Efficacy of chemicals for the management of discolored seeds from dirty panicle disease of rice

Abstract

Dirty panicle disease of rice is a complex due to infection of several mycoflora on the glumes, kernels or both with varied symptoms. Based upon the natural disease pressure, seeds of 3 varieties (IR 36, IR 64 and Kranti) were selected among the 12 commonly grown popular rice varieties with different levels of infections, as per the measurement scale (IRRI, 1998) during Kharif 2017 and 2018. Influence of chemical fungicides on the emergence of seedlings after 10day of sowing indicate that seed treatment with Carboxin + Thiram @ 0.15% exhibited 84% seed emergence as observed in IR 36 in seeds from Level 9 (more than 50% area discolored) as compared to untreated seeds (55%) from Level 0 (with no incidence) which had 88% emergence as compared to untreated seeds (82%). In seeds from L9 category, 52.72% increase was noticed over check, indicating the efficiency of fungicide combination, followed by 49.09% increase in emergence in diseased seeds treated with Carbendazim + Mancozeb (@0.15%), prior to sowing in field soil. Similar trend of enhanced emergence was noticed in variety IR 64 and Kranti in different levels of diseased seeds (L9 and L7) as compared to check. Seed treatment with copper oxychloride (@0.25%) also supported the higher emergence (83%) of seedling when the diseased seeds were treated and sown in natural field conditions as compared to check (55%).