ADOPTION AND DISADOPTION OF SWEETPOTATO
(IPOMOEA BATATAS (L) LAM) PRODUCTION AND
PROCESSING TECHNOLOGIES BY FARMERS IN
SOUTH-EASTERN NIGERIA
BY
MBANASO, EKWURUCHUKWU OGBONNA
PG/Ph.D/98/24889
DEPARTMENT OF AGRICULTURAL EXTENSION,
UNIVERSITY OF NIGERIA, NSUKKA
MAY, 2011
i
1
ADOPTION AND DISADOPTION OF SWEETPOTATO
(IPOMOEA BATATAS (L) LAM) PRODUCTION AND
PROCESSING TECHNOLOGIES BY FARMERS IN SOUTHEASTERN NIGERIA
BY
MBANASO, EKWURUCHUKWU OGBONNA
B. Agric(Agricultural Economics and
Extension)UNICAL,
M. Sc. (Agricultural Extension) FUTO,
PG/Ph.D/98/24889
A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE
REQUIREMENTS FOR THE DEGREE OF DOCTOR OF
PHILOSOPHY IN AGRICULTURAL EXTENSION
(AGRICULTURAL EXTENSION ADMINISTRATION)
TO
THE DEPARTMENT OF AGRICULTURAL EXTENSION
UNIVERSITY OF NIGERIA, NSUKKA.
MAY, 2011.
2
CERTIFICATION
MBANASO, EKWURUCHUKWU OGBONNA, a postgraduate
student in the Department of Agricultural Extension, University of Nigeria,
Nsukka,
with
the
Registration
Number
PG/Ph.D/98/24889,
has
satisfactorily completed the requirements for the award of the degree of
Doctor of Philosophy in Agricultural Extension (Agricultural Extension
Administration).
I also certify that the embodiment of this research work is original
and has never been submitted in whole or in part for the award of any
other diploma or degree in this or any other university.
--------------------------------------
------------------------------------
DR. (MRS) E.A. ONWUBUYA
PROF. A.C. ANYANWU
(Head of Department)
Date:-------------------------------
(Supervisor)
Date:------------------------------
DEDICATION
3
This work is dedicated to the Ancient of Days (Jehovah Rohi), the Almighty
God who loves and cares for me, and who has not yet finished His work with,
and through, me.
ACKNOWLEDGEMENT
4
This research work, which I embarked upon so many years ago, has come to a
successful end at last. People, too numerous to mention, made it possible. I use this medium
to show my appreciation to them.
Foremost among this catalogue of people is my supervisor, Professor Alphonsus C.
Anyanwu, who patiently guided me through this work. I thank him for painstakingly reading
several drafts of this thesis and making useful comments and constructive criticisms.
I am greatly indebted to Professor Agwu Ekwe Agwu (A2) for providing invaluable
guidance and intellectual stimulation that led to the successful completion of this thesis. I
thank him particularly for the prompt and painstaking way he read my work, making useful
comments and constructive criticisms.
My special thanks go to my brother, friend and mentor, Professor Jude Anayochukwu
Mbanasor, for the tireless way he encouraged me throughout the duration of this work. He
was always ready and willing to help me.
I am highly indebted to Miss Jane Chidozie Akuwudike who toiled with me in getting
this work completed. I appreciate all efforts, the hazardous trips she made during the field
work, as well as the computer work she carried out towards the completion of this thesis.
Special thanks go to Dr. (Mrs) E.A. Onwubuya and Dr. (Mrs) M. Dimelu for their
useful comments and encouragement.
My special thanks, also, go to Professor M.C. Madukwe, Professor E.M. Igbokwe and
Professor A.R. Ajayi for their constructive criticisms. The assistance of the members of the
Department of Agricultural Extension, University of Nigeria, Nsukka, is acknowledged here.
I thank my daddy in the Lord, Rev. Chinedu Onyemaechi Johnson, and his beloved
wife, Evangelist (Mrs) Udodirim Blessing Johnson, who upheld me with the arms of prayer
throughout the period of this study. They have been true brethren to me. All the members of
the Glorious Saints Assembly of All Nations are, also, appreciated here for their
encouragement and prayers.
I express my deep appreciation to brothers Ikechukwu Agbugba and Oluwole Matthew
Akinnagbe for their assistance and encouragement.
I wish to express my heartfelt gratitude to Pastor Uzor C. Iheukwumere (of blessed
memory) who supported me morally and financially at critical stages of this work.
My deep appreciation goes to Mr. Godwin C. Onuoha and his wife, Mrs. Felicia
Onuoha, who provided me a home at the University of Nigeria, Nsukka.
5
Special thanks go, also, to Dr. G.O. Chukwu, Dr. (Mrs) Chinyere Aniedu, Mr. Chika
Ezebuiro, Mr. Onyema Chijioke, Miss Chidinma Ikechukwu and Dr. Benjamin C. Okoye for
their assistance.
I am specially thankful to the Executive Director, National Root Crops Research
Institute, Umudike, Dr. K.I. Nwosu, for the permission he granted me to carry out this study.
My special thanks go to my mother, Mrs. Bessie Ogbonna Mbanaso, my elder brother
Mr. Obioma Ogbonna Mbanaso, Masters Chijindu Obioma Mbanaso and Ikenna Obikeh, as
well as all the members of Ogbonna Mbanaso’s family for their love, prayers and
encouragement to me throughout the period of my doctoral degree programme.
Lastly, I lift up my hands in praise to the King of kings, Ancient of Days and
Everlasting Father, for His love, mercies, favour and strength throughout the period of this
study. May His name be glorified and honoured now and forever! Amen!!
ABSTRACT
This study sought to determine the adoption and disadoption of sweetpotato production and
processing technologies by farmers in the South-east zone of Nigeria. The specific objectives
were to: determine the level of awareness of the sweetpotato production and processing
technologies among farmers in the zone; determine the extent of adoption and disadoption of
the sweetpotato production and processing technologies by farmers in the zone; examine the
determinants of adoption and disadoption of the sweetpotato production and processing
technologies in the study area and identify the constraints to the adoption of sweetpotato
production and processing technologies in the zone. Using the multistage sampling technique,
and the structured interview schedule as instrument, data for the study were collected from a
6
sample of two hundred and seventy (270) sweetpotato farmers in the zone. Percentages, mean
scores, probit analysis and exploratory factor analysis procedure were used as statistical tools
for data analysis. The findings of the study showed that majority (79.63%) of the farmers
(270) were aware of the sweetpotato production technology, whereas the processing
technology recorded a low level of awareness. With regard to the extent of adoption of the
sweetpotato production practices, majority (37.9%) of the farmers adopted the use of ridges
and mounds, as well as improved sweetpotato varieties, while majority (40.2%) of them
rejected the recommended plant spacing of 30cm x 100cm on ridges and 25cm x 100cm on
mounds for both sole and intercropped systems. Most (34.2%) of the farmers used the 2-node
and 5/6-node vine cuttings as planting materials, as well as time for planting of sweetpotato,
weeding regime of one major weeding at 4-6 weeks after planting, inorganic fertilizer
application of 400kg of NPK 20:10:10, earthening-up practice, timely harvest of root tubers
and pest and disease control measures. The extent of disadoption of the sweetpotato
production technology was low. In the processing of fermented sweetpotato fufu flour,
majority of the farmers adopted the practices of peeling and washing of sweetpotato root
tubers, cutting of the root tubers into 2.5mm-3.0mm chips, fermenting of the chips by soaking
in water for 24 hours, draining of water from fermented chips and sun-drying of chips on
raised platforms or oven-drying at a temperature of 50 oC. Majority of them also mill the dried
chips properly to produce the flour and package the flour in polyethylene bags or air-tight
containers. With regard to the extent of adoption of the practices involved in the processing
of unfermented sweetpotato flour, most of the farmers adopted the innovation of peeling and
washing of root tubers of sweetpotato, grating of the root tubers into mash and dewatering of
the mash in a clean bag. Majority of the farmers also adopted sun-drying the dewatered mash
on raised platform or oven-drying at a temperature of 50 oC, milling the dried mash and
packaging the flour in polyethylene bags or air-tight containers. In processing of sweetpotato
starch, majority of the farmers adopted the practices of peeling and washing of the root
tubers, grating of the root tubers into mash, dewatering of mash in clean bags and mixing
dewatered mash with quantity of water that is 10 times the volume of mash. Other practices
adopted by majority of the farmers included sieving of mash with muslin cloth, sedimenting,
decanting and collection of starch, sun-drying of starch on raised platform or oven-drying at a
temperature of 50oC, milling of the dried starch and packaging in polyethylene bags or airtight containers. Household size, labour, land and health significantly influenced the adoption
of the sweetpotato production and processing technologies. Age, marital status and
participation in credit system were important in predicting farmers who will continue to use
the sweetpotato technologies, while sweetpotato problems significantly influenced the
disadoption of the technologies. Production/processing complexity problems, economic
problems, poor technical information and pathological problems were the main constraints to
the adoption of the sweetpotato production and processing technologies. It was recommended
that researchers, policy makers and administrators of extension services consider seriously
these issues which constitute limiting factors to increased sweetpotato production and
processing in the study area.
7
8
TABLE OF CONTENTS
TITLE PAGE
ii
CERTIFICATION
iii
DEDICATION
iv
ACKNOWLEDGEMENT
v
ABSTRACT
vii
TABLE OF CONTENTS
ix
LIST OF TABLES
LIST OF FIGURES
CHAPTER ONE
1
INTRODUCTION
1
1.1 Background information
1
1.2 The problem
4
1.3 Purpose of the study
8
1.4 Significance of the study
9
CHAPTER TWO
11
REVIEW OF RELATED LITERATURE
11
2.1 Historical perspective of sweetpotato
11
2.2 Sweetpotato research efforts in Nigeria
14
2.2.1 Germplasm collection, conservation and evaluation
15
2.2.2 Agronomic research
16
2.2.3 Pest and disease management
22
2.2.4 Post harvest handling and processing
25
2.2.5 Socio-economics of sweetpotato
28
2.3 Adoption of improved technologies
29
2.4 Disadoption of improved technologies
35
2.5 Constraints to adoption of improved technologies
36
2.6 Theoretical framework
39
9
CHAPTER THREE
49
METHODOLOGY
49
3.1 Area of study
49
3.2 Population and sample
53
3.2.1 Population
53
3.2.2 Sample
53
3.3 Data collection method
55
3.4 Variable specification
56
3.5 Data analysis techniques
65
CHAPTER FOUR
66
RESULTS AND DISCUSSION
66
4.1 Personal and socio-economic characteristics of the farmers
66
4.1.1 Personal characteristics of the respondents
66
4.1.2 Socio-economic characteristics of the respondents
70
4.2 Level of awareness of the sweetpotato production and processing
technologies by the respondents
73
4.2.1 Awareness of the seetpotato production and processing
technologies
73
4.3 Extent of adoption of sweetpotato production technology
74
4.3.1 Extent of adoption of land preparation methods
74
4.3.2 Adoption of improved sweetpotato varieties
75
4.3.3 Adoption of correct plant spacing
77
4.3.4 Adoption of sweetpotato vine cuttings
78
4.3.5 Adoption of time of planting of sweetpotato
79
4.3.6 Adoption of sweetpotato weeding regime
80
4.3.7 Adoption of inorganic fertilizer application
81
4.3.8 Adoption of earthening-up practice
82
4.3.9 Adoption of timely harvesting of sweetpotato
83
4.3.10 Adoption of pest and disease control measures
84
4.3.11 Disadoption of the sweetpotato production technology
85
4.4 Extent of adoption of sweetpotato processing technologies
88
4.4.1 Extent of adoption of processing of fermented sweetpotato fufu flour
89
4.4.1.1 Adoption of peeling and washing of sweetpotato root tubers
89
10
4.4.1.2 Adoption of cutting sweetpotato root tubers into 2.5-3.0mm chips
89
4.4.1.3 Adoption of fermenting sweetpotato chips by soaking in water
for 24 hours
4.4.1.4 Adoption of draining water from fermented sweetpotato chips
90
91
4.4.1.5 Adoption of sun-drying fermented sweetpotato chips on raised
platform of oven-drying at temperature of 50oC
4.4.1.6 Adoption of milling of dried fermented sweetpotato chips
92
93
4.4.1.7 Adoption of packaging of produce in polyethylene bags or
air-tight containers
94
4.4.2 Extent of adoption of unfermented sweetpotato flour
95
4.4.2.1 Adoption of peeling and washing of sweetpotato root tubers
96
4.4.2.2 Adoption of grating sweetpotato root tubers into mash
96
4.4.2.3 Adoption of dewatering of sweetpotato mash
97
4.4.2.4 Adoption of sun-drying sweetpotato mash on raised platform
or oven-drying at temperature of 50oC
98
4.4.2.5 Adoption of milling of dried sweetpotato mash
99
4.4.2.6 Adoption of packaging of sweetpotato flour in polyethylene
bags or air-tight containers
100
4.4.3 Extent of adoption of sweetpotato starch
101
4.4.3.1 Adoption of peeling and washing of sweetpotato root tubers
102
4.4.3.2 Adoption of grating of sweetpotato root tubers into mash
102
4.4.3.3 Adoption of dewatering of sweetpotato mash
103
4.4.3.4 Adoption of mixing sweetpotato mash with quantity of water
that is ten times the volume of mash
4.4.3.5 Adoption of sieving sweetpotato mash with muslin cloth
104
105
4.4.3.6 Adoption of sedimenting and decanting of sweetpotato mash
for collection of sweetpotato starch
105
4.4.3.7 Adoption of sun-drying of sweetpotato starch on raised
platform or oven-drying at temperature of 50oC
4.4.3.8 Adoption of milling of sweetpotato starch
106
107
4.4.3.9 Adoption of packaging sweetpotato starch in polyethylene
bags or air-tight containers
4.5 Determinants of adoption and disadoption of the sweetpotato production and
108
11
processing technologies
109
4.5.1 The adoption/non-adoption model
109
4.5.2 The continued use/disadoption model
112
4.6 Major factors constraining the adoption of sweetpotato production
and processing technologies
116
CHAPTER FIVE
120
SUMMARY, CONCLUSION AND RECOMMENDATIONS
120
5.1 Summary
120
5.2 Conclusion
124
5.3 Recommendations
127
REFERENCES
130
12
LIST OF TABLES
Tables
1
Percentage distribution of respondents by personal characteristics
69
2
Percentage distribution of respondents by socio-economic characteristics
72
3
Percentage distribution of respondents according to level of
awareness of the sweetpotato production and processing technologies
74
4
Probit regression of the probability of adoption
111
5
Probit regression of the probability of continued use
114
6
Varimax rotated factors constraining the adoption of sweetpotato
production and processing technologies by farmers
119
13
LIST OF FIGURES
FIGURES
1
Paradigm of the innovation-decision process
2
A conceptual representation of the innovation-decision process
41
of sweetpotato production and processing technologies
48
3
Sampling procedure
55
4
Percentage distribution of respondents by their stages on the adoption
of sweetpotato land preparation methods
5
Percentage distribution of respondents by their stages on the adoption
of improved sweetpotato varieties
6
80
Percentage distribution of respondents by their stages on the adoption of
sweetpotato weeding regime
10
79
Percentage distribution of respondents by their stages on the adoption of
time of planting of sweetpotato
9
77
Percentage distribution of respondents by their stages on the adoption of
the sweetpotato vine cuttings
8
76
Percentage distribution of respondents by their stages on the adoption of
correct plant spacing on sweetpotato farms
7
75
81
Percentage distribution of respondents by their stages on the adoption of
inorganic fertilizer application
82
11 Percentage distribution of respondents by their stages on the adoption of
the earthening-up practice
83
12 Percentage distribution of respondents by their stages on the adoption of
the timely harvest practice
84
13 Percentage distribution of respondents by their stages on the adoption of
the pest and disease control measures
85
14 Percentage distribution of respondents according to their adoption and
disadoption of the sweetpotato production technology
15 Percentage distribution of respondents by reasons for disadoption
87
87
16 Percentage distribution of respondents by their stages on the adoption of
the practice of peeling and washing of sweetpotato root tubers
89
14
17 Percentage distribution of respondents by their stages on the adoption of
the practice of cutting sweetpotato root tubers into 2.5-3.0mm chips
90
18 Percentage distribution of respondents by their stages on the adoption of
fermenting sweetpotato chips by soaking in water for 24 hours
91
19 Percentage distribution of respondents by their stages on the adoption of
draining of water from fermented sweetpotato chips
92
20 Percentage distribution of respondents by their stages on the adoption of
sun-drying of sweetpotato chips on raised platform or oven-drying at
temperature of 50 oC
93
21 Percentage distribution of respondents by their stages on the adoption of
milling of dried fermented sweetpotato chips
94
22 Percentage distribution of respondents by their stages on the adoption of
packaging of sweetpotato mill product in polyethylene bags or
air-tight containers
95
23 Percentage distribution of respondents by their stages on the adoption of
peeling and washing of sweetpotato root tubers
96
24 Percentage distribution of respondents by their stages on the adoption of
grating sweetpotato root tubers into mash
97
25 Percentage distribution of respondents by their stages on the adoption of
dewatering of sweetpotato mash in clean bags
98
26 Percentage distribution of respondents by their stages on the adoption of
sun-drying sweetpotato mash on raised platform or oven-drying at
temperature of 50 oC
99
27 Percentage distribution of respondents by their stages on the adoption of
milling of dried sweetpotato chips
100
28 Percentage distribution of respondents by their stages on the adoption of
packaging of sweetpotato flour in polyethylene bags or air-tight
containers
101
29 Percentage distribution of respondents by their stage on the adoption of
peeling and washing of sweetpotato root tubers
102
30 Percentage distribution of respondents by their stages on the adoption of
grating sweetpotato root tubers into mash
103
15
31 Percentage distribution of respondents by their stages on the adoption of
dewatering of mash clean bags
103
32 Percentage distribution of respondents by their stages on the adoption of
mixing sweetpotato mash with volume of water that is ten times the
volume of mash
104
33 Percentage distribution of respondents by their stages on the adoption of
sieving of mash with muslin cloth
105
34 Percentage distribution of respondents by their stages on the adoption of
sedimenting and decanting of sieved sweetpotato mash for collection
of sweetpotato starch
106
35 Percentage distribution of respondents by their stages on the adoption of
sun-drying of sweetpoato starch on raised platform or oven-drying at
temperature of 50 oC
107
36 Percentage distribution of respondents by their stages on the adoption of
milling of sweetpotato starch
108
37 Percentage distribution of respondents by their stages on the adoption of
packaging of sweetpotato starch in polyethylene bags or air-tight containers
109
16
CHAPTER ONE
INTRODUCTION
1.1
Background information
Sweetpotato (Ipomoea batatas (L) Lam) is a herbaceous, warm-weather
creeping plant belonging to the family Convolvulaceae and genus Ipomoea (Woolfe,
1992). The family is made up of 45 genera and 1,000 species, out of which only
Ipomoea batatas is of economic importance to man and animals (Woolfe, 1992). It is
known to be among the world’s most important, versatile and under-exploited food
crops (International Potato Centre (CIP), 1999). With more than 133 million tonnes in
annual production, sweetpotato currently ranks as the fifth most important food crop
on a fresh-weight basis in developing countries after rice, wheat, maize and cassava
(CIP, 1999). Average yields in several countries are well below the average yield of
15 tonnes per hectare for developing countries as a whole, and these in turn are well
below the crop’s potential.
In the last decade, there has been a positive growth rate for sweetpotato
production in China, as well as a number of developing countries (CIP, 1999). China
tops the list of world largest producers of sweetpotato with 106,197,100 metric tonnes
while Nigeria is third largest producer with 2,150,000 metric tonnes annually. In
Africa, Nigeria is second largest producer of sweetpotato after Uganda with 2,600,000
metric tonnes annually (National Root Crops Research Institute, 2009).
In Nigeria, the production, marketing and utilization of sweetpotato have
expanded to almost all the ecological zones within the past decade (NRCRI, 2009),
and 200,000 to 400,000 hectares of land are under sweetpotato cultivation. Yields of
17
sweetpotato root tubers have increased from farmers’ pre-research era of about 3
tonnes per hectare to 20-30 tonnes per hectare due to the availability of improved
varieties (NRCRI, 2009). Ezeano (2006) showed that total annual production of the
crop in Cross River, Ebonyi and Enugu States of Nigeria increased from 37,080 to
84,393 tonnes from years 2000 to 2004. Similarly, its consumption as food increased
from 3,740 to 7,650 for the three states within the same period, utilization as feed
increased from 440 to 1,020 tonnes, export to neighbouring countries increased from
3,070 to 17,810 tonnes, while domestic sales increased from 27,440 to 50,870 tonnes
(Ezeano, 2006).
Sweetpotato is traditionally used as boiled root tubers eaten with stew, boiled
and pounded with either boiled or fermented cassava as fufu or boiled or pounded
yam. It is also dried and milled for sweetening of gruel (‘ogi’) porridge, sliced into
chips, dried and boiled with beans or vegetables, sliced into chips and fried in
vegetable oil, in addition to processing into flour for sweetening ‘kunu’ or pap.
