Management of bacterial blight of cotton caused by Xanthomonas axonopodis pv. malvacearum

An experiment was carried out to see the efficacy of different chemicals and bioagents against bacterial blight disease severity (PDI) and disease incidence (PI). Significantly low disease severity and low disease incidence were recorded in treatment T4 i.e. copper oxychloride 0.25 % + streptocycline 100 ppm sprays to the tune of 11.83 per cent (PDI) and 19.36 per cent (PI) respectively as against the unsprayed control 27.56 per cent and 45.51 per cent respectively and obtained significantly higher seed cotton yield 2567.33 kg/ha followed by carbendazim 0.1 % + streptocycline 100 ppm. Amongst the antagonist tested against Xanthomonas axonopodis pv. malvacearum, Trichoderma hamatum was significantly superior in per cent reduction of mycelia colony diameter (mm) of pathogen at all the incubation periods tested. The next best antagonist noticed was T. harzianum and P. fluorescens. Per cent reduction in colony diameter (mm) of the pathogen after 3, 6 and 9 days of incubation in T. hamatum was noticed to the tune of 50.94, 48.03 and 44.12 per cent, respectively.