Effect of nitrogen and weed control on productivity of wheat

A field experiment was conducted during winter season of 2005–06 and 2006–07 to evaluate the effect of nitrogen levels and weed control on weed growth, productivity and economics of wheat. The treatments comprised of 4 levels of nitrogen, viz. 0, 40, 80, and 120 kg/ha in main plots and 5 weed control methods, viz. weedy control, 2,4-D Na 0.75 kg/ha as post-emergence, isoproturon 1.0 kg/ha as post-emergence, isoproturon 1.0 kg/ha + 2,4-D Na 0.75 kg/ha as post-emergence and weeding by Dutch hoe at 15, 30 and 45 days after sowing. Maximum density and dry weight were recorded with 120 kg N/ha and minimum under N0. Increasing levels of nitrogen from 0 to 40, 40 to 80 and 80 to 120 kg/ha increased weed density by 33.7, 39.9 and 47.3% and weed dry matter by 35.2, 24.9 and 13.5%, respectively while N up take by 68.8, 56.7 and 18.7% phosphorus 13.2, 4.6 and 4.4% and potassium 16.2, 7.0 and 8.7% over preceding lower levels. 120 kg N/ha recorded significantly higher grain (2.90 t/ha) and straw (4.6 t/ha) yield, net return (1 26,616/ha) and B:C ratio (1.52).