1. Department of Horticulture, Texas A&M University, Agricultural Research and Extension Center, Overton, PO Box E, Overton, TX 75684–0290, USA,
2. Agronomy Department, University of Florida, Gainesville, FL 32611, USA,
3. United States Department of Agriculture, Building 164, Gainesville, FL 32611, USA,
4. Agricultural and Biological Engineering Department, University of Florida, Gainesville, FL 32611, USA