ABSTRACT
Worldwide, postharvest losses of fruits and vegetables including citrus have been estimated at 25%, much of which is due to fungal and bacterial infections. In developing countries, postharvest losses are often severe due to the lack of adequate handling and refrigerated storage facilities. Postharvest decay of citrus fruits can be traced to infections that occur either between flowering and fruit maturity or during harvesting and subsequent handling and storage [43]. In the former case, preharvest infections are mainly caused by fungal pathogens such as Phytophthora species, Colletotrichum gloeosporioides, Botrytis cinerea, Diplodia natalensis, Phomopsis citri, and Alternaria citri. Stem-end infections
caused by Diplodia, Phomopsis, and Alternaria spp. remain quiescent until the fruit becomes senescent during prolonged storage [43,67]. Infections initiated by Phytophthora species occur during wet periods before harvest, and B. cinerea infections can occur in the orchard and during storage. On the other hand, postharvest infections that occur through surface wounds inflicted during harvest and subsequent handling are mainly caused by wound pathogens such as Penicillium digitatum, Penicillium italicum, Geotrichum citri-aurantii ( G. candidum), and Trichoderma viride. Among the wound pathogens, green mold (P. digitatum) and blue mold (P. italicum) account for most of the decay of citrus fruits worldwide. Sour rot caused by Geotrichum citri-aurantii is the most rapidly spreading postharvest disease and can be disastrous on fruit stored at temperatures above 10°C. Sour rot is most prevalent on lemon fruit, and the causal yeast-like fungus grows very slowly below 10°C.
