Effect of chemical weed control on weed parameters, growth, yield attributes, yield and economics in soybean (Glycine max).

An agronomic investigation to study the efficacy of different pre and post emergence herbicides and their combinations to control the weeds in soybean was conducted at the Agronomy Farm of Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola in randomized block design with eight treatments and three replications during kharif season of the year- 2012. Application of Imazethapyr @ 0.100 kg a.i./ha + Quizalofop ethyl @ 0.075 kg a.i/ha as PoE was found to be more efficient to control monocot and dicot weeds in soybean which recorded lowest weed density, dry matter and weed index. It also found superior in respect of various growth and yield attributes (viz. plant height, dry matter, number of pods per plant, 100 seed weight and seed yield per plant). The highest seed yield(24.46 q/ha) and straw yield of soybean and maximum gross return (Rs 81500/-) and net return (Rs 56269/-) were also recorded in Imazethapyr @ 0.100 kg a.i./ha + Quizalofop ethyl @ 0.075 kg a.i/ha as PoE with highest B:C ratio of 3.23. It was also found responsible for highest uptake of N, P and K by soybean crop and lowest uptake of these plant nutrients by weed plants.