Ranjan, R KV, ARAVIND G2024-06-142024-06-142023M/PP/162/2021-22https://krishikosh.egranth.ac.in/handle/1/5810210446Sheath blight disease caused by Rhizoctonia solani Kühn is a major disease of rice which causes an economic yield loss. The present study was undertaken to know the status of sheath blight disease, effect of date of sowing on disease incidence with relation to weather parameters and to evaluate the new fungicides molecules, medicinal plant extracts and organic products against R. solani at different concentration in in vitro condition. InKharif 2022 survey conducted in Samastipur and Muzaffarpur districts of Bihar and recorded percent disease incidence (PDI) of Sheath Blight of rice. The survey data revealed that Birauli village of Samastipur recorded highest disease incidence with 27.33% PDI in hybrid rice. While lowest PDI recorded in the villageMirapur of Muzaffarpur district with 2.5% PDI. And this survey also reveals that highest percent disease incidence was observed in the villages of Samastipur district compared to the Muzaffarpur district. Study on effect of date of sowing on incidence of Sheath Blight of rice, to know the effective date of sowing of rice to tackle Sheath Blight of rice, crop was sown at three different dates that is early (15/06/2022), normal (30/06/2022) and late (15/07/2022). Maximum disease severity was observed in early sown crop with 15.7% followed by normal sowing (8.58%) and minimum was recorded in late sowing (4.3%). Hence late sowing emerged as effective date of sowing to minimize the severity of Sheath Blight of rice. Weather parameters played important role in Sheath Blight disease development in rice. Disease severity negatively correlated with maximum temperature and minimum temperature. And positively related with morning relative humidity and evening relative humidity. And rainfall is positively correlated with early sown and normal sown but negatively correlated with late sown crop. For the management of the Sheath Blight of rice, seven fungicides were screened at three different concentrations that is 100 ppm, 250 ppm and 500 ppm. Among them Pyraclostrobin 10% CS was most effective inhibiting 100% growth of pathogen at lowest 100 ppm concentrations followed by Propiconazole 25% EC inhibited 65.55% of growth of mycelia. Besides this six medicinal plant extracts were tested at 5% and 10% concentrations, among them, at 10% concentration of tulsi showed 100% inhibition followed by kalmeg and mandukaparni both showing 71.15% inhibition. In addition to that three organic products were also screened at 2% & 5% concentration, among them panchagavya was effective at 5% concentration with 100% inhibition.EnglishThesis