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This study evaluated threeTrichodermastrains (T. harzianumTR05,T. virensTR06 andT. asperellumTR08) originating from Bangladesh as potential biological control agents against collar rot of tomato under greenhouse conditions. After seed treatment with TR05, a disease incidence of collar rot (5.36%) was lower than for TR06 (34.2%) and TR08 (20.8%). Germination percentage of tomato was highest for TR05 (90.3%). In soil treatment, inoculation with TR08 resulted in the lowest disease incidence (9.78%), and the disease incidence was statistically no different from that for TR05 (16.4%). Thus, TR05 and TR08 have potential as biological control agents of collar rot in tomato. [ABSTRACT FROM PUBLISHER]

NineteenTrichodermaisolates, collected from different locations in Bangladesh, were characterised through phenotypic, biochemical and molecular means. Besides, they were assessed for their antifungal actionin vitro. The isolates were divided into three groups:T. asperellum,T. virensandT. harzianum. A dual culture assay and a culture filtrate assay against 6 phytopathogens revealed that 9 of the 19 isolates showed significant antifungal activities. The isolateT. harzianumTR05 showed the highest inhibition againstFusarium oxysporum,Rhizoctonia solani,Fusarium circinatum and Phomopsis vexans, followed byT. asperellumTR08 andT. virensTR06. TR08 had the highest inhibition againstSclerotium rolfsiiandPythium aphanidermatum, followed by TR05 and TR06. These findings were in agreement with their activities of extracellular hydrolytic enzymes, including chitinase, β-1,3-glucanase, and proteinase. Our results suggest that isolates TR05, TR06 and TR08 have the potential to be effective biocontrol agents against the phytopathogenic fungi. [ABSTRACT FROM PUBLISHER]