Biological Control of Sclerotium rolfsii, the Incitant of Groundnut Stem Rot

Efficacy of isolates ofTrichoderma and six fungicides in suppressing the growth of Sclerotium rolfsii. the groundnut stem rot pathogen, was tested under laboratory and glasshouse conditions. Trichoderma harzianum (73.37%) isolate was found superior than the T. viride (61.47) in reducing the colony diameter of S. rolfsii in dual culture technique. Among the fungicides tested, hexaconazole at 50 ppm caused 100 percent inhibition in S. rolfsii colony diameter and no inhibition in T. harzianum colony diameter in poisoned food technique. Some degree of tolerance to the same fungicide even at higher concentrations was also exhibited by T. harzianum. Hexaconazole and T. harzianum when evaluated individually and in combination for their efficacy under glasshouse conditions, T. harzianum alone proved a potential biocontrol agent for the groundnut stem rot pathogen.