Root and Shoot Growth Response of Three Container-Grown Kalmia latifolia L. Cultivars at Two Locations to Growing Medium and Nitrogen Form
Rooted liners of Kalmia latifolia L. ‘Elf’, ‘Freckles’ and ‘Goodrich’ were shipped to Griffin, Georgia, and Puyallup, Washington and were potted into 3.8 liter (# 1) containers. Factorial combinations of growing media (1 bark: 1 peat, 4 bark: 1 peat), NO3/NH4 ratios (100% NO3/0% NH4, 60% NO3/40% NH4, 20% NO3/80% NH4), and rates of N (40, 80, and 120 mg N/pot; 0.0014, 0.0028, and 0.0042 oz N/pot, resp.) were applied at both locations. Results indicated that a combination of the nitrate/ammonium forms of nitrogen (60/40 NO3/NH4) and the 80 mg/pot N rate produced the best overall shoot and root growth on all 3 cultivars at both locations. Root and shoot growth was not affected by growing media at either location. With the exception of lower pH readings for the Georgia media, results for the two locations were remarkably consistent.Abstract
Contributor Notes
Horticulture/Landscape Architecture paper No. 89-13, Department of Horticulture and Landscape Architecture, Washington State University. This research supported in part by a R.P. White and a Martin Usrey grant from the Horticultural Research Institute, Washington, D.C. The authors wish to express their appreciation to Dr. F.A. Pokorny for his assistance with this research.
2Department of Horticulture, University of Georgia, Griffin, GA 30212.