Application Uniformity for Fixed and Rotating Spray Plate Sprinklers

Field trials with a lateral move irrigation machine were conducted to determine comparative waterapplication uniformities for drop tube sprayers, boom sprayers, and rotators. The averaged Christiansens Coefficient ofUniformity (CU) was highest for the rotator emitter (94.6%), followed by the drop tube sprayers (93.7%), and then theboom sprayers (89.5%). Wind speeds of up to 6.2 m/s had little effect on the CUs for the three sprinkler types tested. Anincrease in machine speed from 0.2 m/min to 0.8 m/min reduced the CU for the drop tube sprayers by approximately 3%;however, the speed change had negligible effect on the CUs for the boom sprayers or rotators. The volume mean dropletdiameters measured in the field for the overlapping sprinkler patterns were as follows: drop tube sprayers (1.4 mm),boom sprayers (1.7 mm), and rotators (2.8 mm).