Seed multiplication of improved open-pollinated varieties
Certified OPV seed
Farmers field
Production
Practical Action
Grain for food, feed and
sale
Shell, dry and then store
the seed under
appropriate conditions
Select good cobs for
seed from the middle of
your field
YOU MAY RECYCLE AN OPV FOR 1 - 3 SEASONS BEFORE BUYING NEW CERTIFIED SEED
How to harvest, dry, shell and store seed
At least 500 cobs should be harvested to ensure that the OPV maintains its own distinct
variability. It it recommended that farmers harvest their ears at grain moisture content of about 16-
20% (i.e, once the husks are dry) and sun dry to about 14 percent moisture content before shelling
for uniformity and quality (i.e, pest and disease-free not discoloured) and spread out in the sun for
drying. In most areas, farmers may sun-dry their seed to the desired, moisture content.
When syn-drying, ensure that the seeds are turned frequently to prevent "sun-burn" damage to the
embryo.
Most farmers sun dry their maize seed on a concrete slab, but if this is not available, the seed may
be spread out on black plastic sheeting. Shelling may begin once the grain has reached moisture
content of 14%. Farmers can apply the simple test to check whether the seed has reached 14%
moisture content. Shell a cob and mix about 100 kernels with one gram of salt; if the salt feels
moist after five minutes, then the cob needs to be dried further, but if the salt remains dry, then
the shelling can begin. Shelling by hand minimises seed damage, but if a mechanical sheller is
used, lower the settings (speed and severity of the threshing action). The shelled seed may then be
cleaned (winnowed), and any chipped or diseased seeds are removed by hand. The
seed is then treated with insecticides and fungicides against storage pests and fungi. When treating
pesticides, observe safety recommendations and ensure that the seed is uniformly treated. Treated
seed must never be used as food for animals or humans.
Conditions necessary for seed storage
It is important to know that seed is living and should be handled with care
• Healthy viable seed has about 10% water.
• Seed that is not dried well wiII rot whist in storage and will not germinate when planted
Good healthy seed
Small and shrivelled seed
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