1. USDA ARS Southern Regional Research Center, New Orleans, LA.
2. Corresponding author. Fax: 504-286-4430. E-mail: etchamp@nola.srrc.usda.gov
3. USDA ARS Rice Research Unit, Beaumont, TX.
4. University of Arkansas Rice Research and Extension Center, Stuttgart, AR.
5. Louisiana State University Rice Research Station, Crowley, LA.
6. California Cooperative Rice Research Foundation, Biggs, CA.
7. USDA ARS Richard B. Russell Research Center, Athens, GA.