Morphological Characterization and effect of Extracts of some Medicinal Plants on the Control of Colletotricum isolates Associated with Papaya Anthracnose Disease

Anthracnose disease caused by Colletotrichum species is a common postharvest disease of papaya fruit in Sri Lanka. The present study was conducted to determine the morphological and pathogenic variations, control of pathogen by the application of extracts of some medicinal plants and commercial fungicides and influence of culture media on the growth of Colletotrichum isolates associated with papaya anthracnose disease in Jaffna. Four Colletotrichum isolates (ISO1, ISO2, ISO3 and ISO4)were isolated from anthracnose diseased papaya (Carica papaya L.)fruits. Length, width and length:width ratio of the spores differed significantly among 4 isolates under light microscope. Among the different culture media tested, potato and beetroot dextrose agar media supported the growth of colletotrichum isolates significantly. When the PDA medium was supplemented with different plant sources, amount of mycelium in cowpea medium of 4 isolates was high compared to other media. ISO2 had dense mycelium in coconut oil seed cake medium. When compared to the control, cinnamon extract showed 11, 18, 9 and 14 percent of inhibition on the growth of isolates ISO1, ISO2, ISO3 and ISO4 isolates respectively. Clove extract completely inhibited the growth of isolates ISO1 and ISO2 and showed more than 50 percent of inhibition of growth of Isolates ISO3 and ISO4. Balloon vine extract showed significant inhibition in the growth of all four Colletotrichum isolates.