1. USDA-ARS-Southern Regional Research Center, 1100 Robert E. Lee Blvd., New Orleans, LA 70124.
2. Corresponding author. Phone: (504) 286-4293. Fax: (504) 286-4419. E-mail: casey.grimm@ars.usda.gov
3. USDA-ARS-Dale Bumpers National Rice Research Center, 2890 Highway 130 E, Stuttgart, AR 72160.