1. Chairman, Irrigation Training and Research Center, California Polytechnic State Univ., San Luis Obispo, CA 93407 (corresponding author).
2. Senior Engineer, Irrigation Training and Research Center, California Polytechnic State Univ., San Luis Obispo, CA 93407.
3. Control Specialist, Irrigation Training and Research Center, California Polytechnic State Univ., San Luis Obispo, CA 93407.