Furthermore, root tubers are boiled, sliced, sun-dried and used later as snacks,
processed into flour for making buns, chin-chin, doughnut, noodles, alcoholic
beverages, protein-enriched pulp and canned foods.
Sweetpotato grows best at a temperature of between 24 oC and 28oC with an
annual rainfall of 700mm to 1000mm. It requires about 500mm of rain during the
period of vegetative growth and the rest during tuber formation and setting (Woolfe,
1992; Onwueme and Sinha, 1991). It is also a drought tolerant crop. However,
drought that occurs within six weeks after planting or during tuber formation reduces
yield greatly. Sweetpotato does not tolerate shade. Day length of 11 hours or less
18
promotes flowering while day length longer than 11 hours tends to favour folial
development at the expense of tubers (Woolfe, 1992; Yayock, 1988). Short day length
with cool temperature of 22 oC to 24oC and low light intensity promotes tuber
formation. The best soil for sweetpotato production is sandy loam. It does not do well
in poorly drained and aerated, or saline soils, as such soils tend to retard root tuber
development. It grows best at a pH of 6; alkaline soils result in poor yields (Onwueme
and Sinha, 1991).
Although its centre of origin, routes and times of its dispersal to some of its
present locations are still in dispute, Edmond and Ammermans (1971) indicated that
Ipomoea batatas originated from Central America and northwestern part of South
America in about 3000 B.C. It was introduced into Europe in the 16th century.
Presently, it is grown throughout the world from latitude 40oN to latitude 35oS, and
Asia produces more than two thirds of the world output. It arrived Nigeria between
1694 and 1698 through the early Portuguese and Spanish explorers.
Ipomoea batatas is a short duration crop with high yield and economic returns
(Klink, 1997). Sweetpotato and potato are the only root and tuber crops that can be
grown and harvested within four months in Nigeria. Specifically, sweetpotato can be
grown two to three times in a year with supplementary irrigation (Nwokocha, 1993). It
has low soil fertility requirement and better opportunity cost relative to the other root
and tuber crops such as cassava, yam and cocoyam (Nwokocha, 1993). Sweetpotato is
highly adaptable to relatively marginal soils and erratic rainfall, has high productivity
per unit of land and labour and guarantees some yield even under the most adverse
conditions (NRCRI, 1987; Nwokocha, 1993; Ogbonna, Nwauzor, Asumugha and
19
Emehute, 2005). It is, thus, a low input crop. It is a good source of vitamin C and provitamin A, and can be substituted for maize in livestock production (NRCRI, 1984;
1989; 1990; Nwokocha, 1993; Anyaegbunam, Asumugha, Mbanaso and Ezulike,
2008). Ipomoea batatas does not have the problem of anti-nutritional factors such as
cyanides and oxalates that exist in cassava and cocoyam respectively (NRCRI, 1989;
Nwokocha, 1993). Furthermore its high yield potentials and short life cycle of less
than 20 weeks make crops like yam (Dioscorea spp) relatively poor competitors for
general industrial starch (NRCRI, 1989).
Sweetpotato is grossly under-exploited as food in Nigeria (Nwosu, 2007). The
minimal utilization of sweetpotato in Nigeria is obviously due to non-availability of
adequate sweetpotato-based recipes that satisfy the food habits of Nigerians (Aniedu
and Oti, 2007).
1.2
The problem
Prior to 1974, the cultivation and utilization of sweetpotato had not received
appropriate attention of the Nigerian populace despite its nutritional constituents,
position in the food reserve of man, ease of propagation, soil conservation attribute
and industrial use. It was regarded as a crop with little economic importance; a
volunteer or discard crop that children picked mostly around refuse dump sites. Its
consumption was surrounded by the erroneous idea that it caused amoebic dysentery
(NRCRI, 2009). Farmers paid no attention to the time of planting sweetpotato, where
it was planted as well as its time of harvest, storage, processing and marketing. No
consideration was given to such agronomic practices as fertilizer application, pest and
20
disease control, weeding regime, earthening up, detopping, rolling and tying of vines
at the base which were required for increased crop yield. The crop was allowed to
grow wild in wasteland, marginal lands and unprepared surroundings of households
without any defined pattern of management. It was often slashed and treated as weed.
The crop was left at the mercy and management of children and the very poor. It was
commonly categorized as ‘strictly subsistent’, ‘food security’ or ‘famine relief’ crop
(Scott and Maldonado, 1999). The children of the very poor harvested the tubers, ate
them in the boiled or roasted forms and with or without palm oil in-between meals
since it never formed a meal or part of a meal. Sweetpotato was never a commodity in
both urban and rural markets and never formed part of any extension message or
technology. Research, too did little or no work on the improvement and husbandry of
the crop.
From 1974, however, the National Root Crops Research Institute (NRCRI),
Umudike, took leadership of, and embarked on rigorous and active research into the
genetic improvement, production, processing, storage, utilization and marketing of
root and tuber crops of economic importance in Nigeria (NRCRI, 2009). The mandate
crops are cassava, yam, sweetpotato, cocoyam, ginger, potato, sugar beet, turmeric,
risga and Hausa potato (Nwosu, 2004). The Institute carries out the research work
sometimes in collaboration with other research centres like the International Institute
for Tropical Agriculture (IITA), International Potato Centre (CIP) and faculties of
agriculture of universities in the country. These research efforts have led to the
development of many production and processing technologies. With regard to
sweetpotato, these technologies included various improved sweetpotato varieties,
21
notable among which is the orange-fleshed varieties. These are rich in beta carotene, a
pro-vitamin A from which the body synthesizes vitamin A (Kapinga, Ewell,
Hagenimana and Collins, 2001).
Some varieties were introduced specifically for livestock production because
of their high yield of foliage and include TIS 8164, Tanzania and Wagabolige
(Ikwelle, Ezulike and Eke-Okoro, 2001; Njoku, Nwauzor, Okorocha and Afuape,
2006). Other varieties with bland taste have been introduced to benefit consumers
averse to the usual sugary taste of sweetpotato. These varieties include TIS 87/0087,
440216, 440163, Naspot 2 and Tanzania (Njoku et al., 2006). Varieties such as
199004.2, 440216, 440031, 440163, Tanzania and Centennial have low oil absorption
capacity when fried, a desirable quality in sweetpotato varieties that are demanded for
preparation of snacks (Njoku, et. al., 2006). Other technologies developed for
sweetpotato production included seedbed preparation, plant population (30cm on
ridges and 25cm on mounds), planting material, soil requirement, time of planting,
weed control methods, earthening up, pest and disease control methods and time of
harvest. With regard to processing, sweetpotato can be processed into fufu flour
(fermented), unfermented sweetpotato flour for use in confectioneries, toasted
sweetpotato, sweetpotato starch, in addition to its use as livestock feed (Aniedu and
Oti, 2007; Ojeniyi and Tewe, 2001; Ezeano, 2006).
In order to disseminate these technologies to the farmers for uptake and
subsequent use, NRCRI programmed the sweetpotato production and processing
technologies into the technology review meetings of the Agricultural Development
Programmes (ADPs) in the South-east zone
22
of Nigeria through the Research-Extension-Farmer-Input-Linkage System (REFILS)
(Odurukwe and Anuebunwa, 1996). Since 1996, the Institute embarked upon regular
and intensive campaigns aimed at educating the farmers on the benefits of sweetpotato
production and processing to ensure their widespread adoption (Odurukwe and
Anuebunwa, 1996). It did this in conjunction with the State Ministries of Agriculture
through their respective ADPs, with the farmers in the South-east agro-ecological
zone as the initial targeted clients. The zone comprises Abia, Anambra, Akwa Ibom,
Bayelsa, Cross River, Ebonyi, Enugu, Imo and Rivers States.
Further more, efforts are being made to popularize sweetpotato production and
processing in other parts of the country. In this regard NRCRI has so far opened six
sub-stations to serve as service centres and channels for disseminating the Institute’s
research findings (Nwosu, 2008). These sub-stations are Gassol in Taraba State,
Igbariam in Anambra State, Maro in Kaduna State, Nyanya in Abuja (Federal Capital
Territory), Otobi in Benue State and Vom in Plateau State. There is, hitherto, no study
carried out to elucidate the level of awareness and extent of adoption and disadoption
of the sweetpotato production and processing technologies in the zone. A work by
Udealor, Ikeorgu, Ukpabi and Nwauzor (2004) showed a low level adoption of the
technologies in all the surveyed states, but failed to detail the extent of initial uptake
or adoption of these technologies, their continued use, abandonment or disadoption, as
well as the determining factors. Ezeano (2006), which studied the changes over time
(trends) of the levels of sweetpotato production, utilization and marketing in the
South-east zone, similarly did not cover the continued adoption and disadoption of the
sweetpotato technologies. It would, therefore, be necessary to know the extent of the
23
initial uptake (adoption) of these technologies and their continued use or abandonment
(disadoption) by the farmers in the zone. Moreover, it would be necessary to know the
level of awareness of the cultivation and processing of sweetpotato the farmers, as
much human, material and financial resources have been committed into the research
and extension of these technologies. This study will, therefore, fill the information gap
and answer such pertinent questions as: What are the characteristics of those farmers
who are cultivating and processing sweetpotato? Were the sweetpotato production and
processing technologies disadopted by the farmers in the zone? What are the factors
affecting the adoption and disadoption of this crop in the study area? What are the
constraints to continued use of the technologies by farmers in the zone?
1.3
Purpose of the study
This study sought to determine the adoption and disadoption of the sweetpotato
production and processing technologies by farmers in the South-East zone of Nigeria.
Specifically, the objectives were to:
i)
determine the level of awareness of the sweetpotato production and processing
technologies among farmers in the zone,
ii)
determine the extent of adoption and disadoption of the sweetpotato production
and processing technologies by the farmers in the zone;
iii)
examine the determinants of adoption and disadoption of the sweetpotato
production and processing technologies in the study area; and
iv)
identify the constraints to the adoption of sweetpotato production and
processing technologies in the zone.
24
1.4
Significance of the study
There is need for increased staple food production in Nigeria both for meeting
the food demand of the population, and for export. This increase cannot be attained
without synchronization of efforts by research institutes, extension service outfits,
input agencies and farmers in the adoption of relevant technologies. Technologies
developed by research institutes are not likely to be adopted by the farmer-clients if
they are not adapted to the farmers’ conditions. These conditions include accessibility
to the technologies either in the form of availability of resources to purchase needed
inputs or in the form of the relevance and appropriateness of the technologies to their
needs, capabilities and environmental conditions.
Indeed, effectiveness of agricultural research effort is in terms of adoption of
developed technologies by the ultimate users to increase production. Agricultural
technologies that fail to increase production on this premise, implicate ineffective
research effort. It is, therefore, necessary to always determine the status of adoption of
transferred technologies by target farmer groups. This will elicit information on the
usefulness and relevance of the technologies to farmers. It will also elucidate further
modifications that need to be made to enhance adoption of the technologies.
The National Root Crops Research Institute, Umudike, would benefit from this
work as the Institute has expended a great deal of research efforts targeted at
increasing the production of sweetpotato as alternative/complement to yams, cassava
and cocoyam, among others. This study seeks to provide information that would help
the National Root Crops Research Institute, Umudike, and other related research
25
institutes and universities, to develop technological packages on sweetpotato
production and processing that would be relevant to the needs and problems of the
farmers in the zone. It will also provide policy makers, development planners and
workers with necessary data and insight for effective and sustainable policies and
programmes that would facilitate adoption of sweetpotato production and processing
technologies in South-eastern Nigeria. The study would, hopefully, add to the existing
body of knowledge in rural sociology and extension, which would be useful to the
government.
26
CHAPTER TWO
REVIEW OF RELATED LITERATURE
Literature is reviewed under the following headings;
(1)
The
historical
perspective
of
sweetpotato
vis-à-vis
its
importance
internationally and nationally;
(2)
Sweetpotato research efforts in Nigeria;
(3)
Adoption of improved technologies;
(4)
Disadoption of improved technologies;
(5)
Constraints to adoption of improved technologies;
(6)
Theoretical framework for the study.
2.1
Historical perspective of sweetpotato
Sweetpotato is a very important crop in many parts of the world and cultivated
in more than 100 countries. It is the seventh among total world food crop production
after wheat, maize, rice, potato, barley and cassava (Collins, 1987). It is grown mostly
in developing countries where it is ranked as the fifth most valuable crop after rice,
wheat, maize and potatoes (Woolfe, 1992; FAO 1997).
The developing world grows 72 percent of all root and tuber crops and 98
percent of the hectarages of sweetpotatoes. These hectarages are located in three
major regions of the world, namely, Africa, Far East (Asia) and Latin America
(Collins, 1987). About 90 percent is grown in Asia, a little less than five percent in
Africa and about five percent in the rest of the world. The major producers in Asia are
China, Indonesia, India, Japan, Vietnam, the Philippines and the Republic of Korea.
27
The largest producers in Africa are Uganda and Nigeria, while production from Latin
America and the Caribbean is relatively small. Only about two percent of the world’s
sweetpotato production comes from the industrialized countries, mainly, the United
States and Japan (FAO, 1997).
The world’s largest producer of sweetpotato is China. It contributes over 60
percent of the land area planted to sweetpotato and more than 80 percent of the
world’s supply. It also has the world’s highest farm yields (18t/ha). In Africa, yields
are as low as 4.7t/ha, whereas in Latin America and Asia, excluding China, yields are
about 7.4 and 8.6t/ha, respectively (Tewe, Ojeniyi and Abu, 2003;Ezeano, 2006).
Yields are generally low in many countries, but there are great potentials for
increasing yields by introducing improved varieties and more efficient cultivation
practices.
Sweetpotato provides reasonable amount of energy and protein. It ranks second
to cassava among the root crops in energy content and first in protein supply (FAO,
1997). Its roots are a rich source of vitamins A and C. The yellow or orange-fleshed
varieties provide more vitamin A than those with white or pale-coloured flesh
(Kapinga et al., 2001). They also provide dietary fiber and contain significant amounts
of other vitamins such as thiamine, riboflavin, niacin, pyridoxine, pantothenic, folic
acid and tocopherol, in addition to minerals such as calcium, potassium, phosphorus,
iron, magnesium and sodium. The tender leaves and shoots are high in vitamins A and
C, contain more protein than the roots, and can be used as vegetables (International
Potato Centre, 1991; Woolfe, 1992; Kapinga et al., 2001).
28
Sweetpotato is an important source of dietary energy in Central and Southern
Asia, the Pacific Islands and parts of tropical America. It is a staple crop in the
highlands of Papau New Guinea (Hall and Phathak, 1993). In sub-Saharan Africa,
sweetpotato ranks third among the root and tuber crops after cassava (Manihot
esculenta), and yam (Dioscorea spp). About 90 percent of the total output comes from
Eastern and West Africa (FAO, 2007; NRCRI, 2009). FAO report for the mid-1980s
had it that over 6 million tonnes of sweetpotato were grown on 1.2 million hectares in
Africa or about 5 percent of the total for developing countries of the world. During the
1980-1992 period, its production in Africa increased as a result of the significant
increase (2.6 percent per annum) in the area planted (FAO, 1997). According to FAO
statistics (2007) and NRCRI (2009), the highest sweetpotato producing countries in
sub-Saharan Africa with their production figures (thousand tonnes) in brackets are
Uganda (2,602), Nigeria (2,432), United Republic of Tanzania (960), Burundi (874),
Kenya (816), Rwanda (800), Angola (700) and Ethiopia (389). Sweetpotato is also an
important crop in Southern Africa as secondary food crop in the grain-based food
systems. It provides a food reserve when the major grain reserve fails due to drought
or pests (Ewell and Mutuura, 1994; Ewell, 1997).
Sweetpotato roots may be boiled, baked or fried, or prepared in various
combination dishes. The roots can be prepared into sweet dessert, processed into a
variety of products or the multi-purpose flour and various drinks, both alcoholic and
non-alcoholic. It can also be used as partial substitute for other feed ingredients,
especially maize, for several livestock species such as pigs and poultry. Both roots and
tops ,(above-ground vegetative parts), can be used as fresh materials or as dried meal
29
and fermented silage. It can also be used industrially in the production of starch and
alcohol, since starch constitutes 70 percent of the root dry matter, which ranges from
30 to 35 percent (Woolfe, 1992).
Sweetpotato is reported to have been introduced into Nigeria in the late 16 th
century (Chinaka, 1983). It was cultivated in a few restricted areas by farmers for their
own consumption. As at 1971, the areas under potato cultivation (which includes
sweetpotato) were the middle-belt and riverine States of Nigeria (Tewe, Ojeniyi and
Abu, 2003).
Today, areas of sweetpotato production have expanded to the humid,
sub-humid and semi-arid regions of the country. National production figures reported
by FAO show that both production and area cultivated has been increasing (Tewe,
Abu, Ojeniyi and Nwokocha, 2001). Farm yields vary from 3.5 tonnes in the Northern
zone to 8.0 tonnes per hectare in the Central and South-eastern Zones (Tewe et al,
2003). Figures from the experimental fields range from 23.5 to 71.0 tonnes per
hectare. Among the root and tuber crops, it is rated fourth in importance after cassava,
yam and cocoyam (Nwokocha 1993; Ikwelle et al, 2003).
2.2
Sweetpotato research efforts in Nigeria
In Nigeria, government institutions and universities are involved in research on
sweetpotato. Foremost among these institutions are the National Root Crops Research
Institute (NRCRI) Umudike, and the International Institute of Tropical Agriculture
(IITA), Ibadan. NRCRI, Umudike, has the specific national mandate to conduct
research into the genetic improvement, production, processing, storage, utilization and
marketing of root and tuber crops of economic importance, including sweetpotato
30
(Nwosu, 2005). More focused research work on sweetpotato has been going on at the
NRCRI since 1972 when NRCRI took leadership in the research on root and tuber
crops in Nigeria (NRCRI, 1972 – 1974). Research activities carried out include
germplasm collection, conservation and evaluation; agronomic research; pest and
disease management; post harvest handling and processing, and socio-economics of
sweetpotato production (Tewe et al., 2003).
2.2.1 Germplasm collection, conservation and evaluation
Germplasm forms the crop gene bank, and is central to plant breeding work.
The NRCRI obtains sweetpotato germplasm accessions from both local sources and
international research centres like IITA, Ibadan, and International Potato Centre,
(CIP), Peru. These accessions are mostly conserved in-situ. Efforts are being made to
conserve them in the form of in-vitro culture at the tissue culture laboratory of
NRCRI, Umudike. Characterization of the germplasm is carried out following the
procedure of Huaman (1992) and involves morphological characters, yield potential
and quality. They are evaluated for such attributes as tolerance to biotic and abiotic
stress, dry matter content, flowering ability and disease resistance (NRCRI 1979-80,
1990).
Specifically, Federal Agricultural Research and Training Station (FARTS)
(1974) carried out sweetpotato germplasm collection, evaluation and characterization,
collecting a total of 104 cultivars. It also carried out studies aimed at determining the
part of the sweetpotato vine that is most suitable as planting material. FARTS (1975)
carried out a sweetpotato survey and germplasm collection in Nigeria in order to map
31
out best available cultivars for specific ecological zones, in addition to yield trials to
select the high yielders in the germplasm. It also had a study on the classification of
sweetpotato cultivars with the aim of describing and classifying all the cultivars in the
national germplasm collection.
Ochuba (1983) screened fifty-eight sweetpotato seedlings for selection of
promising ones. He showed that twenty promising seedlings, with fresh tuber yields
of 24.54 to 86.92 tonnes per hectare, were selected. Agbo, Anioke, Abazie and Azoke
(1990) evaluated 329 sweetpotato accessions for selection of genotypes with desirable
traits such as flowering ability and high yields. They showed that 98% of the
accessions flowered during the early season, variety TIS 2498 gave the highest tuber
yield of 41 tonnes per hectare while TIS 3092 gave the highest foliage yield of 75
tonnes per hectare. NRCRI (1996) evaluated ten genotypes of sweetpotato for root
tuber yield in different ecological zones of Nigeria and showed that five genotypes
had high root yields. The highest yielder was TIS 8164, followed by TIS
2532.OP.1.13, TIS 8441, TIS 87/0087 and TIS 8470. It also found that the genotypes
TIS 8164, TIS 87/0087 and TIS 2532.OP.1.13 have wide adaptation across the
country.
2.2.2 Agronomic research
Agronomic work that has been carried out included studies of fertilizer
application involving optimum NPK (Nitrogen,45kg; Phosphorus, 15kg; and
Potassium, 40kg) requirements, time and methods of placement of inorganic fertilizer
(NPK 20:10:10), appropriate planting material (5-node vine cutting), time of planting
32
of vine (late May to June), plant spacing (30cm x 100cm on ridges; 25cm x 100cm on
mounds for both sole and intercrops), weeding frequency (one major weeding for
sole-cropped sweetpotato at 4-6 weeks after planting), time of harvesting (3-4 months
after planting) and water requirement of sweetpotato (700mm-1000mm, 500mm of
this amount is required during vegetative growth) (NRCRI, 1978; 1982; 1984).
