Donald W. Grimes is Assistant Water Scientist, Department of Water Science and Engineering, University of California, Davis, and at the U. S. Cotton Research Station, Shafter. Lamar Dickens is Laboratory Technician, Department of Water Science and Engineering, University of California, Davis, and at the U. S. Cotton Research Station, Shafter. Wayne Anderson is Laboratory Technicians, Department of Agronomy and Field Stations, University of California, Davis, and at Shafter and the West Side Field Station, Five Points, respectively. Hidemi Yamada is Laboratory Technicians, Department of Agronomy and Field Stations, University of California, Davis, and at Shafter and the West Side Field Station, Five Points, respectively.