1. Department of Plant and Environmental Sciences, 171 Poole Agricultural Center; Clemson University; Clemson SC 29634 USA
2. Institute of Food and Agricultural Sciences, Fort Lauderdale Res. and Ed. Center, Univ. of Florida; 3205 College Ave Fort Lauderdale FL 33314 USA
3. Division of Science, Berks Campus; Pennsylvania State University; 111 Luerssen Building Reading PA 19610 USA