Symptomatology of the leaf blight of periwinkle (Catharanthus roseus L.) G.don caused by Alternaria alternata (fr.) Keisslar

Abstract

Periwinkle (Catharanthus roseus L.), is an important medicinal and ornamental plant growing worldwide. Periwinkle plant is attacked by Alternaria alternata (Fr.) Keissler causing leaf blight. The disease starts as small light brown to dark brown lesions at margin and tip off the leaf extended inside. Spots enlarge and coalesce forming large patches on the leaf blade. Under favorable conditions the disease extents to leaf petiole.