Water use in three apple cultivars from the second season to sixth season in a drainage lysimeter

Limitations in the availability of water for agricultural purposes makes necessary to improve irrigation planning and the use efficiency of this resource. Plant–water relationships have been study in apple trees but differences in water use among cultivars have received little attention. In this study, the monthly and seasonal water consumption in cvs. Fuji, Galaxy and Granny Smith were evaluated in a drainage lysimeter, located in field conditions in a Mediterranean environment of central Chile. Soil and stem water potential indicated that plants were not exposed to water stress throughout the experiment. The amount of water used increased exponentially from the second (368 L tree−1) to the sixth (694 L tree−1) growing seasons in the three cultivars. The monthly water use and crop basal coefficient (Kcb) varied among cultivars and increased with tree age. During fruit production (January and February) water use and Kcb increased exponentially with tree age, but linearly during vegetative growth (December and March). Galaxy cultivar presented lower leaf area (27%) but higher water use per trunk cross-sectional area and per leaf area (7% and 19%, respectively) than cv. Granny Smith, suggesting higher hydraulic conductance and/or stomatal conductance in the former cultivar.

► In this study, during five growing season, the monthly and seasonal water consumption of three apple cvs. were evaluated in a drainage lysimeter.
► The water use increased exponentially from second to sixth growing season.
► The tree water use and the Kcb showed a linear relation with the trunk cross sectional area (TCSA) for the three cvs.
► Galaxy cultivar presented higher water use per TCSA and per leaf area than Granny Smith, suggesting higher hydraulic conductance and/or stomatal conductance.