Water Status of Olive Trees

Leaf water potential (') and leaf conductance (gl) were measured in the field in 20-year-old olive trees subjected to two treatments of soil water content (dry-farming and drip-irrigation). Differences between treatments of up to 0.35 MPa were observed in predawn , values. At midday, these differences were of up to 0.83 MPa. However, no significant differences between treatments were observed in gl values. Maximum gl values of about 0.77 cm S-l were found early in the morning, clossing the stomata afterwards. In just 12 hours after rewatering following the drought period, the differences between treatments on , values were reduced from 0.29 MPa to 0.14 MPa for predawn values, and from 0.64 MPa to 0.23 MPa for midday values. The recovery was virtually total at the third day after rewatering.