Hydrothermal treatment in the management of anthracnose in 'Prata-Ana' banana produced in the semiarid region of Minas Gerais, Brazil

Anthracnose stands out among rot diseases that can occur in the post-harvest phase of banana. The aim of this study was to evaluate the thermotherapy in the control of anthracnose in 'Prata Ana' banana produced in northern state of Minas Gerais. Bananas 'Prata Ana' variety were divided into groups of three fruits and inoculated with Colletotrichum musae. Groups were submitted to thermotherapy using five temperatures (40 degrees C, 44 degrees C, 48 degrees C, 52 degrees C and 56 degrees C) and four immersion times (4, 8, 12 and 16 minutes) and control. Treatments were repeated five times in a completely randomized design. Area under the incidence progress curve (AUIPC) and area under the severity progress curve (AUSPC) were calculated. To evaluate the thermotherapy efficiency compared to chemical control, fruits were submitted to the following treatments: thermotherapy with and without fungicide application and fruits treated with fungicide only, the control fruits without thermotherapy and without fungicide application. After fifteen days of storage, fruits were evaluated for anthracnose severity. The results of experiments were submitted to analysis of variance and regression and means were compared by the Scott-Knott test (p<0.05). Control was compared to treatments by the Dunnett test (p<0,05). The lowest anthracnose AUIPC values were observed when using temperature of 48 degrees C for eight and 12 minutes. Thermotherapy at 52 degrees C from eight minutes of immersion, in addition to reducing the anthracnose AUSPC in fruits up to 81.6%, delayed maturation of fruits. Fruits submitted to thermotherapy at 56 degrees C presented higher severity of the disease and resulted in the maturation of fruits. Thermotherapy reduces anthracnose severity in fruits in a manner similar to fungicide use, but the association of both results in better control of the disease in 'Prata Ana' banana. Thermotherapy is an efficient technique to reduce the severity of the disease in 'Prata Ana' banana produced in northern state of Minas Gerais.