Chemical and biological management of bacterial blight of cotton caused by Xanthomonas axonopodis pv. malvacearum

摘要

Foliar sprays of copper oxychloride @ 0.2 per cent+streptomycin sulphate @ 100 ppm were proved effective to reduce the bacterial blight incidence (37.41%), intensity (13.08%) and with a maximum yield (1287 kg/ha), bioagent, Pseudomonas fluorescens Pf_1 @10 g/kg seed treatment followed by three foliar sprays 0.2% at 30, 60 and 90 days after germination were also equally effective in reducing the disease incidence (38.34%), disease intensity (14.54%)>and with a higher seed cotton yield (1252 kg/ha). These treatments were equally effective for managing the disease. The incremental cost benefit ratio (ICBR) was maximum (1:3.48) in P. fluorescens Pf, treatment, whereas it was low in chemicals (1:2.08). Maximum disease incidence (57.59%), disease intensity (32.84%) and minimum seed cotton yield was recorded in untreated control. Hence, the application of seed treatment of bioagent i.e. talc based formulation of P. fluorescens Pfj @ 10 g/kg seed followed by three foliar sprays of @ 0.2 per cent at 30, 60and 90 days after germination were found effective and economical for management of bacterial blight of cotton.