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PRINT ISSN : 2319-7692
Online ISSN : 2319-7706 Issues : 12 per year Publisher : Excellent Publishers Email : editorijcmas@gmail.com / submit@ijcmas.com Editor-in-chief: Dr.M.Prakash Index Copernicus ICV 2018: 95.39 NAAS RATING 2020: 5.38 |
Considerable losses caused by Alternaria blight on the oilseed crop rapeseed-mustard annually caused by Alternaria brassicae and Alternaria brassicicola. The study was conducted with the aim to assess tolerant sources of mustard lines against dark spot and to ascertain the optimum time of screening against the disease in Bihar region. We screened 50 lines of mustard against Alternaria blight under natural incidence in the year 2015-16 and 2016-17 using Area Under Disease Progress Curve (AUDPC). Visual estimation of disease severity was taken into consideration which was rated as no spot (0 %) on the leaves to more than 50 % spots on the leaves and the same was corresponded with the scale given by AICRP, 2011 ranging from 0 to 9. Germplasms showed moderate tolerance to high susceptibility. Based upon average AUDPC values for two years, 4 genotypes namely IC-399840, IC-312496, IC-342778 and IC-399802 showed lowest AUDPC values between 300-500 showing tolerance and 4 genotypes namely IC-426392, Varuna, IC-264131 and IC-491566were found to be highly susceptible with AUDPC values of 900-1100 to Alternaria blight. Disease response was recorded at three different time intervals in order to find out optimum time of screening of mustard lines against Alternaria blight. Results suggested that at around 76 DAS would be the optimum time for assessment of mustard lines against Alternaria blight. At this time period (76 DAS) the disease distribution among the germplasm lines screened were found to be normally distributed. The tolerant sources will be useful for selecting elite genotypes for managing Alternaria blight where mustard cultivation is prevalent as well as in breeding for improved genotypes against Alternaria blight.