Ozônio, tratamento hidrotérmico e fungicida no manejo da antracnose da manga e qualidade pós-colheita

Abstract

Anthracnose is one of the most frequent post-harvest diseases of mango, responsible for limiting production, reducing fruit quality and causing large financial losses. For its control efficient and feasible measures that do not generate residues are required, due to the socioeconomic and environmental pressures on the control exclusively with fungicides. Heat treatment or the combination with other methods, such as the use of ozone, has been used in the control of postharvest diseases. The objective of this work was to evaluate the sanitization of 'Palmer' mangoes, with ozonated water or not, combined with hydrothermal treatment and fungicide in the control of anthracnose and the physical and chemical characteristics of the treated fruits. To evaluate the intensity of anthracnose in 'Palmer' mango, the experiment was set up in an entirely randomized design with eight treatments, with four repetitions, containing two fruits in each repetition. Mangoes of the cultivate “Palmer” were inoculated with Colletotrichum gloesoporioides and submitted to the following treatments: ozonated water; hydrothermal; fungicide; ozonated water + hydrothermal; ozonated water + fungicide; hydrothermal + fungicide; ozonated water + hydrothermal + fungicide and control (inoculated fruits / no treatments). The fruits were stored at 25 °C and the intensity of anthracnose was evaluated by the incidence and severity every three days for 15 days. The areas under the curve of progress of the incidence and severity of the disease were calculated. The data were submitted to variance analysis and the means were compared using the Scott-knott test at 5% probability. To evaluate the post-harvest characteristics of the fruits, the experiment was set up in an entirely randomized design with an 8 x 5 factorial scheme (eight treatments and five days of evaluation), with four repetitions, containing two fruits in each repetition. Fruits treated with the same treatments described above were used, but the control was formed by fruits without inoculation/no treatments and stored at 13 °C during 28 days. Firmness, fresh mass loss, skin and pulp coloration, titratable acidity and soluble solids content were evaluated. The data were submitted to variance analysis and the means were compared using the Tukey test at 5% probability and regression at 5% significance level for the storage day’s factor. The hydrothermal treatment and the combination of treatments: ozonated water + hydrothermal, hydrothermal + fungicide and ozonated water + hydrothermal + fungicide showed positive results in the control of anthracnose in fruits. The treatments only with ozonated water and fungicide did not differ statistically from the control. In the chemical and physical evaluations of the fruits, there was a significant interaction of the storage period and treatments, only for the chromaticity of the peel and titratable acidity. The highest values of acidity were observed in the first days of storage, after which there was a decline during fruit ripening. It was observed that the treatments did not influence the firmness and coloration of the fruits. The loss of fresh mass and the contents of soluble solids increased during the days of storage, independent of the treatments, corresponding to the beginning of fruit ripening. It is concluded that hydrothermal treatment in combination with ozone and fungicide were able to reduce the incidence and severity of anthracnose in mango. All treatments applied during post-harvest did not alter the post-harvest characteristics of the fruits, keeping them suitable for consumption for 28 days.