POST-HARVEST FUNGAL DISEASES OF PAWPAW ( CARICA PAPAYA L.) FRUITS AND SEEDS IN NIGERIA

Abstract

Post-harvest fungal diseases of pawpaw (Carica papaya L.) fruits sold in Mile 3 Market, Port Harcourt were investigated bi-weekly for sixteen weeks using the Standard Blotter Method. The following fungi were isolated from the tissues of diseased fruits: Fusarium solani, Phoma carica-papaya Aspergillus flavus, Aspergillus niger, Botryodiplodia theobromae, Cladosporium herbarum, Colletotrichum dematium, Fusarium moniliforme, Phomopsis carica-papaya, Penicillium sp., and Rhizopus stolonifer. Seeds of diseased fruits were also tested for health using the Standard Blotter Method and all the fungi isolated from the fruit tissues were found to be seed-borne except F. moniliforme. Pathogenicity test of all the fungi isolated from ripe fruit tissues and seeds were carried out on mature green pawpaw fruits and they were found to be pathogenic. Rhizopus stolonifer and F. solani caused the greatest rot on the fruits. Agar discs (3.0mm, diameter) of these fungi were subjected to hot water treatment at varying periods of time, (40°C for 30 mins., 50°C for 20 mins., and 60°C for 10 mins.) to determine the efficacy of the treatments on the pathogens. The hot water treatments could not eliminate the pathogens; instead their lineal growths on PDA medium were just inhibited, when compared with their controls. A first report of seed-borne fungi of pawpaw and their pathogenicity is provided. KEY WORDS: Pawpaw fruits, seed-borne fungi, pathosenicity test, hot water treatment. Global Jnl Pure & Applied Sciences Vol.10(1) 2004: 69-73