Dynamics of Weed Growth, N-Depletion and Yield Synthesis in Wheat as Influenced by Nitrogen Rates, Seed-Furrow Mulching and Weed Management under Late Sown Condition in North Bihar

Field experiments were conducted at the research farm of Rajendra Agricultural University, Pusa (Samastipur), Bihar during the rabi seasons of 1989–90 and 1990–91 to find out the dynamics of weed growth, N-depletion and yield synthesis in wheat as influenced by nitrogen rates, seed furrow mulching and weed management underlate sown condition. Weed count, weed dry biomass production, N-content and N-depletion by weeds increased with increasing levels of nitrogen and seed-furrow mulching with FYM and recorded the maximum values at N₁₀₀ and higher level of mulching (50 q/ha). Weed management practices (H.W. or herbicides) reduced crop weed competition and significantly lowered the weed count, weed dry biomass, weed growth rate and N-depletion by weeds. Isoproturon recorded higher weed control efficiency and significantly lower N-depletion by weeds. Significantly higher grain and straw yields were recorded at N₁₀₀, and higher level of FYM mulching (50 q/ha). Among the weed management practices, the values for these parameters were the maximal in hand weeded plot.