Effect of herbicide combinations on weed dynamics, nutrient removal and yield of Wheat (Triticum aestivum L.) under north western plain zone

Abstract

A field experiment was conducted to study the effect of different weed control practices on weed dyanamics, nutrient uptake and yield of wheat (Triticum aestivum L.) in rabi seasons of 2010-11 and 2011-12 at Crop Research Centre of SVPUA&T, Meerut. The treatments 
comprising pre-emergence application of pendimethalin @ 1000 g/ha,  post  emergence application  of  isoproturon @1200  g/ha,  isoproturon+2,4-D @  1200+600  g/ha, isoproturon+metsulfuron methyl @ 1200+4 g/ha, fenoxaprop -p-ethyl @ 80 g/ha, fenoxa prop -p-ethyl +2,4-D @ 80+600 g/ha, fenoxa prop -p-ethyl +metsulfuron methyl @ 80+4 g/ha, clodinafop propargyl @ 60 g/ha, clodinafop propargyl+2,4-D @ 60+600 g/ha and clodinafop propargyl+metsulfuron methyl @ 60+4 g/ha were tested with weed free and weedy check. Among the herbicides, application of clodinafop propargyl+ metsulfuron (60+4 g/ha) though statistically on par with clodinafop propargyl+ 2,4-D (60+600 g/ha) reduced the weed population significantly than weedy check (97.2%), clodinafop propargyl alone (88.0%), fenoxaprop -p-ethyl  alone (83.0%), isoproturon alone (80.0%), isoproturon+metsulfuron (72.2%), pendimethalin (71.4%), isoproturon+2,4-D (53.8%), fenoxa prop -p-ethyl +2,4-D (53.8%) and fenoxa prop -p-ethyl + metsulfuron (40.0%) at 60 days after sowing stage. Among the herbicides, application of Clodinafop propargyl+ metsulfuron methyl (60+4 g/ha) as post emergence resulted into highest grain yield of wheat (49.28q/ha) which was on par with weed free and clodinafop propargyl+2,4-D @ 60+600 g/ha but statistically significant than rest of the treatments. Highest NPK uptake by grain and straw of wheat was recorded in weed free conditions compared to the herbicidal treatments, except lodinafop propargyl+metsulfuron methyl and clodinafop propargyl+ 2, 4-D. Highest removal of NPK (63.6 kg/ha) by weeds was recorded in weedy check whereas, the minimum NPK uptake (28.4 kg/ha) was noticed with the application of clodinafop propargyl+metsulfuron methyl due to efficient control of weeds (weed control efficiency 84.7%), which resulted in lowest weed dry matter in this treatments.