Authors:D. Mohanraj, P. Padmanaban and M. Karunakaran
A phytotoxin produced by the sugarcane red rot fungus, Colletotrichum falcatum Went. was partially purified and its effects studied on sugarcane callus development, plantlet differentiation and shoot growth in tissue culture. The findings indicate that all the above attributes were markedly reduced by the fungal toxin. Potential for the possible use of the toxin to produce red rot resistant sugarcane genotypes by pathogen toxin induced somaclonal variation is examined.
Authors:P. Malathi, P. Padmanaban, R. Viswanathan, D. Mohanraj and A. Ramesh Sundar
The control of sugarcane red rot was studied in model experiments with carbendazim and thiophanate methyl. In axenic cultures carbendazim inhibited the pathogen more efficiently than thiophanate methyl (MIC 1 and 100 mgL-1, respectively). However, under greenhouse conditions, the reverse picture was revealed. Carbendazim, the metabolite of thiophanate methyl, exhibited lower efficacy against red rot disease than its precursor. Fungicides applied before infection reduced the disease incidence and improved both germination of setts and plant survival. Soaking of sugarcane setts in a 0.25% suspension of fungicides for 24 h before planting was found to be more effective in controlling debris-borne infection than soaking for 1 h period at elevated doses. The persistence of effects both on disease incidence and on promoting plant growth can be observed up to 60 days after planting (DAP).