In vitro antagonism of Colletotrichum falcatum by rhizospheric Trichoderma spp. isolated from sugarcane ecosystem

Abstract

Red rot of sugarcane caused by Colletotrichum falcatum is one of the most destructive diseases affecting sugarcane productivity worldwide, particularly in major sugarcane growing regions of India. The present investigation was undertaken for in vitro evaluation of the antagonistic potential of rhizospheric Trichoderma spp. isolated from sugarcane ecosystem against virulent pathotypes (Cf-07 and Cf-08) of C. falcatum. Soil samples were collected from rhizosphere healthy sugarcane plants from Pusa and Harpur Jhilli blocks of Samastipur district, Bihar. A total of 54 Trichoderma isolates were obtained, out of which 35 isolates were selected based on morphological and cultural characteristics. The antagonistic activity of these isolates was assessed using dual culture technique. Among the isolates obtained from Pusa block, isolate T SR 11 exhibited maximum inhibition of pathogen growth showing 92.11% and 92.22% inhibition against pathotypes Cf-07 and Cf-08, respectively, which was significantly higher than Trichoderma asperellum (positive check). Similarly, among isolates obtained from Harpur Jhilli block, isolate T HJ 7 recorded highest inhibition of 88.77% and 87.84% against Cf-07 and Cf-08, respectively, which was at par with the positive check. The results indicated significant variability among different Trichoderma isolates residing in the rhizosphere of sugarcane crop. The study highlights the potential of native rhizospheric Trichoderma isolates as promising eco-friendly biocontrol agents for management of sugarcane red rot disease.