryzae populations based
on degree-days. The behavioral activity of S. oryzae towards intact and damaged kernels of
Triticum aestivum, T. durum, T. dicoccum, T. monococcum and T. spelta was investigated by
Trematerra et al. (1999).
Although both species are capable of flight, S. zeamais has a greater ability and tendency to fly
(Giles, 1969). Where grain is stored on small farms, S. zeamais is thus more likely than S. oryzae
to fly to the ripening crop in the field and establish an infestation in the grain before harvest.
The Confused
beetle
(Tribolium sp)
Confused beetle or Flour beetle (T. confusum and T. castaneum), though a temperate pest is an
important secondary pest of flour and cereal products. It infests maize after the other pests have
damaged the maize grain. The pest(s) were very common in maize which had been destroyed
to flour by the LGB alone or in a combination with other storage pests in Malawi, Tanzania and
Kenya.
78
Biology
The biology and ecology of T. confusum resemble those of T. castaneum in many respects.
However, the optimum temperature for development (32.5°C) and minimum (a little below
20°C) and maximum (37.5°C) temperatures where development is possible for T. confusum are
all about 2.5°C lower than for T.castaneum (Howe, 1960). T. confusum is not cold-hardy; 7°C
seems to be the critical temperature at or below which all stages are killed when exposed for 3
weeks or more.
1. Eggs
A total of 4-500 eggs are produced over a period of a few months by a single adult T. confusum
or T. castaneum. Under favourable conditions, eggs hatch in 3-5 days.
2. Larval development
Larvae go through a series of instars while feeding in grain or processed grain products. In
whole grain, the presence of grain dust and debris provides a suitable environment for the
development of early instars. In such an environment, larvae can develop at moisture contents
as low as 8%. Larvae molt 5-11 times, depending on the food source and environment.
3. Pupae
Pupae are naked (no cocoon). The development from egg to adult can be completed in 26 days
under ideal conditions. Adults normally live for about 1 year, but have been known to live for up
to 5 years (Sauer, 1992). The maximum rate of increase is about a 60-fold increase in population
size per lunar month, which is lower than for T. castaneum.
4. Adults
Adults and large larvae eat conspecific eggs and pupae, and will also attack immobile stages of
other species.
T. confusum is more successful than T. castaneum on undamaged cereal grains, and is more
capable of development on food with low vitamin B content (Haines, 1991). It is reported to
be commonly found in processed grain products, possibly because of its reduced dispersal
capabilities: T. confusum is not known to fly, despite the presence of flight wings similar to those
of T. castaneum (Sauer, 1992).
Mixed populations of the two species are only found when populations are small. Competition
between the two species is complex, involving differences in nutrition, physical preferences,
cannibalism and many other factors. T. castaneum is always dominant in tropical conditions,
but elsewhere the outcome of competition is difficult to predict. T.confusum is known to be an
alternate host for various cestode parasites of man, rodents and poultry: Hymenolepis diminuta
uses (amongst other arthropods) T. confusum as an intermediate host, and this flour beetle is
usually the host used for laboratory maintenence. H. diminuta is mainly a parasite of rodents,
and man is only occasionally infected. Infections in man are light and of short duration.
Angoumois
grain moth
(Sitotroga
cerealella
(Olivier))
The grain moth is a pest of stored products. Plants are attacked at a post harvest stage,
although some are also attached at the fruiting stage. Most host plants whose seeds are
affected are maize, oats, barley, rice, pearl millet, rye, sorghum, and wheat. However, Grain
moth is often found alongside other pests, with which it may act synergistically.
Biology and ecology
Infestations of S. cerealella occur during storage, or preharvest (Howlander and Matin, 1988)
or postharvest (Seck, 1991a). In the field, S. cerealella is able to attack whole (undamaged)
grains (Evans, 1987), which poses a greater problem in tropical and subtropical countries than
elsewhere (ARS, USDA, 1978). There are about five generations per year in southern Europe,
but in warmer climates S. cerealella is continuously brooded with up to 12 generations per year.
