Vol. 12, Issue 10 (2023)

Author(s):
Soundarya Nayak, Gowdar SB, Ashwathanarayana DS, Amaresh YS and Badariprasad PR

Abstract:
Rice (Oryza sativa L.) is the principal staple food for more than two billion people, most of them live in rural and urban areas of tropical and subtropical Asia. Sheath rot caused by Sarocladium oryzae (Sawada) Gams and Hawksworth, has recently become a serious disease of rice when climatic conditions are favourable during flag sheath development. The present studies were undertaken to investigate the effect of various fungicides viz., three contact, three systemic and four combi-products against S. oryzae. Ten fungicides were tested against the rice sheath rot pathogen S. oryzae under lab conditions at various concentrations viz., 500, 750, 1000, 1250 and 1500 ppm for analysing the mycelial growth. The results revealed that, among the various contact fungicides, copper oxychloride 50% WP showed 100 percent inhibition of radial growth at all the concentration tested and minimum inhibition was recorded in mancozeb 75% WP (54.20%). Among the systemic fungicides, all three fungicides viz., carbendazim 50% WP, tebuconazole 60 FS, carboxin 75% WP exhibited 100 percent inhibition of mycelial growth at all the tested concentrations. Among the different combi-fungicides tested, carbendazim 50% + mancozeb 25%, flusilazole 12.5% + carbendazim 25% SE and carboxin 37.5% + thiram 37.5% WP fungicides were significantly superior by exhibiting 100 percent inhibition at all the concentration except hexaconazole 5% + captan 70% WP which recorded minimum inhibition of 78.30 percent.