Young olive trees responses (Olea europea, cv "Arbequina") to different water supplies.: Water function determination

Research to determine the water production function of young olive trees has been developed in a commercial orchard (cv "Arbequina) located at the Segria county (Lleida-Spain). Irrigation treatments where based on crop coefficients (Kc) (0.25, 0.38, 0.50, 0.57, 0.64, 0.71 and 0.85), which were applied to determine irrigation water requirement. Because olive trees were young and the shaded area was low, a factor that relates shaded area and water requirements (Kr) was applied for each treatment and adjusted at least twice per year. As a consequence, applied irrigation water was not only related to the Kc but also to the growth of the olive trees; therefore trees that received higher Kc grew faster and comparatively received substantially more water than the expected solely by Kc's. Not only vegetative growth increased with Kc's, also fruit yield and oil yield had a positive response; however % extracted oil from fresh fruits diminished with the increase of irrigation. The final consequence was that optimal Kc for oil yield (0.66) was considerably lower than optimal Kc for vegetative growth (0.74).