Revisiting the efficacy of hot water treatment in managing anthracnose and stem-end rot diseases of mango cv. 'Carabao'

- Hot water treatment (HWT) as postharvest protocol for 'Carabao' mangoes was revisited.
- 53 °C for 20 min was the optimal exposure for 'Carabao' mango.
- Anthracnose- and stem-end rot pathogens at 53 °C for 20 min.
- HWT was volatile in practical use with substantial variation in the incidence of anthracnose and stem-end rot.
- HWT reduced anthracnose and stem-end rot by 48.71%-52.63% and 48%-60.86%, respectively after 14 days.

This study was conducted to revalidate the efficacy of hot water treatment (HWT) as a standard protocol in managing postharvest disease in 'Carabao' mangoes. We elucidated the possible reasons for the inadequacy of HWT in management of anthracnose and stem-end rot. The effect of HWT on the cultures of anthracnose and stem-end rot-causing pathogens and on the overall quality of fruit was examined. The present investigation suggested 53 °C for 20 min as optimal exposure for 'Carabao' mango. At this exposure however, the propagules of Colletotrichum gloeosporioides and Lasiodiplodia theobromae were not totally controlled. HWT was unstable in controlling C. gloeosporioides and L. theobromae as demonstrated by high standard deviation of radial growth. HWT manner of control is fungistatic rather than fungicidal as pathogens developed after treatment. Fungistatic activity of HWT was perhaps inadequate to protect the fruit from decay due to absence of residual action. There were no significant changes in the quality of 'Carabao' mangoes submerged in hot water at 53 °C for 20 min whilst the severity of anthracnose was reduced by 48.71%-52.63% and stem-end rot by 48%-60.86%.