Symptoms and Signs
Crinkle leaf is caused by a spontaneous mutation that occurs within buds. Leaves that develop from affected buds have irregular, deeply indented margins and are distorted. The distorted portion of the leaf is often light green or mottled. Leaf symptoms are most pronounced early in the season, and become less noticeable by mid summer and fall. Blossoms on the affected portions of the tree are often deformed and fruit set is very light. Fruit that do form are small and pointed with a pebbly texture and have either short or long stems. Sutures on affected fruit may be raised. Misshapen fruit ripen unevenly.
Deep suture is a fruit symptom that develops spontaneously on trees that were previously free of symptoms. Leaves become longer and narrower than normal, and are often thickened, with a roughened surface appearance. A deep cleft develops in fruit along the suture line. Trees may be stunted. The presence of long narrow leaves distinguishes this disorder, because deep sutures also develop on fruit doubles caused by stress during bud development the previous season.
Comments on the Disease
Crinkle leaf (cherry crinkle) and deep suture are genetic disorders that affect certain varieties of cherry. Both are serious problems of Bing and Black Tartarian, and can cause substantial yield losses. Both can develop in previously symptomless trees and can be spread when wood from affected branches is used for budding or grafting.
Management
To reduce the incidence of crinkle leaf and deep suture disorders, use symptom-free trees for budwood. In nurseries, inspect trees carefully during the spring and remove any scion source trees that develop symptoms. In orchards, inspect trees closely during the first 5 years. Remove any branches that develop symptoms and top-work them with disease-free scion wood. Lambert and Napoleon (Royal Ann) are not susceptible to these disorders.