Question
I am working on the storage of mango under controlled temperature (10C) and humidity (85%). I have gotten a life of 34 days with good color and firmness. Unfortunately on some mangoes black spots appeared which have penetrated into the flesh by 3-5 mm. I think this is a problem with Achaetomilla, and would appreciate some suggestions from you. (A.R.K.)
Answer
It sounds like you are seeing the symptoms of anthracnose disease, caused by a fungus Colletotrichum gleosporioides. The fungus is especially a problem in humid growing regions where the infection begins in the field and then the symptoms develop after the fruit begins to ripen. This problem can be reduced by bagging fruit on the tree with a specialized paper bag to reduce spore load on the fruit, hot water treatment after harvest (50 to 53C for up to 5 minutes) or a combination of hot water with fungicide (imazalil) treatment.
You can find photos of anthracnose on mangoes on our Postharvest Technology website at the following link: http://ucanr.org/sites/postharvest/PFfruits/MangoPhotos/
-Beth Mitcham