Management of emerged weeds in irrigated blackgram (Vigna mungo L.) through post-emergence herbicides

Field experiments were conducted during summer (April to June), 2010 and 2011 to study the effect of post-emergence herbicides in irrigated blackgram (ADT 5). Treatments comprising of three levels (50, 75 and 100 g /ha) of the post- emergence herbicides viz., Imazethapyr 10% SL and Quizalofop ethyl 5% EC were tested alone and in combination and compared with hand weeding twice on 15 and 30 DAS(farmers’ practice). Herbicides were sprayed on 15 DAS when the weeds were 2-4 leaves stage using flat-fan nozzle as per treatment schedule. The results revealed that minimum total weed density (8.44) and weed dry weight ( 27.2 g/m2) and higher weed control efficiency (84.4%) were obtained under combined application of imazethapyr and quizalofop ethyl as tank mix at 100 g /ha. However, this was comparable with application of both the herbicides at 75g /ha. Application of imazethapyr + quizalofop ethyl each at 75 g/ha registered significantly taller plants, higher dry matter production, more number of pods per plant, seeds per pod and higher grain yield (826 kg/ha), net returns (Rs.26621/ha) and benefit cost ratio (2.76). Thus, application of post- emergence herbicides imazethapyr + quizalofop ethyl each at 75 g /ha as tank mix on 15 DAS could be recommended for controlling of emerged weeds in irrigated blackgram.