Field resistance of sesame cultivars to Cercospora leaf spot induced by Cercospora sesame

During 1986 and 1988, 49 sesame cultivars were evaluated in the field at Samaru, Nigeria, for resistance to Cercospora leaf spot disease induced by Cercospora sesami Zimin. Disease severity scores showed that none of the cultivars was immune to the disease. More than 90% of the cultivars were either susceptible or highly susceptible to the disease. However, four cultivars, 65B-58, 60/2/3-1-8B, 69B-392, and 73A-96B, were found to be the most resistant. Late maturing and branched types were less affected by the disease than the early maturing and unbranched types. There was a high incidence of disease-induced leaf defoliation, especially amongst the early maturing cultivars.