Exploring mycoparasitic potential of indigenous Trichoderma strains for the effective control of red rot disease in sugarcane

Colletotrichum falcatum is the most infectious pathogen of sugarcane which not only affects crop productivity but also lowers sugar recovery. Vegetative mode of propagation, long breeding cycle and anatomy of the plant further vulnarize it to pathogen infection. Owing to limitations in the control of pathogen with chemicals and conventional methods, mycoparasitic agents are more effective and efficient. Indigenous Trichoderma strains were used in these studies to see their impact on the control of this infectious pathogen under in vitro and in planta conditions. Both, the pathogen and Trichoderma isolates were purified and confirmed through molecular tools. Phylogenetic analysis was carried out to assess their genetic relatedness with other Colletotrichum species. In vitro dual plate culture assay was performed to assess mycoparasitic potential of all of the isolates. Trichoderma harzianum showed 85.5% inhibition in the growth of Colletotrichum falcatum whereas Trichoderma viride showed 81.1% growth inhibition. Further, in planta infection assay was conducted in red rot susceptible sugarcane genotype SPF-234 to seek for its potential to suppress pathogen infestation. Six months old plants were inoculated with C. falcatum alone and in combination with T. viride by plug method of inoculation. The infected canes were dissected out and observed for red discoloration. Both of the biocontrol agents inhibited growth of the pathogen yet T. harzianum appeared to be more effective for the control of aforementioned pathogen. Hence, Trichoderma harzianum isolates can effectively be used for the control of red rot infection in sugarcane leading to enhanced crop production and sugar recovery.