|Mango Malformation (Fusarium subglutinans)|
Mango Malformation Disease is a fungal disease of mangoes caused by several species of Fusarium (Fusarium subglutinans), some yet to be described. Mango is the only known host of the disease.
The disease spreads on a tree very slowly, but if left unchecked, can severely reduce yields. The main method of spreading Mango Malformation Disease to new areas is through infected vegetative planting material. There is no evidence that the disease can spread on fruit or the seeds, or that it affects human health.
Trees with the disease developed galls in the leaf axils of flush tissue that had been produced at least six months earlier. The galls were roughly circular, 20– 50 mm in diameter and consisted of a proliferation of shoots which grew to a length of 10–30 mm, before dying and promoting the growth of new shoots. No galls or other malformations were seen at the terminals of branches. Symptoms were seen on trees from three to more than 12 years old. These are generally on poorly maintained older trees and are found on the terminals of the branches. They are much more irregular in shape, have high numbers of bud mites and no floral malformation has been observed. It is thought that the Mango Malformation Disease symptoms are a result of a hormonal imbalance in the trees, induced by the Fusarium infections, and associated with bud mite infestations.