A review of the management alternatives for controlling fungi on papaya fruit during the postharvest supply chain

Due to their flavor and nutritional characteristics, papaya fruit are consumed worldwide. As a tropical commodity, storage has serious limitations that result in their rapid deterioration and high incidence of rots during handling and storage. Postharvest handling of papaya differs according to destination. For export markets, there are well-defined postharvest steps established that include technologies that generally avoid disease incidence. For national markets, the postharvest chain is short but characterized by poor handling practices that can result in serious losses due to microorganisms. Anthracnose is considered the main postharvest disease, but development of other rots may also limit good fruit quality, as is the case with, among others, stem-end rots. Control of papaya rots for export markets are applied in accordance with import-export regulations, while for the national market it has typically relied on synthetic fungicides; however, due to their already known 'side-effects' on humans and the environment, other alternatives alone or combined should be tested in integrated technologies. We reviewed the available literature on different control methods to reduce postharvest diseases during papaya storage, including those that reported on their effects on fruit quality. Wax combined with fungicides and heat is currently in use. Other methods, such as the application of irradiation, antagonistic microorganisms and natural compounds [e.g. chitosan and plant derivatives (extracts, essential oils and isothiocynates)], are still under evaluation, but have yielded promising initial results. The application of various organic salts and minerals and modified and controlled atmosphere technologies using ozone and volatiles such as 1-methycyclopropane are also under experimentation. We believe that research areas that include preharvest experimentation aimed at reducing postharvest diseases on papaya fruit should be taken into account. Finally, the integration of more than one control method will reduce the incidence of rots, and therefore improve and extend the storage life of this important commodity.