Some Safe Treatments for Controlling Postharvest Diseases of Mango (Mangifera indica L.) Fruits

This study was conducted to reveal the spread and disease severity of mango decayed after harvesting on the most commercial verities (Keitt, Kent and Tommy Atkins). Disease survey was studied on mango fruits collected from the fields of two localities: Ismaillia and Nobaria district. In addition of diseased samples were collected after harvesting and marketing from El-Aboor and 6th October markets. Varietal susceptibility was studied under laboratory conditions. Three attempts were carried out as save treatments to control the disease using chitosan, citral; two bioagents Pseudomonaes fluorescens and Candida tennis as well as hot water. Shelf life, fruit contents of total soluble solids (TSS), titratable acidity (TA) and vitamin C were also taken into consideration.
The results revealed that the most dominant fungi attacking mango fruits during field growth, harvesting and marketing were Colletotrichum gloeospirioides Pass. and Botryodiplodia theobromae Pat., which caused infection of 65.0 and 43.23%, respectively. In concern with varietal susceptibility all the tested cultivars were liable to the infection by the disease without any resistant.
All of the tries treatments succeeded to control the decay on the mango fruits along the period after harvesting and increased the shelf life of the fruit when stored at temperature 22±2°C. Chitosan applied with 8.0g/l to coat the treated fruits gave a very high efficient against the disease .In the same category citral (as a volatile oil from the exocarpe of fresh citrus fruit) which exhibited strong toxicity towards several fungal pathogens when applied at 8.0g/l. Meanwhile, the bioagent P. fluorescens was more effective than C. tennis, but still not efficient as chitosan and citral. Hot water treatment was very effective to control fruit decay with longer to shelf life as well as chitosan and citral.
The study revealed no marked differences of the treatments on the fruit quality, i.e. total soluble solids (TSS) and titratable acidity (TA), except a slight high in vitamin C in all cultivars.