Anthracnose—Gnomonia
leptostyla
Anthracnose causes circular reddish brown or grayish brown spots to form on leaves. On green shoots, the
lesions are sunken, light grayish brown oval to circular areas with dark reddish brown margins. Sunken,
dark spots appear on husks. If nuts are very young when infection starts, they may not develop normally
and may drop prematurely. Infected leaves also drop. Trees may become completely defoliated.
Solutions
The fungus that causes anthracnose on walnuts survives in twig lesions and on plant debris and is spread
by spring rains. Remove and destroy infected and fallen leaves and nuts. Remove infected twigs and branches
as soon as symptoms appear. Keep plants pruned. |
