Yield response of almond trees to transpiration deficits

Irrigation optimization under limited water supply requires knowledge of the relation between consumptive use and production. The recent expansion of almond production is highly dependent on irrigation which may be limited by water scarcity in the future. A 3-year experiment was conducted in Cordoba, Spain, to determine the yield and water productivity (WP) responses of almond (cv. Guara) to irrigation deficits. Maximum yields of 2508.4 kg/ha (3-year average) were obtained when the crop evapotranspiration (ET C ) was fully met. Three deficit irrigation treatments that supplied 66.9, 69.7 and 43.2% of the full irrigation requirements yielded 2147.5, 2038.2, and 1496.9 kg/ha, respectively. Assessment of the consumptive use (ET C ) and its components, E S and T , yielded seasonal values of 1088, 887, 894 and 699 mm of ET C , of which T represented 831, 640, 648 and 479 mm, for the four different treatments, respectively. The relations between yield and irrigation, ET C , and T were used to determine the WP values as affected by water. Although values varied from year to year, the WP ET averaged 0.23 kg/m 3 for the 3 years and did not differ among treatments. The transpiration efficiency (WP T ) had a value of 0.32 kg/m 3 and was roughly the same for all treatments.