Since sweetpotato roots are mostly used for human consumption, the criteria
used for breeding and selections have been based on parameters related to food
preferences such as taste, texture, water and fibre content. Selections for industrial
uses emphasize canopy structure, root size and dry matter content. These research
efforts have led to the introduction of improved varieties such as TIS 87/0087, TIS
2532.OP.1.13, TIS 8441 and TIS 8164 which are high yielding and tolerant to
prevalent pests, notably sweetpotato weevil, Cylas spp.
Worthy of note are the
varieties TIS 8164, TIS 87/0087 and TIS 2525.OP.1.13, which have wide adaptation
across Nigeria (NRCRI, 1990). These have led to increase in yields of sweetpotato
from 5t/ha to 20t/ha in farmer’s fields (Nwosu, 2005). Specific research work
includes:
FARTS (1974), which carried out a study to determine the effect of NPK
fertilizers on the growth and yield of sweetpotato.
It also carried out a study on
planting and harvesting dates for different sweetpotato varieties with the aim of
determining the optimum time for planting and harvesting different sweetpotato
varieties.
33
Chinaka and Nwinyi (1976) carried out nutrient requirements and adaptability
studies to determine the effect of NPK fertilizers on the growth and yield of
sweetpotato.
Chinaka (1976) carried out studies on sweetpotato propagation materials aimed
at identifying the part of the vine which was most suitable as planting material, as well
as examining the performance of waste root tuber parts as planting materials.
Okonko and Ajugwo (1976) carried out studies on planting and harvesting
dates and cultivars with the aim of determining the optimum time for planting and
harvesting different sweetpotato cultivars. NRCRI (1979) investigated the effect of
population density and nitrogen (N) fertilization on the yield of two cultivars of
sweetpotato, namely, CV 065 and TIS 1487.
It showed that neither population
density nor the levels of nitrogen significantly affected root tuber yield of the two
cultivars, although varietal differences in performance were great. It investigated
further the effect of time and method of planting of the vines on the yield of
sweetpotato, showing that best yields were obtained from those vines which were
planted early, and decreased progressively as the season advanced. Chinaka (1981)
worked on the optimum population for sole and mix cropped sweetpotato. He
intercropped the sweetpotato with maize, using two sweetpotato varieties, Dokobo and
TIS 2421, at two locations of Ubiaja and Lafia. Unanma (1981) studied the critical
period of weed interference in a sweetpotato intercrop. He intercropped sweetpotato
variety Dukukpuku with maize and cocoyam. In another study on the effect of
fertilizer rates on crop yield of sweetpotato intercropped with cassava, yam, cocoyam
and maize under weed interference, Unanma (1981) showed sweetpotato was very
34
sensitive to weed competition for NPK nutrients in intercropped situations. Fertilizers
application to a weedy intercrop of either yam or cocoyam and maize with
sweetpotato led to increase in the fresh tuber yield of sweetpotato but reduction in the
yield of maize and cocoyam. Where cassava was planted instead of yam, however,
fertilizer application in a weedy situation led to high reduction in the yield of
sweetpotato root tuber.
Unanma (1981) also carried out a study to assess the performance of promising
herbicides, such as fluometuron, alachlor and primextra, on weeds and sweetpotato
intercropped with cassava and soyabean in Umudike and Lafia. He showed that
uncontrolled weed growth resulted in the loss of 82% of the fresh tuber yield of
sweetpotato in both locations, and 98.7% and 65.5% in soyabean seed yield in
Umudike and Lafia respectively. It also showed that sweetpotato yield loss was
reduced by weeding at 3 and 8 weeks after planting, as well as applying fluometuron
at 2kg per hectare active ingredients pre-emergence at Umudike. At Lafia 4kg/ha of
fluometuron or 2kg/ha of primextra reduced yield loss considerably.
Ochuba,
Ogbuehi, Okonko and Nnodu (1982) evaluated ten sweetpotato varieties for yield and
resistance to pests and diseases in ten locations in the rain forest and guinea savanna
zones of Nigeria. These varieties were TIS 146/3092, Dukukpuku, TIS 2534, TIS
1176, BIS 23, TIS 2421, TIS 3252, Dokobo, Anoma and one local variety.
They
showed that highest yields were recorded at Ubiaja and Igbariam from varieties TIS
146/3092, Dukukpuku, TIS 2534, TIS 1176 and TIS 2421, and that mosaic disease
attacked the improved sweetpotato varieties more than the local varieties. They also
showed that Cylas, Isopods and foliar insect infestations were evenly distributed, and
35
that none of them was severe enough to affect root tuber yield. In a study on the
determination of optimum time of application of N, P and K fertilizer to sweetpotato
in different locations of Umudike, Igbariam, Ubiaja and Lafia, Udealor (1983) showed
that time of fertilizer application had no significant effect on the yield of sweetpotato
root tubers in all the locations except Lafia. At Lafia, the application of fertilizer at
four to six weeks after planting gave the highest yield. Nwinyi and Emezie (1983)
evaluated fertilizer placement methods on sweetpotato and indicated that there was no
significant difference on yield of sweetpotato due to method of fertilizer placement. A
study on the nutrient requirements of sweetpotato in sole cropping, which was carried
out by Chinaka (1983), indicated that increase in N levels did not affect the yields of
variety Anoma, whereas it increased the yields of variety TIS 146/3092. He also
showed that increase in the levels of P decreased yields in both varieties. Ochuba,
Okonkor, Omenukor and Akuma (1983) carried out an adaptation study on nine
improved sweetpotato varieties, showing that six of the improved varieties gave
significantly higher yields than the local varieties at Ubiaja and Umudike, and that
four of the improved varieties out-yielded the local variety (control) at Igbariam. They
also showed that the local varieties at Lafia gave significantly higher yields than the
improved varieties. Nwinyi and Emezie (1984) carried out a trial to assess the effect
of length of sweetpotato vine storage on root tuber yield. They showed that highest
yields were obtained with vines that were cut and planted the same day, and that
yields decreased progressively to the lowest, which was at four weeks after cutting.
Ochuba and Akuma (1984) investigated the effect of ‘age’ of sweetpotato vines
on the yield of marketable root tubers. The ‘age’ of the vine was defined as the portion
36
of the vine that was used, namely, apical end, middle and basal portions. The apical
end was regarded as the youngest portion while the basal position was recorded as the
oldest. They indicated that highest yields of both marketable and total root tubers were
obtained with the apical end, followed by the middle and basal end cuttings in the
varieties TIS 2498, TIS 2544 and Anoma. With variety TIS 8/727, however, the
highest yields were obtained from the apical cuttings, followed by the basal cuttings
and then the middle vine cuttings. Okonko (1984), in a study on dry matter
distribution pattern of five sweetpotato cultivars, showed that in all the cultivars, the
dry matter content of the leaves increased until the 14th week, when it started
declining. He also showed that the distribution of dry matter between the tops and
tubers differed significantly between the five cultivars.
Nwinyi and Ene (1987)
studied the effect of time of vine cutting or pruning on root tuber yield of five
cultivars of sweetpotato. They showed that pruning of vine that was done beyond four
weeks after planting resulted to low tuber yield, as only about 50% of tuber yield
would be obtained. Ogbuehi, Anioke and Nwinyi (1987) carried out a study on the
influence of spatial planting arrangement on total sweetpotato yield and showed that
placement of vines at 25cm on top of ridges (to give 40,000 stands per hectare) gave
the highest tuber yield of 5.9 tonnes per hectare, while placement at 30cm on top of
ridges (to achieve 33,000 stands per hectare) gave the second highest yield of 5.5
tonnes per hectare. Nwinyi and Onyenobi (1987) indicated that the recommended
method of preserving vine cuttings of sweetpotato is by storing them in open baskets.
They showed that a preservation method, such as covering with dry grass, reduces the
fresh tuber and saleable tuber yields by 20.2% and 18.2% respectively. Onyekwere
37
and Nwinyi (1989), in a study on the water requirements of sweetpotato, showed that
sweetpotato yield increased progressively with increase in water application.
Nwokocha, Agbo, Ezulike and Anioke (1991) determined the causes of yield
depressions in sweetpotato by planting four sweetpotato cultivars at three sequential
planting dates. They showed that the root tuber yield declined with delay in planting
date. They also showed that there was increase in virus incidence with delayed
planting. NRCRI (1996) studied the effect of number of nodes and planting materials
on the performance of sweetpotatoes, indicating that vine cuttings with one or two
nodes established poorly in the field and, subsequently, had poor root tuber yields.
2.2.3 Pest and disease management
The major pests of sweetpotato in Nigeria are termites, root knot nematodes,
weevils (Cylas puncticolis) and the butterflies, Acrea acerata. These cause varying
degrees of damage to sweetpotato. Studies carried out on control measures showed
that soil insecticides were effective against weevil and prevented root losses, but were
ineffective in preventing losses to vegetative parts of the plant (Tewe et al., 2003).
Foliar insecticides were, however, effective against damage on vegetative parts but
ineffective against root damage. A number of screenings for resistance to weevil
damage were carried out and showed sweetpotato cultivars to have varying degrees of
resistance (Tewe et al., 2003). Efforts are being made at integrated pest management
of sweetpotato weevils involving field sanitation, cultural practices, use of resistant
varieties and spraying with insecticides. Studies on general assessment and
identification of major pests and diseases of sweetpotato showed that the major field
38
diseases were caused by viruses. Leaf spot disease was implicated as being endemic
and affects mature and senescent sweetpotato leaves. It is caused by the virus Saptona
batahcola. Another disease problem is the tuber rot, which affects sweetpotato roots in
storage. Infection is through cuts and other wounds on the tuberous roots. The most
frequently encountered damage to sweetpotato is that caused by the fungus
Lasiadiplodia theobromea.
Some specific research works in this area include:
Studies on the control of sweetpotato weevil aimed at investigating the efficacy
of some selected insecticides on the control of sweetpotato weevil, Cylas puncticollis,
(FARTS, 1975). FARTS (1975), also, carried out studies on virus diseases of
sweetpotato with the aim of investigating the incidence and mode of spread of the
mosaic disease of sweetpotato.
Nwana and Okeke (1976) carried out studies on virus diseases of sweetpotato
aimed at investigating the incidence and mode of spread of the virus disease complex
of sweetpotato. Nwana (1976) studied the biology and ecology of Cylas puncticollis
with a view to determining possible weaknesses in the nature of the insect, which can
be exploited against it. Nwana and Okonkwo (1976) screened sweetpotato for
resistance to sweetpotato weevil with the aim of determining sweetpotato cultivars
which are resistant to the weevil. NRCRI (1979) collected 353 cultivars of
sweetpotato which were screened for susceptibility to viral diseases. It showed that the
disease pattern differed among the sweetpotato cultivars, and that the predominant
disease was the mosaic strain.
Nnodu (1981) carried out a study to identify economic field diseases and pests
of sweetpotato, showing that the most important field diseases were the sweetpotato
39
mosaic virus (SPMV) and internal cork. He also showed that Cylas spp was the
prominent pest at Umudike while Cylas and Isopods were the prevalent pests at Lafia.
Atu, Ezulike and Odie (1984) evaluated the use of selected insecticides for the control
of the sweetpotato weevil, indicating that Monocrotophos (Azodrin) insecticide was
the most effective, followed by carbosulfan (Marshal) and decamethrin.
Anioke, Ene and Abazie (1987) screened the sweetpotato germplasm for
resistance to pests and indicated that the incidence of Acraea acerata (sweetpotato
butterfly) was minimal while that of Agricus convolvuli (sweetpotato moth) escalated.
Anioke (1988) evaluated sweetpotato cultivars for resistance to Cylas spp, Acraea
acerata and Agricus convolvuli, showing that cultivars TIS 8/727, AK/83/7, TIS 2421,
TIS 1176 and TIS 2534 were least damaged by the pests while TIS 2498 and BIS 22
were the most damaged cultivars. Anioke (1989) screened sweetpotato germplasm for
high yield and pest resistance in early season planting (June) and late season planting
(September). He showed that there were no incidences of Acraea acerata and Agricus
convolvuli on all the sweetpotato accessions during the early season. He also showed
that damage by Acraea acerata on sweetpotato planted during the late season was
very serious, with only few accessions showing moderate resistance.
Anioke, Agbo and Onyenobi (1991) evaluated time of planting and harvesting
of sweetpotato on yield and pest damage, indicating that sweetpotato that was planted
early (May to mid June) had lower Acraea acerata damage than those planted later.
They also showed that sweetpotato planted in May and harvested 12 weeks later gave
the highest foliage yield. In another study to assess the effect of first generation larvae
of Acraea acerata on sweetpotato planted in a glass house, Anioke and Onyenobi
40
(1991) showed that first generation early instars of the sweetpotato butterfly at a
population of less than 20 larvae per plant, and at the plant age of 6 weeks after
planting, did not constitute a serious problem to leaf and root tuber development in
sweetpotato.
2.2.4 Postharvest handling and processing
Sweetpotato root tuber has high moisture content and deteriorates rapidly after
harvest. Research work on postharvest handling, processing into intermediate products
with longer shelf life and increased storage life of fresh roots have shown that, among
others, underground storage is a better option. Under this condition tubers can be
stored for two to three months (Tewe et al., 2003). Other research work carried out
included those on biochemical characteristics, sensory and nutritional valuations,
storage of processed products and microbiological studies such as production of
culture media from sweetpotato roots. Specific research works include:
Studies on the preparation of sweetpotato flour aimed at producing flour, which
may be combined with wheat flour and used for baking bread and preparing more
acceptable sweetpotato dishes (Igwebuike, 1976). NRCRI (1979) carried out studies
on the processing and utilization of sweetpotato tubers with the aim of developing
processed foods and food from sweetpotato. It indicated that the raw sweetpotato flour
had slightly higher protein content than sweetpotato instant flour. Nwokedi (1981)
carried out varietal selection of sweetpotato for flour and chips production, and
showed that varieties TIS 146/3092 and TIS 2534 gave the highest yield of chips of
36.20% each and flour yields of 28.05% and 25.00% respectively. Ochuba (1981)
41
determined the level of protein contained in sweetpotato leaves which are used as
vegetables by humans, indicating that the protein contents of the leaves of the eight
sweetpotato varieties he analyzed varied from 16.34% to 20.77%. Nnodu (1982)
worked on the development of sweetpotato storage system, showing that storing fresh
sweetpotato tubers in sterilized moist sawdust preserved them in good saleable
condition for four months. He also showed that treating the sweetpotato tubers with
thiobendazole increased their rate of sprouting, but gave best protection against decay.
Nnodu (1983) carried out further studies on storage of sweetpotato, indicating that
both sterilized and unsterilized moist sawdust was effective in prolonging the shelf life
of sweetpotato tubers for up to 4 months.
Ukpabi and Ijioma (1984) evaluated
selected sweetpotato cultivars for primary processing into flour, starch and reducing
sugar, showing that cultivars Dukukpuku and Dokobo had flour yields of 30% each.
They also showed that cultivars TIS 2498 and Anoma, which were remarkably high
flour yielders, had low reducing sugar content and flour which was whiter than the
others. Cultivars TIS 2352, TIS 8/727 and TIS 2544 were rich in vitamin A while,
generally, all the cultivars which were analyzed were good sources of edible and
industrial starch.
Ukpabi and Oji (1984) evaluated sweetpotato cultivars for suitability as
vegetable, indicating that sweetpotato leaves were acceptable as food after boiling for
3 minutes in water. They also indicated that the fibre content of sweetpotato leaves
was not high and that their protein and ash contents compared favourably with those
of the other commonly used vegetables like Telfairia. In another study, Ijioma and
Ukpabi (1984) evaluated sweetpotato cultivars for fufu production. They showed that
42
fufu made from sweetpotato flour was dark-brown in colour in all the tested cultivars.
They also showed that the colour of fufu prepared from the sweetpotato fresh tubers
varied from yellow in cultivars TIS 8/727 and TIS 2352, white in Anoma, Dukukpuku
and TIS 2493 to cream in BIS 23, TIS 2534, TIS 2421 and TIS 146/3092. Ukpabi
(1987) evaluated sweetpotato cultivars for different food forms, feed and industrial
raw materials.
He showed that sugar syrup from sweetpotato gave a dextrose
equivalent of 28.30, meaning that moisture free starch from sweetpotato has the
potential of producing sugar syrup of 32.34 dextrose equivalent. He explained that
sugar syrup is a major ingredient in the preparation of ice creams and jams, and an
important raw material in the production of alcohol (ethanol) in distilleries and
breweries.
Ukpabi and Orji (1987) assessed the use of sodium metabisulphite in
maintaining colour in sweetpotato flour and meals, indicating that by peeling the
sweetpotato tubers under water and then treating with sodium metabisulphite, the
colour of sweetpotato flour and meals is maintained. Ukpabi (1989) estimated the
starch and amylose contents of some Nigerian sweetpotato, indicating that the starch
contents of NRCRI top yielders at Umudike in 1988 (with yield potentials of 24.5 to
71.7 tonnes per hectare) ranged from 15.08 to 24.68%. He stated that, with such
starch values, the sweetpotato cultivars were good sources of starch for food and
industrial uses. Ejiofor and Ohambela (1989) carried out preliminary studies on the
use of sweetpotato flour in the production of micro-biological media, indicating that
the media from the sweetpotato flour exhibited remarkable jellying abilities, which
encouraged profuse growth of micro-organisms when inoculated. The media also
43
showed clear transparency, consistency and jellying abilities that permitted easy
inoculum growth and counts of micro flora and, therefore, compared favourably with
conventional nutrient agar media. In a study to evaluate current elite varieties of
sweetpotato for starch and flour potentials, Ukpabi, Anioke, Agbo and Ene (1990)
showed that the starch and flour contents of the test cultivars ranged from 20.95% to
25.05% and 18.59% to 33.04% respectively. They also showed that cultivars AK/83/7,
TIS 2534, TIS 8441 and TIS 8504 were good materials for production of sweetpotato
starch and flour. Ukpabi (1991) carried out preliminary studies on the storage of
sweetpotato pulp and starch under anaerobic conditions, showing that the anaerobic
storage of sweetpotato pulp and starch at high levels of moisture significantly affected
their colour and smell. He said that, although the colour of the starch was acceptable
throughout the period of the study, its smell was unacceptable at the 8 th and 9th month
of storage.
2.2.5 Socio-economics of sweetpotato
Studies carried out in this area included economics of sweetpotato production
and economic analysis of sweetpotato production and marketing. These showed that
sweetpotato production and marketing were profitable ventures. Most of the farms
were less than one hectare in size and labour cost accounted for over 81 percent of
total cost of production (Tewe et al., 2003). Most of the producers sold more than
half of their harvests (Eluagu, Okonkwo, Ikeorgu and Ugwu, 1989; Asumugha, Agbo,
Ezulike and Chukwu, 1990; Klinke, 1997). They, also, indicated that yields, price
returns, variable costs and gross margins per hectare to be expected from growing,
44
processing and marketing of sweetpotato as compared with cereals showed that
sweetpotato is more profitable than cereals. They noted, however, that the danger of
considerable fluctuations in yields, price and high cost of capital equipment needed
for sweetpotato production makes it a high risk crop. Nayak and Mandal (1988), in a
study using fourteen crops to test their economic suitability for replacing rice in West
Bengal, showed that maximum benefit from invested unit cost was obtained from
sweetpotato (3.39), followed by black grain (2.88), pigeon peas (2.05) and cassava
(1.58). Bajwa and Belobal (1997) studied the cost and benefit differences of
sweetpotato production in various growing areas of Pakistan, and showed that
sweetpotato prices were high in the summer season in the hills and in autumn in the
plain, despite higher yields.
Asumugha et al., (1991) studied the economics of sweetpotato production
under conventional and reduced tillage land preparations and showed that the
conventional system was more profitable than the reduced tillage system in terms of
root yield and returns on investment.
Eluagu et al., (1989), in a study on the
economics of sweetpotato production using improved management systems, showed
TIS 8504 as the elite variety that could be produced profitably in both the rainforest
and derived guinea savannah areas of Nigeria.
2.3
Adoption of improved technologies
According to Rogers (1995), adoption is a decision to make full use of an
innovation or technology as the best course of action available. It is the decision of an
individual or group of people to use or apply an innovation. This decision is a process
45
involving the acquisition and processing of information about an innovation, followed
by a behavioural change. The process, according to van den Ban and Hawkins (1996),
consists of five stages or steps, namely,
1. Awareness stage, the individual first hears about the
existence of the innovation;
2. Interest stage, he develops interest and actively seeks
further information about it;
3. Evaluation stage, he weighs the advantages and
disadvantages of using it;
4. Trial stage, he tries the innovation on a small scale if
he is satisfied with the outcome of the evaluation stage;
5. Adoption stage, he decides to use the innovation as the
best course of action available.
