SPRINKLER IRRIGATION for tree crops in the San Joaquin Valley has increased rapidly during the past ten years, particularly in areas planted to citrus. While no exact figures are obtainable, it is estimated that more than 20,000 of the 100,000 acres in citrus are now irrigated by sprinklers- Large acreages of walnuts, olives, and deciduous fruit are also being irrigated by sprinklers. Nearly all of this increase in sprinkler irrigation involves systems using the new hose-pull or overhead methods, as described in this study.