ABSTRACT
One of the major problems in guava commercialization is the incidence of postharvest diseases, which coincides with fruit ripening. The effect of alternative products [potassium phosphite, calcium chloride, cassava starch, 1-methylcyclopropene (1-MCP), ethanol followed by sodium dichloro s. triazinetrione dehydrate (ethanol+chlorine)] and hydrothermal treatment, singly and in association, was evaluated on anthracnose control and on the physicochemical characteristics of ‘Pedro Sato’ guava. Treatments were applied to naturally infected guavas, in three maturity stages, which were stored at 22 or 25ºC for eight days. The incidence of anthracnose was evaluated by visual observation of symptoms and signs of the pathogens under an optical microscope, and the evaluated physicochemical parameters were skin color, pulp firmness, fresh mass loss, soluble solids, titratable acidity and ascorbic acid. The association of treatments ethanol+chlorine/cassava starch, hydrothermal treatment/cassava starch and ethanol+chlorine/1-MCP reduced the incidence of anthracnose in all three maturity stages in at least one storage period, leading to longer shelf life of fruits and a delay of two to four days in the onset of the disease. The maintenance of guava quality by means of treatment association was evidenced by delayed change in the skin color and less reduction in pulp firmness, especially for ethanol+chlorine/1-MCP. There was a positive correlation between the incidence of anthracnose and the maturity stage, expressed by the fruit skin color. The higher efficiency of treatment association in controlling anthracnose was directly related to the delay in fruit ripening, evidenced by the parameters skin color and pulp firmness.
Keywords
rot; Psidium guajav; Colletotrichum spp.; management