Walnut blight—Xanthamonas
campestris
pv. juglandis
Symptoms of walnut blight may include one to several black lesions on catkins (clusters of male flowers;
no fruit develop from these). Husks develop black, slightly sunken lesions at the stigma end when young;
more lesions will develop on the sides of fruit as it matures. Lesions are always dry. Shoots and leaves
may develop symptoms; symptoms are more common on fruit. Shoots develop black lesions and leaves show
irregular lesions on blade. All leaflets of a leaf usually show signs of infection.
Identification | Life cycle
Solutions
Walnut blight is worse in early-leafing varieties. Avoid getting foliage wet with sprinklers and avoid
irrigation altogether during bloom. Open up trees with pruning to get better air circulation. | 
