Effect of heat treatment on the fungus Colletotrichum gloeosporioides and anthracnose of mango fruit.
Sopee J., Sangchote S.
Author Affiliation: Department of Plant Pathology, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand.
: 2049-2056
Abstract : The efficacy of heat treatments in the control of Colletotrichum gloeosporioides [Glomerella cingulata] and anthracnose disease was evaluated by using hot water at 55°C (HWT55), vapour heat (VHT), and hot water at 38°C for 5 min combined with vapour heat (HWT38+VHT). Conidial germination was inhibited by application of HWT55 for 5 min. After 36 h of incubation the heat-treated conidia produced only 1% in length of appressoria with respect to appressoria of untreated conidia which developed normally. Disease incidence on mango fruits inoculated with heat-treated conidia at 55°C for 5 min was reduced by 93%. One day after inoculation, at the depth of 1 mm, fungal colonization was reduced by 80%. Disease incidence on fruit treated with HWT55, VHT and HWT38+VHT was reduced by 0.24, 0.26 and 0.14%, respectively. An antifungal extract obtained from the peel of heat-treated mango after 5 days of storage at 25°C inhibited conidial germination of C. gloeosporioides, whereas unheated fruits had no effect. Disease development on heat-treated fruits was also delayed as compared to untreated ones.