Fruit drop

October 2003. American Samoa asked about fruit drop in breadfruit: what was the cause?

There are the obvious pathological problems, caused, for instance, by Phytophthora species and Colletotrichum gloeosporioidies, and damage caused by fruit flies. Other than those, fruit drop is also caused by physiological processes: it’s a self-thinning mechanism, with the tree adjusting the number of fruits in relation to its carbohydrate and other reserves. Dry weather was also said to cause the condition as well as strong winds. It is particularly noticeable in heavy fruiting years.