Avocado Tree Wilting

Identification

• Avocado trees are susceptible to avocado root rot caused by Phytophthora cinnamomi. Avocado root rot is cited as the most serious avocado tree disease by the University of California Extension. Fungal growth is favored by poorly drained soil.

Damage

• The disease is characterized by stunted foliage growth. Leaves are initially light green to yellow in color and then start to wilt and develop brown tips. Infected trees stop growing leaves and branches start to die starting from the top. The sparse foliage makes fruit prone to sunburn. Roots get brittle and black. Infected trees gradually die.

Control

• Obtain disease-free trees from reliable sources and plant in a well-drained soil. A number of avocado species are more resistant to the fungus. Using resistant varieties helps to minimize chances of infection. Chemical control options include the use of phosphonate-based fungicides to control infection.