Management of sugarcane smut (Ustilago scitaminea) with fungicides and bio-agents

The efficacy of nine fungicides with different concentrations was tested against Ustilago scitaminea, using spore germination inhibition technique. Tilt and Emisan (50 µg/ml) are proved to be the most effective against the spore germination of U. scitaminea, and they completely inhibit it. These are followed Score with 100 µg/ml after 24 h of incubation. Vitavax, Dithane M-45 and Antracol (200 µg/ml) seem to be next in order of efficacy. The efficacy of two bio-agents, Trichoderma viride and T. harzianum was evaluated in vitro by the dual culture technique. T. harzianum showed mycoparasitism and completely covered the growth of U. scitaminea within seven days of incubation. The above fungicides and bio-agent were also tested on smut inoculated sets in the field for bud germination and disease control. There was maximum increase (21.11%) in germination when Emisan of 0.25% was used, followed by T. viride (20.00%, 1 × 106 spore/ml) and Tilt (16.40, 0.2%). Regarding smut disease control, tilt (0.2%) controlled it the most by 97.27% followed by Emisan (0.25%) by 94.96% and T. viride (1×106 spore/ml) by 9.70%.