| Longan (Dimocarpus longan Lour.) is a popular subtropical fruit. Longan fruit metabolize vigorously after harvest since it matures during the hot summer season and deteriorate rapidly because of microbial decay and pericarp browning. However, with increasing resistance to the use of chemical, there is a need to finding alternative non-chemical treatments. In this study, we found that post-harvest decay of longan fruits were mainly caused by the infection of latent fungal pathogens after isolation of fungi from different mature stage and different production area of longan fruits. Furthermore, we studied biological characteristics of two latent pathogenic fungi mainly cause decay of post-harvest fruits and non-chemical method controlling the post-harvest longan fruit diseases. The results were as follows:(1) Isolation and identification of fungal pathogens latent-infected in longan fruits: There were many fungi lies on surface of decaying longan fruits. Such as Penicillium sp., Rhizopus sp., Aspergillus sp., Nimbya sp., Alternaha sp., Pestalotiopsis sp., Cladosporium sp., Fusarium sp., Colletotrichum sp.,Thichothecium sp., Peronophthora sp., Geotrichum sp., Phomopsis sp. and yeasts. But there are only a few fungal pathogens by isolated from heath longan fruits. Lasiodiplodia theobromae (Pat.)Griff. & Maubl. and Phomopsis longanae Chi. are two mainly latent pathogens during premature and post-harvest stage. By isolation of fungi from different mature stage and different production area of longan fruit, It was suggested that P. longanae could cause infection at the flowering stage, however L. theobromae mainly started to infect the longan fruits at the fruit enlargement stage.(2) The efficiencies of controlling dormant infection of fungal pathogens by paper-bag packing pre-matured longan fruits: the average incidence of diseases of longan fruits that had packed by paper-bag during pre-matured was 20% compare with... |
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