Evaluation of Sesame Cultivars for Resistance to Cercospora Leaf Spot

Abstract

White leaf spot and angular leaf spot caused by Cercospora sesami and C. sesamicola respectively were monitored in plots of 16 sesame accessions at Siaya Farmers' Training Centre and Kibwezi Dryland Research Field Station, Kenya, to determine the relative susceptibility of these accessions. Increases in percentage diseased leaves and percent defoliation fitted the Gompertz model more closely than the logistic model. Rates of disease increase in inte:cted leaves and defoliation as well as areas under disease progress curves (AUDPC) varied among the 16 accessions. Accessions with larger AUDPC generally had faster rates of disease progress, although this was not always the ~ase. The most susceptible accessions to both diseases were SPS 071 and SIK 134. Accession SIK Ol3, and accessions SIK 031 and SPS 045 exhibited the least susceptibility to white leaf spot and angular leaf spot, respectively and are suggested as future standards for comparing reaction of other genotypes to Ce,.cospo/,a leaf diseases of sesame.