Study on Corky Bark and Gummosis of Mango

Abstract

Corky bark and gummosis are probably the most serious groups of diseases of mango causing tree decline and death in some cases. differences in symptom appearances can be separated into 5 groups as follow:
a) Severe corky bark with gum exudation observed on "Rad" variety. The symptoms could be transmitted by grafting, but the caussal agent was not yet determined.
b) Cracking of the bark with gummosis normally observed on Khaew-Sa-wei and some other varieties, such as Nam-dok.mai or Pim Saen-mun.
c) Gummosis and drying of branches observed on several mango varieties during dry season. The fungus, Botryodiplodia sp., was always inolated from the lesions. The inoculation of the fungus through wound caused gum exudation from the infected parts.
d) Corky bark observed in Pim saen-mun. The symptoms also could be transmitted by grafting but the cause was unknown.
e) Gummosis with stem pitting was observed on "Sam-pee", "Kaew" , and "Ok-rong" with differences in the appearance of pitting on the stem of each variety. The causal agent and its relationship to the pitting disorder a mango trees were not determined.