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Consumers See Value in Disease-Resistant Dogwoods

W.E. Klingeman1, J.R. Brooker2, D.B. Eastwood2, B.K. Behe3, J.R. Riley2, and P. Knight4

1Plant Sciences & Landscape Systems & 2Agricultural Economics, Univ. Tennessee, Knoxville, TN; 3Horticulture, Michigan State Univ., East Lansing, MI; & 4Horticulture, Mississippi State Univ., Poplarville, MS

A paper from the Proceedings of the 12th Metropolitan Tree Improvement Alliance Conference (METRIA 12), Landscape Plant Symposium: Plant Development And Utilization, held in Asheville, NC, May 23-25, 2002, co-sponsored by the North Carolina State University, North Carolina Division of Forest Resources, USDA Forest Service Southern Region, North Carolina Landscape Association, North Carolina Association of Nurserymen, The Landscape Plant Development Center, The North American Branch of The Maple Society, and The International Ornamental Crabapple Society.

Overview and Objectives

Native flowering dogwoods (Cornus florida) are key components of eastern U.S woodlands and were present in 83% of landscapes surveyed in metropolitan Atlanta (Braman et al. 1998). Tennessee nursery producers grow and sell more flowering dogwoods, which account for 16% of TN sales, than the next two leading states, North Carolina and Oregon, combined (USDA, 1998). Annual TN sales of flowering dogwoods exceed $120 million. In 1994, dogwood powdery mildew (Microsphaera pulchra Cooke and Peck) became epidemic throughout the eastern U.S. (Klein et al., 1998; Ranney et al., 1995). The severity and recurrence of powdery mildew outbreaks, across the range for Cornus florida, has increased production and maintenance costs associated with this attractive ornamental tree. Consequently, cost estimates to produce an acre of dogwood, during a 3-year period, have risen from $290 (Badenhop et al., 1985) to $1,075 (Windham and Riley, unpublished data).

Disease resistance characteristics, both for powdery mildew and dogwood anthracnose, have been discovered (Windham and Witte, 1998). Trees are already being grown for commercial sale. However, limited information exists about consumer willingness-to-pay for value added traits -- like disease resistance. In 2000 and 2001, a consumer survey was conducted at "home and garden" shows in four metropolitan cities. Our objectives were 1.) to quantify the relative importance of ornamental characteristics when consumers are purchasing an ornamental tree and 2.) to determine if consumers perceived "added value" for powdery mildew disease resistance in a flowering dogwood tree. A portable display provided visual images and descriptive text that introduced respondents to the disease. Participants completed a two-page questionnaire that included a question designed to quantify their "willingness-to-pay" for a disease-resistant dogwood described as being "5-feet tall with a 1-inch caliper grown in a 5-gallon container". Consumers also rated the relative importance of 22 tree and shrub characteristics at point-of-purchase. Characteristics were evaluated among cities using X2 comparisons.

Results and Significance

We used "Contingent Valuation" techniques and "Maximum Likelihood Estimations" to determine an average willingness-to-pay value among consumer responses that ranged from $0 to $30 "more." Results of this survey indicate that retail consumers are willing to pay a $13.35 premium for a powdery mildew resistant flowering dogwoods. The positive response by consumers directly translates into increased profits for growers and landscape professionals. These profits are expected to provide incentives to develop other disease- or pest-resistant plants.

For more information, or to view "Consumer Perceptions of Landscape Characteristics, Disease and Pest Problems, and the Value of Powdery Mildew Resistant Dogwoods" (UTIA Research Series 07-01) and "Consumer's Willingness-to-pay for Powdery Mildew Resistant Flowering Dogwoods" (UTIA Research Series 02-02), please visit our web site at

Related References

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Format updated January 19, 2010