Patogenicidade e agressividade de Curvularia eragrostidis em inhame (Dioscorea rotundata)

Abstract

The leaf spot of yam, caused by Curvularia eragrostidis, is one of the main diseases on this crop. The lack of information on pathogenicity and aggressiveness of the pathogen are limiting factors to the development of programs to control the disease. The aim of this work was to evaluate the pathogenicity and aggressiveness of C. eragrostidis isolates obtained from different commercial yam fields in the Recôncavo Baiano region in a detached leaf assay. From the 113 C. eragrostidis isolates obtained, 39 were evaluated for their capacity to induce disease in the host. The inoculation of the C. eragrostidis isolates was done in the abaxial side of the leaves with wounding. The first symptoms of the disease were recorded after one to six days of the inoculation. Among the 39 isolates of C. eragrostidis evaluated, two were not pathogenic when inoculated in detached leaves of yam. Different levels of aggressiveness were found among the pathogenic isolates as revealed by the evaluation of the area under the lesion progress curve. We conclude that there is variability among the epidemiological components within the C. eragrostidis isolates studied.