1. Tree Fruit Research and Extension Center, Washington State University, 1100 N Western Ave, Wenatchee, WA 98801, USA
2. United States Department of Agriculture-Agricultural Research Service Tree Fruit Research Lab, 1104 N Western Ave, Wenatchee, WA 98801, USA
3. Department of Plant Pathology, Stellenbosch University, Private Bag X1, Matieland 7600, South Africa