1. a Agricultural Economics Department , University of Arkansas , Agriculture Bldg, Room 221, Fayetteville , AR , 72701
2. b Agronomy Department , University of Arkansas , NEREC, P.O. Box 48, Keiser , AR , 72351
3. c Plant Pathology Department , University of Arkansas , PTSC, Room 217, Fayetteville , AR , 72701
4. d Agronomy Department , University of Arkansas , PTSC Room 115, Fayetteville , AR , 72701