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% SLand 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.