The objective of present study was to evaluate the relationship between different planting dates, densities and cultivars on soybean seed germination and vigor of seeds from plant growing in the field. Seeds of two soybean cultivars (Epps, [MG] V and Williams 82, [MG] III) were produced in the field from four planting dates and three planting densities in Peshawar, NWFP-Pakistan during 2000 and 2001. Brown (mature) pods were harvested, threshed and all shriveled and abnormal seeds were removed before determining standard germination and other vigor tests. Standard germination and other vigor tests decreased linearly (R2 = 0.53) from early planting dates to delay planting dates. Similar trend of decrease was observed from low planting density to high planting density. The decrease in AA was curvilinear (R2 = 0.78) and germination reached 15% in May planted crop. Seeds of Williams 82 was more sensitive to high temperature stress than seeds of Epps and seed vigor (AA) were much more sensitive to high temperature stress than was standard germination. Present findings support the results of experiments in controlled environments by demonstrating that high temperature during seed filling in the field, without seed infection with P. longicolla or physical injury, reduced soybean seed germination, vigor and all quality parameters of soybean seed under temperate environment.
Amir Zaman Khan , H. Khan , Adel Ghoneim , R. Khan and Azza Ebid , 2007. Seed Quality and Vigor of Soybean as Influenced by Planting Date, Density and Cultivar under Temperate Environment. International Journal of Agricultural Research, 2: 368-376.