1. USDA–ARS Forage, Seed, and Cereal Research 3450 Campus Way Corvallis OR 97331 USA
2. Crop & Soil Science Dep. Oregon State Univ. Corvallis OR 97331 USA
3. Dep. of Botany and Plant Pathology Oregon State Univ. Corvallis OR 97331 USA
4. Washington State Univ. Irrigated Agriculture Research and Extension Center Prosser WA 99350 USA