A review on the management of postharvest anthracnose in dragon fruits caused by Colletotrichum spp

Colletotrichum spp is one of the major cosmopolitan phytopathogens that cause postharvest anthracnose in dragon fruits. The pathogen attacks fruits on the field, during long-distance transport, and cold storage, leading to shorter shelf life. Traditionally, the plants are sprayed with synthetic fungicides, which is a strategic approach to control diseases in general and anthracnose in particular for dragon fruit production. Due to the demand for safe storage methods for consumers and the concerns about the use of synthetic fungicides, their use is restricted to control dragon fruits anthracnose after harvest. Despite "Umikai" (natural Calcium) is the commonly used preservative by some exporters of dragon fruits in Vietnam, recent reports indicated that Sodium nitroprusside (a Nitric oxide donor) markedly controlled anthracnose in dragon fruit at recommended levels. However, due to detrimental effect of these nitric oxide donors and other synthetic chemicals on human health, concerns are raised by the governments and other stakeholders to abolish, if not regulate the use of these synthetic chemicals in pre- and postharvest management of anthracnose. Consequently, several alternative methods have been developed to control postharvest decay, but with little success. This review summarizes the findings published within the last decade on current management practices on postharvest anthracnose in dragon fruit. We conclude that hot air/vapor heat treatment, water treatment, modified and controlled atmosphere packaging are commercially practiced and effective in reducing postharvest decay in dragon fruits while, X-ray irradiation is still under experimentation, Additionally, natural products (propolis and chitosan) shows promising effect without leaving residual harmful effect and could be adopted on a commercial scale to reduce postharvest losses after further commercial trials.