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The effectiveness of different postharvest treatments to control different levels of quiescent infections of Alternaria alternata causing Alternaria rot in mango fruits during storage was compared. A combined hot water spray and fruit brushing (hot water brushing - HWB) treatment for 15 - 20 s with 225 μg ml -1 prochloraz was the most effective treatment to control Alternaria rot in fruits with a high relative quiescent infected surface (RQIS) rating of 36 at harvest. Comparable control was obtained with the commercially used treatment of 900 μg ml prochloraz spray. However Alternaria rot in mango fruits with intermediate levels of RQIS rating of 25 was controlled by HWB treatment alone or HWB with chlorine (300 μg ml -1 Troclosene Na). HWB alone was effective enough to control postharvest decay in fruits with a RQIS of 5. Present results have indicated that effectiveness of postharvest HWB and prochloraz applications, are dependent on the quiescent infected area of the fruit by A. alternata at harvest. A RQIS rating, before harvest, has resulted in the use of effective, mild, fungicides as a single postharvest treatment thus avoiding wide use of less friendly synthetic fungicides.

The effectiveness of different postharvest treatments to control different levels of quiescent infections of Alternaria alternata causing Alternaria rot in mango fruits during storage was compared. A combined hot water spray and fruit brushing (hot water brushing-HWB) treatment for 15–20 s with 225 μg ml−1 prochloraz was the most effective treatment to control Alternaria rot in fruit with a high relative quiescent infected surface (RQIS) rating of 36 at harvest. Comparable control was obtained with the commercial treatment of 900 μg ml−1 prochloraz spray. However, Alternaria rot in mango fruit with an intermediate level of RQIS rating of 25 was controlled by HWB treatment alone or HWB with chlorine (300 μg ml−1 Troclosene Na). HWB alone was effective enough to control postharvest decay in fruit with a RQIS of five. Present results have indicated that effectiveness of postharvest HWB and prochloraz applications are dependent on the quiescent infected area of the fruit by A. alternata at harvest. A RQIS rating, before harvest, has resulted in the use of effective, mild, fungicides as a single postharvest treatment thus avoiding wide use of less friendly synthetic fungicides.

A treatment of hot water brushing and prochloraz followed by 2,4-dichlorophenoxyacetic acid (2,4-D) diluted in wax, reduced postharvest diseases by 50–70% and improved fruit quality during prolonged storage. Alternaria alternata, Phomopsis spp. and Lasiodiplodia spp. were the main causal organisms of stem end decay. The best control was obtained by concentrations of 2,4-D ranging from 75 to 175 μg ml−1, which could efficiently control side rots caused by A. alternata and the stem end rot-causing pathogens. The combination of hot water brushing, prochloraz application and 2,4-D treatment reduced the incidence of stem end rot after 4 weeks of storage at 14°C and 7 days of shelf life at 20°C from 86 to 10% in cv. Tommy Atkins and from 63 to 12% in cv. Keith. At 175 μg ml−1 2,4-D did not affect fruit firmness or colour development but ensured high quality and fewer rotten fruits.

A combined hot water spray and fruit brushing (hot water brushing–HWB) treatment for 15–20 s was developed for reducing the incidence of postharvest disease caused by Alternaria alternata and improving mango fruit keeping quality. The efficacy of the hot water treatment was tested over a range of temperatures from 48 to 64°C, in combination with prochloraz treatment and fruit waxing. Hot water brushing of fruits significantly reduced decay (infected area) development by A. alternata. But after storage for 3 weeks at 12°C and another week at 20°C, the reduction of disease incidence by HWB and prochloraz treatment (900 μg ml−1) was more effective than by HWB alone. HWB treatment for 15 s improved colour development and was more effective than the common, commercial 5 min dip treatment at 55°C. The combination of fruit HWB and waxing yielded high quality fruits with less decay development.