RELATION OF NUTRIENT CONTENT OF RUTABAGA LEAVES TO FERTILIZATION WITH N, P, AND K

Abstract

Rutabagas (Brassica napobrassica Mill., cult York) were grown at three locations per year for 3 yr in factorial experiments of four levels of N, P, and K. Uppermost mature leaves were sampled at the beginning of root enlargement, at harvest time, and once between these dates. The leaf tissue was dried, ground, and analyzed for total N, P, and K. Percent N in leaf tissue was substantially increased by applied N, increased by applied P at some locations, and decreased by applied K. Percent P was increased by applied P and somewhat by applied N but decreased by applied K. Applied K increased the K content of leaf tissues but applied P and N caused substantial decreases in tissue K. Tissue N, P, and K decreased as the crop matured. To prevent nutrient deficiencies, rutabaga leaf-tissue at the beginning of root enlargement must contain at least 4.1% N, 0.46% P, and 2.0% K. Optimum nutrient levels for good yields are in the ranges 5.4–5.9% N, 0.58–0.70% P, and 3.0–3.8% K at this stage of growth.