Effect of herbicides and nutrient management on weed flora, nutrient uptake and yield of wheat (Triticum aestivum) under irrigated conditions.

摘要

Isoproturon, clodinafop and sulfosulfuron alone at 750, 60 and 30 g/ha, respectively, and tank mixture of isoproturon at 500 g/ha+2, 4-D at 500 g/ha, isoproturon at 500 g/ha+clodinafop at 30 g/ha and isoproturon at 500 g/ha+sulfosulfuron at 15 g/ha were evaluated against mixed weed flora in wheat. All the herbicide treatments significantly reduced the dry weight of complex weeds, although they differed in their effect on weed species. While sulfosulfuron and clodinafop alone and as a tank mixture with isoproturon effectively controlled grassy weeds than all other herbicide treatments, the tank mix application of isoproturon at 500 g/ha+2, 4-D at 500 g/ha and isoproturon at 500 g/ha+sulfosulfuron at 15 g/ha were equally effective against broadleaf weeds. The broadleaf weeds being dominant in the experimental field, the overall weed density and dry matter production at different stages of crop growth were minimized by isoproturon at 500 g/ha+sulfosulfuron at 15 g/ha and isoproturon at 500 g/ha+2, 4-D at 500 g/ha. Uninterrupted weed growth depleted 20.97 kg N, 3.13 kg P and 26.94 kg K/ha, while it was lowest with isoproturon at 500 g/ha+sulfosulfuron at 15 g/ha. Maximum uptake of N (150.20 kg/ha), P (41.00 kg/ha) and K (194.14 kg/ha) by wheat crop was in plots treated with tank mixture of isoproturon at 500 g/ha+sulfosulfuron at 15 g/ha, while in weedy check plots N, P and K uptake by crop was 87.87, 23.82 and 118.04 kg/ha, respectively. Uncontrolled weeds in weedy check plots reduced wheat yield by 31.4% as compared to herbicide treated plots. Highest grain yield obtained with isoproturon at 500 g/ha+sulfosulfuron at 15 g/ha (58 q/ha) followed by isoproturon at 500 g/ha+2, 4-D at 500 g/ha (55.34 q/ha) was significantly higher than all other treatments. Among nutrient management treatments, application of 75% RDF+vermicompost at 1.5 t/ha and 50% RDF+vermicompost at 3.0 t/ha resulted in significant increase in weed dry matter, NPK uptake, chlorophyll and protein content and grain and straw yield over RDF alone.