10. SEEDS

10.7 Seed extraction

After collection, seeds should be extracted. The methods for this vary according to the seed type.

Pods, cones and certain other types of fruits, e.g. of Croton spp., can be dried in the sun until they split open. When they begin to open, the fruits can be shaken or beaten to remove the seed. This can be done by placing the drying pods or capsules in a sack and beating the sack with a stick (threshing). There are some pods for which this method is not appropriate, e.g. Prosopis spp. and Piliostigma thonningii do not easily split open when they are dried. Such pods either have to be mechanically opened, which is cumbersome, or alternatively the whole pod can be sown.

Figure 10.3 Methods of seed extraction

Seeds which are in fleshy fruits should also preferably be extracted before sowing. This is best done by soaking in water for a day or two until the fruits start to ferment or decompose. It is generally recommended to extract the seeds from fleshy, pulpy fruits rather than to dry the fruit since dried fruit pulp normally inhibits germination to some extent.

After seed extraction, the seed should be separated from the husk, fruit pulp, etc. The method for doing this may vary according to the nature of the seed. Sometimes wind can be used, or the seed can be sieved out, or simple mechanical separation may do.