Wet 0 to -6

Field Capacity/ Runoff.

Good -6 to -11

Low stress. Stimulates shoot growth, especially in developing orchards. Higher yield potential may be possible if these levels of crop stress are sustained over a season, barring no other limitations related to frost, pollination, diseases, or nutrition. Sustaining these levels may result in higher incidence of disease and reduced life span.

Slight/Moderate Stress -11 to -18

Mild stress. Suitable from mid-June until the onset of hull split (July). Still able to produce competitively. Recommended crop stress level after harvest. May reduce energy costs or help cope with drought conditions. (-11 to -14)

​

Moderate stress. Stops shoot growth in young orchards. Mature almonds can tolerate this level of crop stress during hull split (July/August) and still yield competitively. May help control diseases such as hull rot and alternaria, if present. May expedite hull split and lead to more uniform nut maturity. Also may help reduce energy costs and cope with drought conditions. (-14 to -18)

Dry -18+

Moderate to high stress. Should be avoided for extended periods. Likely to reduce yield potential, and may contribute to lower limb dieback. (-18 to -20)

​

High stress. Wilting observed. Some defoliation. Impacts yield potential. (-20 to -30)

​

Very high to severe stress. Extensive or complete defoliation is common. Trees may survive despite severe defoliation and may be rejuvenated. (-30 to -60)

https://anrcatalog.ucanr.edu/pdf/8503.pdf