Several researchers (Goldhamer et al, Pastor et al) imply that using KC of 0.55-0.65 as a crop coefficient in the maximum water consumption period can be used as a general guideline for determining irrigation applications.
 Below this value, yields respond negatively and pre-dawn leaf water potential measurements are in line with these observations.
 
Water stress in KC < 0.55 mpa resulted in less shoot growth and earlier bloom period (Paul D. Metheney).

As a general statement it can be said that KC of .4 will be the optimum in beginning the spring irrigation period where KC of .55 or .6 will be used in the high water consumption phase.
If RDI strategy is applied, KC of 3 can be used during the period of pit hardening, for 6-7 weeks.

In locations where water is scarce, lower KC is used according to water availability with the same pattern of changing KC during the entire growing season.