In Vivo Screening of Antagonistic Fungi Used for Biocontrol of Sclerotium Stem Rot of Tomato

Abstract

Thirty-eight isolates of fungi antagonistic to Sclerotium rolfsii on potato dextrose agar were screened for the isolates capable to control tomato stem rot under lath house condition. The 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 base of 70-day-old tomato plant grown in 6-inch-clay pot. Fungal treated plants were inoculated with S. rolfsii colonized sorghum seeds supplemented with rice bran. Twenty-four fungal isolates including Trichoderma Gliocladium group (23 isolates) and single isolate of Penicillium sp. could control disease effectively by enhancing significant (P=0.05) number of surviving plants over the control. Many effective isolates reduced the numbers of sclerotia produced in soil by 13.2 to 95.9% when compared to the control. Average percent colonization of sclerotia with Trichoderma-Gliocladium group ranged from 5.7 to 26.8 at 10 days after incubation.