1. Dep. of Plant Sciences North Dakota State Univ. Fargo ND 58102 USA
2. Dep. of Plant Pathology North Dakota State Univ. Fargo ND 58102 USA
3. USDA‐ARS Edward T. Schafer Agricultural Research Center Sunflower and Plant Biology Research Unit, USDA Fargo ND 58102 USA
4. USDA ARS NCAUR Peoria IL 61604 USA
5. North Central Research Extension Center Minot ND 58701 USA
6. Williston Research Extension Center Williston ND 58801 USA
7. Hettinger Research Extension Center Hettinger ND 58639 USA
8. Carrington Research Extension Center Carrington ND 58421 USA
9. Langdon Research Extension Center Langdon ND 58249 USA