Management of cotton boll rot complex through fungicides and bioagents

Abstract

Boll rot complex is one of the major diseases of cotton which is responsible for loss of yield and quality. Anexperiment was conducted at Agricultural Research Station, Dharwad farm, University of Agricultural Sciences, Dharwadduring kharif 2017 under rainfed conditions to know the efficacy of 7 fungicides and 2 bioagents for managing boll rotcomplex of cotton. Two control plots viz., one with the insecticide spray alone and the other with no spray weremaintained. The experiment was laid out in replicated trial of randomized block with 11 treatments. The study revealed thatamong the treatments evaluated, trifloxystrobin 25% + tebuconazole 50% WG at the rate of 1.0 g/ lit (8.97 PDI), pyraclostrobin5% + metiram 55% WG at the rate of 3.5 g/ lit (11.37 PDI) and tebuconazole 25.9% EC at the rate of 1.0 ml/ lit (12.69 PDI)were found very effective against the disease as they reduced the severity of the disease and enhanced the yield. Maximumyield of 14.11 q/ ha was recorded in the plots treated with trifloxystrobin 25% + tebuconazole 50% WG at the rate of1.0 g/ lit. Spray of biocontrol agents also reduced the severity of disease and increased the yield significantly over thecontrol. Tebuconazole 25.9% EC at the rate of 1.0 ml/ lit was found economical with the highest B: C ratio of 1.52:1.However, trifloxystrobin+ tebuconazole (1.43:1) and pyraclostrobin+ metiram (1.43: 1) may be recommended as thecomponents in integrated disease management of cotton, as the combi products are broadspectrum and can take care ofother foliar diseases of Bt cotton than the solo products like tebuconazole alone