Corynespora cassiicola the Causal Fungus of Target Spot of Papaya

Abstract

Corynespora cassiicola (Berk&Curt) Wei as the cause of leaf spot on papaya was first reported in Thailand in 1962. with increased plantings of papaya reflecting its increasing importance as a horticultural crop, the disease has been increasingly observed. All papaya plantation areas on teh provinces of Ratchaburi, Nakhon - Pathom, Rayong, Si Sa Ket, Chumphon and Nakhon Ratchasima have been noted to have the disease.
Symptoms of the disease commonly found on the leaves are also found on teh stems of affected plants. Eleven isolates of C. cassiicola obtained from naturally infected papaya leaves from different locations were morphologically tested. Koch's postulates carried out using 10 week old seedings inoculated with C. cassiicola conidia isolated from papya, tomato and sesame produced typical disease symptoms after 2-6 days for all inoculation attemtps.