Management of rice blast through new fungicidal formulations.

摘要

An in vitro study was conducted to evaluate the efficacy of 5 fungicides against rice blast pathogen, Magnaporthe oryzae, by poisoned food technique. The 5 fungicides were isoprothiolane 40% EC (Fuji-one) at 1, 1.5 and 2.0 ml, carpropamid 27.8% SC (Protiga) at 0.5, 1.0 and 2.0 ml/l, carbendazim 50% WP (Bavistin) at 0.75, 1.0 and 1.5 g/l, tricyclazole 75% WP (Beam) at 0.1, 0.6 and 1.0 g/l and propiconazole 25% EC (Tilt) at 0.5, 0.75 and 1.0 ml/l. Isoprothiolane at 1.5 ml/l recorded the maximum inhibition of mycelial growth (94.85%), followed by carpropamid at 1.0 ml/l (91.48%). A pot culture experiment was conducted to evaluate the 5 fungicides under greenhouse condition during rabi 2008. The most effective concentration of each fungicide was selected: isoprothiolane at 1.5 ml, carpropamid at 1.0 ml/l, carbendazim at 1.5 g/l, tricyclazole at 1.0 g/l and propiconazole at 1.0 ml/l. Foliar spraying of these chemicals was performed on 15 and 45 days after transplanting. Isoprothiolane significantly decreased the disease incidence (78.3%) and intensity (89.7%), followed by carpropamid (67.5 and 80.5% disease incidence and intensity, respectively) and carbendazim (56.9 and 73.1% disease incidence and intensity, respectively) over the control. The highest increase in grain and straw yield over the control was also recorded with isoprothiolane (22.5 and 28.3%), followed by carpropamid (20.5 and 25.7%).