Studies on Cercospora Leaf Spot (Cercospora sp.) of Sesame

Among the foliar diseases, Cercospora leaf spot (CLS) caused by Cercospora sp. on sesame is the most important causing 22-53 % losses. The experiments were aimed at determining the prevalence of CLS in Taraba state, to determine the effectiveness of some plant extracts on the disease and to evaluate the reaction of some sesame varieties to the disease. Three sets of experiments involving field survey, field trials and screenhouse were carried out in 2011 and 2012. The results on survey revealed that, CLS was prevalent in all the areas visited. Field and screenhouse results revealed the effectiveness of plant extract (Ocimum and Chomolaena) and sesame varieties (E8 or NCRIBEN - 01M) on CLS. Crop loss studies revealed that plant extracts and Benomyl gave 15- 21 % reduction in severity of CLS and 24 - 57 % higher yields. From this study it was observed that the plant extracts (Occimum and Chomolaena) significantly reduced severity, while varieties (E8 and NCRIBEN-01M) were moderately resistant to CLS. Further investigation be carried out on bioactive constituents, method of extraction, frequency of application and different parts for plant extracts and more genotypes be incorporated.