Abstract

                                A study was undertaken at Agricultural College & Research Institute, Coimbatore during Summer and Kharif seasons of 1994 to investigate the effect of three levels of plant densities with various weed management methods in Soybean. The results revealed that the weed density significantly reduced in the higher plant density of 6.66 lakh plants ha in both the seasons. Among the weed management methods, pre-emergence application of alachlor 1.25 kg ha-1 hand weeding (40 DAS) and hand weeding twice (20 and 40 DAS after sowing) have considerably reduced the weed population and enhanced the grain yield. However, hand weeding twice had exhibited similar effect as that of alachlor 1.25 kg ha-1 + hand weeding (40 DAS) in suppressing the weed population at 40 DAS. The yield attributes like number of pods per plant, number of seeds per pod and test weight of the seeds were greatly influenced at lowest plant density of 3.33 lakh plants ha-1, however it was comparable with 4.44 lakh plants ha in registering the test weight. There was significant increase in yield of the crop under 4.44 lakh plants ha-1.

Key words : Weed management, Plant density. Weed population and Yield attributes