Wendland and Sills (2008) defined adoption as ‘having ever implemented the
technology’. This definition is at variance with the common notion that adoption is
synonymous with the ‘use of the technology in the survey year’. They said further
that, by defining adoption as use of the technology in the survey year, the important
distinction between the farmers who have never trialled the new technology and
farmers who have trialled it is obscured. They, therefore, defined adoption as ‘having
ever implemented the technology before the survey year’, and continued adoption as
‘implementing the technology in the survey year’. Subsequently, in this study, the
adoption of the sweetpotato production and processing technologies by farmers in
South-eastern Nigeria will mean having ever cultivated sweetpotato and used its
46
processing technologies before the survey year by farmers in South-eastern Nigeria
while continued adoption of the sweetpotato production and processing technologies
will mean cultivating sweetpotato and using its processing technologies in the survey
year.
The understanding of the factors that lead to the adoption and disadoption of
agricultural technologies, including new cultivation techniques and new crops such as
sweetpotato, is necessary for targeting technologies appropriately, designing
dissemination strategies and ultimately ensuring they have the intended impact
(Wendland and Sills, 2008). Some literature on the adoption of agricultural
technologies has been reviewed and presented below:
Amegbeto, Manyong, Colibaly and Asiedu (2001), in a study of factors
affecting the adoption of agricultural technologies within yam-based production
systems, identified gender, education level, family size, the number of yam mounds
planted, road conditions and the number of out-going visits made by the household
head in search of agricultural information as significantly influencing the adoption of
chemical fertilizer application on yams. These variables, with the exception of gender,
increased the likelihood of chemical fertilizer application on yams. The same study
also showed that formal education and contact with extension services either by
inward or outward visits increased the probability of chemical fertilizer application on
rice, whereas formal education, availability of family labour, commercial or market
oriented farming, accessibility to market as described by road conditions, and farmers
effort to seek information (out-visits) significantly influenced fertilizer application on
maize.
47
With regard to adoption of improved varieties of soyabean, rice and cassava in
the yam-based production system, the study revealed experience in growing yams,
formal education, availability of family labour, number of women in the household
and visits received from extension agents to positively and significantly increase the
likelihood of adoption of improved soyabean varieties. It also indicated that extension
contact and age influenced that of improved rice varieties while that of cassava
varieties was influenced by age, education and farm type (market oriented yam
farming).
The study differed from the notion that non-adoption of agricultural
technologies by women was solely due to lack of access to information through
extension contact, ascribing it to include such factors as accessibility to productive
resources and having the right to manage separate farms or economic activities under
customary practices.
Tologbonse, Alabi and Tergama (2005) studied the adoption of recommended
crop protection practices by sesame farmers in Benue State, Nigeria. The result
showed low adoption which was probably due to the fact that the technology did not
fit into the farmers existing practices and, therefore, unattractive to farmers, as
reported by Okoro (1997) and Igbokwe (2000). They reported significant relationship
between adoption and awareness, household size and years of farming experience.
Onyenweaku and Mbuba (1991) found that labour availability, attendance at
farmers meetings and extension contacts were positively and significantly associated
with the adoption of the seed yam minisett technique by farmers in Anambra State of
Nigeria. They found a negative as well as no clear-cut relationship between its
adoption and age, education, farming experience, tenancy status, co-operative
48
membership and credit. Profitability was implicated as the major reason for adoption
and lack of awareness of the techniques as the most limiting factor to its adoption.
Chikwendu, Chinaka and Omotayo (1995) reported that age, household size,
co-operative membership, tenural status and intensity of extension contact were the
significant determinants of adoption in a study on the adoption of minisett technique
of seed yams production by farmers in the eastern forest zone of Nigeria. It noted that
scarcity of complementary inputs, lack of credit and the technical nature of the
technique which was tedious were the main constraints to its adoption.
Obeta and Nwagbo (1991) observed that frequency of extension contact and
level of profit of agricultural innovations significantly influenced the adoption of an
improved IITA cassava technology package in Anambra State.
Imoh and Essien (2005) found that farm size and level of formal education
were the determinants of adoption of improved cassava varieties by small-scale
farmers in Ikot-Ekpene agricultural zone of Akwa Ibom State of Nigeria. Nzekwe and
Afolami (2001) observed that farmers adopted more of innovations that were less
capital intensive or require less expenditure.
Mbanaso, Chukwu and Chijioke (2005) showed that age, farm size, sex and
extension contact were the significant factors affecting the adoption of the two-node
cutting technique of sweetpotato production in Ebonyi State, Nigeria.
Tokula (2003) showed farming experience, household size, membership of cooperative societies and level of education to be factors that influenced the adoption of
cocoyam production and processing technologies in Ikwuano Local Government Area
of Abia State. Agwu and Anyanwu (2000) showed that land and labour problems,
49
marketing problems, poor technical information, cultural incompatibility, high cost of
farm inputs and unavailability of necessary inputs were the major factors constraining
the use of improved cowpea technologies in the north-east savanna zone of Nigeria.
Uwakah (1985) showed age, level of formal education and training, farm size,
exposure and use of communication media, leadership role, farmer’s participation in
voluntary organizations, farming experience and frequency of change agent’s contact
with farmers to be the farmer’s personal and socio-cultural characteristics which
constitute critical factors in the technology adoption process.
Ijere (1992) and Nweze (1995) identified income status, labour rate, internal
resource mobilization, investment rate, saving potential and marketing pattern as
important farmers’ economic characteristics, which could influence adoption of
innovations.
Ajala (1992), in a study of factors associated with adoption of improved
practices by goat producers in South-eastern Nigeria, found that age, education, sex,
herd size, organizational participation, nature of farming experience and management
systems were positively related to adoption. Similarly, Auta, Ariyo and Akpoko
(1992), in a study of the socio-spatial variations in the adoption of agricultural
innovations in selected villages in Funtua and Jema’a local government areas, found
that age was significantly related to the adoption behaviour of the respondents. Nweke
(1981) and Voh (1982), however, found no positive relationship between age and
adoption of improved practices.
50
2.4
Disadoption of improved technologies
Wendland and Sills (2008) defined disadoption as ‘having implemented the
technology but later abandoned it’. It is the abandonment of an innovation after initial
uptake. In this study, therefore, disadoption of the sweetpotato production and
processing technologies will mean cultivating the sweetpotato and using its
processing technologies but later abandoning them.
While there is extensive literature on the factors that influence the adoption of
improved technologies, fewer studies have examined the reasons (or determinants) for
abandonment (disadoption) of such technologies after uptake (Feder and Umali, 1993;
Doss, 2006). The overall finding of the few studies on the disadoption process is that
disadoption is influenced by the characteristics of, and experiences with, the
technology itself, in addition to other determinants of adoption. Some studies
estimated disadoption conditional on adoption (Moser and Barrett, 2006; Marenya and
Barrett, 2007). Some others estimated it as part of sample selection models (Neill and
Lee, 2001), or by using recall data (Neill and Lee, 2001; Moser and Barrett, 2006).
Others estimated it using panel data (Marenya and Barrett, 2007).
Neill and Lee (2001) examined the adoption and abandonment of maizemucuna farming systems in the Honduras. They found that limited market access
encouraged disadoption, and farmers that experienced problems with the noxious
weed Rottboellia were, also, more likely to disadopt. Similarly, farmers who used the
maize-mucuna system for more years, who had employed best management practices
such as annual reseeding, and who cultivated more hectares of maize and high-value
crops were less likely to disadopt.
51
Moser and Barrett (2002; 2006) worked on the diffusion of a high-yielding,
low-external input rice intensification system in Madagascar. Estimation results
suggested that better educated farmers (with better understanding of agronomic
principles) and those with more access to labour (including less participation in offfarm labour) were more likely to continue with the system. In addition, farmers who
had planted a greater cumulative area under the system were more likely to continue
using the new rice system.
Marenya and Barrett (2007) modeled the determinants of adoption and
disadoption of soil fertility management practices in Kenya. They found that several
variables like small farm size, scarcity of labour and increased off-farm income
(resource endowment) contributed to the abandonment of these practices, as did
educational attainment and gender of the household head.
2.5 Constraints to adoption of improved technologies
In the process of adopting improved technologies, farmers often encounter
problems. These problems impose limits on the levels of adoption of the technologies
by the farmers. The limits so imposed on the farmers are known as constraints. These
constraints include: lack of funds, high cost of agro-chemicals, lack of credit facilities
and poor extension agent-farmer contact, which were factors shown by Agada (2009)
to constrain the adoption of the IITA improved Imperata cylindrica control
technologies. Ironkwe (2005) indicated that the problems to the adoption of yam
minisett technology included lack of fertilizer, lack of minisett dust, lack of credit,
lack of good roads and transportation, lack of storage facilities and termite attack.
52
Others included high cost of labour for ridge making, highly complex technology, lack
of market and small size of seed yam. Agwu (2000) showed that the major constraints
to the adoption and diffusion of improved cowpea technologies in the North-east
Savanna zone of Nigeria included land and labour problems, poor technical
information, cultural incompatibility, high cost of imputs as well as unavailability of
necessary inputs, while Hoff and Stiglitz (1990) showed lack of collateral and
possession of below average incomes as to production capacities of ural dwellers.
Furthermore, Atala and Abdulahi (1988) showed that shortage of inputs, lack
of adequate extension advice and non-availability of credit constrained farmers’
adoption of improved technologies in Northern Nigeria. High cost of farm inputs, pest
attack, storage loss, negative socio-cultural perception of cocoyam production and low
income from sales of cocoyam were implicated by Akuwudike (2010) as constraints to
increased adoption of cocoyam in Ikwuano Local Government Area of Abia State,
while Kunju (1992) showed susceptibility to pests and diseases, high requirement for
fertilizer and plant protection measures, poor cooking quality, low straw yield and low
market value as some of the factors constraining the adoption of improved rice
varieties by farmers in Kerala. He also included weed problem, non-tolerance of
unfavourable soil conditions, low yield and dearth of irrigation and drainage facilities
as additional factors constraining farmers’ adoption of the improved rice varities.
Ezeano (2006) categorized the factors that constrained the use of improved
sweetpotato technologies among households in South-eastern Nigeria into four. These
were financial limitations, input limitations, technical limitations and marketing
limitations. Under the financial limitations were such factors as low market returns,
53
high cost of hired labour, lack of capital to carry out necessary farm activities, high
cost of improved planting materials, high cost of hiring tractor for land preparation,
high cost of inorganic fertilizer and high cost of storage/processing facilities. Others
included high cost of available agrochemicals, failure of Federal Government to make
specific budgetary for sweetpotato production and marketing, as well as high cost of
transportation. Input limitations had such factors as storage/processing problems,
scarcity of improved planting materials, limited choice of cultivars/varieties, scarcity
of farm land, low soil fertility, unavailability of labour required to carry out essential
farming activiyies, unavailability of tractors for land preparation, unavailability of
inorganic fertilizer and unavailability of agrochemicals.
The technical factor category contained such variables as aggressive
competition of sweetpotato with other crops in mixed cropping system, pest and
disease problems, lack of adptability to any soil ecology, non-mechanization of all
aspects of production, improved sweetpotato technologies conflict with the norms and
life style of the people and improved sweetpotato technologies cannot be easily
integrated into the existing production systems. Others include the planting materials
do not store well, recommended improved sweetpotato production practices are
complex to carry out, lack of adequate technical knowledge about recommended farm
practices associated with growing improved sweetpotato varieties and lack of contact
with important information sources. He stated the marketing factor to include lack of
ready market to sell the increased quantity of sweetpotato and low consumer
preference associated with the products of improved sweetpotato varieties.
54
2.6
Theoretical framework
Several social theories have advanced explanations for human behaviour
during the process of individual, social, cultural, economic and technological change.
Their explanations suggest that change results from confronting existing power centre
with a new power centre, and that the outcome is based on the size and dedication of
the power centre rather than on the control of wealth or institutions. The conflict
pushes the existing power centre to negotiate. The result of the negotiation manifests
in various forms, one of which is change (Ekong, 2003). Change, according to
Alinsky (1993), is the working out of conflicts. It is thus believed that an individual’s
behaviour changes as a result of conflicts between his aspirations and prevailing
environmental conditions which create tension, a negotiation and then a change in
behaviour. The introduction of an innovation, a new power centre, engenders conflict
within an individual with resultant tension, a negotiation and then the specific type of
accommodation. This may be resistance to change (rejection), or acceptance of change
(adoption).
Thus,
negotiation
for
resolution
of
conflict
is
akin
to
the
adoption/disadoption process.
The adoption/disadoption process involves sequential behavioural changes in
the farmer, from the time he becomes aware of an innovation to the time he adopts or
disadopts it. There is no consensus among authors as to the number of stages that are
involved (Agwu, 2000). However, what is consistent among various approaches is that
a minimum of three sub-processes are involved in the adoption decision-making
process, and includes the acquisition and evaluation of information, as well as some
observable behaviour relevant to the innovation (McEwen, 1975) in Agwu (2000).
55
Thus, there is a consensus that adoption/disadoption is a product of a sequence of
events (thoughts and actions), and not a random behaviour (Rogers and Shoemaker,
1971). It, therefore, follows that the adoption and disadoption of the sweetpotato
production and processing technologies are a product of a sequence of events, rather
than a random behaviour.
Lionberger (1960) as cited by Agwu (2000) conceptualized a five-step
diffusion model which comprises awareness, interest, evaluation, trial and adoption.
He showed that the process of change involves an awareness of the innovation by a
prospective adopter who may develop interest in it if it appeals to him. He may later
compare the innovation with his usual practice and mentally assess its profitability. If
he is satisfied with the result of his evaluation, he will try it in a small scale and
subsequently adopt it. If, however, he is not satisfied with the evaluation result, he will
reject it. An adopter may also become dissatisfied with the innovation after some
period of use and will, consequently, abandon or disadopt it.
Rogers and Shoemaker (1971) and McEwen (1975) in Agwu (2000)
conceptualized a four-stage process in their innovation decision models. They gave it
as the mental process through which an individual passes from first knowledge of an
innovation to a decision to adopt or reject it, and later confirmation of this decision
(Figure 1). It is made up of knowledge, persuasion, decision and confirmation. At the
knowledge stage, the individual gains some understanding of how the innovation
works after being exposed to its existence. He then shows his attitude towards the
innovation at the persuasion stage. This may be favourable or unfavourable. At the
decision stage he manifests his choice of adopting or rejecting the innovation through
56
Continued
Adoption
(Channels)
Receiver
variables
Adoption
Discontinuance/
Disadoption
1.Personality
characteristics (eg.
General attitude
toward change)
2.Social
characteristics (eg.
Cosmpoliteness)
3.Perceived need for
innovation
4. Etcetera.
Persuasion
Knowledge
Decision
2.Tolerance of deviance
3.Communication integration
1. Replacement
2. Disenchantment
I
Perceived characteristics
of Innovation
Later
Adoption
Rejection
Social System
Variables
1.Social system norms
Confirmation
1.
2.
3.
4.
5.
Relative Advantage
Compatibility
Complexity
Trialability
Observability
4.Etcetera
TIME
Figure I: Paradigm of the innovation-decision process
Source: Adapted from Rogers and Shoemaker, 1971
Continued
Rejection
57
the activities he engages in, while at the confirmation stage he seeks reinforcement
for the decision he has made.
A careful examination of the aforementioned four-stage adoption process
reveals the effects of the attributes of the innovation, channels of communication, as
well as other influencing variables, on adoption/disadoption behaviour. Agricultural
innovations vary in their inherent characteristics which, to a large extent, affect the
decision of farmers on innovation adoption or disadoption. As a result, the farmer will
be more inclined to accept a recommended practice if it is profitable, compatible with
existing farming practice, divisible, simple to use and has relevance to his labour use,
credit, community values and crop situation. He would be disinclined to accept the
practice if it does not meet the foregoing conditions. The model also implies that an
individual will endeavour to acquire such amount of information which, in addition to
the evaluation of the information, will induce him to select a course of action. As is
also evident in the model, communication sources, which constitute the source of the
new power centre or confronting idea, provide stimuli which make the decision-maker
to react in a particular way in support of, or opposition to, a given innovation.
Communication factors, therefore, may affect the direction of change of an individual
adopter on the basis of the attributes of the innovation and receiver’s variables.
Forster (1973) as cited in Agwu (2000) emphasized two forces which can affect
an individual namely, change inhibiting and change-promoting forces. He indicated
that, in order to study the dynamics of the change process from the point of view of
the individual, a minimum of four points should be noted:
a) the individual must recognize a need and perceive its achievement as possible;
58
b)
the individual must have information on how the need must be met;
c)
the individual must have access to whatever materials or services the
achievement of the goal requires and at a cost that he can readily afford; and
d)
his society must not impose excessive negative sanctions on him for adopting
the innovations.
Leagans (1971) in Agwu (2000) identified two opposing forces which interact
to cause behavioural change. These are change incentives and change inhibitors.
These create tensions that motivate action and result in change. The interaction
influence of these two sets of opposing forces shapes and controls the nature of
change, which may be broadly classified as passive (static), dynamic and semidynamic.
The static or passive behavioural change phase indicates a static situation
where forces for and against behavioural change offset each other. To create the
dynamic situation requires the introduction of change incentives that are sufficient
enough to create an imbalance, or a greater incentive for change than is exerted by the
existing change inhibitors through planned programmes of intervention and
communication efforts.
According to Leagans (1971), this requires four steps,
namely:
a)
introduction of forceful new incentives;
b)
strengthening existing change incentives;
c)
improving the complementarity of change incentives; and
d)
weakening or removal of existing change inhibitors.
59
The semi-dynamic phase suggests that upward trend in behavioural change
tends to revert to static situation, but remains at a higher level of desirable behavioural
change and the upward trend continues with a slight incline resulting from
accumulation or multiplied effects. This situation results when the physical,
technological, educational and other inputs associated with the sweetpotato production
and processing technologies reach optimum levels. These processes are educational in
nature and constitute the role of extension communication strategies.
In other words, adoption is largely determined by the number and kinds of
change incentives introduced, the complementarities of the inputs, the speed with
which they are communicated and the effectiveness of the information transfer
mechanism in the internalization of the change incentives by the target clientele.
Hence, the perception of needs by farmers for adoption of agricultural innovations is
crucial in the whole process of change (Agwu, 2000). Purcell and Anderson (1997)
cited in Agwu (2000) observed that farmers would adopt new technologies and
modify their resource use when they believe that the proposed change is relevant to
their circumstances and can help them achieve their objectives, regardless of their
resources and socio-economic status. They further stated that the rate of adoption of a
technology (using technology adoption as a proxy for any desirable change in resource
use) by a farming population will depend on:
a)
the characteristics of individuals’ production circumstances (land, labour, and
capital resources, climatic and other production uncertainties; and access to
inputs and markets);
60
b)
the characteristics of the technology itself, its benefit/resource cost ratio
(degree of profitability) at acceptable levels of risk; the skill needed to adopt it;
the level of infrastructure and resource needed to adopt it; the degree of
complexity of introducing it into the farming system;
c)
the socio-cultural characteristics of individual farmers (such as their education
and attitude) and the farming community (for instance their cohesiveness,
values and attitude towards change) which can influence their perception of the
relevance of the technology; and
d)
the speed with which the population is made aware of the technology and its
application to local production systems.
It follows, therefore, that the adoption of the sweetpotato production and processing
technologies by farmers in South-eastern Nigeria will depend on:
(a) the characteristics of individual farmer’s production and processing
circumstances;
(b) the characteristics of the sweetpotato production and processing
technologies, their benefit/resource cost ratio at acceptable levels of risks,
the skills needed to adopt them; the level of infrastructure and resource
needed to adopt them; the degree of complexity involved in introducing
them into the farming system of South-eastern Nigeria;
(c) the socio-cultural characteristics of individual farmers and the farming
community which can influence their perception of the relevance of the
sweetpotato production and processing technologies; and
61
(d) the speed with which the population is made aware of the sweetpotato
production and processing technologies and their application to local
production systems.
Figure 2 below schematically presents a conceptualized representation of the
innovation – decision process for explaining the generation of sweetpotato production
and processing technologies, transfer and utilization by farmers.
In the Schema, Block A shows the technology generating institutes (National
Root Crops Research Institute, International Institute of Tropical Agriculture and
International Potato Centre) involved in sweetpotato research. These institutes
generate and develop relevant sweetpotato technologies. Block B indicates some of
the sweetpotato production technologies that have been generated. Block C shows the
communication sources on the sweetpotato technology, which include the state
Agricultural Development Programmes (ADPs), National Agricultural Extension and
Research Liaison Services (NAERLS) and Non-Governmental Organizations (NGOs).
This is the source or sender of the new power centre (sweetpotato innovation) that
confronts the existing power centre, Block D. These agencies make use of channels
such as mass media (Radio, Television, Newspapers, etc), and interpersonal sources to
disseminate sweetpotato innovations to the farmers.
Block D shows the original status of the farmers in the zone, as growers of root and
tuber crops. The introduction of the sweetpotato production and processing
technologies to the farmers in Block D by the agencies in Block C produces a conflict
which triggers off the negotiation process. The negotiation process entails the
activities of the factors that influence the farmers’ adoption/disadoption decisions
62
contained in Block D. These include the personal and socio-economic characteristics
of the farmers, characteristics of the innovation (extent to which it contributes to cost
reduction, risk reduction and production increase, its benefit/resource cost ratio
(degree of profitability) at acceptable levels of risk; the skill needed to adopt it; the
degree of complexity of introducing it to the farming system; level of infrastructure
needed to adopt it, etc), availability of key inputs and complementary knowledge and
other economic factors. These factors influence the farmers in a number of ways as
shown in Block E, depending on the dedication and persistence of the group in Block
C.
