Field Plot Screening of Antagonistic fungi Used for Biocontrol of Tomato Root and Stem Rot Caused by Sclerotium rolfsii

Abstract

Thirteen isolates of Trichoderma spp. and a single isolate of Penicillium sp. capable to control tomato stem rot caused by Sclerotium rolfsii under lath house test were screened for antagonistic activity against S. rolfsii under field plot condition. All test fungi were cultured on autoclaved sorghum seeds and prepared in powder formulation by using diatomite as a carrier. Mixture of fungal powder preparation, rice bran and organic compost in the ratio of 1:5:25 by weight was applied around the basal stem of 68-day-old tomato plants grown in natural field plots. All treated and non-treated (control) plants were inoculated with S. rolfsii-colonized sorghum seeds supplemented with rice bran. Ten isolates of Trichoderma spp. and a single isolate of Peinciilium sp. significantly (P=0.05) reduced disease incidence as compared to the control. Surviving plants of ten Trichoderma and single Penicillium treatments ranged from 26 to 63% over a control. Yields (fruit weight) of tomato plants treated with Trichoderma isolates T-21, T-23, T-31 and T-34 were significantly higher than the control.