In temperate countries, it overwinters in the larval stage in stored grain kernels or in scattered
wheat in litter, straw piles or baled straw.
79
The eggs are laid at night on the outside of cereal grains, in cracks, grooves or holes made
by other insects (Hammad et al., 1967). Eggs are laid singly or in clumps; the number laid is
variable. The adult lifespan may be up to 15 days (Mondragon and Almeida, 1988) and one
female may lay up to 200 eggs (Dobie et al., 1984) although 40 is a more average number (ARS,
USDA, 1978).Larvae bore into the grain after hatching, entering sorghum kernels primarily in
the germ end and its periphery (Wongo, 1990). Larvae complete their development in a single
grain; two or three larvae may develop in single grains of maize, but only one adult is produced
from single grains of other hosts (Cox and Bell, 1981).The rate of development is dependent
on temperature. Mondragon and Almeida (1988) found that development was favoured at
25°C, and that at this temperature, with 70±2% RH and a diet of maize, the mean period of
development for the larval stage was 29.4 days. Although larvae will hatch at temperatures
down to 12°C and up to 36°C (Cox and Bell, 1981), 16°C and 30% RH are cited as the minimum
conditions for population increases (Evans, 1987) and the upper temperature limit is 35°C
(Dobie et al., 1984). Humidity in the range 50-90% RH has little effect on the development rate
(Boldt, 1974).
The nature of the host may also affect the rate of larval development, with development times
of 20 days reported for wheat (Cocurt X-71) and 22.4 days for barley (Cleaper) (Mahdi et al.,
1988). Even under laboratory conditions, there may be wide variation in life cycles, with adults
emerging after 20 to 90 days (Grinberg and Palii, 1981). Before pupation, the larva extends the
anterior of its chamber to just beneath the surface of the grain, forming a small circular ‘window’
of translucent seed coat, which is the first visible sign of infestation. Mondragon and Almeida
(1988) recorded an average pupal stage of 10.4 days, but this may be as short as 5 days (Dobie
et al., 1984). In very small grains (e.g. some sorghum grains), pupation may occur between two
or more grains held together by the silken threads of a thin cocoon. The newly emerged adult
pushes through the window of the seed coat, leaving a small, but characteristic, round hole,
usually in the crown end of the grain (Wongo, 1990). Part of the window often remains at the
edge of the hole in the form of a ‘trapdoor’ or shallow cone. At 30°C and 80% RH, the complete
life cycle can take as little as 25 to 28 days, although at 25°C, the total life cycle was found to last
48.6 days (Mondragon and Almeida, 1988). Under optimal conditions, the estimated intrinsic
rate of increase of the population is 50 times per lunar month. The effect of different rearing
temperatures (21, 24, 27 and 30°C) at 65% RH and different relative humidities (30, 40, 50, 60,
70, 80 and 90%) at 26°C on the biology of S. cerealella reared on wheat grains was investigated
in Egypt. The duration of the egg stage, preoviposition, oviposition and postoviposition periods,
and adult lifespan was negatively correlated with temperature. The highest number of eggs was
laid at 27°C (155/female).Adults are strong fliers and cross-infestation occurs easily. However,
they are also delicate and cannot penetrate far into closely packed grain. Because the larvae
also stay in the same grain throughout their development, infestations in bulk grain are usually
confined to the outermost exposed layers.
The lesser
grain borer
(Rhizopertha
dominica)
This is a tiny beetle (2-3 mm long) with a slim and cylindrical shape and red-brown to black
in colour. The thorax bears rows of teeth on its upper front edge and the head is turned down
underneath the thorax so that it cannot be seen from above. Eggs are laid loose among the
cereal grains. The larvae are mobile. Both larvae and adult bore through the stored produce
usually causing characteristic round tunnels (up to 1 mm diameter).
