Vol. 11, Issue 3 (2022)

Author(s):
Sadhna Chauhan and Rajesh Pratap Singh

Abstract:
Minimum inhibitory concentration (MIC) is defined as the minimum concentration of a compound that will result in the inhibition of growth of a microorganism. These are principally used to confirm resistance in chemical fungicides, but most often as a tool to determine the in vitro efficacy of new fungicides as well as antibiotics. In this study, four fungicides viz. Carbendazim 50% WP, Azoxystrobin 11% + Tebuconazole 18.30% SC, Tebuconazole 50% + Trifloxystrobin 25% WG (at 1, 2, 4, 6, 8 and 10 ppm concentration) and Azoxystrobin 18.2% + Difenoconazole 11.4% SC (at 10, 12, 14, 15, 20, 25 and 30 ppm concentration) were evaluated against Rhizoctonia solani causing banded leaf and sheath blight (BLSB) in maize for determining their minimum inhibitory concentrations (MICs) in vitro using poison food technique. All the tested fungicides exhibit variable response in inhibiting the mycelial growth of the fungus. Among all the tested MICs fungus proved highly sensitive to Carbendazim 50% WP at 6 ppm concentration, Azoxystrobin 11% + Tebuconazole 18.30% SC and Tebuconazole 50% + Trifloxystrobin 25% WG each at 10 ppm concentration and Azoxystrobin 18.2% + Difenoconazole 11.4% SC at 14 ppm concentration with 100% growth inhibition. Such studies can be helpful in exploring R. solani for determing its resistance development to specific fungicides and thereby devising suitable management strategy against BLSB in maize.