Essential Oils in the Management of Anthracnose in Postharvest of 'Palmer' Mango Fruits

In Brazil, the control of anthracnose and other mango diseases postharvest is accomplished by using a five-minute submersion in hot water at 55 ºC, with 0.2% thiabendazol added. Although efficient in controlling the disease, this fungicide can leave residues in the fruits. This does not satisfy the consumer, who is increasingly on the demand for environmentally correct fruits and with no agrochemical residues. The objective of this work was to evaluate the effect of the essential oils of the species Eugenia caryophyllus, Melaleuca alternifolia, Thymus vulgaris, and Zingiber officinale in the management of anthracnose postharvest in ‘Palmer’ mango fruits. The study was developed in the Fruits and Vegetables Postharvest Pathology from the Montes Claros State University, MG, Brazil. The fruits were atomized until dripping with the aid of a painting pump containing a suspension with 5x10⁵ mL of Colletotrichum gloeosporioidesspores, and the control was not inoculated. After inoculation, the fruits were incubated in a wet chamber at 25 ºC and 85% RH for 24 hours. After this period, three fruits were transferred to 21 cm x 14 cm x 18 mm expanded polystyrene trays and stored in 3 kg capacity plastic bags, each one containing a plastic recipient with a filter paper containing aliquots of 100 µL of the essential oils. The control consisted I the addition of 100 µL to the filter paper. The incidence was obtained by the number of affected fruits per repetition, being those values expressed in percentage per treatment. The experiment was installed in a completely randomized design in a 4 x 5 factorial. The results were subjected to analysis of variance using the software SISVAR and the means compared by Scott-Knott test at a 5% significance level. The essential oils showed significant effect on the incidence of anthracnose in the ‘Palmer’ mangos until the sixth storage day, and the more efficient extracts were Eugenia caryophyllus, Melaleuca alternifolia, and Thymus vulgaris. From the ninth day on, the treatments did not differ from the control. The essential oil extracts show a great potential for the alternative control of anthracnose in ‘Palmer’ mangos (Financial support: FAPEMIG and CAPES).