Efficacy of fungicides for the management of blast disease in rice seed production

Efficacy of different fungicidal sprays viz., carbendazim, mancozeb and tricyclazole were tested at three growth stages viz., fifty per cent flowering, milk/dough stage and physiological maturity for control of blast disease (Pyricularia grisea) in rice cv. Shalivahana at Ponnampet, Karnatak. The seeds produced were evaluated for various seed quality parameters including standard blotter test. Among the 10 treatment combinations, tricyclazole significantly increased number of tillers hill-1 (8.63), productive tillers hill-1 (8), number of filled spiklets panicle-1 (58) and germination (91 %). Whereas, number of chaffy seeds panicle-1 (14), infected seeds (1 %) and discoloured seeds (5 %) were reduced significantly. Spraying the crop, once at 50 per cent flowering + milk/dough stage and at physiological maturity recorded higher yield, quality and disease free seeds. Detection of seed borne and storage fungi by "standard blotter test" revealed that the percentage of seeds infected ranged from 4-63(%). Lowest infection (4 %) of samples by pathogens were recorded upon spraying of tricyclazole at all the three critical stages indicating it as potential chemical for controlling rice blast in seed production.