Division of Agronomy, Indian Agricultural Research Institute, New Delhi-110 012, India.
A replicated Held trial was conducted for two years to study the interactive effect of crop cultivar, seed rate and planting method on weed competition in winter wheat. Tall cultivar C-306 (mean height 110 cm) was able to suppress weeds better than Mexican semi-dwarf (65–80 cm) varieties HD 2329 or Kundan. The biomass of both Phalaris minor and Avena ludoviciana during 1990–91 and total weed biomass during both the years were significantly lower with tall cultivar C-306. The differences between HD 2329 and Kundan were, however, not significant. Neither bidirectional sowing against normal sowing, nor higher seed rate 150 kg/ha against 100 kg/ha (recommended) had any significant and consistent effect on weed growth. However, bi-directional sowing had significantly lower number of P. minor during 1989–90 and lower total weed biomass during 1990–91 as compared to its normal sowing. However, neither bi-directional sowing nor higher seed rate had any suppressing effect on A. ludoviciana in either year.
