Weed management in Bt cotton through pre-sowingapplication of pendimethalin capsulated suspensionand emulsified concentrate formulations

Abstract

A field experiment was replicated thrice in Randomized Complete BlockDesign at the Main Agricultural Research Station, University ofAgricultural Sciences, Dharwad on medium black soil during kharif2015-16 to study the effect of pre-sowing application of Pendimethalincapsulated suspension (CS) and emulsified concentrate (EC) formulationagainst weeds in Bt cotton. There were 10 treatment combinationswhich consisted of Pendimethalin 37.8 CS @ 500, 700 and 900 g a.i. ha-1pre-sowing application (2-3 days) followed by POE (post emergent)of Quizalofop ethyl 5 EC (50 g a.i. ha-1 at 30 DAS) and Pendimethalin30 EC @ 1.0, 1.5 and 2.0 kg a.i. ha-1as pre-sowing application (2-3days) followed by POE Quizalofop ethyl 5 EC (50 g a.i. ha-1 at 30DAS) in comparison with, recommended package of practices (3intercultivations at 15 days intervals and one hand weeding),weed freecheck, weedy check and farmers practices (one hand weeding at 15days after sowing (DAS) and one intercultivation at 20 DAS). Theseed cotton yield differed significantly among different herbicideapplications, the pre sowing application of Pendimethalin 37.8 CS @900 g a.i. ha-1 followed by POE application of Quizalofop ethyl 5 EC(50 g a.i. ha-1 at 30 DAS) recorded higher seed cotton yield (31.28 q ha-1),yield per plant (146.06 g) and stalk yield (39.91 qha-1). Among herbicidetreatments, higher gross return, net return and BC ratios recorded withpre-sowing application of Pendimethalin 37.8 CS 900 g a.i. ha-1 followedby Quizalofop ethyl 5 EC (50 g a.i. ha-1 at 30 DAS) (`140700, 96147and 3.2, respectively)