1. USDA-ARS Southern Regional Research Center, New Orleans, LA.
2. Corresponding author. Fax: 504-286-4430. E-mail: etchamp@srrc.ars.usda.gov
3. Biological & Agricultural Engineering, University of California, Davis.
4. University of California Cooperative Extension.
5. USDA-ARS Rice Research Unit, Beaumont, TX.