Evaluation of fungicides, botanicals and bio-agents against Curvularia lunata, a causal agent of gain discoloration in rice

In vitro evaluation of four systemic fungicides revealed that the maximum inhibition of mycelial growth of Curvularia lunata was obtained from difenoconazole (98.80%) and propiconazole (98.10%) at 0.1 per cent concentration. Among the three non-systemic fungicides tested, mancozeb (98.80%) was found most effective followed by chlorothalonil (63.67%) at 0.2 per cent concentration. When the seeds were treated with fungicides, mancozeb gave highest seed germination (99.36%) and vigour index (1253.3) followed by difenoconazole with germination and vigour index of 94.88 per cent and 1232.4 respectively. Among the seven botanicals tested, garlic bulb extract (96.7%) was found to be effective at 10 per cent concentration followed by Eucalyptus leaf extract (93.45) in inhibiting the spore germination after four hours of incubation. Whereas, after 24 hours of incubation, leaf extract of neem (66.80%), eucalyptus (64.56%) and datura (64.20%) were found effective in inhibition of spore germination. Bacillus subtilis (97.77%), Trichoderma viride (96.44%) and T. harzianum (93.50%) among the bio-agents were found effective in inhibiting the radial growth of fungus. Whereas, seed treatment with T. viride recorded highest germination per cent (90.50) and vigour index 1170.00 followed by Bacillus subtilis.