Leaf and Fruit Mineral Nutrient Partitioning Influenced by Various Irrigation Systems in 'Fuji' Apple over Four Years

摘要

Increasing water shortage crises, meshed with an increasing demand for newer cultivars, higher orchard density, and different canopy architectures mandates the study of the impact of various irrigation systems and rates of water application on tree growth, fruit quality, yield, and mineral partitioning. In a long-term study between 2004 and 2007, use of crop evapotranspiration (ETc), when a precise crop coefficient value (Kc) was used, provided a reliable tool (irrigation scheduling) for determination of the water requirement for 'Autumn Rose Fuji' apple (Malus x domestica Borkh). In this process, the crop coefficient was modified by percentage of ground shade (GS) and tree canopy maturity (M). Application of water at full ET rates through a full sprinkler (FS) or full drip (FD) system increased the size of tree canopy and leaf area and increased yield per tree and leaf K but reduced leaf Mg and Zn. Application of irrigation through a FS system decreased percentage of dry matter in the fruit but increased leaf Cu concentration and is potentially a preferred method for areas with Cu deficiency. Leaf Ca concentration in trees with a FS system was higher than those with a FD system but no significant differences were found among different irrigation systems in fruit Ca concentrations. A greater volume of water was delivered to trees under full-micro-jet sprinkler systems than those with drip systems. However, application of water through a drip system, calculated based on full ETc rate and adjusted for ground cover, resulted in major water saving and often improved yield.