Crooked leaders and nutrition in Fraser fir Christmas trees

Abstract

Current-year foliage from the upper crown of Fraser fir (Abiesfraseri (Pursh) Poir.) Christmas trees with normal and abnormally spiraled or crooked leaders was sampled monthly between July and November over a 3-year period. Bark, wood, and small roots were also collected in November 1988, and foliage was collected from the upper whorl and leader on two dates in 1989. Concentrations of several nutrients varied significantly between crooked and straight trees in some years, but not across all years. With several elements, changes in concentration during the growing season were inconsistent across years. Some differences were too small to be of practical significance; others favored trees with crooked leaders when compared with nutritional guidelines. Concentrations of all elements varied considerably among trees, and nearly all nutrients exhibited significant temporal changes in concentration during the growing season. Concentrations also varied by sampling position. Nitrogen concentration tended to be higher in the foliage of crooked trees. Because there was no consistent pattern of deficiency, excess, or imbalance for any particular nutrient, the crooked leader problem in Fraser fir appears to have no distinct nutritional basis.