There may be idea adoption (mental acceptance), or idea rejection (mental
rejection), of the innovation communicated as shown in Blocks E1a and E2a. In a
situation of mental acceptance, adoption is most often the result, especially when
complementary factors like additional knowledge are provided. This is shown in
Block E1b. Innovations such as the sweetpotato production and processing
technologies, may be adopted and used continuously, or they may be
disadopted/discontinued at a later date due to farmers’ experiences with it, Blocks E1c
and E1d . Where these experiences are favourable, the innovation will be adopted and
used continuously as shown in Block E1c. Where, however, the experiences are
unfavourable, the innovation will be disadopted as shown in Block E1d. Finally, the
innovation may be rejected initially but adopted later, or it could be continuously
rejected, as shown in Blocks E2c and E2d respectively.
63
E
Communication
sources on
sweetpotato
innovation
 State ADPs
 NGOs
 Members of the
social system
Channels (eg. mass
media, interpersonal
etc.)
Figure 2: A Conceptual Representation of the Innovation-Decision
Process of Sweetpotato Production and Processing Technologies.
(Adapted from Rogers and Shoemaker, 1971;Agwu, 2000).
Disadoption/
Discontinuance
Adoption
Mental
Acceptance
Continued
Adoption
C
Sweetpotato Production and
Processing Technologies
 Technology factors (seedbed
preparation, improved
varieties, correct spacing,
planting material, time of
planting, use of herbicide,
application of fertilizer,
earthening up, timely
harvest)
 Sweetpotato processed into:
fermented fufu flour,
unfermented flour, starch and
toasted sweetpotato
E1d
E2a
E2b
E2d
Later
Adoption
B
Non Adoption
Generation of
Innovation
Factors Influencing Farmers
 Personal and socio-economic
characteristics
 Characteristics of the innovation,
namely, the extent to which it
contributes to cost reduction, risk
reduction and production increase,
its benefits (resources cost) ratio at
acceptable levels of risk; the skill
needed to adopt it; level of
infrastructure and degree of
complexity of introducing it to the
farming system; etc.
 Availability of necessary inputs
 Complementary knowledge
 Economic factors (profitability and
social values of innovation)
Mental
Rejection
D
E1b
E2c
Improved standard of living
E1a
Continued
Rejection
Institutes Involved in Sweetpotato
Research
 National Root Crops Research
Institute (NRCRI) Umudike
 International Institute of Tropical
Agriculture (IITA) Ibadan
 International Potato Centre (CIP) Peru
 Faculties of Agriculture of Nigerian
Universities
64
CHAPTER THREE
METHODOLOGY
3.1 Area of study
The study was carried out in South-eastern Nigeria. This is the geo-political zone
formerly known as East Central State, presently comprising Abia, Anambra, Ebonyi,
Enugu and Imo States. This was chosen because of its proximity to National Root Crops
Research Institute, Umudike.
The area under study stretches from Latitude 04o15’N to Latitude 07o00’N and
Longitude 05o34’E to Longitude 09 o24’E (Unamma, Odurukwe, Okereke and Ene, 1985;
FMANR, 1990). It is bounded in the east by Cross River and Akwa Ibom States, in the
west by Delta and parts of Kogi States, in the south by Rivers State and in the north by
parts of Kogi and Benue States (Aniedu, 2006). It has a land area of 29,526 square
kilometers and a population of 10,712,675 people comprising a female population of
5,569,241 and a male population of 5,142,434 persons (CBN, 1997). Its vegetation is
tropical rainforest, although some of the northern parts of the zone seem to be ‘derived’
savannah, which is as a result of reduced fallow period in these areas (Lekwa, Akamigbo
and Lekwa, 2001).
The zone experiences two main seasons in the year, namely, the rainy season
(April – November) and the dry season, which occupies the rest of the year. The average
annual rainfall amounts to about 1730mm in about 110 rain days. Its maximum monthly
atmospheric temperature is about 32.5oC (Ufot, Okere, Anene and Ugwu, 2001). Abia,
Ebonyi and Imo States were randomly selected for the study.
65
Abia State
Abia State is one of the five states in the South-east geo-political zone of Nigeria,
with Umuahia as its capital. It is located between latitudes 405’ and 60 North and
longitudes 7010’ and 80 East and occupies an estimated land area of 5,582.2 square
kilometers (Abia State Ministry of Commerce and Industry, 1998). It is bounded in the
east by Cross River State, west by Imo State, north by Enugu and Ebonyi States and south
by
Rivers
and
Akwa
Ibom
States.
It
has
a
population
of
2,833,999
(wikipedia.org/wiki/population, 2006) and seventeen Local Government Areas, namely,
Aba North, Aba South, Arochukwu, Bende, Ikwuano, Isiala Ngwa North, Isiala Ngwa
South, Isuikwuato, Obioma Ngwa, Ohafia, Osisioma Ngwa, Ugwunagbo, Ukwa East,
Ukwa West, Umuahia North, Umuahia South and Umunneochi. It is delineated into three
agricultural zones by the State Agricultural Development Programme (ADP). These
zones are Aba, Ohafia and Umuahia. The state is situated in the rainforest zone, with a
mean annual rainfall of about 2400mm, which is distributed over a 10-month period of
February to December (Unanma, Odurukwe, Okereke and Ene, 1985). Its soil types range
from loamy through the red, deep soil rich in iron, and grey sandy soil to clay and gravel
(Abia State Development Committee, 1991). Agriculture is the main occupation of the
people of the state, as about 70% of the population earns its living from it. The state
produces such crops as cassava, yam, cocoyam, rice, plantain, banana, maize, palm
produce, cocoa, rubber, melon, garden egg, and livestock such as poultry, goat, sheep and
rabbit.
66
Ebonyi State
Ebonyi State is one of the thirty-six states of Nigeria, with Abakaliki as its capital. It
lies between latitudes 504’ and 6045’ North and longitudes 7030’ and 8 046’ East (Awoke
and Okorji, 2004). Located in the South-east geo-political zone, it occupies a land area of
about 5,935 square kilometers and divided into thirteen Local Government Areas,
namely, Abakaliki, Ebonyi, Izzi, Ishielu, Ohaukwu, Ikwo, Ezza North, Ezza South,
Afikpo North, Afikpo South, Ohaozara and Ivo. It is bounded in the North by Benue
State, in the South by Abia State, in the East by Cross River State and in the West by
Enugu State. It has a population of about 1.7 million people with farming as its major
occupation. The state has a mean temperature of 300C during the hottest period of the
year (February to April) and a mean temperature of 21 0C during the coldest period
(December to January). Its mean annual rainfall is between 1,500mm and 1,800mm
(Awoke and Okorji, 2004). The state produces such crops as yam, cassava, rice, pulse
crops, sweetpotato, pepper, oil palm and banana. It was delineated into three agricultural
zones by the State Agricultural Development Programme (ADP). These are Ebonyi
North, Ebonyi South and Ebonyi Central zones.
Imo State
Imo State came into existence in 1976, having been previously part of the then East
Central State. Part of it was split off in 1991 as Abia State. Imo State lies within latitudes
4045’N and 7015’N, and longitudes 6050’E and 7 025’E (wikipedia.org/wiki/Imo_State,
2010). It has an area of about 5,100 square kilometers. It is borderd by Abia State on the
East, the River Niger and Delta State on the West, Anambra State to the North and Rivers
67
State to the South. It has an estimated population of 4.8 million people
(wikipedia.org/wiki/Imo_State, 2010) and twenty-seven Local Government Areas,
namely, Aboh Mbaise, Ahiazu Mbaise, Ehime Mbano, Ezinihitte, Ideato North, Ideato
South, Ihitte/Uboma, Ikeduru, Isiala Mbano, Isu, Mbaitolu, Ngor Okpala, Njaba,
Nkwerre, Nwangele, Obowo, Oguta, Ohaji/Egbema, Okigwe, Onuimo, Orlu, Orsu, Oru
East, Oru West, Owerri Municipal, Owerri North and Owerri West. It is delineated into
three agricultural zones by the State Agricultural Development Programme (ADP). These
zones are Orlu, Owerri and Okigwe. The state is situated in the rainforest zone, with a
mean annual rainfall of about 2400mm, which is distributed over a 10-month period of
February to December (Unanma, Odurukwe, Okereke and Ene, 1985). It has average
annual temperature of over 20 0C which creates an annual relative humidity of 75%, with
humidity reaching 90% in the rainy season (wikipedia.org/wiki/Imo_State, 2010). The
state produces such crops as cassava, yam, cocoyam, rice, vegetables, melon, plantain,
banana, maize, palm produce and pepper. In areas of the state where there are rivers,
especially in areas where the state shares boundaries with Delta and Rivers States,
appreciable quantities of fish are produced.
68
3.2 Population and sample
3.2.1 Population
The population comprised all farmers in the South-east geo-political zone of
Nigeria.
3.2.2 Sample
The multistage sampling technique was used. Purposive sampling technique was
used in selecting the states while simple random sampling technique was used in selecting
the agricultural zones, blocks, circles and farm households. The three states that were
randomly selected were Abia, Ebonyi and Imo. In order to select the farmer respondents
for the study, three agricultural zones, according to the state ADP delineation, were
selected from Abia, Ebonyi and Imo States. However, since each of the randomly selected
states had three agricultural zones, all the agricultural zones in each state were, therefore,
used for the study.
Abia State
In Abia State, the three agricultural zones that make up the state were selected. These
are Aba, Ohafia and Umuahia. Three extension blocks were randomly selected from each
zone while two circles were selected from each of the extension blocks. Five farmers
were randomly selected from each of the selected circles using a list of farmers provided
by the extension agents overseeing the circles. This gave a total of ninety (90) farmers
selected from Abia State.
69
Ebonyi State
Ebonyi State was delineated into three agricultural zones, namely, Ebonyi North, Ebonyi
South and Ebonyi Central. All the three zones were selected for the study. From each of
the agricultural zones, three extension blocks were were randomly selected, and two
circles were similarly selected from each of the extension blocks. Using a list of farmers
from the respective extension agents, five farmers were randomly selected from each of
the selected circles to give a total of ninety (90) farmers from Ebonyi State.
Imo State
Imo State has Orlu, Owerri and Okigwe as agricultural zones. These were selected for the
study. Three extension blocks were randomly selected from each of the agricultural
zones, while two circles were selected from extension blocks previously selected. Five
farmers were randomly selected from each of the circles using lists of farmers from
respective extension agents. This gave a total of ninety (90) farmers selected from Imo
State and used for the study, as shown diagrammatically below:
70
Abia
Ebonyi
Imo
-------------------------------- (States 3)
1
2
1
2
1
1
---------------------------------- (Zones 3 x 3 = 9)
3
---------------------------------- (Blocks 3 x 3 x 3 = 27)
3
2
---------------------------------------------- (Circles 2 x 3 x 3 x 3 =54)
2
3
4
---------------(Farmers 5 x 2 x 3 x3 x 3 = 270)
5
Figure 3: Sampling procedure
3.3 Data collection method
A structured interview schedule was prepared and used for data collection. The
instrument was validated by academics (lecturers from University of Nigeria, Nsukka,
Michael Okpara University of Agriculture, Umudike, and a chief research officer from
National Root Crops Research Institute, Umudike) who were knowledgeable in the
subject of study and gave independent opinions on the relevance and adequacy of the
instrument in accordance with the objectives of the study. It was, also, pre-tested on a
group of farmers from Amawom Oboro in Ikwuano block of Umuahia agricultural zone
71
of Abia State. Necessary adjustments were made before the interview schedule was
administered in the field.
The instrument was divided into four sections (Sections A to D). Section A elicited
information on personal and socio-economic characteristics of the respondents (age,
gender, marital status, household size, major occupation, formal education, farming
experience, participation in farmers’/social organizations, extension contact and credit).
Section B surveyed the level of awareness of the sweetpotato production and processing
technologies, sources of information and adoption stages of the sweetpotato production
and processing technologies. Section C sought information on farmers’ production and
processing environment, such as farm size, sources of labour and planting materials,
ownership of land, price of produce and topography of farm land. Others variables
include sweetpotato production and processing technologies in use and varieties of
sweetpotato grown. Section D contained information on the factors constraining the
adoption of the sweetpotato production and processing technologies.
Nine extension agents from each state ADP were trained by the researchers to
assist in the collection of the data. A total of 27 extension agents were selected, trained
and used in data collection from the three states selected in the geo-political zone. The
data were collected in the year 2010 and the results refer to this period.
3.4 Variable specification
Personal and socio-economic characteristics of the respondents were measured as
follows: age was measured as the actual number of years of the respondent at the time of
the survey; level of formal education was measured at two levels – highest educational
72
level attained and number of years of formal education. Gender was measured as male or
female; marital status as single, married or widowed; household size as the actual number
of household members of the respondent, while occupation was measured as the major
occupation of the respondent. Farming experience was measured by the absolute number
of years of experience in farming, farm size was measured at two levels – (1) total land
area (in hectares) owned by respondent in the past 3 years and, (2) total land area devoted
to sweetpotato production each year for the past 3 years; social participation was
measured as respondents membership of any farmers’ or social organization. Extension
contact was measured using selected extension effectiveness indicators such as: contact
farmer? (Yes = 1, no = 0); ever received advice from contact farmer? (Yes = 1, no = 0);
aware of extension agent? (Yes = 1, no = 0); know the name of EA? (Yes = 1, no = 0);
where EA meets you? (at farmers field/contact point = 1, others = 0); ever visited EA?
(Yes = 1, no = 0). The total gave the extension contact score. The maximum extension
contact indexed score was 6 while the minimum score obtainable was 0. The mean score
is 3. Indexed scores of 3 and above were accepted as having extension contact while
those below 3 were regarded as having no extension contact.
Objective (1), determination of the level of awareness of the sweetpotato
production and processing technologies, was carried out by asking the farmers whether
they were aware of the technologies. A ‘Yes’ response scored 1, while a ‘No’ response
scored 0. Each response category was summed up, divided by the total number of
respondents and multiplied by 100. This gave the level of awareness.
Objective (ii), determination of the extent of adoption and disadoption of the
sweetpotato production and processing technologies by farmers in the zone, was carried
73
out using the seven steps (not aware to rejection) adoption model (Madukwe, 1995;
Agwu, 2000). The farmers were asked to indicate their adoption stages for the various
sweetpotato production and processing technologies. The response categories and the
corresponding weighted values were as follows:
Not Aware (Have not heard about)
0
Aware (Have heard about but know few details)
1
Interest (Know details but have not considered using)
2
Evaluation (considered using, but have made no decision)
3
Trial (Used it on a small scale)
4
Adoption (Have already been using in my farm)
5
Rejection (Have definitely decided not to use)
6
Total adoption score for each farmer was calculated by adding up the adoption
scores for the various technologies. In calculating farmers’ scores, however, rejection,
with a weighted value of six was converted to zero to give meaningful interpretation to
the results (Agwu, 2000). Extent of disadoption was calculated by summing up the
farmers who did not implement the technology in the survey year (2010). This was
divided by the total number of respondents who were aware of the technologies, and then
multiplied by 100. The components of the sweetpotato production technology are:
i)
Seed bed preparation (ridges or mounds; never flats)
ii)
Use of improved sweetpotato varieties (TIS 87/0087, TIS 8164, TIS 2532.OP.1.13,
Ex-Igbariam)
74
iii)
Use of correct spacing (30cm x 100cm on ridges; 25cm x 100cm on mounds on
both sole and intercrops)
iv)
Planting material (vine cutting containing 5-6 nodes)
v)
Time of planting (Late May to June)
vi)
Weed control/Use of herbicide (2.5kg ai/ha of Primextra super) at 4-6 weeks after
planting
vii)
Application of fertilizer (45kg N, 15kg P, 40kg K - 400kg or 8 bags of NPK
20:10:10)
viii)
Earthening up (at weeding, 4-6 weeks after planting)
ix)
Pest and disease control (Timely harvest, use of resistant varieties, use of neem
dust, earthening up, crop rotation and use of clean planting materials)
x)
Time of harvest (3 – 4 months after planting)
Items standardized at NRCRI, Umudike, and included in the package of the sweetpotato
processing technologies are:
xi)
Fermented sweetpotato fufu flour. The procedure is as follows –
1. Peel and wash sweetpotato roots,
2. Cut into chips (2.5 – 3.0mm thickness)
3. Ferment by soaking in water for 24 hours
4. Drain off water from fermented chips
5. Spread out to sun-dry on raised platform. Drying may be carried out in a
cabinet dryer at 50 oC
6. Mill properly when dried
7. Package in polyethylene bags or any air-tight container
75
xii)
Unfermented sweetpotato flour for use in confectioneries. The procedure is
as follows –
1. Peel and wash sweetpotato roots
2. Grate into mash
3. Dewater in a clean bag
4. Break the caked mash and sun-dry on raised platform
5. Mill finely
6. Package in polyethylene bags or any air-tight container.
xiii)
Sweetpotato starch. The procedure includes:
1. Peel and wash sweetpotato roots
2. Grate roots into mash
3. Mix with much clean water (about 10 times the volume of mash)
4. Sieve, using muslin cloth
5. Allow water to sediment, decant and collect starch
6. Sun-dry on raised platform or oven-dry at 50 oC
7. Mill finely
8. Package in polyethylene bags or any air-tight container.
xiv)
Toasted sweetpotato. The procedure includes:
1. Peel and wash sweetpotato roots
2. Grate roots into mash
3. Dewater mash by pressing into clean bag
4. Pulverize cake and sieve to obtain fine granules
5. Toast the granules in a toasting pot at 80oC
76
6. Cool and store in air-tight container.
Objective (iii), examination of the determinants of adoption and disadoption of the
sweetpotato production and processing technologies, was carried out using the probit
regression model (Maxwell, 1995; Wendland and Sills, 2008). The estimated probit
function is given by:
Pi = bo +b1Xi
Where
Pi = estimated probit value, such that P1 = estimated probit value for adoption (ZA)
P2 = estimated probit value for disadoption (ZD)
Xi = the independent or explanatory variables for adoption (ZA) and disadoption (ZD),
bo = Intercept
b1 = regression parameter to be tested for significance
ZA = {H, R, M, U, B}, where:
H (household preference) = age, gender, education, marital status, household size
Age, X1; measured in years
Gender, X2; male= 1, female=0
Education, X3; dummy variable for education of head of household. 1 if any
education, 0 otherwise
Marital status, X4; dummy variable for having life partner; 1 if there is life partner,
0 otherwise
Household size, X5; total number of household members
R (resource endowments) = labour, credit, land, health
77
Labour, X6; total number of adult household members
Credit, X7; dummy variable for participating in a formal or informal credit system.
1 if participates, 0 otherwise
Land, X8; hectares of land a household farmed (with sweetpotato) in the previous
year
Health, X9; dummy variable for having been treated at a hospital=1; not treated=0
M (market incentives) = price
Price, X10; producer market price of sweetpotato, Naira per kilogramme(N/Kg)
U (risk and uncertainty) = member, extension
Member, X11; dummy variable for membership of any social/farmers’ organization.
1 if involved in any organization, 0 otherwise
Extension, X12; dummy variable for having received sweetpotato education. 1 if
received such education, 0 otherwise
B (biophysical characteristic of farmland) = topography
Topography, X13; average reported slope for a household’s agricultural land. 1 if
most fields are hilly, 0 if they are flat
ZD = {H, R, M, U, B, E}; that is, all the explanatory variables for adoption, in addition
to those variables that characterize the farmer’s experience with the technologies,
labeled E here. These E variables include area planted with sweetpotato,
number of years of sweetpotato cultivation and processing, soil type and
sweetpotato cultivation and processing problems.
78
E (experience with technology) = extent, yearsweet, soiltype, sweetp
Extent, X14; dummy variable for area of land devoted to sweetpotato in last year of
cultivation. 1 if greater than 0.5ha, 0 otherwise
Yearsweet, X15; dummy variable for number of years sweetpotato was cultivated. 1 if
greater than 3 years, 0 otherwise
Soiltype, X16: dummy variable for type of soil where sweetpotato was cultivated. 1 if
sandy loam, 0 otherwise
Sweetp, X17; discrete variable for whether household experienced sweetpotato
problem. 0 if no; 1 if experienced one problem, 2 if experienced 2 or more.
Sweetpotato (Adoption,ZA): The dependent variable in the adoption model; 1 if
household had cultivated and processed sweetpotato at some time prior to the survey date
(2010, in this study), 0 otherwise.
Continue (ZD): The dependent variable in the disadoption model; 1 if household was
cultivating sweetpotato as at the survey date, 0 otherwise.
