1. USDA‐ARSVegetable and Forage Research Unit24106 N. Bunn Rd.ProsserWA99350
2. Irrigated Agric. Research and Ext. CenterWashington State Univ.I24106 N. Bunn Rd.ProsserWA99350
3. Dep. of Biological Systems EngineeringWashington State Univ.PullmanWA99164‐6120
4. Center for Sustaining Agric. and Natural ResourcesWashington State Univ.1100N Western AveWenatcheeWA98801