Aluminum Toxicity in Sweet Cherry Trees Grown in an Acidic Volcanic Soil

Abstract

Chile is the world’s largest exporter of sweet cherries. New plantings have been shifted to southern regions, where aluminum (Al) phytotoxicity could be a serious constraint on establishing orchards in acidic volcanic soils. This study investigated the effects of soil Al on growth and macronutrient uptake in non-bearing ‘Bing’ on Gisela®6 trees grown in 120 L pots containing volcanic soil with four concentrations of exchangeable Al (0.12, 0.40, 0.60, and 1.24 cmol kg−1). At the end of the first and second seasons after planting, the trees were destructively harvested, and individual organs were analyzed for dry weight, Al concentration, and macronutrient concentration. Increasing soil Al concentrations had a detrimental effect on nutrient uptake and growth, particularly in the second season. However, fine-root growth was significantly reduced from the first season and from low soil Al concentrations. In sweet cherry trees, Al was preferentially accumulated in root tissues and its translocation to aerial organs was restricted. In addition, Al accumulation in fine roots, in conjunction with a reduction in root growth, severely restricted the uptake of N, P, K, Mg, and, particularly, Ca. Therefore, soil acidity must be corrected to ensure the successful establishment of sweet cherry orchards in southern Chile.