1. Department of Horticulture, Washington State University, Northwestern Washington Research and Extension Center, 16650 State Route 536, Mount Vernon, WA 98273
2. Department of Crop and Soil Sciences, Washington State University, Irrigated Agriculture Research and Extension Center, 24106 North Bunn Road, Prosser, WA 99350
3. Department of Horticulture, Oregon State University, Hermiston Agricultural Research and Extension Center, 2121 South 1st Street, Hermiston, OR 97838
4. Washington State University Extension, Washington State University, 620 Market Street, Prosser, WA 99350