1. Dep. of Crop, Soil, and Environmental Sciences Univ. of Arkansas Fayetteville AR 72701 USA
2. Fisher Delta Research Center Univ. of Missouri Portageville MO 63873 USA
3. North Carolina State Univ. Williams Hall 1304B, Box 7620 Raleigh NC 27695 USA
4. USDA‐ARS 3127 Ligon St. Raleigh NC 27607 USA