Cherry Leaf Spot
Mirjana Bulatovic-Danilovich, WVU Extension Specialist, Consumer Horticulture –
Agriculture & Natural Resources
Cherry leaf spot is a fungal disease caused by Blumeriella jaapii (Rehm) Arx, formally known
as Coccomyces hiemali. It attacks the leaves, leaf stems, fruit and fruit stems.
Cherry Leaf Spot
In severe cases, the pathogen will cause early defoliation (Figure
1). Early leaf drop interferes with fruit ripening and color development,
resulting in poor tasting, small, off color fruit. Severely affected trees have
poor reserves of stored carbohydrates and are ill-prepared for winter, making them
prone to winter injury and dieback. Tart and sweet cherry varieties differ
greatly in their susceptibility to cherry leaf spot.
At petal fall when the first leaves start to unfold, use Daconil (chlorothalonil) until shuck split on a 7- to 10-day interval. After the shuck split, use Captan or Immunox (mycobutanil), or a half rate of Captan in combination with full rate of Immunox. This is for resistance management. Fungicide applications should continue through the middle of summer.
Preventive treatment is key – once the disease is established on leaves, it is difficult to control in rainy seasons.
Spray treatments are needed throughout the season until harvest. Watch for pre-harvest intervals, and read the label for proper spray use. After the harvest,one application of Daconil will help suppress fall infection and reduce the inoculum presence.
Sweet cherry varieties are generally less susceptible to cherry leaf spotthan tart cherries but still need some fungicide protection post bloom in wet years. Montmorency tart cherry is very susceptible. Tart cherry varieties with better leaf spot resistance include Northstar and Meteor.