Necrotic rusty mottle is believed to be caused by a virus. Affected trees are slower to leaf out and bloom in the spring. Terminal buds may be killed and the leaf and flower buds open irregularly. About a month after bloom, leaves begin to show angular purplish to brown spots. The spots may dry and drop out, giving leaves a tattered appearance. They can also coalesce and affect most of the leaf. Severely affected leaves develop a yellowish mottling along the veins and often drop. Defoliation can be severe. In the fall, remaining leaves turn mottled yellow and green, dropping prematurely. Decayed areas with gumming may be present on the bark. Twigs, larger branches, and whole trees may die. The necrotic rusty mottle virus is probably spread primarily by grafting with infected wood. 'Lambert' is severely affected, while 'Royal Ann' shows no symptoms.

Management Options

Non-Chemical Management

Plant and graft only with certified virus-free stock.
Remove and destroy infected trees, if desired.

Select non-chemical management options as your first choice!

Chemical Management

IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides

None recommended

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Caption: Necrotic rusty mottle virus symptoms Photo by: R.S. Byther

WSU Extension

Hortsense