What symptom indicates sudden oak death?

Sudden oak death is characterized by specific symptoms related to the health of oak trees and other affected species. The presence of irregular necrotic leaf lesions is a primary indicator of this disease. These lesions appear as dark, dead areas on the leaves, which can spread and lead to further decline of the tree. This symptom is directly linked to the pathogenic organism Phytophthora ramorum, which causes the disease and manifests in leaf tissue.

Recognizing these irregular lesions is crucial for early diagnosis and management of sudden oak death, as intervention strategies may need to be employed to mitigate the spread of the pathogen. Other symptoms listed, such as stunted or deformed leaves, yellow spots, or honey-colored mushrooms, can be indicative of different conditions or diseases affecting trees, but they do not specifically correlate with sudden oak death, making the identification of necrotic lesions the most relevant sign for this particular disease.