PREHARVEST AND POSTHARVEST PATHOGENS CAUSING FRUIT ROT IN MANGOSTEEN (GARCINIA MANGOSTANA)

The research determined the incidence of mangosteen (Garcinia mangostana) diseases in the field and postharvest in the East of Thailand. A number of diseases at varying severity were observed in the fruit orchards. Major fungal pathogens isolated from persistent sepals of mangosteen fruits aged 15-110 days and postharvest were Pestalotiopsis sp., Phomopsis sp., Lasiodioplodia theobromae, Colletotrichum gloeosporioides, Phoma sp. and Fusarium sp. Pestalotiopsis sp. Had the highest incidence, ranging from 41.1-74.4% in all fruit age. Fruit hardening occurred after infection especially young fruits. Postharvest fruits were found infected with Pestalotiopsis sp., Phomopsis sp. and L. theobromae, with 46.3, 22.5 and 19.1% incidence, respectively. The results suggest that the infection level at flowering stage may be earliest indicator of the incidence of postharvest fruit rot. Pestalotiopsis sp. and L. theobromae wound inoculated 2 mm into the fruit peel did not produce necrotic lesions on fruit surface; instead, small patches on the exocarp developed with mycelial growth.