Impact of different fungicides combination against brown leaf spot (Drechslera oryzae) of rice under the in vitro and in vivo

Abstract

Drechslera oryzae is the causal agent of rice brown spot disease and is responsible for significant economic losses. In order to control this disease, four fungicides were tested (carbendazim (Bavistin) 50 WP, carboxin (Vitavax) 50 WP, propiconazole (Tilt) 25 EC and hexaconazole (Contaf) 25 EC). The antifungal activity of the tested substances were investigated against D. Oryzae at different concentrations in vitro, as well as the efficacy of their exogenous application in controlling rice brown spot disease under field conditions. In vitro, propiconazole (Tilt) at 500 ppm maximum inhibited (96.58 %) the growth of D. oryzae. Under field conditions, seed treatment (ST) with Bavistin @ 0.2 g a.i/kg and foliar spray (FS) with Tilt @ 1ml/liter led to a significant reduction in disease severity (37.26%), in addition to a significant increase in the grain yield (55.49 %) and its components.