Distribution Uniformity (DU) is a value, given as a percentage, indicating the water distribution uniformity of your irrigation system and how evenly the irrigation water is distributed throughout the grove. It is highly recommended to test your grove for its DU. This service is provided in many communities by the local Conservation District. If you are not familiar with your grove’s DU use 70% as the value.
A description of how to evaluate your DU is provided at the following link.
http://www.ucavo.ucr.edu/AvocadoWebSite%20folder/AvocadoWebSite/Irrigation/Uniformity.html
For further information on the importance of evaluation of pressurized irrigation systems, see the following link:
Uniformity in pressurized irrigation systems depends on design, installation - Gordon E. Little, David J. Hills and Blaine R. Hanson
See also:
Avocado Irrigation - How to Deal With High Water Costs - Gary Bender and Margarita Engle