Exotic fruit trees can be demanding plants to keep. After all, they need lots of sun, lots of warm weather and lots of care and attention. One of the best ways to keep your exotic fruit tree healthy and happy is to know the signs and symptoms specific to exotic fruit trees and their diseases. Knowing exactly what types of problems can arise for your fruit tree will help you monitor its health and growth so that you can take fast, effective action should a problem arise.
Barbados Cherry Tree
The Barbados cherry tree has beautiful rose-pink blooms and has soft, juicy, thin-skinned fruit. This tree has blooms throughout the summer, and bears fruit in the fall. Barbados cherry trees can develop problems with root-knot nematodes, which are a particular problem in sandy soils. An infestation manifests itself through dropped, discolored leaves. You can fumigate the soil around the tree to remove the nematodes or prevent them via heavy mulching. Leaf spot can also create difficulties, with brown, discolored lesions forming on the leaves. Left untreated, these spots will enlarge and develop yellow rings around them. Eventually the leaves will die and fall, and the spots can spread to the fruit. Use sterile pruning to remove all affected foliage and dispose of it in a sealed bag or by burning. Monitor your tree to prevent recurrence and remove symptomatic foliage the second you see a problem.
Star Apple or Start Fruit Tree
The star apple tree has nearly-evergreen leaves and, according to the Purdue horticultural department, has been grown in Florida and Hawaii since 1901 and needs very warm weather to thrive (hort.purdue.edu). Star apple suffers from leaf spot diseases and requires sterile pruning of affected leaves in order to keep this problem under control. Removing plant debris from beneath the tree will also help prevent reinfection. Additionally, the fungal infections pestalotia and diplodia may cause fruits to mummify in Florida. These infections can be treated with preventative fungicides before the fruits appear or you can remove all affected fruit using sterile pruning.
Mango trees are susceptible to disease at all stages of their lives. These tropical fruit trees bear a popular and delicious fruit, but they can be difficult to manage. Powdery mildew, anthracnose and botrytis all attack the mango tree. These infections can be controlled in most cases by fast response by sterile pruning and removal of all plant debris from below the tree to prevent reinfection. All of these diseases cause the wilting of leaves and death of limbs, but powdery mildew is first evidenced by a thick, chalky coating in black, white, gray or pink. Additionally, mangoes can develop phoma blight, a relatively new disease, according to Horticulture World. Phoma causes lesions to develop on older foliage and can eventually result in defoliation and dieback. Phoma, like bacterial cankers, which are swollen, bulging, corky areas that choke and kill the limbs of the mango tree, can be controlled with copper pesticides, but you will need to check with a local professional before treating your tree since not all treatments are legal in all areas.