Effects of environmental conditions and pre-and post-harvest management on soybean and mungbean seed quality

1.Effect of date of harvest and benomyl fungicide on seed quality of mungbean (Vigna radiata): Seed quality of mungbeen (Vigna radiata) var. U-Thong 1 grown in rainy season, 1983 revealed that benomyl spraying had no significant effect on mungbean seed quality, and there was no interaction between benomyl and date of harvest. Mungbean seeds harvested after 70 DAP had a lower seed germination and percent clean and undamaged seed, and produced a higher percentage of split (crack) seed and fungirs infested seed. From experiment in dry season, 1989, it was found that seed germination and seedling dry weight of seed harvested at 80 DAP were lower than of seeds harvested at 65 DAP. Seed damage (percent by weight) increased with time of harvest. It can be concluded that seeds produced in rainy season bad a lower quality than seeds produced in dry season, and the time of harvest for mungbean seed production should not be later than 70 DAP. 2.Effect of paclobutrazol on yield and seed qualty of mungbean (Vigna radiata (L.) Wilczek): Pod number per plant and seed yield (kg/rai) were significantly increased by paclobvtrazol (23 and 16 percent over the control, respectively). Paclobutrazol had no effect on node number and branch number per plant in mungbean, although there was a tendency in reducing plant height at harvest. Paclobutrazol tended to delay leaf senescence and seed desiccation during plant maturation while seed germination was not affected by paclobutrazol Among U-Thong 1, KPS 1, KPS 2 and Chainat 60 varieties KPS1 showed higher pod number per plant while Vthong 1 demonstrated a greaster vegetative growth than the other 3 varicties. However, there was no significant differences between varieties in terms of seed yield. KPS 2 produced the highest quality seed in this study. 3.Study on germinability, vigour and storability of seeds of 18 soybean lines: It was found that seed germination of 28 Soybean lines varied from 54-94 percent and they were divided into 3 levels of germinability. By considering initial seed germination together with another 2 tests, it revealed that KUSL 10006, SJ 4, SJ 5, KUSL 2004, KUSL 20043, KUSL 20050, CM 001-1 and 8122-7 were the soybean lines that produced high quality seed while cm 60, KUSL 10001, KUSL 10009, SK1 and LN 14 showed the poorest quality. The rest, ie. KUSL 20010, KUSL 10008, KUSL 30006, KUSL 10002 and KUSL 20018 could be judged as medium quality. According to the seed storability indices which were estimated after 3 months of Storage, it was found that 8122-7, KUSL 20043, KUSL 20004, KUSL 20010, KUSL 10002 and KUSL 20018 seemed to be interesting lines in terms of sed storability.