1. United Graduate School of Agricultural Science, Tottori University, Tottori 680-8553, Japan
2. Agricultural Research Corporation, P.O. Box 126, Wad Medani 22212, Sudan
3. Hydraulics Research Center, P.O. Box 318, Wad Medani 22212, Sudan
4. Arid Land Research Center, Tottori University, Tottori 680-0001, Japan
5. Faculty of Agriculture, Yamaguchi University, Yamaguchi 753-8515, Japan