Abstract

Weeds are one of the most important factors that impose a great threat to the crop yield. In order to alleviate the weeds infestation in wheat (Triticum aestivum L.), the efficacy of various pre and post-emergence herbicides were tested during Rabi 2009 to 2010 at the Agronomic Research Area, University of Agriculture, Faisalabad, Pakistan. Results promised that clodinafop propargyl at 0.045 kg a.i. ha^-1 with maximum weed kill efficiency severely reduced the Avena fatua, Coronopus didymusand Melilotus indica population and dry weights compared with the control. Poor weed control was achieved using isoproturon at 1.5 kg a.i. ha^-1, isoproturon + diflufenicon at 0.98 kg a.i. ha^-1, fenoxaprop-p-ethyl at 1.00 kg a.i. ha^-1, tralkoxydim at 0.5 kg a.i. ha^-1  and chlorsulfuron at 0.074 kg a.i. ha^-1. Considering total grain and straw yields (4900 kg ha^-1); (6600 kg ha^-1), post-emergence clodinafop propargyl at 0.045 kg a.i. ha^-1causes an excellent increase in wheat yield (51.02%) over control. The highest spikebearing tillers (380.67), number of grains spike^-1 (47.28) and 1000-grain weight (49.38 g) were maximum in clodinafop propargyl at 0.045 kg a.i. ha^-1 as post-emergence treated plots. Based on the total wheat yield (grain and straw) obtained, isoproturon at 1.5 kg a.i. ha^-1, metribuzin + fenoxaprop-p-ethyl at 1.00 + 1.00 kg a.i. ha^-1, chlorsulfuron at 0.074 kg a.i. ha^-1 seemed someway phytotoxic to crop plants and depressed wheat yield. Hence, maximum net income of Rs. 136997 ha^-1 and maximum MRR (%) of 231316.6 was recorded with the use of clodinafop propargyl at 0.045 kg a.i. ha^-1 as post applied followed by carfentrazone ethyl (0.015 kg a.i ha^-1) with the MRR (%) of 89700.

Key words: Triticum aestivum L., Avena fatua, Coronopus didymus, Melilotus indica, clodinafop propargyl, weed control, herbicides.