Pathogenic variability of Phaeoisariopsis personata (Berk. & Curt.) V. ARX. in groundnut (Arachis hypogaea L.)

Resistant and susceptible groundnut genotypes obtained from the Institute o f Plant Breeding (IPB), UPLB, Philippines and from ICRISAT, India, were tes ted against the most virulent and the least virulent isolates of Phaeoisari opsis personata. The resistant genotypes had delayed symptom appearance for an average of 2.09 days, reduced lesion number per leaflet by 42.41%, lesi on size by 50%, spore per lesion by 88.60% and caused defoliation by 64.83% compared to the susceptible genotypes. Resistant and susceptible genotypes delayed symptom appearance for 1.25 days, reduced lesion number per leafle t by 28.84%, lesion size by 20.96%, spore production per lesion by 48.12% a nd caused defoliation by 27.41% when inoculated with the least virulent iso late compared to the most virulent isolate.