APPLICATION OF STONE MEAL (MINERAL DUST)
Introduction
This brochure outlines key information for the use of Integrated
Pest Management (IPM) in horticulture; specifically, the
flowering period of tomatoes. The document is aimed at
increasing farmer awareness of the advantages of IPM, with
the focus on increased farm profitability. The brochure's
extension message is one of a larger programme of on-farm
demonstrations that is being delivered by MAFRD.
The brochure is being funded through a two-year EU project to
strengthen MAFRD's advisory and technical services. The
project is helping MAFRD to coordinate the advisory network of
local advisers and private advisory bodies, as well as promote
the opportunities and benefits to the farming community of
using the advisory services. The project is also supporting the
implementation of rural development measures aimed at using
farm advisory services, as well as ensuring that training is
harmonised with EU requirements under the Common
Agriculture Policy (CAP) and the Instrument for Pre-accession
Assistance for Agriculture and Rural Development (IPARD)
Physiological
due to
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Bumblebees
aredisorder
very efficient
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pollination,
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The application of stone meal on the leaf surface of tomatoes
aims at binding the humidity in the tunnel and inhibiting disease
growth. Stone meal is a plant-fortifier that makes the plant
stronger and better able to cope with pests and diseases.
 For an area of 500 m2, it is recommended to use
0.5-1 kg. More than this is not recommended.
Using too much may result in reduced
photosynthesis, due to blocked pores.
 Up to 5 treatments can be applied during the
cultivation period.
 The application of stone meal can be done using
simple hand-operated dust pumps.
Pollination
Bee hives
Hand operated dust pump
Bee hives are sold to ensure good pollination. If you do not
have access to these, you should gently shake or vibrate the
entire tomato plant during the whole flowering period.
Tomato flowers
Tomato flowers need to be pollinated to develop fruits. The
flowers have both male and female organs, and are selffertilizing. Pollination is usually by wind or insects. In wellventilated tunnels or the field, the wind pollinates the flower
sufficiently. In integrated production, chemical pollination
regulators are not used.
High humidity (>90 %) hampers pollination, since pollen grains
stick together, resulting in poor or non-existent pollination. High
temperatures (>27°C or < 13°C) also hamper pollination. Both
might cause blossoms to drop, or result in physiological
disorders, such as small fruit of low quality.
Application of stone meal after the removal of bottom
leaves avoids disease infection through wet wounds.
Shaking during flowering period
FERTILIZATION

When the fruit of the oldest truss starts to ripen, remove
the leaf below it and the two leaves above.
Tomatoes are heavy consumers of nutrients. The requirements
of macro-nutrients, and the secondary nutrient magnesium, for
one hectare of tomato (4–5 months cultivation in cold
polytunnels) with an anticipated yield of 10 kg of tomatoes per
m2 are approximately:

Also, remove the leaves that show disease symptoms.

Note that a tomato plant does not need more than 18
leaves for best growth.

To keep the leaf wound small, use a clean knife to take
leaves off in the morning, so that wounds can dry out
during the daytime.
130 kg N
/
50 kg P2O5
/
260 kg K2O
/
30 kg Mg

Split the total amount of fertilizer into several
applications

Consider weather conditions when taking off leaves. The
lower the humidity, the faster the wound dries out.

Do not add too much fertilizer in the seedbed, as too
much N will lead to (a) plenty of leaves but no flowers,
and (b) weak plants that are susceptible to diseases.

The application of stone powder helps large wounds to
dry out faster.

Blossom end rot is also a consequence of too much
N, as it blocks the Calcium uptake from the soil.
After removing leaves
and/or
side-shoots,
remove them from
the greenhouse, as
they might be a
source of infection.
REMOVAL OF SIDE SHOOTS
The removal of side shoots diverts nutrients towards the flower
clusters and fruits on the main stem, as well as allows more
efficient air circulation.
Remove the side shoots twice per week, early in the morning.
Remove them whilst they are small (5-10 cm); this will keep the
wounds small, (which can be entrance doors for diseases); it
will also keep the energy that the plant puts into these side
shoots low; never allow side shoots to grow beyond 10 cm.
Remove a side shoot by grasping it between your thumb and
second finger, and bending it until it breaks.
Removing old
side shoots
REMOVAL OF LEAVES

Remove three to four bottom leaves of the plant.
An EU funded project
managed by the European
Office in Kosovo
Rural Agricultural Advisory
Service of Kosovo
TOMATO PRODUCTION BEST PRACTICE DURING
THE FLOWERING PERIOD
MINISTRY OF AGRICULTURE, FORESTRY AND
RURAL DEVELOPMENT
DE-TOPPING
Cutting or pinching off the growing point of the tomato plant
induces it to focus all its energy on the flowers and/or existing
fruit clusters. This results in their earlier ripening, as well as
uniform fruit maturity. Maintain 5-10 fruit clusters for the whole
growing period. Each fruit cluster should have four or five fruit
of a similar size.
When the last fruit cluster has set, allow three leaves to grow
above it, and then cut or pinch off the growing point to promote
uniform fruit maturity. If you do not de-top, the plant will use its
energy for tomatoes that will not ripen, and provide less energy
for the market tomatoes that are available.
Implemented by CA 17 International in consortium with the
Chamber of Agriculture (France), Etcharry (France) and Novus
(Kosovo)