The coffee bean tree is quite hardy. It is generally resistant to cold weather, and can grow at altitudes higher than most other fruit trees. However, although hardy, it is susceptible to a number of diseases of varying severity. Some will cause no more than minor leaf blemishes, while others can wipe out an entire population of trees.
Coffee Berry Disease
Coffee berry disease is caused by a fungus that feeds on the flowers and immature berries of the coffee bean tree. Affected berries turn brown while they are still immature, then develop sunken pits of dead tissue surrounded by a pink crust, and eventually wither and drop. If left untreated, coffee berry disease can destroy up to 75 percent of a crop. To stop the spread of the fungus, pick all affected leaves and berries as soon as possible and burn them. To prevent subsequent infection, spray your coffee bean tree with a fungicide approved for use on coffee berry disease in early spring before bud break.
Coffee Wilt Disease
Coffee wilt disease is a deadly and virulent fungal infection. Healthy, mature coffee bean trees can be killed in as little as six months after the initial infection. The first stage of the infection causes the leaves to yellow, wilt, dry and eventually drop. Coffee berries turn red and appear to ripen early, and as the disease progresses, the tree's wood cracks and dies. The best remedy for coffee wilt disease is to uproot infected trees and replace them with cultivars that are resistant to the disease.
Tracheomycosis is one of the most virulent coffee bean tree fungal infections. The fungus spreads quickly, drying out the stems and branches of the tree before the entire tree dries out and dies. There is no cure for tracheomycosis and infected trees must be dug up immediately and burned before the infection spreads.
Coffee Leaf Disease
Coffee leaf disease is a relatively innocuous fungal infection if properly managed. The fungus spreads among the leaves, branches and fruit of the coffee bean tree, and causes the affected tissue to dry out. The best way to manage coffee leaf disease is to quickly prune affected tissue to stop the fungus from spreading.