Consequences of Water and Nitrogen Management on Growth and Aesthetic Quality of Drought-Tolerant Woody Landscape Plants
Two drought-tolerant California native plant species (a nonselected form of Ceanothus griseus var. horizontalis, C. griseus var. horizontalis ‘Santa Ana’, a nonselected form of Rhamnus californica, and R. californica ‘Eve Case’) and a widely planted non-native landscape species (Photinia fraseri) received the same total volume of water (63.8% ET0) over a 14 week period in one of four irrigation treatments (water applied daily, every three days, every five days, or every seven days). Each irrigation treatment also received one of three rates of nitrogen application (0, 20 g N/m2, and 40 g N/m2 [0, 180, and 360 lb. N/A]). The irrigation frequencies or fertilization rates had few significant effects on plant growth and survival. Selection of a cultivar of R. californica has resulted in increased growth rates and aesthetic quality, but has also increased susceptibility to root pathogenic fungi.Abstract
Contributor Notes
Appreciation is expressed to M. Goeden, D. Messore, and S. Gilbert for their efforts in the field, often under extreme conditions. We also express appreciation to the Horticultural Research Institute Inc., 1250 I Street, N.W., Washington D. C., 20005 and the California Association of Nurserymen, 1419 21st Street, Sacramento, CA 95814, for partial support of the study.
2Assistant Professor.
3Staff Research Associate.
4Extension Urban Horticulturist, Department of Botany and Plant Sciences, University of California, Riverside, CA 92521.
5Assistant Professor, Department of Plant Pathology, University of California, Riverside, CA 92521.
6Staff Research Associate, Current Address: Department of Entomology, University of Maryland, College Park, MD 20742.