Vol. 11, Issue 3 (2022)

Author(s):
Gurumayum Robert Daniel, AK Tewari, Devanshu Dev and Pooja Upadhyay

Abstract:
The aim of present study was to evaluate the antagonistic potential of 6 Bacillus subtilis strains (PBBSR1, PBBSR2, PBBSR3, PBBSR4, PBBSR5 and PBBSR6 against 5 fungal phytopathogens viz. Drechslera oryzae, Fusarium monoliforme, Pythium sp., Sclerotium rolfsii, Curvularia sp. and to check the compatability between the B. subtilis strains and 10 commercially used fungicides. Dual culture assay between the B. subtilis strains and the fungal pathogens showed all the strains to be effective in inhibiting mycelial growth of the studied pathogens with formation of inhibition zone. However, among the 6 strains, 2 strains (PBBSR1 and PBBSR2) were found to be most efficient with consistent results of efficacy under dual culture assay. Further, strains PBBSR1and PBBSR2 were checked for their compatibility with 10 commonly used fungicides that are usually recommended for disease management under in-vitro condition. A total of 8 fungicidal concentrations (25, 50, 100, 250, 500, 1000, 1500 and 2000 ppm) were considered for the test. The compatibility study showed 5 fungicides viz. Carbendazim 50% WP, Hexaconazole 5% SC, Thiophanate Methyl 70% WP, Azoxystrobin 18.2% + Difenconazole 11.4% SC and Azoxystrobin 23% SC to be compatible with both PBBSR1and PBBSR2 strains.