In later stages of infestation this beetles may also hollow out the grains. Pupation usually takes
place within the eaten grain. The lesser grain borer is primarily a pest of cereal grains, other
seeds, cereal products and dried cassava. It will be controlled by any method that controls the
LGB,
Storage moth
or tropical
warehouse
moth (Ephestia
cautella)
The main storage moths are the tropical warehouse moth (Ephestia cautella), the rice moth
(Corcyra cephalonica), and the Indian meal moth (Plodia interpunctella). These storage moths
are small (15-20 mm wingspan), greyish brown in colour. The moth of the Indian meal moth is
dinstinctive with the outer half of the forewings a coppery-red separate from the creamy inner
half by dark grey bands.Female moths lay eggs through holes in the bags. Larvae are elongated
whitish caterpillars about 2 cm long. They feed on the seed germ, moving about freely in the
stored foodstuff. They cause extensive damage in cereal Flours and other milled products,
but also in whole grains, mainly feeding on the germ. They also attack nuts, groundnuts, dry
fruit, cocoa, copra and other foodstuff. The dense white cocoons of the pupae are often seen
attached to the bag surfaces. Infestations are characterised by aggregations of kernels, frass,
cocoon and dirt caused by webbing, which contaminates the foodstuff reducing its quality.
80
Dried fruit
beetles
(Carpophilus
spp.)
They are slightly flattened ovate to oblong beetles, 2-5 mm in length. The wing cases are short,
leaving part of the abdomen exposed. They are light brown to black in colour, but
Fungi
Storage fungi include species of Aspergillus and Penicilium. Storage fungi require a relative
humidity of at least 65%, which is equivalent to equilibrium moisture content of 13% in cereal
grain. Storage fungi grow at temperatures of between 10°C to 40°C. Infection with certain
species of fungi may already occur in the field, reducing considerably the storage life of grains.
Infection with storage fungi can cause:
several species have yellow or red markings on the wing cases. They are secondary pests;
presence of these beetles is an indicator of damp, mouldy conditions. Adults and larvae cause
damage on poorly dried cereal grains, cocoa, copra, oilseeds, dried fruit, vegetables, herbs and
mouldy produce.
• Loss of nutrients
• Discolouration of the grain
• Reduction of germination capacity
• Caking of grains
• Increase in the temperature of the stored goods up to spontaneous combustion
• Mouldy smell and taste
• Production of mycotoxins;
These are toxic substances produced various fungi under certain conditions, which remain
in the stored product as residues. They are highly poisonous to both human and animals.
The best-known mycotoxins are aflatoxin, ochratoxin, patulin and citrin. Aflatoxins, which are
produced by Aspergilus flavus are regarded as very dangerous substance causing liver cancer
Damage caused by fungi is often neglected until it has reached and advanced stage. However,
it is very important to prevent growth of fungi, since it the only way of avoid mycotoxins.
Mycotoxins are very stable and cannot be destroyed by boiling, pressing and processing.
This means that infected produce has to be destroyed. Mycotoxins can be found in the stored
product as soon as 24 hours after infection with fungus. To prevent contamination by fungi, the
produce must be properly dried, and any source of moisture in the store should be avoided.
The major moulds and mycotoxins they produce are shown below:
Fungi
Mycotoxin(s) produced
1. Aspergillus parasiticus
Aflatoxins B1, B2, G1, G2
2. A. flavus
Aflatoxins B1, B2
3. Fusarium sporotrichioides
T-2 toxin
4. F. graminearum
Deoxynivalenol (vomitoxin) zearalenone
5. F. moniliforme
Fumonisins
6. Penicillium verrucosum
Ochratoxin A
81
The MDG Centre
E A S T
&
S O U T H E R N
A F R I C A
Submitted To:
By:
The MDG Centre
East And Southern Africa
Box 30677-00100
Nairobi, Kenya
Tel: +254 20 7224485
Fax: +254 20 7224490
CABI Africa
UN Avenue, ICRAF Complex
Box 633-00621
Nairobi, Kenya
Tel.: +254 20 7224450
Fax: +254 20 7122150
Email: [email protected]
JUNE 2008
82