Eight irrigation rates were applied to mature olive trees (Olea europea cv.
Manzanillo) over three seasons in the San Joaquin Valley of California.
These levels corresponded to Eto (modified Penman grass reference) crop coefficients (Kc) of 0.16, 0.26, 0.36, 0.46, 0.55, 0.65, 0.75, and 0.85 which resulted in mean seasonal water applications of 232, 338, 424, 599, 729, 838, 945, and 1016 mm, respectively.
Predawn leaf water potential (LWP) measurements suggest that irrigation-related tree water stress occurs with Kc values of 0.55 or less.
The most important yield components affected by deficit irrigation were fruit yield and fruit value.
Fruit yield ranged from 10500 to 22100 kg/ha for the lowest and highest irrigation rates, respectively.
Fruit values for those treatments were 0.328 and 0.558 $/ha, respectively.
These was a strong correlation between revenue and applied water up to about 950 mm.
Using two linear expressions to describe this relationship, revenue per unit of applied water was $0.585/m3 from 250 to 600 mm and $2.39/m3 from 600 through 950 mm.