1. Department of Horticultural Science, North Carolina State University, Mountain Horticultural Crops and Research Station, 455 Research Drive, Mills River, NC 28759, USA
2. Department of Horticulture, University of Georgia, 1111 Plant Science Building, Athens, GA 30602, USA
3. Department of Statistics, University of Georgia, 310 Herty Drive, Athens, GA 30602, USA
4. The Pennsylvania State University, 318A Tyson Building, University Park, PA 16802, USA