Crop Coefficients for Avocados

Using CIMIS or an E-pan, you end up with a number that's called Reference evapotranspiration or ETo for short. This number approximates the evapotranspiration of a field of 4 to 6 inch tall, cool-season grass that is not water stressed. To use this number to calculate water use for avocados you must multiply the ETo by a crop coefficient (Kc) that accounts for the ET difference between the avocado and the cool-season grass. Below are the crop coefficients for avocado based on research done in Corona, Ca (1988-92) and Covey Lane, North San Diego County, Ca (1992-97).

Months
Kc's
Jan
0.40
Feb
0.50
Mar
0.55
Apr
0.55
May
0.60
Jun
0.65
Jul
0.65
Aug
0.65
Sep
0.60
Oct
0.55
Nov
0.55
Dec
0.50
For Further Information

Irrigation Scheduling, a guide for efficient on-farm water management. University of California Division of Agriculture and Natural Resources Publication #21454. 1989.