Avocado branch canker disease (ABC) is an increasing concern in orchards across Southern California and in other avocado-growing regions worldwide. This fungal disease can reduce productivity in infected trees and, in severe cases, lead to branch dieback and even tree loss. The fungi involved belong to the family Botryosphaeriaceae. Our 2023-2024 survey in Southern California orchards showed Neofusicoccum luteum as the most prevalent species recovered from symptomatic trees, followed by Lasiodiplodia theobromae, Botryosphaeria dothidea, and Neofusicoccum australe . Symptoms often appear when the tree is under stress and can vary. The signs of infection usually start with dark cankers appearing on the main trunk and branches. As the disease progresses, twigs die back, with the tips of branches turning downward and dying off. When cutting into an infected branch, a dark wedge-shaped stain extending deep into the wood can be seen. Often, these dead branches retain their mummified leaves rather than falling to the ground. Also, white dried sap leaking from necrotic lesions on the bark can be present. In severe cases, entire limbs will wither and die, which thins out the tree’s canopy and significantly cuts down the amount of fruit the tree can produce.
Read more about ABC in Topics in Subtropics