Boundary-Line Approach to Determine Minimum and Maximum Leaf Micronutrient Concentrations in Wild Lowbush Blueberry in Quebec, Canada

Abstract

Minimum and maximum leaf micronutrient concentrations in wild lowbush blueberry (Vaccinium angustifolium Ait.) were determined under the climatic and edaphic conditions of the Saguenay–Lac-Saint-Jean region (Quebec, Canada). The boundary-line approach was used to determine the relationship between leaf micronutrient concentrations and yield. The data were obtained from nitrogen and phosphorus fertilization trials conducted from 2001 to 2008 on 13 commercial lowbush blueberry fields in the Saguenay-Lac-Saint-Jean region. On average, more than 80% of the samples met the new minimum leaf micronutrient concentrations. Minimum leaf concentrations were revised downward for aluminum (Al), copper (Cu), iron (Fe), and zinc (Zn) compared to actual reference values. Minimum leaf boron (B) and manganese (Mn) concentrations were revised upward. Maximum leaf concentrations for all micronutrients were also revised downward. Minimum and maximum leaf concentrations were 26.2–73.5, 32.2–52.9, 3.2–6.5, 27.8–61.4, 873–1394, and 11.0–17.3 mg kg−1 for Al, B, Cu, Fe, Mn, and Zn, respectively. The determination of these new minimum and maximum leaf micronutrient concentrations established sufficiency ranges for the growing conditions in the region.