Negi, H.S.Kumar, Pradip2021-07-232021-07-232020-12-04Kumar Pradip 2020. STUDIES ON EPIDEMIOLOGY AND MANAGEMENT OF ALTERNARIA BLIGHT OF MUSTARD. M.Sc. Thesis. 72p.https://krishikosh.egranth.ac.in/handle/1/5810170811The present investigation entitled “Studies on epidemiology and management of Alternaria blight of mustard” was carried out in the laboratory and farm of the Department of Plant Pathology, College of Agriculture, Banda University of Agriculture and Technology, Banda, UP during 2018-2020. After isolation and purification, the pathogenicity test of the pathogen (Alternaria brassicae) was conducted in pots. In screening of 32 oilseed brassicas varieties/lines of SBG-18 series, no germplasm was found to be immune or highly resistant, one germplasm was found as resistant, 5 germplasm were moderate resistant, 1 germplasm was moderate susceptible, 17 germplasm were susceptible and 8 germplasm were highly susceptible. Out of the 60 germplasm of the UDN-18 series, none was found as immune or highly resistant, whereas, 2 germplasm were found as resistant, 2 germplasm were moderately resistant, 8 germplasm were moderately susceptible, 47 germplasm were susceptible and 1 germplasm was found as highly susceptible. In epidemiological studies the first symptom of the disease in Varuna and Ganga varieties of Indian mustard appeared on 49th meteorological weak i.e. eight weeks after sowing during which the maximum average temperature recorded was 22.14ºC, minimum average temperature was 10.29ºC, average morning RH was 91.57%, average noon RH was 60.57%, average evening RH was 80.57% and total weekly rainfall of 19.2 mm was received. Per cent disease index of Alternaria blight of mustard was reported positively correlated with the average minimum temperature whereas, it was significantly negative correlated with all other parameters in both the varieties. Regression coefficient was significant at 5% level with Maximum Temp. and RH Noon whereas, it was significant with Minimum Temp. and RH Evening at 1% level for both Varuna and Ganga. Coefficient of determination (R2) of 0.812 and 0.818 was calculated in Varuna and Ganga, respectively. In Varuna and Ganga varieties of Indian mustard sown four times at seven days interval, lowest mean PDI of the disease (15.49 and 14.43%) was recorded from the 1st sown plots on 20th October, 2019 and the highest mean PDI of 28.57 and 26.71% was recorded from 4th sowing on 10th November, 2019 in variety Varuna and Ganga, respectively. Maximum mean yield of 19.18 q/ha was obtained from mustard crop sown on 1st date which significantly reduced with the delay in sowing and was minimum in 4th sowing (13.39 q/ha). Ganga variety resulted in more average yield (17.10 q/ha) as compared to Varuna (15.41 q/ha) which also differed significantly from each other. Minimum AUDPC of 1236.11 and 1146.28 was resulted in 1st sowing whereas, maximum AUDPC of 2007.72 and 1862.14 was resulted in 4th sowing of Varuna and Ganga, respectively. Among six different systemic and combination fungicides evaluated in vitro against Alternaria brassicae, propiconazole, hexaconazole and captan + hexaconazole were the most effective with 100 per cent mycelial growth inhibition in all the tested concentrations. Whereas, among three non-systemic fungicides, mancozeb was the most effective with 94.09 per cent average mycelial growth inhibition. During in vivo evaluation of nine fungicides, propiconazole resulted as most effective to reduce the disease severity of Alternaria blight to 17.84% followed by captan + hexaconazole (19.87%) and hexaconazole (20.20%) and these fungicides did not differ significantly with each other. Maximum yield was also obtained with propiconazole (21.56 q/ha) followed by captan + hexaconazole (20.26 q/ha) and hexaconazole (19.82 q/ha).EnglishThesis