Exploring biocontrol efficacy of Trichoderma spp. against Fusarium sacchari, the causal agent of sugarcane wilt

Wilt caused by Fusarium sacchari, is one of the major diseases of sugarcane (Saccharum spp.) causing considerable economic loss. Trichoderma spp. are important biocontrol agents which have been exploited effectively for the management of several plant diseases including wilt in various crops. The present study was undertaken to evaluate the antagonistic potential of Trichoderma spp. against sugarcane wilt pathogen. A total of 103 Trichoderma isolates comprising of 43 isolates established from sugarcane rhizosphere soils as well as 60 endophytic isolates established from root, leaf and stalk tissue of sugarcane were assessed for their antagonistic activity against F. sacchari by dual culture technique. We observed considerable variability in the inhibitory activity of the 103 isolates against the pathogen with inhibition ranging from 1.4% to 27.2% (SER42). In general, the endophytic Trichoderma isolates were more effective in inhibiting F. sacchari as compared to rhizospheric isolates in dual culture studies. Twelve most promising endophytic isolates were selected and assessed further for production of soluble inhibitory metabolites against F. sacchari by poison food technique. Variability was observed among the Trichoderma isolates in inhibition of F. sacchari growth with inhibition ranging between 1.4% (SER 43) to 44.2% (SER10). Overall, based on the in vitro assays, Trichoderma isolate SER 10, isolated from root tissue of sugarcane, was found most promising showing 44.2% inhibition of F. sacchari growth in poison food and 26.3% inhibition in dual culture studies. This is the first study reporting biocontrol potential of endophytic Trichoderma spp. against F. sacchari, a causative agent of wilt in sugarcane