Symptomatology of leaf spot disease of cotton caused by Curvularia lunata (Wakker) Boedijn

Abstract

The Curvularia leaf spot is the most important and destructive disease of cotton. The research was conducted to prove Curvularia lunata as an Incitant of Curvularia leaf spot of cotton. Infected leaves with typical symptoms were subjected to isolation and purification. As a result, brown to brownish-black fungal colonies were found. The morphological study was carried out by using microscope, the spores of fungus found slightly curved or straight; mycelium was septate and brown to black in colour, and conidia was found 25-27×8-10 µm in size. The pathogenic nature of incitant was proved and typical symptoms such as small, brown to black in coloured spots were observed. Further, re-isolated pure culture resembled with original culture on the basis of their cultural characteristics. Hence it is identified as Curvularia lunata (Wakker) Boedijn - an Incitant of Curvularia leaf spot of cotton.