The Effect of Temperature and Relative Humidity on Pawpaw Fruit Rot in South-Western Nigeria

Fungi found associated with fruit rot of pawpaw (Carica papaya L. ) in South-western Nigeria includes Rhizopus nigricans, Aspergilus niger, Fusarium moniliforme, Curvularia lunata and Collectotrichum capsicis. All were pathogenic on the test pawpaw fruits varieties (Isolo, JS22 and Homestead) in this study. The most pathogenic being C. lunata followed by R. nigricans, while the least rot was induced by C. capsicis. Results reveal that optimum temperature for maximum rot, range from 30-35°C, while fruits stored above or below this temperature showed blemishes. The relative humidity for maximum rot in this research range from 60-80%. Pawpaw fruits stored well at relative humidity below 40%. Hence, 30-35°C temperature and 35-40% relative humidities are recommended for the control of these common pawpaw fruit rot pathogens.