1. Dep. of Crop Sciences Univ. of Illinois AW‐101 Turner Hall, 1102 South Goodwin Ave. Urbana‐Champaign IL 61801 USA
2. Current address: ShoreRivers 114 South Washington St, Ste. 301 Easton MD 21601 USA
3. Dep. of Plant Sciences Univ. of California Davis CA 95616 USA
4. Dep. of Agricultural and Biological Engineering Univ. of Illinois Urbana‐Champaign IL 61801 USA