Submersion and soaking methods of processing finger millet seed in southern Tanzania

Finger millet (Eleusine coracana) is an important grain crop mostly processed after harvest in the normal dry threshing method just like other cereal crops. In Tanzania a unique wet processing method is being practiced by local farmers in the Southern highlands. The technique is less laborious than dry threshing and may be practiced as submersion or soaking. Nothing scientific has been investigated, however, concerning characteristics of the seed after been kept in wet conditions for a long period during processing. Samples of submersion and soaking-processed seeds were collected from farmers and tested for germination characteristics. An attempt was also made to imitate the submersion processing technique in the laboratory. Among collected seed samples submersion and soaking-processed seeds retained high germinability and were quicker in germination than dry threshed seeds in most instances. Proper aeration of the seeds during submersion is a critical prerequisite for subsequent good germination capacity. There is need for more investigation on specific physiological changes that appear to happen during wet processing and brewing quality of so-processed seed.