1. Dep. of Crop Science; North Carolina State Univ.; Raleigh NC 27695 USA
2. International Institute of Tropical Agriculture; IITA PMB 5320 Ibadan Nigeria
3. Institute for Crop Research in the Semi-Arid Tropics; Patancheru India
4. Dep. of Nematology; Univ. of California; Riverside CA 92521 USA