Responses of Banana Cigar End Rot Pathogen to Chemical Fungicides

Abstract

In vitro study was carried out to investigate the responses of cigar end rot pathogen Musicillium theobromae (Turconi) Zare & W. Gams (syn. Verticillium theo­bromae E.W. Mason & S. Hughes) to chemical fungicides viz., Gemstar, Score, Tilt, Nativo, Tecto, Scholar and Aerosal. The efficacy of fungicides against cigar end rot was determined by measuring the colony growth, fresh weight of biomass and dry weight of biomass. Among seven fungicides evaluated against colony growth of M. theobromae, Tecto was highly effective followed by Aerosal and Score. Gemstar and Scholar appeared less effective than other fungicides. Although, all fungicidal treatments significantly reduced the fungus growth as compared to the control. The test pathogen M. theobromae failed to grow at all concentrations of Tecto; able to produce less growth at 0.1 ppm of Aerosal;  0.1 and 1 ppm of Score. Similarly, 100 and 1000 ppm of Tilt and Nativo appeared highly effective, as no growth of test pathogen was observed in these treatments. In regards of fresh biomass weight, all fungicidal treatments were effective in reducing the growth of M. theobromae in liquid culture. However, some were more effective than others. Fungicides like Score, Tilt, Nativo, Tecto and Aerosal were highly effective, their all concentrations produced no or negligible amount of fresh biomass of M. theobromae. Among different fungicides, Gemstar appeared significantly less effective than other fungicides; it’s all concentrations produced more or less fresh biomass of test pathogen. The test fungus was only able to grew at lower concentration (0.1 ppm) of Scholar, but produced negligible growth at 1 to 1000 ppm. In term of dry biomass production, most of the fungicides were highly effective against M. theobromae, produced either no or negligible dry biomass weight. However, few fungicides such as Scholar and Gemstar produced comparatively more dried biomass weight as compared to the control. Although, both of these fungicides produced significantly less dried biomass as compared to the control. The other fungicides like Aerosal, Nativo, Tecto, Score and Tilt were highly effective in reducing the dry biomass weight of M. theobromae. Further studies should be conducted to evaluate the effective fungicides like fungicides like Tecto, Score. Tilt, Nativo and Aerosal under field and storage conditions against cigar end rot of banana.