Can graphical vector analysis be used to identify micro nutrient deficiency?

Initial analysis of needle nutrient status and visible symptoms suggested that a declining Norway spruce (Picea abies L. Karst.) stand in south Sweden was suffering from B and Cu deficiency. Effects of addition of 1000 kg ha super(-1) of a commercial N-free fertilizer containing macro nutrients plus B, Cu, and Zn were investigated. B concentrations and B/N ratios were increased significantly in needles from fertilized trees compared to the control, to levels well above critical levels of deficiency and optimum nutrient ratios. In contrast, the treatment did not change the low needle Cu status and there was no effect on growth measured as needle mass after one growing season. Graphical vector analysis together with the absence of change in needle mass suggested a luxury uptake of B. Application of the concepts for critical levels of deficiency and optimum nutrient ratios in relation to N suggested B and Cu deficiency were contributing factors to the observed forest damage in the area. Graphical vector analysis requires a rapid response in needle mass, in combination with improved needle nutrient status in order to identify nutrient deficiencies. The applicability of the technique appears to be limited to primarily growth-promoting nutrients.