1. Biology Dep. Univ. Federal de Lavras Lavras Minas Gerais 37200‐900 Brazil
2. Agronomy Dep. Univ. of Florida 2005 SW 23rd St. Bldg 350 Gainesville FL 32608 USA
3. VSN International, Hemel Hempstead UK
4. Horticultural Science Dep. Univ. of Florida 2550, Hull Rd. Gainesville FL 32611 USA
5. Environmental Horticulture Dep. Univ. of Florida, West Florida Research and Education Center 4253 Experiment Rd., Hwy 182 Jay FL 32565 USA
6. Dep. of Crop and Soil Sciences North Carolina State Univ. Campus Box 7620 Raleigh NC 27695 USA
7. Dep. of Crop and Soil Sciences Univ. of Georgia, Tifton Campus 2360 Rainwater Rd. Tifton GA 31793 USA
8. Dep. of Crop and Soil Sciences Univ. of Georgia, Griffin Campus 1109 Experiment St. Griffin GA 30223 USA
9. Dep. of Soil and Crop Sciences Texas A&M AgriLife Research‐Dallas 17360 Coit Rd. Dallas TX 75252 USA
10. Dep. of Soil and Crop Sciences Texas A&M Univ. 370 Olsen Blvd. College Station TX 77843 USA
11. Dep. of Plant and Soil Sciences Oklahoma State Univ. 371 Agricultural Hall Stillwater OK 74078 USA
12. Dep. of Horticulture & Landscape Architecture Oklahoma State Univ. 358 Agricultural Hall Stillwater OK 74078 USA