Improving the identification, handling and storage of “difficult” seeds ...

The second problem associated with sun drying is that of erratic drying. During the dry season, sundrying
can be a realistic and predicable option. During wet weather farmers are forced to cover their
seeds. To avoid re-absorption of moisture by seeds at night, seeds should be transferred to airtight
containers after daytime drying.
Controlling pests and diseases
Resource poor farmers in Kenya use indigenous local products for the control of stored product
pests. The most commonly used products include:
▪ Ash
Farmers use various types of ash with the most common types include cow dung ash, sheep’s dung
ash, ashes collected from kitchens and ashes from specific plants such as neem tree and rice. Ash
has been reported to damage the cuticle of insects and to have a detrimental effect on egg
development (Grant, 1990).
▪ Smoking
Smoking acts not only as a seed storage and drying method but also a method to control insects.
The farmers themselves believe that the smoke has both an insecticidal and a repellent effect.
▪ Oil
In Kenya, Rheenen et al., (1983) found that an application of vegetable oil can be as effective as
chemical insecticides such as Lindane in protecting Phaseolus sp. or Vigna unguiculata seeds
against bruchid damage. The exact mechanism by which vegetable oils works is not completely
clear, but it appears that they affect egg laying, embryo and larva development on the surface of
seed. Vegetable oils cause the eggs and larvae to die before they can bore into the seed. The oil may
also cause suffocation on the insects thereby leading to death.
▪ Local plant extracts
Some of the indigenous local plant products that have been used by resource poor farmers to treat
their seeds during storage in Kenya include pepper, leaves of neem trees and Lantana camara. The
cost and availability of conventional insecticides and potential health hazards, both to the
environment and consumers, have necessitated continued use of these local plant products.
However, some of the materials provide unsatisfactory protection due to their limited efficacy.
▪ Mixing seeds with other non-plant based products
Other compounds that have been used by farmers in Kenya include kerosene, cement, and crushed
dry cells (Muasya et al., 2004).
Germination testing
Most farmers do not conduct any germination tests but they have an idea of how to select seeds
which most likely will have good germination capacity on planting. In Western Kenya, farmers use
the floatation method to select good quality seeds. The seeds are soaked in water and those that float
are discarded while those that sink are taken for planting. It has also been reported that a very small
proportion of farmers conduct germination tests in soil.
Constraints to in-situ conservation
Seed insecurity is caused by the following:
▪ Inadequate facilities and methods for seed storage thus leading to reduced seed quality and in
some cases loss of seed
▪ Inadequate skills in seed production and inappropriate on-farm post-harvest seed handling hence
compromising seed quality
▪ Inability of small-scale farmers to save seeds of some species due to their short-lived nature
▪ Inability of farmers to propagate some species due to seed germination problems especially
caused by seed dormancy
▪ Limited access to seeds of some species and appropriate varieties particularly by the resource
poor farmer