Nutrient status of apple leaves not affected by three years of irrigation using partial rootzone drying

Partial rootzone drying (PRD) is a water‐saving irrigation technology that may affect apple (Malus domestica Borkh cv. Golden Delicious/Malling7)‐tree nutrition if applied for an extended period. The objective of this study was to test the hypothesis that long‐term application of PRD causes seasonal changes in macro‐ and micronutrients of apple leaves. The irrigation treatments were: (1) commercial irrigation as control (CI) and (2) PRD. After 3 years of evaluation, PRD irrigation had saved about 3240 m³ of water per hectare. Leaf xylem water potential was slightly lower in the PRD treatment than in CI. The seasonal concentration of macro‐ and micronutrients was comparable between treatments, although significant differences were found at times. The macronutrient concentrations were within the normal range in PRD apple leaves. All micronutrient concentrations were slightly above the normal range except for Zn, which was slightly below the normal range. No physiological disorders associated with plant nutrition were observed on leaves or fruits. Therefore, data suggest that PRD did not alter apple‐tree nutrition during the 3‐year trial. Thus, PRD may be feasible for apple production in Central Mexico. However, further studies need to be conducted in those regions where groundwater is the main water source for irrigation and rain is negligible, particularly during the growing season.