Effect of post emergent herbicides on yield and economics of blackgram (Vigna mungo. L)

The field experiment was conducted at the AICRP on Agro-forestry unit, University of Agricultural Sciences, GKVK, Bengaluru during kharif 2018 to evaluate the effect of weed management practices on weed dry weight, yield attributes, yield and economics of blackgram (Vigna mungo L.). Experiment consists of application of three post emergent herbicide molecules and their combinations (Fomesafen, Propaquizafop and Imazethapyr) at 20 DAS, two hand weedings at 15 and 30 DAS, weed free check and unweeded control were replicated thrice in RCBD. Major weeds observed were Achyranthes aspera, Ageratum conyzoides, Alternanthra sessilis, Borreria articularis, Cynodon dactylon, Dactyloctenium aegyptium, Echinochloa colonum, Eleusine indica and Cyperus rotundus. Post-emergent application of Fomesafen 18.8% SL @ 252 g a.i. ha-1 + Propaquizafop 5.83% EC @ 78 g a.i. ha-1 recoded a higher seed yield, net returns and BC ratio (1290 kg ha-1, Rs. 50,106 ha-1 and 3.27, respectively) and it was on par with Fomesafen 18.8% SL @ 210 g a.i. ha-1 + Propaquizafop 5.83% EC @ 65 g a.i. ha-1 (1248 kg ha-1, Rs. 48,030 ha-1 and 3.20, respectively) and two hand weedings at 15 and 30 DAS (1348 kg ha-1, Rs. 48,776 ha-1 and 2.60, respectively). Unweeded control recorded a lower seed yield (456 kg ha-1), lower net returns (Rs. 3,051 ha-1), lower BC ratio (1:15) and higher weed index (68.27%) compared to other treatments.