Abstract
Eight antagonistic fungi; Chaetomium spp., Aspergillus versicolar, A. terreus, Talaromyces (Penicillium) wortmanni, Epicoccum sp., Trichoderma viride, T harzianum and T hamatum were isolated from sclerotia of R. solani infested tomatoes growing under greenhouse in Riyadh, Saudi Arabia. T hamatum, T harzianum, T viride and A. terreus were the most antagonistic against R. solani by 94.44, 93.89, 92.22 and 75.22% reduction in mycelia growth, respectively. Where, A. terreus and T viride were found to affect sclerotial viability of R. solani, caused 100% mortality of sclerotia. Greenhouse tests showed that the most effective treatment was the amendment of pathogen-infested soil by T hamatum and T viride which resulted in a disease severity of 12.50 and 12.90%, respectively compared to controls. Application of bioagents soil fungi significantly increased biomass of total fresh weight. The highest of biomass% (47.02) was observed in T harzianum and the lowest biomass% (2.86) was obtained with A. terreus.