How to Manage Pests

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.