1. USDA-ARS; Plant Science Research Unit and Dep. of Crop Sci.; North Carolina State Univ.; 3908 Inwood Rd. Raleigh NC 27603
2. Dep. of Crop Sci.; North Carolina State Univ.; Raleigh NC 27695
3. USDA-ARS; Soybean and Nitrogen Fixation Research Unit and Dep. Crop Sci. North Carolina State Univ.; 3127 Ligon St. Raleigh NC 27607