Influence of Pre and Post-emergent Applied Herbicides on Weed Dynamics, Nutrients Uptake and Yield of Pigeonpea (Cajanus cajan L.)

Abstract

Field experiments was conducted during kharif season of 2011–12 at G.B. Pant University of Agriculture and Technology, Pantnagar (Uttarakhand), India to study the effect of pre and post-emergent applied herbicides on dynamics of weed flora in the pigeonpea field. The results indicated that the integration of post-emergence application of imazethapyr 75 g a.i. ha^-1 10 DAS+quizalofop ethyl 50 g a.i. ha^-1 PoE 15 DAS followed by 1 HW 50 DAS and tank mix application of imazethapyr 75 g a.i. ha^-1 +quizalofop ethyl 50 g a.i. ha^-1 PoE 15 DAS followed by 1 HW 50 DAS proved effective in reducing the density and dry weight of Echinochloa colona,Cynodon dactylon, Cyperusr otundus and other weeds species. In over all reducing total weed density and dry weight. It was also found that these herbicides treatments were also effective in reducing NPK uptake by weeds, and increasing the weed control efficiency and weed index. The similar trend was also observed in grain and stover yield of pigeonpea under these treatments. Therefore, it may be concluded that a post-emergence application of imazethapyr 75 g a.i. ha^-1 10 DAS+quizalofop ethyl 50 g a.i. ha^-1 PoE 15 DAS followed by 1 HW 50 DAS, may be an alternative to two or more hand weeding for efficient control of weed flora, reducing nutrient uptake by weeds and achieving more grain yield of pigeonpea.