Abstract

Containerized seedlings of eastern redbud were grown in a greenhouse for 10 weeks with nitrogen application rates (NARs) ranging from 0 to 300 mg·L⁻¹. Seedlings fertilized with nitrogen (N) at 180 mg·L⁻¹ had the greatest leaf area, leaf dry weight, and total plant dry weight. Plants allocated more resources to root growth at NARs < 60 mg·L⁻¹. At NARs ≥ 60 mg·L⁻¹, allocation of carbon to roots and tops was constant, with a root:top ratio of 0.25. Foliar concentrations of N, phosphorus, and sulfur increased linearly with increasing NAR while concentrations of potassium were not affected by NAR. Foliar concentrations of calcium and magnesium responded quadratically with minimum concentrations at 240 and 180 mg·L⁻¹, respectively. Boron also responded quadratically with maximum concentrations predicted at a NAR of 175 mg·L⁻¹. Concentrations of copper decreased linearly with increasing NAR. Foliar iron, manganese (Mn), and sodium were not significantly affected by NAR. Foliar Mn concentrations were generally low and approached critical levels. Based on observed growth and the concentrations of various mineral nutrients, we conclude that during the first season of growth containerized eastern redbud should be fertilized with N at 180 mg·L⁻¹ per daily irrigation.