Subsequently, the determinants of adoption and disadoption of the sweetpotato
production and processing technologies are given, respectively, as:
ZA = bo + b1X1+b2X2+b3X3+b4X4+b5X5+b6X6+b 7X7+b 8X8+b9X9
+b10X10+b11X11 +b 12X12 +b13X13
ZD = bo+b1X1+b2X2+b3X3+b 4X4+b5X5+b6X6+b 7X7+b 8X8+b9X9
+b10X10+b11X11+b12X12+b13X13+b14X14+b15X15+b16X16+b17X17
79
The full probit model containing all the variables (as in ZD above) was produced
together with a reduced model that excluded E variables (as in ZA above) to compare
results. This is because disadoption is influenced by many of the same factors that
influence adoption, in addition to experience with the technology itself, such as, in this
study, area planted with sweetpotato and cultivation problems (Wendland and Sills,
2008). This is labelled E. Generally, the same factors that influence adoption are expected
to influence the decision to continue using the technology, in this case the sweetpotato
production and processing technologies. Estimation results included the coefficients for
each variable in ZA and ZD. These identified the characteristics of households (and their
farms) who are most likely to adopt, and among those adopters, the characteristics of
households who are most likely to continue planting and not abandon the crop.
Objective (iv), identification of the constraints to the adoption of the sweetpotato
production and processing technologies in the zone, was achieved using a five-point
Likert-type rating scale. The response options and assigned values were:
To a very great extent
5
To a great extent
4
To some extent
3
To a little extent
2
None at all
1
A list of possible constraints was supplied, from which the respondents were asked
to indicate the extent of their perceived seriousness of each constraint according to the
response options provided. Data were subjected to exploratory factor analysis procedure,
using the principal factor model with varimax rotation in classifying the constraint
80
variables into major constraint factors. In factor analysis, the factor loading under each
constraint variable (beta weight) represents a correlation of the variables (constraint
areas) to the identified constraint factor, and has the same interpretation as any correlation
coefficient. The variables with loadings of 0.40 and above (10% overlapping variance;
Chukwuone, Agwu and Ozor, in Akinnagbe 2009) were used in naming the factors.
3.5
Data analysis techniques
Data collected was summarized on master table through the use of frequency
counts. Percentages and means were used to describe the personal and socio-economic
characteristics of the respondents.
Percentages and means were similarly used in
determining the level of awareness and extent of adoption and disadoption of the
sweetpotato production and processing technologies by farmers in the South-eastern zone.
The probit analysis was used in examining the determinants of adoption and disadoption
of the technologies in view, while factor analysis using a varimax rotated matrix was used
in determining major variables constraining the adoption of the sweetpotato production
and processing technologies.
81
CHAPTER FOUR
RESULTS AND DISCUSSION
4.1 Personal and socio-economic characteristics of the farmers
In this section, a general description of the personal and socio-economic
characteristics of the farmers in the South-east geo-political zone of Nigeria is given. A
total of eleven personal and socio-economic variables were investigated. These are age,
gender, marital status, formal education, household size and farming experience. Others
include major occupation, membership of farmers’/social organizations, participation in
formal or informal credit system, farm size and extension contact. Distribution of the
respondents according to these characteristics is shown in Tables 1 and 2.
4.1.1 Personal characteristics of the respondents
Age
Entries in Table 1 show that 10.37 percent of the respondents were within the range
of 20 to 29 years, 17.78 percent were within the age range of 30 to 39, 24.82 percent were
between 40 and 49 years, 23.70 percent fell within the 50 and 59 age range, while 23.33
percent were either 60 years of age or more. The average age of the respondents was
about 48 years, showing that there was a relatively high proportion of middle aged
farmers among the respondents. This falls within the economically productive proportion
of the population as defined by Food and Agriculture Organization (1983) cited in Emodi
(2009). Moreover, the farmers were still in their active years, as majority (66.30%) of
82
them were between 30 and 59 years, a situation that is likely to favour the adoption of the
sweetpotato production and processing technologies.
Gender
As revealed in Table 1, about 51 percent of the respondents were males while 49
percent were females. This implies that gender distribution among farmers in the Southeast zone is skewed slightly towards males in sweetpotato production. This is at variance
with the findings of Okwusi, Amamgbo and Asumugha (2005) which showed that
females predominated in the production, processing and utilization of sweetpotato in
South-eastern Nigeria.
Marital status
As shown in Table 1, 72.59 percent of the respondents were married, followed by
14.82 percent who were widowed, 9.26 percent who were single and 3.33 percent were
divorced or separated. This means that majority of the sweetpotato farmers in the zone
were married, confirming the assertion of Jibowo (1992) that majority of the rural farmers
consisted of married people.
Formal education
Entries in Table 1 also reveal that 14.07 percent of the farmers had no formal
education, 26.30 percent had primary education, 38.89 percent had secondary education,
while 20.74 percent had post secondary education. This means that majority of the
farmers were literate, as about 86 percent of them had one form or other of formal
83
education. The high proportion of literate people among the farming population implies
that majority of them are in a better position to be aware of, understand and adopt the
sweetpotato production and processing technologies. Education has always been known
to play a positive role in the adoption of improved technologies among farmers (Sheikh,
Ather, Arshed and Kashi, 2006).
Farming experience:
Table 1 also shows that 10 percent of the respondents had below 6 years of farming
experience, about 18 percent had between 6 and 10 years of experience, while 13 percent
had between 11 and 15 years of farming experience. Those that had 16 to 20 years of
farming experience constituted 18.52 percent of the respondents whereas 40.74 percent
had 21 years or more of such experience. The mean years of farming experience was
22.22 years, implying that the farmers have long period of farming experience that will
enhance their understanding and subsequent adoption of the sweetpotato production and
processing technologies.
Household size
The table further shows that households that had between one and five people made
up 37.78 percent of the respondents, those with six to ten members constituted 49.26
percent, while those households with 11 persons or more made up 12.96 percent of the
respondents. The average household size was 7. This means that the farmers had
relatively large-sized households. This is advantageous to farming since it will enable the
84
farmer to use family labour and thereby reduce the cost of hiring labour for sweetpotato
production.
Table 1: Percentage distribution of respondents by personal
characteristics (N = 270)
Personal characteristics
Frequency
%
Mean (Ẍ)
Age (Year)
20 – 29
30 – 39
40 – 49
50 – 59
≥ 60
28
48
67
64
63
10.37
17.78
24.82
23.70
23.33
138
132
51.11
48.89
196
25
9
40
72.59
9.26
3.33
20.74
None
38
Primary
71
Secondary
105
Post secondary
(OND, HND, NCE, B.Sc/B.A,,M.Sc/MBA) 56
14.07
26.30
38.89
48.31 years
Gender
Male
Female
Marital status
Married
Single
Divorced/Separated
Widowed
Formal education
20.74
Farming experience
1–5
6 – 10
11 – 15
16 – 20
≥ 21
27
48
35
50
110
10.00
17.78
12.96
18.52
40.74
22.22 years
102
133
35
37.78
49.26
12.96
7 persons
Household size
1–5
6 – 10
≥ 11
85
4.1.2 Socio-economic characteristics of the respondents
Major occupation
Entries in Table 2 show that 59.63 percent of the respondents indicated farming as
their major occupation, 15.92 percent indicated trading to be their major occupation,
18.52 percent were in the civil service while 5.93 percent were artisans. This means that
majority of the respondents in the zone had farming as their major occupation. This is in
agreement with Emodi (2009) and Aniedu (2006) who found that most of the farmers in
the South-eastern zone have farming as their major occupation.
Membership of farmers’/social organizations
As shown in Table 2, 9.26 percent of the respondents did not belong to any
farmers’/social organization, 66.67 percent belonged to one to three farmers’/social
organizations, while 24.07 percent belonged to four or more farmers’/social
organizations. This means that majority (90.74%) of the respondents were members of
farmers’/social organizations. This is advantageous to farming since, according to
Peterson (1997) in Agwu (2000), farmers’/social organizations offer an effective channel
for extension contact with large numbers of farmers, as well as opportunities for
participatory interaction with extension organizations. This enhances farmers’ uptake of
new practices such as the sweetpotato production and processing technologies.
86
Participation in formal or informal credit system
Table 2 further shows that only 4.44 percent of the respondents participated in formal
or informal credit system for the production of sweetpotato while majority (95.56%) of
the respondents did not participate in any. This implies that their scales of operation were
such that can easily be funded from their personal earnings without resorting to loans.
This should be expected since sweetpotato is a low input crop, and does not require large
capital outlay to produce (Nwokocha, 1993; Ogbonna et al. 2005).
Farm size
The table also shows that majority (62.96 percent) of the respondents cultivated less
than one hectare of land for sweetpotato, 25.93 percent of them cultivated 1 to 1.99
hectares, 7.41 percent cultivated 2 to 2.99 hectares, 1.85 percent cultivated 3 to 3.99
hectares while another 1.85 percent cultivated 4 to 4.99 hectares. The average farm size
was 1.34 hectares.
Shaib, Aliyu and Bakshi (1997) classified farm holdings in Nigeria into three broad
categories of small-scale, medium-scale and large-scale. Small-scale farm holdings were
less than 6 hectares in size, medium-scale farm holdings were 6 to 9.99 hectares in size
while large-scale farm holdings were 10 hectares and more in size. In this study, none of
the farmers cultivated more than 4.99 hectares of land. This means that all the
sweetpotato farmers in the zone were small-scale farmers. This finding is in agreement
with the findings of studies by Aniedu (2006) and Emodi (2009) which found small-scale
farmers predominating in the zone.
87
Extension contact:
Entries in Table 2 show that 60 percent of the respondents have had contact with the
extension agency in the zone while 40 percent had none. This means that majority of the
respondents have had contact with extension and are, therefore, expected to be more
exposed to relevant technologies like the sweetpotato production and processing
technologies being disseminated through the agency.
Table 2: Percentage distribution of respondents by socio-economic characteristics
(N = 270)
Socio-economic characteristics
Frequency
%
Mean (X)
Major occupation
Farming
Trading
Civil Service
Artisan
161
43
50
16
59.63
15.92
18.52
5.93
Membership of farmer/social organisation
None
1–3
≥4
25
180
65
9.26
66.67
24.07
Participation in formal/informal credit system
Yes
No
12
258
4.44
95.56
170
70
20
5
5
62.96
25.93
7.41
1.85
1.85
162
108
60.00
40.00
Farm size (Ha)
≤ 0.99
1.00 – 1.99
2.00 – 2.99
3.00 – 3.99
4.00 – 4.99
Extension contact
Yes
No
1.34 ha
88
4.2 Level of awareness of the sweetpotato production and processing technologies
by the respondents
In assessing the level of awareness of the sweetpotato production and processing
technologies, distinction was made between awareness of the sweetpotato production
technology and that of the processing technology. This was based on the fact that the
dissemination of the sweetpotato production technology had been carried out for a longer
time (over 12 years) than the processing technology which is more recent.
4.2.1 Awareness of the sweetpotato production and processing technologies
Entries in Table 3 show that 79.63 percent of the respondents were aware of the
sweetpotato production technology, while 20.37 percent were not aware of it. This means
that majority of the farmers in the South-east geo-political zone of Nigeria were aware of
it. This is of advantage to the adoption of the sweetpotato production technology, as
awareness is an indispensable and preceding step towards the adoption of any improved
practice. The table also shows that 28.90 percent of the respondents were aware of the
sweetpotato processing technology while 71.10 percent were not aware of it. This means
that majority of the respondents were not aware of this technology. This situation is,
however, not surprising, as the dissemination of the sweetpotato processing options has
been on for only a few years.
89
Table 3: Percentage distribution of the respondents according to level of awareness of
the sweetpotato production and processing technologies (N = 270)
Awareness
Sweetpotato production technology
Yes
No
Sweetpotato processing technology
Yes
No
Frequency
(%)
215
55
79.63
20.37
78
192
29.90
71.10
4.3 Extent of adoption of sweetpotato production technology
This section discusses the extent of adoption of the sweetpotato production
technologies by the farmers, using the seven steps (not aware to rejection) adoption
model. The technologies discussed here in the sweetpotato production package are the use
of ridges or mounds, use of improved varieties, plant spacing, vine cuttings, time of
planting, weeding and fertilizer application. Others include earthening up, timely harvest
and pest and disease control.
4.3.1 Extent of adoption of land preparation methods
Figure 4 shows the distribution of the respondents based on their stages in the
adoption of sweetpotato land preparation methods of ridges or mounds. Majority (37.9
percent) of the respondents were planting sweetpotato on ridges or mounds in their farms.
About 19 percent of the respondents were not aware of the use of ridges or mounds for
90
sweetpotato production, 24.2 percent were aware of the land preparation methods, 12.7
percent were at the interest stage, while about one percent of the respondents were at the
evaluation stage in the adoption of this technology. Furthermore, the figure shows that 4.9
percent of the respondents were at the trial stage of this technology while none of them
rejected it.
Figure 4: Percentage distribution of respondents by their stages on the adoption
of sweetpotato land preparation methods
4.3.2 Adoption of improved sweetpotato varieties
Figure 5 reveals that 50.1 percent of the respondents were using the improved
sweetpotato varieties on their farms. Eight percent, 7.1 percent, 3.1 percent and 6.2
percent were at the not aware, aware, interest and evaluation stages respectively. About
3.1 percent of the respondents were at the trial stage in the adoption of this technology,
91
while 22.3 percent rejected it. This means that majority of the respondents were at the
adoption stage in the use of improved sweetpotato varieties. One of the reasons proffered
by the farmers for rejecting the improved sweetpotato varieties was the consumption
preference of sweetpotato varieties among urban and rural consumers. The improved
varieties absorbed oil when fried and, as a result, was not in high demand. Another reason
for rejection was the sugary taste of the improved varieties, which was a quality disliked
by many of its consumers. There are, however, improved varieties with bland taste, such
as TIS 87/0087; these can be used by people who are averse to the sugary taste.
Figure 5: Percentage distribution of respondents by their stages on adoption of
improved sweetpotato varieties
92
4.3.3 Adoption of correct plant spacing
The recommended plant spacing on sweetpotato farms is 30cm x 100cm on
ridges and 25cm x 100cm on mounds for both sole and intercropped systems. Figure 6
shows that about 9 percent of the respondents were not aware of this technology. Eight
percent were aware of it, 12.1 percent were at the interest stage, while 6.1 percent and 4.1
percent were at the evaluation and trial stages respectively. Twenty percent of the
respondents were using the recommended plant spacing on their sweetpotato farms, while
40.2 percent rejected it. This means that a greater proportion of the farmers rejected the
plant spacing recommended for sweetpotato production. The reason for rejecting this
technology by the farmers was that it was too wide and did not enable them to get their
envisaged plant population. It is evident from research, however, that high population
densities in sweetpotato farms produce root tubers that are small in size (NRCRI, 1979).
Figure 6: Percentage distribution of respondents by their stages on adoption of correct
plant spacing on sweetpotato farms
93
4.3.4 Adoption of sweetpotato vine cuttings
Figure 7 shows the distribution of farmers based on their stages in the adoption of
vine cuttings as planting materials for sweetpotato production. The recommended vine
cuttings are 2-node cuttings and 5/6-node cuttings. The figure reveals that 4.1 percent of
the respondents were not aware of this technology, whereas 5.1 percent, 12.1 percent and
15.1 percent were at the aware, interest and evaluation stages in the adoption process of
the sweetpotato production technology. About 9 percent of the respondents were at the
trial stage, 34.2 percent had adopted the technology while it had been rejected by about
20.1 percent of the respondents. Thus majority of the respondents are using the sizes of
vine cuttings recommended as planting material for sweetpotato production. The reason
indicated by the farmers for the rejection of the recommended size of vine cuttings was
that longer vine cuttings which had more nodes rooted faster than the recommended vine
cuttings which were shorter and with fewer nodes. Research has, however, shown that
there is no significant difference between the performances of long vine cuttings with
more nodes and the 5/6-node cuttings recommended (Chinaka, 1976; NRCRI, 1996).
94
Figure 7: Percentage distribution of respondents by their stages on adoption of the
sweetpotato vine cuttings
4.3.5 Adoption of time of planting of sweetpotato
The recommended time for planting of sweetpotato in the South-east agroecological zone of Nigeria is late May through June. This is when the rains are relatively
steady. Figure 8 shows that 70.2 percent of the respondents had adopted the
recommended time for planting of sweetpotato, 5.5 percent were unaware of the
technology, 12.1 percent were aware of it while 3.5 percent, 2.5 percent and 4.1 percent
were at the interest, evaluation and trial stages respectively. Only 2.1 percent rejected the
technology. This means that majority of the respondents have adopted the time of
planting sweetpotato in the zone.
95
Figure 8: Percentage distribution of respondents by their stages on adoption of time
of planting of sweetpotato
4.3.6 Adoption of sweetpotato weeding regime
Figure 9 shows that 80.1 percent of the farmers have adopted the weeding regime
for sweetpotato, which is one major weeding at 4 to 6 weeks after planting. None of the
respondents was unaware of this technology, 2.1 percent were aware of it while 8.1
percent, 3.4 percent and 6.3 percent were at the interest, evaluation and trial stages in the
adoption of the technology. Moreover, none of the respondents rejected it. It, therefore,
means that majority of the respondents give their sweetpotato farms one major weeding at
4 to 6 weeks after planting.
96
Figure 9: Percentage distribution of respondents by their stages on adoption of
sweetpotato weeding regime
4.3.7 Adoption of inorganic fertilizer application
The recommended inorganic fertilizer application rate for sweetpotato production is
400 kg NPK 20:10:10 per hectare. Figure 10 shows that none of the respondents was
unaware of the technology, 9.9 percent were aware of it and 8.1 percent were at the
interest stage of the adoption of the inorganic fertilizer application rate for sweetpotato
production. About 12 percent and 14.9 percent were at the evaluation and trial stages
respectively, while 46.9 percent had adopted the technology. Moreover, 8.1 percent of the
respondents had rejected the use of the recommended rate of inorganic fertilizer
application for sweetpotato production. The farmers indicated that their soil was fertile
enough for sweetpotato production and that they would use available inorganic fertilizer
on their cassava farms.
97
Figure 10: Percentage distribution of respondents by their stages on adoption of
inorganic fertilizer application
4.3.8 Adoption of earthening-up practice
Figure 11 shows that only one percent of the respondents were not aware of the
earthening-up practice in sweetpotato production, 5.1 percent were aware of it, 9.1
percent were at the interest stage while 5.1 percent were at the evaluation stage. About 17
percent of the farmers were at the trial stage whereas 62.3 percent had adopted the
technology. None of them rejected it.
98
Figure 11: Percentage distribution of respondents by their stages on adoption of
the earthening-up practice
4.3.9: Adoption of timely harvesting of sweetpotato
As shown in Figure 12, 80.3 percent of the respondents harvest their sweetpotato
root tubers as soon as they mature. This is within the period of 3 to 4 months after
planting. About 2 percent of the respondents were not aware of this technology, 8.1
percent were aware of it, while 4.1 percent, 2.1 percent and 3.3 percent were at the
interest, evaluation and trial stages, respectively, in the adoption of the technology. None
of them rejected it. This means that majority of the farmers have adopted timely
harvesting of sweetpotato root tubers.
99
Figure 12: Percentage distribution of respondents by their stages on adoption of
the timely harvest practice
4.3.10 Adoption of pest and disease control measures
Figure 13 shows that 80.7 percent of the respondents use the recommended pest
and disease control measures on their sweetpotato farms. About 1.7 percent of the
respondents were not aware of the control measures, 6.5 percent were aware of them
while 5.1 percent were at the interest stage. Those who were at the evaluation stage
constituted 3.5 percent of the respondents, with 2.5 percent being at the trial stage. There
was no farmer that rejected the pest and disease control measures.
100
Figure 13: Percentage distribution of respondents by their stages on adoption of
the pest and disease control measures
4.3.11 Disadoption of the sweetpotato production technology
In this study, adoption has been defined as having ever cultivated sweetpotato,
and disadoption as having cultivated sweetpotato but later abandoned it. Thus the
respondents who have ever cultivated sweetpotato before the survey year, 2010, were said
to have adopted the technology, while those who have cultivated it previously, but are not
cultivating it in the survey year 2010 were said to have disadopted it.
As shown in Figure 14, about 24.0 percent of the farmers who cultivated
sweetpotato had stopped growing it after the initial uptake. The major reason for
disadoption, as revealed in Figure 15, is pest attack. This was indicated by 90 percent of
the farmers who had disadopted. The sweetpotato weevil, Cylas spp. is a major pest of the
crop and increases in incidence as the soil becomes drier with the approach of the dry
season. Farmers who harvest their crops piece meal, thereby leaving their crops in the soil
101
far into the dry season, suffer more from this attack. Another reason for disadopting the
technology was the unavailability of sweetpotato vines for use as planting material, as
indicated by 70 percent of the disadopters. The sweetpotato production technology
requires regular water supply for nursery operations during the dry season. Farmers who
do not, therefore, have a regular source of water supply will suffer from this handicap.
Low root tuber yield was another reason for disadopting the sweetpotato production
technology by some farmers (65 percent). This is obviously a soil fertility problem since
the varieties disseminated to the farmers were the improved and high yielding varieties.
