Effect of bentazone Na Salt 48% Sl W/V against weeds in soybean and its residual effect on succeeding chickpea crop

Afield experiment wasconducted at MainAgricultural Research Station, Dharwad during kharif seasons of 2011 and 2012 to study the effect of Bentazone Na Salt 48% SL w/v against weeds in soybean and its residual effect on succeeding chickpea crop. The treatments consisted of application of Bentazone Na salt 48% SL w/v @ 720, 960 and 1200 g a.i./ha, Chlorimuron ethyl 25% WP @ 15 g a.i./ha, Fenoxypropethyl 9% EC @ 80 g a.i./ha, Imazethapyr 10% SL 100 g a.i./ha andweedy check. Common weed flora observed in the experimental field were Cynadon dactylon, Panicum isachne, Digitaria sanguinalis among the monocot weeds, Cyperus rotundus as sedge and Acalypa Indica, Digeria arvensis, Parthenium hysterophorus and Sida aculeate among dicot weeds. The results revealed that post-emergence application of Bentazone Na salt 48% SL w/v @ 1200 g a.i./ha recorded significantly lower weed count, weed dry weight/m2, higher weed control efficiency and seed yield (1788.50 kg/ha) compared to Bentazone Na salt 48% SL w/v @ 720 g a.i./ha and Weedy check. However, it was on par with Bentazone Na salt 48% SL w/v @ 960 g a.i./ha, Chlorimuron ethyl 25% WP @ 15 g a.i./ha, Fenoxypropethyl 9% EC @ 80 g a.i./ha, Imazethapyr 10% SL 100 g a.i./ha. Soybean growth, yield and yield attributing parameters followed the similar trend. Application of Bentazone Na salt 48% SL w/v @ 1200 g a.i./ha had no phytotoxicity effect on soybean and succeeding chickpea crop.