Inventory and incidence of plant diseases affecting vegetables in selected areas in the Visayas and Mindanao

Abstract

The identification of different vegetable diseases in a particular area is key to managing them. An inventory of diseases affecting important vegetables was conducted in selected areas in the Visayas, and Mindanao. The vegetable diseases were documented in Leyte, Samar, Biliran, Bohol and Claveria Misamis Oriental. Disease surveys were conducted and samples were brought to the laboratory for diagnosis. Pathogenicity tests were conducted for uncommon diseases and PCR and nest PCR assays were done for suspected Phytoplasma diseases. The most common and major disease that affect vegetables in Eastern Visayas is bacterial wilt caused by Ralstonia solanacearum which attacked tomato, pepper, eggplant, bittergourd and was also detected in a wilt infected lettuce. Downy mildew is another which affected bittergourd and pechay. Cercospora diseases were found to commonly affect pepper, eggplant, tomato and bittergourd. Phytophthora diseases were common in tomato, eggplant, pepper and pechay. Fusarium wilt had affected tomato and pepper in Claveria Misamis Oriental, but not common in Eastern Visayas. Emerging diseases were recorded such as Phytoplasma and Corynespora cassiicola which affected tomato and bittergourd, bacterial canker, bacterial speck, target spot, Septoria leaf spot and pith necroses were also found affecting tomato. Information gained from the inventory informed the production of extension materials aimed at farmers and farm extension officers.