Another problem that caused some of them to disadopt the technology was intercropbased. The farmers, who constituted 50 percent of those who had disadopted, indicated
that the sweetpotato crop smothered other crops, thereby reducing their productivity.
Certainly, sweetpotato is not intercropped successfully with all crops. However, the use
of wider spacing of crops, which is a common practice among most of the farmers in the
South-east zone, can provide some temporary respite, as work is still going on in the
development of appropriate crop mixtures.
102
Figure 14: Percentage distribution of respondents according to their adoption and
disadoption of the sweetpotato production technology
Figure 15: Percentage distribution of respondents by reasons for disadoption
103
4.4 Extent of adoption of sweetpotato processing technologies
In this section, the extent of adoption of the sweetpotato processing technologies
in the study area is discussed. The technologies discussed here are the sweetpotato
processing options standardized by the National Root Crops Research Institute, Umudike,
and disseminated to the farmers in the South-east agro-ecological zone of Nigeria. A total
of 78 respondents (28.90 percent) had indicated they were aware of three of these
technologies. These include fermented sweetpotato fufu flour, unfermented sweetpotato
flour and sweetpotato starch. The extent of adoption of toasted sweetpotato is not
discussed because none of the respondents indicated being aware of it.
4.4.1 Extent of adoption of processing of fermented sweetpotato fufu flour
The standardized practices involved in processing fermented sweetpotato fufu
flour are: peeling and washing of sweetpotato root tubers, cutting the root tubers into 2.53.0mm chips, fermenting the chips by soaking in water for 24 hours and draining of water
from fermented chips. Others include sun-drying of chips on raised platform or ovendrying at a temperature of 500C, proper milling of the dried chips to produce the flour and
packaging of flour in polyethylene bags or air-tight containers.
104
4.4.1.1 Adoption of peeling and washing of sweetpotato root tubers
Figure 16 shows that all (100 percent) the respondents had adopted peeling and
washing of sweetpotato root tubers which they use in processing fermented sweetpotato
fufu flour. This means that they have moved from the stages of unawareness, awareness,
interest, evaluation and trial, to adoption. None of them rejected the practice.
Figure 16: Percentage distribution of respondents by their stages on adoption of the practice of
peeling and washing of sweetpotato root tubers
4.4.1.2 Adoption of cutting sweetpotato root tubers into 2.5-3.0mm chips
As shown in Figure 17, majority (78.92 percent) of the respondents were cutting
their sweetpotato root tubers into 2.5-3.0mm chips as recommended to them. Those who
were at the trial stage constituted 10.82 percent of the respondents while 10.26 percent of
the farmers rejected the practice. Their major reason for rejecting it was that it was
difficult to measure.
105
Figure 17: Percentage distribution of respondents by their stages on adoption of the practice of
cutting sweetpotato root tubers into 2.5-3.0mm chips
4.4.1.3 Adoption of fermenting sweetpotato chips by soaking in
water for 24 hours
Figure 18 reveals that all (100 percent) the respondents had adopted the
recommended practice of fermenting sweetpotato chips by soaking in water for 24
hours in order to process the fermented sweetpotato fufu flour. This implies
that they had moved from the stages of unawareness, awareness, interest,
evaluation and trial, to adoption. None of them rejected the practice.
106
Figure 18: Percentage distribtuion of respondents by their stages on adoption of fermenting
sweetpotato chips by soaking in water for 24 hours
4.4.1.4 Adoption of draining water from fermented sweetpotato chips
Figure 19 shows that all (100 percent) the respondents had adopted draining
of water from fermented sweetpotato chips, one of the practices included in the
processing of fermented sweetpotato fufu flour. The implication is that the farmers
had moved from the stages of unawareness, awareness, interest, evaluation and
trial, to adoption. None of them rejected the practice.
107
Figure 19: Percentage distribution of respondents by their stages on adoption of draining of water
from fermented sweetpotato chips
4.4.1.5 Adoption of sun-drying of fermented sweetpotato chips
on raised platform or oven-drying at temperature of 500C
Figure 20 shows the extent of adoption of the practice of sun-drying fermented
sweetpotato chips on raised platforms or oven-drying them at a temperature of 500C.
Majority (66.60 percent) of the farmers had adopted the practice, while 10.20 percent and
10.20 percent, respectively, were at the stages of evaluation and trial. About 13.0 percent
of the respondents rejected it on the ground that raised platforms were not always
feasible, whereupon they can dry the chips any where that is clean, including road sides.
108
Figure 20: Percentage distribution of respondents by their stages on adoption of sun-drying of
sweetpotato chips on raised platform or oven-drying at 50o C
4.4.1.6 Adoption of milling of dried fermented sweetpotato chips
Figure 21 shows that all (100 percent) the farmers had adopted the practice of
proper milling of the dried, fermented sweetpotato chips to produce the fermented fufu
flour. This implies that the farmers had moved from the stages of unawareness,
awareness, interest, evaluation and trial, to adoption. None of them rejected it. The extent
of adoption recorded here should be expected, not only because the milling operation is
pivotal to this technology, but that the practice is also simple and feasible. van den Ban
and Hawkins (1996) showed that simplicity of innovations enhances their adoption by
farmers.
109
Figure 21: Percentage distribution of respondents by their stages on adoption of milling of dried
fermented sweetpotato chips
4.4.1.7 Adoption of packaging of produce in polyethylene bags or
air-tight containers
Figure 22 shows that all (100 percent) the respondents package their produce
from the mills in polyethylene bags or air-tight containers. This implies that they
had passed from the stages of unawareness, awareness, interest, evaluation and
trial, to adoption, without any of them rejecting it.
110
Figure 22: Percentage distribution of respondents by their stages on adoption of packaging of
sweetpotato mill product in polyethylene bags or air-tight containers
4.4.2 Extent of adoption of unfermemnted sweetpotato flour
The practices that were standardized for processing unfermented sweetpotato flour
include: peeling and washing of the sweetpotato root tubers, grating of the root tubers into
mash, dewatering of the mash in a clean bag, sun-drying on a raised platform or ovendrying at a temperature of 500C, milling of the dried mash and packaging the flour in
polyethylene bags or air-tight containers. The extent of adoption of these practices is
discussed below.
111
4.4.2.1 Adoption of peeling and washing of sweetpotato root tubers
Figure 23 shows that all (100 percent) the respondents peel and wash their
sweetpotato root tubers. This means that they have passed the stages of unawareness,
awareness, interest, evaluation and trial, to adoption of the practice. None of them
rejected it.
Figure 23: Percentage distribution of respondents by their stages on adoption of peeling and washing
of sweetpotato root tubers
4.4.2.2 Adoption of grating sweetpotato root tubers into mash
Figure 24 reveals that all (100 percent) the farmer respondents had adopted
the practice of grating their sweetpotato root tubers into mash in order to process
unfermented sweetpotato flour. None of them rejected it.
112
Figure 24: Percentage distribution of respondents by their stages on adoption of grating sweetpotato
root tubers into mash
4.4.2.3 Adoption of dewatering sweetpotato mash
Figure 25 shows that all (100 percent) the respondents have adopted the
practice of dewatering their sweetpotato mash in clean bags. This means that they
have passed through the stages of unawareness, awareness, interest, evaluation and
trial, to adoption. None of the farmers rejected the practice.
113
Figure 25: Percentage distribution of respondents by their stages on adoption of dewatering
sweetpotato mash in clean bags
4.4.2.4 Adoption of sun-drying sweetpotato mash on raised
platform or oven-drying at temperature of 500C
Figure 26 shows that none of the respondents is at the stages of unawareness,
awareness, interest or evaluation in the practice of sun-drying sweetpotato mash on
raised platform or oven-drying at a temperature of 500C to process unfermented
sweetpotato flour. Majority (76.92 percent) of them have adopted the practice,
10.26 percent were at the trial stage while 12.82 percent of them rejected it. Their
reason for rejecting this technology was the difficulty in constructing raised
platforms on which to dry the mash.
114
Figure 26: Percentage distribution of respondents by their stages on adoption of sun-drying
sweetpotato mash on raised platform or oven-drying at 50o C
4.4.2.5 Adoption of milling of dried sweetpotato mash
As shown in Figure 27, all (100 percent) the respondents have adopted
proper milling of dried sweetpotato mash to produce the unfermented sweetpotato
flour. This implies that they have passed the stages of unawareness, awareness,
interest, evaluation and trial, to adoption of the practice. None of the farmers
rejected the practice.
115
Figure 27: Percentage distribution of respondents by their stages on adoption of milling of dried
sweetpotato mash
4.4.2.6 Adoption of packaging of sweetpotato flour in
polyethylene bags or air-tight containers
Figure 28 shows that all (100 percent) the respondents have adopted the
packaging of the milled sweetpotato dry mash or flour in polyethylene bags or airtight containers. This means that they have passed the stages of unawareness,
awareness, interest, evaluation and trial, to adoption of the practice. None of them
rejected it. The reasons for this level of adoption could be that the practice was
simple and and the materials needed to carry it out were easily available.
116
Figure 28: Percentage distribution of respondents by their stages on adoption of packaging
sweetpotato flour in polyethylene bags or air-tight containers
4.4.3 Extent of adoption of processing of sweetpotato starch
The standardized practices for processing of sweetpotato starch include:
peeling and washing of sweetpotato tubers, grating of root tubers into mash,
dewatering of mash into clean bags and mixing dewatered mash with quantity of
water that is 10 times the volume of mash. Others are: sieving of mash with muslin
cloth; sedimenting, decanting and collection of starch, sun-drying of starch on
raised platform or oven-drying at a temperature of 500C, milling of the dried starch
and packaging in polyethylene bags or air-tight containers. The discussion of the
extent of adoption of each practice follows:
117
4.4.3.1 Adoption of peeling and washing of sweetpotato root
tubers
Figure 29 shows that 100 percent of the respondents had adopted the
practice of peeling and washing of sweetpotato root tubers for processing of
sweetpotato starch. None of them rejected the practice.
Figure 29: Percentage distribution of respondents by their stages on adoption
of peeling and washing of sweetpotato root tubers
4.4.3.2 Adoption of grating sweetpotato root tubers into mash
As shown in Figure 30, all (100 percent) the respondents grated their peeled
and washed sweetpotato root tubers into sweetpotato mash. This implies that they
had moved from the stages of unawareness, awareness, interest, evaluation and
trial, to adoption of the practice. None of the farmers rejected it.
118
Figure 30: Percentage distribution of respondents by their stages on adoption of grating of
sweetpotato root tubers into mash
4.4.3.3 Adoption of dewatering of sweetpotato mash
Figure 31 reveals that all (100 percent) the respondents dewatered their
sweetpotato mash in clean bags. None of them rejected the practice.
Figure 31: Percentage distribution of respondents by their stages on adoption of
dewatering of sweetpotato mash in clean bags
119
4.4.3.4 Adoption of mixing of sweetpotato mash with
quantity of water that is ten times the volume of mash
Figure 32 reveals that majority (64.12 percent) of the respondent
s had adopted the practice of mixing sweetpotato mash with quantity of water that
is ten times the volume of mash. Those farmers who were at the evaluation stage
constituted 12.72 percent of the number of farmers who were aware of the
sweetpotato processing technologies, while 13.16 percent rejected the practice. The
farmers indicated their reason for rejecting this technology as the difficulty in
measuring accurately the quantity of water required for the mixture.
Figure 32: Percentage distribution of respondents by their stages on adoption of mixing sweetpotato
mash with volume of water that is ten times the volume of mash
120
4.4.3.5 Adoption of sieving sweetpotato mash with muslin cloth
As shown in Figure 33, all (100 percent) the respondents have adopted the
practice of sieving their sweetpotato mash with muslin cloth in order to process
sweetpotato starch. It means that all of them have moved from the stages of
unawareness, awarenesss, interest, evaluation and trial, to adoption. The practice
was not rejected by any of the farmers.
Figure 33: Percentage distribution of respondents by their stages on adoption of sieving
sweetpotato mash with muslin cloth
4.4.3.6 Adoption of sedimenting and decanting of sweetpotato
mash for collection of sweetpotato starch
As shown in Figure 34, all (100 percent) the respondents have adopted the
practice of sedimenting and decanting of sieved sweetpotato mash for the
collection of sweetpotato starch. None of them rejected the practice.
121
Figure 34: Percentage distribution of respondents by their stages on adoption of sedimenting and
decanting of sieved sweetpotato mash for collection of sweetpotato starch
4.4.3.7 Adoption of sun-drying of sweetpotato starch on raised
platform or oven-drying at temperature of 500C
Figure 35 reveals that majority (76.92 percent) of the respondents have
adopted the practice of sun-drying of the sweetpotato starch on raised platform or
oven-drying at a temperature of 500C. The farmers who were at the trial stage
comprised 12.82 percent of the respondents while 10.26 percent rejected it. Their
reason for the rejection was that raised platforms were not always feasible, and that
they could dry the starch anywhere that is clean and not shaded from the sun. None
of the respondents was at the unawareness, awareness, interest or evaluation stages.
122
Figure 35: Percentage distribution of respondents by their stages on adoption of sun-drying of
sweetpotato starch n raised pltatform or oven-drying at 50oC
4.4.3.8 Adoption of milling of sweetpotato starch
Figure 36 shows that all (100 percent) the respondents had adopted the
practice of milling the dried sweetpotato starch. This means that they had passed
the stages of unawareness, awareness, interest, evaluation and trial, to adoption.
None of them rejected the practice.
123
Figure 36: Percentage distribution of respondents by their stages on adoption of milling of
sweetpotato starch
4.4.3.9 Adoption of packaging sweetpotato starch in
polyethylene bags or air-tight containers
Figure 37 reveals that all (100 percent) the respondents had adopted the
packaging of milled sweetpotato starch in polyethylene bags or air-tight containers.
This means that they have passed the stages of unawareness, awareness, interest,
evaluation and trial, to adoption of the practice. None of the respondents rejected
the practice.
124
Figure 37: Percentage distribution of respondents by their stages on adoption of packaging of
sweetpotato starch in polyethylene bags or air-tight containers
4.5 Determinants of adoption and disadoption of the sweetpotato production
and processing technologies
4.5.1 The Adoption/non-adoption model
Table 4 shows the results of the probit regression model for the adoption of the
sweetpotato production and processing technologies. The goodness of fit, measured by
the chi-square (χ2) in the table, shows that the explanatory variables included in the probit
model explained the variations in decisions to adopt the sweetpotato technologies. Four
variables, household size, labour, land and health, were found to be statistically
significant in the adoption/non-adoption model. From H (household preferences), only
household size was statistically significant. The coefficient for household size had a
negative coefficient, but statistically significant at 5% level. This implies that any
increase in household size will lead to a corresponding decrease in the adoption of the
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sweetpotato production technology. This is, however, contrary to a priori expectation,
since a large household size is expected to increase the probability of adoption as it
provides ready and cheap labour. It is, however, possible that with increase in household
size, farmers move from sweetpotato production to other ventures they perceive to be
more rewarding financially. The H variables of age, gender, education and marital status,
were not significant.
Under R, the variables labour, land and health were statistically significant. The
coefficient for labour was found to be positive and significantly related to adoption of the
sweetpotato production and processing technologies at 1% level. This is expected, as an
increase in labour will lead to a corresponding increase in the adoption of sweetpotato
cultivation and processing. The variable, land, had a negative coefficient and significantly
related to adoption of the sweetpotato technologies at 5% level. This indicates that any
increase in farm size will lead to a corresponding decrease in the adoption of the
sweetpotato technologies. Small farm size can encourage farmers to intensify agricultural
production (Mafuru, Kileo, Verkuijl and Mwangi, 1999). The variable health was positive
and significantly related to adoption of the sweetpotato technological package at 5%
level. This indicates that any increase in the number of times a farmer was treated in a
hospital will lead to a corresponding increase in the adoption of the sweetpotato
technology. Farmers who have received treatment will be physically fit to engage in
productive activities. Only credit was not significant among the R variables. This finding
of significance of the R variables is consistent with literature on technology adoption
which posits that resource constraints play an important role in whether a household
uptakes a technology (Wendland and Sills, 2008). The M variable, price, was not
126
statistically significant, and agrees with Wendland and Sills (2008) which showed price
beliefs to be insignificant in the adoption model for soybean. None of the variables under
U (extension and co-operative membership) was significant. Non-significance of the
membership of co-operatives is in agreement with Wendland and Sills (2008) who found
membership of social organizations non-significant to the adoption of soyabean in Togo
and Benin Republic.
Table 4: Probit regression of the probability of adoption
Category
Variable
Coefficient
Standard error
H
AGE
H
GENDER
H
t-value
-.00458
.00251
-1.82132
.04221
.06209
.67986
EDU
-.05323
.08605
-.61856
H
HHS
-.07973
.02920
-2.73033*
H
MAST
-.09837
.08071
-1.21877
R
LABOUR
.08825
.02776
3.17867**
R
CREDIT
.32721
.30036
1.08941
R
LAND
-.02413
.00975
-2.47419*
R
HEALTH
.20887
.07742
2.69779*
M
PRICE
.00050
.00033
1.54366
U
COOP
-.09491
.06044
-1.57032
U
EXT
.13238
.06866
1.92803
B
SLOPE
.01838
.06166
.29805
Constant
-1.30069
.18784
-6.92451**
Prob˃ chi2
406.674
* Indicates significance at 5% level and ** at 1% level
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4.5.2 The continued use/disadoption model
The continued adoption/disadoption model (full probit regression) was
constructed by adding variables measuring the household’s experience with the
sweetpotato technologies (E) to the adoption model. As shown in the full probit results in
Table 5, there are some important differences in the variables that affect continued
cultivation and processing of sweetpotato, as compared to initial adoption. Under H, the
variables age and marital status were significantly related to the continued
adoption/disadoption of the sweetpotato technologies, whereas only household size was
significant under the adoption model.
Age has a positive coefficient and is significantly related to continued adoption of
sweetpotato at 5% level. This means that increase in age of the farmers will enhance
continued cultivation and processing of sweetpotato. Thus age is a significant factor in
both adoption and continued cultivation and processing sweetpotato, similar to the
findings of Moser and Barrett (2002, 2006) and Wendland and Sills (2008). Older
farmers, perhaps because they have invested several years and resources into a particular
technology, may not want to take the risk of disadopting it (Wendland and Sills, 2008).
With regard to marital status, its coefficient was positive and significantly related to
continued adoption at 5% level. This implies that having a life partner enhances continued
adoption of the sweetpotato technologies.
Under resource endowment, (R), only credit was significant in the continued
adoption of the sweetpotato technologies, whereas labour, land and health were
significant in the adoption/non-adoption model. The coefficient for credit was positive
and significantly related to continued adoption of the sweetpotato production and
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processing technologies at 1% level. This implies that an increase in access to credit will
increase continued adoption of the technologies. The labour, land and health variables
under R were not significant. The variable in M, price, was not statistically significant to
the disadoption model, as was the case in the adoption model. Under U, none of the
variables of membership of co-operatives or social organizations and extension contact
was statistically significant. The B variable, slope, was also not significant to the
continued adoption of the sweetpotato technologies. This is consistent with the findings
of Wendland and Sills (2008) which showed that none of the variables in M, U or B was
statistically significant to the continued adoption/disadoption model.
Under U,neither membership of co-operatives or social organizations nor
extension contact , was statistically significant, as was the case in the adoption model.
In the category of sweetpotato experience (E), only sweetpotato problem was
significant to the continued adoption/disadoption of the technologies. The variables extent
of land under sweetpotato cultivation, ( EXTENT), years of farming experience in
sweetpotato production and soil type were not significant. The coefficient of sweetpotato
problems was negative and significantly related to continued adoption/disadoption of the
sweetpotato technologies. This implies that an increase in the number of problems
encountered in sweetpotato cultivation and processing will diminish continued adoption
and increase disadoption.
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Table 5. Probit regression of the probability of continued use
Category
Variable
Coefficient
Standard error
t-value
H
AGE
.00507
.00209
2.42712*
H
GENDER
.04343
.05171
.83987
H
EDU
-.12481
.06748
-1.84941
H
HHS
.01303
.02992
.43547
H
MAST
.15616
.06592
2.36903*
R
LABOUR
-.02349
.02923
-.80372
R
CREDIT
.75777
.22478
3.37115**
R
LAND
-.01407
.00819
-1.71774
R
HEALTH
-.05888
.05918
-.99485
M
PRICE
.00045
.00029
1.56806
U
COOP
-.03313
.05146
-.64387
U
EXT
.11541
.06038
1.91149
B
SLOPE
-.00391
.04768
-.08204
E
EXTENT
.02353
.05048
.46619
E
YEARS
.03189
.04689
.68010
E
SOIL
.00594
.18831
.03154
E
SWEETP
-.24568
.10489
-2.34230*
-1.31596
.18815
-6.99402**
Constant
2
Prob > chi
1458.397
* Indicates significance at 5% level and ** at 1%
The foregoing analysis of adoption and disadoption determinants provides insights on
the factors that influence the cultivation and processing of sweetpotato in Nigeria. First,
many of the categories of determinants found in such adopton literature as Wendland and
Sills (2008), Lee (2005), Pattanayak et al. (2003) and Doss (2006) are also significant
indicators of adoption and continued use of the sweetpotato production and processing
technologies. The determinants of adoption include variables from the two categories H and
130
R. In the decision to continue using the technologies, H and R remain important, along with
measures of E. Of particular importance is the fact that land resources (LAND) is significant
in the adoption decisions, highlighting the fact that sweetpotato faces the same resource
constraints as other types of agricultural technologies. Similarly, categories M, B and U
were not significant in the adoption or disadoption decisions as obtained in other literature
on technology adoption, as well as Wendland and Sills (2008).
