Isolation, characterization and management of brown spot disease of rice

Rice brown spot is the one of the most important disease of rice, a major cause of Bengal famine. The brown spot infected leaf samples were collected from five major rice growing location of Tamil Nadu. Based on the colony character, the pathogen was isolated and characterized into 3 groups; greyish with cottony mycelium mixture of grey and white mycelium with fluffy growth and greyish cottony mycelium with white spots. The condium was slightly curved, multi-septate and fusiform in shape. PCR based method was used for molecular characterization of the brown spot pathogen using universal primers ITS-1/4 and the partial sequences were obtained and submitted in NCBI database. In vitro and in vivo evaluation of twelve fungicides were carried, among the twelve fungicides, Hexaconazole 5% EC and Tebuconazole 25% + Trifloxystrobin 50% WP and Zineb 68% + Hexaconazole 25% WG were effective even at 50 ppm concentration with 100 per cent inhibition over control.