Post-Emergence Chemical Weed Control in Kharif Greengram (Vigna radiata)

An experiment was carried out during kharif 2018 to evaluate the effect of imazethapyr and pendimethalin on the growth and productivity of greengram at the instructional farm of Krishi Vigyan Kendra Langroya, district Shaheed Bhagat Singh Nagar. The experiment was laid out in Randomized Complete Block Design (RCBD) consisting of 6 treatments viz, T₁-pendimethalin @ 750 g a.i.//ha as pre-emergence; T₂pendimethalin @ 750 g a.i.//ha as pre-emergence followed by imazethapyr @ 37.5 g a.i.//ha at 25–30 DAS; T₃-pendimethalin @ 750 g a.i.//ha as pre-emergence followed by imazethapyr @ 50 g a.i.//ha at 25–30 DAS; T₄-pendimethalin @ 750 g a.i.//ha as pre-emergence followed by imazethapyr @ 62.5 g a.i.//ha at 25–30 DAS; T₅-pendimethalin @ 750 g a.i.//ha as pre-emergence followed by imazethapyr @ 75 g a.i.//ha at 25–30 DAS; T₆-weed free (manual weeding) with four replications. Post-emergence application of imazethapyr @ 75 g a.i./ha after pre-emergence application of pendimethalin @ 750 g a.i./ha resulted in significant decrease in weed density, weed dry matter, highest weed control efficiency and weed control index relative to other herbicide treatments. Post-emergence application of imazethapyr @ 62.5g a.i./ha resulted in significantly higher number of pods/plant followed by of imazethapyr @ 75 g a.i./ha. A non-significant difference between pod length, 100 seed weight and seeds/pod were observed. Form the study it can be concluded that farmers can go for pre-emergence application of pendimethalin @ 750g a.i./ha followed by post-emergence application of imazethapyr @ 62.5g a.i./ha at 25–30 DAS for better weed management and higher seed yield.