Second, in addition to the categories of determinants found in other adoption
literature, there are other variables that are important for understanding disadoption. As seen
in this analysis, the household’s experience with the production and processing of
sweetpotato, (E), is important to this decision process. Specifically, it was found that
households that were increasingly having problems in the production and processing of
sweetpotato were more likely to disadopt the technologies. Wendland and Sills (2008),
however, found years of farming experience and extent of land as the specific variables in E
that were important in the continued adoption/disadoption decision by soybean farmers.
This study, therefore, highlights the importance of understanding the various stages of
dissemination of a new technology, including both initial uptake and trialling (adoption),
and the decision whether to continue with or abandon a new technology (disadoption).
Adoption and disadoption decisions can be affected by different factors, and technology
dissemination strategies need to consider all of these factors. To obtain lasting impacts from
any new technology like the sweetpotato production and processing technologies, attention
cannot be focused exclusively on the factors that drive the adoption decision, but must also
consider what encourages households to stick with the new technology after the initial
promotion effort.
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4.6
Major factors constraining the adoption of sweetpotato production and
processing technologies
This section discusses the major factors that constrain the adoption of the sweetpotato
production and processing technologies. The exploratory factor analysis procedure using the
principal factor model with varimax rotation was used in grouping the constraint variables
into major constraint factors. Only variables with factor loadings of 0.40 and above were
adopted in naming and interpreting the factors and constraint variables. Variables that
loaded in more than one factor, or that have loadings of less than 0.40, were not used. Based
on the clustering of items, factor 1, 2, 3 and 4 were named production/processing
complexity, economic, poor technical information and pathological problems respectively.
Factors constraining the adoption of technologies
Table 6 shows the varimax rotated constraint factors influencing the adoption of the
sweetpotato production and processing technologies as perceived by the farmers.
Production/processing complexity problem was dominated by recommended sweetpotato
production practices are costly to carry out (0.805), high cost of sweetpotato vine needed for
planting (0.709), low consumer preference associated with sweetpotato product (0.707),
difficulty in integrating sweetpotato production and processing technologies into existing
production system (0.684) and recommended sweetpotato processing technologies are costly
to carry out (0.674). Other constraining variables included unavailability of sweetpotato
vines needed for planting (0.643), recommended sweetpotato production practices are
complex to carry out (0.628), recommended sweetpotato processing technologies are
complex to carry out (0.617) and lack of market to sell increased quantities of sweetpotato
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(0.595). Most farmers in the rural areas will not adopt any innovation which they find to be
complex. In this regard, the farmers will be unable to manipulate the innovation (van den
Ban and Hawkins, 1996; Adekoya and Tologbonse, 2005). Subsequently, they will not be
able to integrate such innovations, like the sweetpotato innovation, into their existing
production system.
Items that loaded high in factor 2, (economic problem), included high cost of available
inorganic fertilizer (0.774), available agro-chemicals (herbicides) are costly (0.758),
unavailability of inorganic fertilizer (0.748) and unavailability of agro-chemicals (0.673). In
many situations, the development of sustainable production requires increased use of
purchased inputs such as inorganic fertilizers and agro-chemicals like herbicides (Agwu,
2000). These inputs require funds, and the poor economic conditions of the farmers often
constrain them from using these sweetpotato technologies. This situation is compounded by
the unavailability of the inputs.
Issues which loaded high under factor 3, (poor technical information), included: lack
of contact with important sources of information on sweetpotato production and processing
(0.768), lack of adequate technical knowledge about recommended farm practices
associated with sweetpotato production (0.725) and lack of adequate technical knowledge
about recommended processing practices associated with sweetpotato (0.697). The transfer
of agricultural technologies is a process that involves multiple functions of information,
teaching, technology supply and technology service (Asiabaka, 1991). The implication is
that the recipients of the technology require the technical knowledge that underlie the
formulation and design of the technology (Okono,1994, in Agwu, 2000). Thus the poor
133
technical knowledge of the farmers may contribute in making the adoption of the
sweetpotato technologies difficult.
Specific issues with high loading under factor 4 (pathological problem) included
problem of pest attack on sweetpotato (0.809), problem of disease attack on sweetpotato
(0.783) and scarcity of land (0.504). The major pathological problem of sweetpotato in the
South-east agro-ecological zone of Nigeria (Abia, Akwa Ibom, Anambra, Bayelsa, Cross
River, Ebonyi, Enugu, Imo and Rivers States) is attack by the sweetpotato weevil, Cylas
spp. The incidence of this pest increases with increase in the dryness of the soil. Therefore,
farmers who harvest their crops piece-meal or leave their crops in the soil into the dry
season stand the risk of losing more of their produce through the attack of this pest than
those who harvest their crops earlier (Nnodu, 1981; Anioke et al, 1987).
However, some variables were loaded high in more than one factor and were, as a
result, not considered in the process of naming the extracted factors. These included:
unavailability of labour (loaded in factors 3 and 4), high cost of labour (loaded in factors 2
and 3) and lack of capital to carry out necessary farm activities (loaded in factors 2 and 3).
One variable, low soil fertility, had loadings that were below 0.40 which was used in
naming the factors. It was, therefore, not included in the extracted factors.
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Table 6: Varimax rotated factors constraining the adoption of sweetpotato production
and processing technologies by farmers
S/N Constraint variables
i.
ii.
iii.
iv.
v.
Factor1 Factor2 Factor3 Factor4
Scarcity of land
-0.127 0.066 -0.344 0.504
Low soil fertility
0.275 0.265 0.028 0.205
Unavailability of labour
-0.037 0.328 -0.577 0.438
High cost of hired labour
-0.167 0.430 -0.527 0.340
Difficulty in integrating sweetpotato
production and processing technologies
into existing production system
0.684 0.134 0.141 -0.155
vi.
Low consumer preference associated with
sweetpotato product
0.707 -0.051 0.178 -0.053
vii.
Lack of market to sell increased quantity
of sweetpotato
0.595 -0.088 -0.097 -0.091
viii. Lack of capital to carry out necessary
farm activities
0.022
0.459 -0.457 0.314
ix.
Unavailability of sweetpotato vines
needed for planting
0.643 -0.048 0.012 0.383
x.
High cost of sweetpotato vines needed
for planting
0.709 -0.147 -0.099 0.332
xi.
Unavailability of inorganic fertilizer
0.017
0.748
0.020 0.044
xii.
High cost of inorganic fertilizer
0.051
0. 774 -0.107 0.309
xiii. Unavailability of agro-chemicals
(herbicides)
-0.013
0.673
0.210 -0.140
xiv. Available agro-chemicals are costly
0.037
0.758
0.101 -0.167
xv.
Recommended sweetpotato production
practices are complex to carry out
0.628
0.165
0.377 -0.050
xvi. Recommended sweetpotato processing
technologies are complex to carry out
0.617
0.279
0.056 -0.185
xvii. Recommended sweetpotato production
practices are costly to carry out
0.805
0.068
0.125 -0.143
xviii. Recommended sweetpotato processing
technologies are costly to carry out
0.674
0.155
0.140 -0.207
xix. Lack of adequate technical knowledge
about recommended farm practices
associated with sweetpotato production
0.224 0.200
0.725 -0.073
xx.
Lack of adequate technical knowledge
about recommended processing practices
associated with sweetpotato
0.160 0.195
0.697
-0.012
xxi. Lack of contact with important sources of
information on sweetpotato production and
processing
0.069 0.066 0.768 0.329
xxii. Problem of pest attack on sweetpotato
-0.105 0.021 0.052
0.809
xxiii. Problem of disease attack on sweetpotato
-0.115 -0.034 -.032
0.783
Extraction method: Principal Component Analysis
Rotation method: Varimax with Kaiser Normalization
135
CHAPTER FIVE
SUMMARY, CONCLUSION AND RECOMMENDATIONS
This section summarizes the problem objectives, methodology and finding of
the study, as well as the conclusion and recommendations.
5.1 Summary
The overall purpose of this study was to determine the adoption and disadoption of
the sweetpotato production and processing technologies by farmers in the South-East
Zone of Nigeria. The specific objectives of the study were to: determine the level of
awareness of the sweetpotato production and processing technologies among farmers in
the zone; determine the extent of adoption and disadoption of the sweetpotato production
and processing technologies by farmers in the zone; examine the determinants of adoption
and disadoption of the sweetpotato production and processing technologies in the study
area; and identify the constraints to the adoption of the technologies in the zone.
The study was carried out in the South-east geo-political zone of Nigeria, made up
of Abia, Anambra, Ebonyi, Enugu and Imo States. Three states, Abia, Ebonyi and Imo,
were randomly selected for data collection. A total of 270 farmers constituted the sample
size for the study.
Data for the study were collected through the use of structured interview schedule
from a randomly selected sample of two hundred and seventy (270) farmers in the Southeast geo-political zone of Nigeria. Section A of the interview schedule was designed to
elicit information on the personal and socio-economic characteristics of the respondents.
136
Section B surveyed the level of awareness of sweetpotato cultivation and processing,
sources of information and adoption stages of the sweetpotato production and processing
technologies, while section C sought information on farmers’ production and processing
systems and environment. Section D of the interview schedule elicited information on the
factors constraining the adoption of the sweetpotato production and processing
technologies.
Percentages and means were used in describing the personal and socio-economic
characteristics of the farmers, level of awareness of the sweetpotato production and
processing technologies, and extent of adoption and disadopton of the technologies by the
farmers. The probit regression model was used in determining the influence of some
personal and socio-economic characteristics of the farmers in the adoption, continued
adoption and disadoption of the sweetpotato technologies. Exploratory factor analysis
procedure, using the principal factor model with iteration and varimax rotation, was used
in determining major variables constraining the adoption of the sweetpotato production
technology.
The findings of the study showed that majority (51 percent) of the respondents
were males with a mean farming experience of 22.22 years. Similarly, a majority (71.59
percent) of the respondents were married. The mean age of the farmers was 48 years,
while the mean household size was 7 persons per family. Information on the level of
formal education showed that majority (86 percent) of the respondents had one form or
other of formal education, and that about 60 percent of them had farming as their major
occupation. The study further showed that the average farm size of the respondents was
1.34 hectares, majority (90 percent) of them belonged to at least one farmers’/social
137
organization, while 60 percent of them had contact with extension agency in the zone.
Most (95.56 percent) of the respondents did not participate in any formal or informal
credit system for sweetpotato production.
On the level of awareness of the sweetpotato technologies in the zone, the study
showed that majority (79.63 percent) of the respondents were aware of the sweetpotato
production technology. There was, however, a low level of awareness of the sweetpotato
processing technology, as only 28.90 percent of the farmers in the zone were aware of it.
With regard to the extent of adoption of the sweetpotato production practices,
results of the study revealed that majority (38 percent) of the respondents had adopted the
recommended land preparation methods of ridges or mounds, 50 percent of them were
using the improved sweetpotato varieties while 20 percent were using the recommended
plant spacing in their sweetpotato farms. The recommended sweetpotato planting
materials of 2-node and 5/6-node vine cuttings were adopted by 34.5 percent of the
respondents, 70.2 percent of the farmers had adopted the appropriate time of planting, 80
percent were using the recommended weeding regime while 47 percent of the respondents
had adopted the application of inorganic fertilizer to their sweetpotato farms. About 63
percent of the farmers were using the earthening-up innovation on their sweetpotato
farms, 80.5 percent had adopted timely harvest of sweetpotato root tubers, while 80.7
percent were using the sweetpotato pest and disease control measures on their farms.
Moreover, the study showed that 24 percent of the respondents had disadopted the
sweetpotato technology after initial uptake.
Similarly, results of the extent of adoption of the sweetpotato processing
technologies showed that the respondents were aware of processing of sweetpotato into
138
fermented fufu flour, unfermented flour used in confectioneries and sweetpotato starch. In
the processing of fermented sweetpotato fufu flour, all the respondents adopted the
practice of peeling and washing their sweetpotato root tubers, 76.92 percent of them were
cutting the sweetpotato root tubers into 2.5-3.0mm chips while all (100 percent) of them
were fermenting the sweetpotato chips by soaking in water for 24 hours. Furthermore, all
(100 percent) the respondents had adopted the practice of draining water from fermented
sweetpotato chips, 66.66 percent adopted the practice of sun-drying the fermented chips
on raised platforms or oven-drying at a temperature of 500C, all (100 percent) of them
adopted milling of the dried fermented chips, as well as packaging the produce in
polyethylene bags or air-tight containers. In the processing of unfermented sweetpotato
flour, the results showed that all the respondents were peeling and washing their
sweetpotato root tubers, grating them into mash and dewatering the mash in clean bags.
Majority (76.92 percent) of the respondents were sun-drying the sweetpotato mash on
raised platforms or oven-drying at a temperature of 500C. All the respondents milled the
dried sweetpotato mash and packaged in polyethylene bags or air-tight containers. To
process sweetpotato starch, all (100 percent) the respondents peeled and washed their root
tubers, grated them into mash and dewatered the mash in clean bags. Majority (64.10
percent) of them mixed the mash with quantity of water that is 10 times the volume of
mash, all (100 percent) of them sieved it with muslin cloth, as well as sedimenting and
decanting the sieved mash in order to collect the sweetpotato starch. In addition, majority
(76.92 percent) of the respondents sun-dried the sweetpotato starch on raised platforms or
oven-dried at a temperature of 500C; all of them milled the starch properly and packaged
in polyethylene bags or air-tight containers.
139
The probit regression analysis showed that, of the thirteen variables studied under
the adoption model, four variables (household size, labour, land and health) significantly
influenced the adoption of sweetpotato technologies and were, thus, important in
predicting the adoption behaviours of the farmers. Similarly, in the probit regression
analysis involving seventeen variables studied under the continued adoption/disadoption
model, four variables (age, marital status, credit and sweetpotato problem) significantly
influenced the continued use or disadoption of the sweetpotato technologies. Whereas
increases in the age of the farmers, marital status and participation in credit system
ensured continued use of the sweetpotato technologies, only increases in the number of
problems encountered in sweetpotato cultivation and processing increased the probability
of disadoption of the technologies.
Finally, the study established the existence of major factors constraining the
adoption of the sweetpotato technologies. Major constraints identified include:
production/processing complexity problems, economic problems, poor technical
information and pathological problems.
5.2 Conclusion
On the bases of the major findings of the study, the following conclusions and
implications are drawn:
Majority of the farmers were middle-aged and literate, implying that many of them
were in a good position to be aware of, understand and adopt the sweetpotato production
and processing technologies. They were predominantly males, with long period of
farming experience. In addition, most of them were married and had average household
140
size of 7 members, which is fairly large. This is expected to serve as an incentive to
continued adoption of the sweetpotato production and processing technologies since
supply of labour is ensured. Moreover, majority of the farmers had farming as major
occupation and belonged to farmers’/social organizations. This implies that they have
access to innovations like the sweetpotato technologies as membership of social
organizations enhances interaction with sources of relevant information on innovations
and by the fact that majority of them had contact with extension. The farmers also had
mostly small farm holdings, and majority of them did not participate in any credit system
for sweetpotato production and processing.
In terms of the level of awareness of the sweetpotato technologies, it was concluded
that majority of the farmers were aware of the sweetpotato production technologies more
than the processing options. This implies that dissemination efforts on the sweetpotato
technologies were skewed towards the sweetpotato production options.
With regard to the extent of adoption of the sweetpotato production technologies,
majority of the farmers had adopted the use of ridges and mounds, and improved
sweetpotato varieties, while majority of them rejected the recommended plant spacing of
30cm x 100cm on ridges and 25cm x 100cm on mounds for both sole and intercropped
systems. Moreover, most of the farmers use the 2-node and 5/6-node vine cuttings as
planting materials, as well as time for planting of sweetpotato, weeding regime of one
major weeding at 4-6 weeks after planting, inorganic fertilizer application rate of 400kg
NPK 20:10:10, earthening-up practice, timely harvest of root tubers and pest and disease
control measures. This implies that the extent of adoption of the sweetpotato production
technologies was high. Furthermore, the extent of disadoption was low. Similarly, the
141
extent of adoption of the sweetpotato processing technologies was high inspit of the low
level of their awareness. The processing technologies adopted by the farmers were
fermented sweetpotato fufu flour, unfermented sweetpotato flour and sweetpotato starch.
In the processing of fermented sweetpotato fufu flour, majority of the farmers had
adopted the practices of peeling and washing of sweetpotato root tubers, cutting the root
tubers into 2.5-3.0mm chips, fermenting the chips by soaking in water for 24 hours,
draining of water from fermented chips and sun-drying of chips on raised platform or
oven-drying at a temperature of 500C. Majority of them also mill the dried chips properly
to produce the flour and package the flour in polyethylene bags or air-tight containers.
With regard to the extent of adoption of the practices involved in the processing of
unfermented sweetpotato flour, majority of the farmers had adopted the innovation of
peeling and washing of the sweetpotato root tubers, grating of the root tubers into mash
and dewatering of the mash in a clean bag. They had also adopted sun-drying of the
dewatered mash on raised platforms or oven-drying at a temperature of 500C, milling of
the dried mash and packaging of the flour in polyethylene bags or air-tight containers. In
processing of sweetpotato starch, majority of the farmers had adopted the practices of
peeling and washing of the sweetpotato root tubers, grating of the root tubers into mash,
dewatering of mash in clean bags and mixing dewatered mash with quantity of water that
is 10 times the volume of mash. Other innovations in the processing of sweetpotato
starch, and which were adopted by majority of the farmers, included sieving of mash with
muslin cloth, sedimenting, decanting and collection of starch, sun-drying of starch on
raised platform or oven-drying at a temperature of 500C, milling of the dried starch and
packaging in polyethylene bags or air-tight containers.
142
The socio-economic variables which significantly influenced the adoption of the
sweetpotato technologies and, subsequently, important in predicting the farmers’ adoption
behaviours were household size, labour, land and health. However, in predicting the
farmers who will continue to use the sweetpotato technologies the variables age, marital
status and participation in credit system, are important, while the variable, sweetpotato
problems, is significant in determining farmers who will disadopt the sweetpotato
production and processing technologies after initial uptake.
The study concluded that there were production/processing complexity problem,
economic problems, poor technical information and pathological problems constraining
the increased adoption of the sweetpotato production and processing technologies. This
suggests the need for researchers, policy makers and administrators of extension services
to consider seriously these issues which constitute limiting factors to increased
sweetpotato production and processing in the study area.
5.3 Recommendations
1.
The high level of unawareness associated with the sweetpotato processing
technologies implies that more farmers need to be reached by extension staff for the
introduction of the technologies. In this regard, the extension agents should use the group
approach in extension service delivery and identify farmer groups that should be taught
the technical skills involved in the sweetpotato technologies. In this way a large number
of farmers would be reached at the same time. These farmers would in turn teach these
technologies to other farmers in the area.
143
2.
Research should develop technologies that are less complex and easy to be
manipulated by the farmers to enhance their adoption. A practice like cutting of
sweetpotato root tubers into 2.5mm-3.9mm chips needs to simplified further to make it
easier for farmers to adopt.
3. Government should intervene in the problems of high cost and unavailability of such
farm inputs as inorganic fertilizer and agrochemicals by strengthening the input delivery
system of the extension service. This will enable the agency to timely, adequately and
regularly meet the inputs needs of the farmers.
4.
The problem of scarcity of planting materials can be solved by Government
encouraging self-effort and contracted out-growers in the multiplication of quality
planting materials. The State ADPs and research institutes should be involved in this.
5. Farmers should be encouraged to participate actively in farmers’/social organizations
and co-operative societies in order to strengthen their group action, since such
organizations act as effective channels for extension contact with large number of
farmers. It also creates opportunities for participatory interaction of farmers with
extension organizations. Furthermore, co-operative societies help in providing credit, as
well as marketing facilities, for the mutual benefit of the farmers.
6. The poor economic condition of the farmers occasioned by lack of funds to carry out
necessary farm activities associated with the sweetpotato production and processing
technologies, among other variables, was a major constraint to the productive capacity of
the farmers. Many of the farmers were handicapped in this area. Thus, even though the
issue of provision of credit is an intractable problem in Nigerian agriculture, it is
suggested that a realistic policy on provision of credit to sweetpotato farmers in particular
144
be put in place. The Governmnt may have to revisit this issue. Once this is done, the
credit facilities must be accompanied with supervision and advice from the disbursing
agency to ensure their proper utilization for increased sweetpotato production and
processing.
7. Government should encourage such industries as paper and pulp, textile, livestock,
bakery, pharmaceuticals and beverage, to increasingly use sweetpotato.
145
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