Leguminous Vegetable Cultivation and Seed Production S ...

37 2 GREEN MANURE IN RICE FARMING
on soybean in storage. An intact seed coat is an effective barrier to infestations.
Soybean saponin extracts have been found to inhibit development of mungbeari
.
weevil and soybean almond moth. The saponins or their glucosides seem to produce
typical antibiotic symptoms (Sirisingh and Kogan 1982).
Future of seed production
Rapid advances in innovative breeding concepts and procedures will surely modify
concepts of crop varieties in the future ( Jensen 1 965). In soybean, there are blends,
mixtures of two or more pure lines, multiline varieties, and short breeding cycle
varieties ( less uniform )
; there is a potential for hybrids and genetically engineered
varieties. Some of these will not conform to the variety norm of purity, homogeneity,
and distinctness. Seed production and certification of these new products will be a
challenge ( Jensen 1965, Lafever 1985). The products will have greater variability for
plant type. The working philosophy of the future will emphasize performance over
uniformity. In such cases, seed certification probably should monitor seed quality
rather than distinctness.
Diagnostic tests for germination should include rapid vigor tests, disease tests,
seed treatment tests, and variety identification tests (Voris 1985). A simple,
inexpensive, and practical way to efficiently produce, harvest, thresh, clean, and
store good quality seed for small farmers is needed. The mechanisms involved in
protecting against insects using home remedies such as peanut oil need further
exploration. Research also should focus on the reasons for good seed quality with
small seeds and black seeds, with or without hard seededness. The role of the
environment at different stages of seed development and its relevance to seed
deterioration deserve further study. Because farmers are interested in storing seed
at most for 6-9 coo, research with that objective should be distinguished from
commercial concerns for longer term storage.
There is growing awareness, even in developing countries, of the need to obtain
quality seed for planting. Farmers consider it an important single investment that is a
prerequisite-if all other management inputs are to pay off. But both government and
private industry are unable to meet the demand or provide good quality seed. The
price of certified seed is almost double the price of regular seed ( in Thailand, regular
seed costs US$1.40/kg; certified seed costs $3.0/k p )(Potao 1987). However, the
government offers subsidies or other means of obtaining quality seed. Governments
also should encourage the private seed industry to meet local demand without
unduly exploiting the farmers.