M.T. Windham, W.T. Witte, and R.N. Trigiano
R.N. Trigiano, M.T. Windham, and W.T. Witte
Powdery mildew (Microsphaera pulchra) of flowering dogwood (Cornus florida L.) has become a significant problem of trees in nursery production as well as in the landscapes and forests of the eastern United States. The disease significantly reduces growth and berry production by older established trees and may contribute to the inability of younger trees (liners) in production to survive winter dormancy. Disease resistance in named cultivars is limited to partial resistance found in `Cherokee Brave'—all other cultivars are extremely susceptible. Until now, the only disease control measure was to establish an expensive, labor-intensive, preventive fungicide program. We examined >22,000 seedlings and identified 20 that were extremely resistant to powdery mildew. Three trees with white bracts were selected from the 20 and released as patent-pending cultivars. `Karen's Appalachian Blush' has long, non-overlapping, pink fringed bracts with a delicate appearance. `Kay's Appalachian Mist' has creamy white, slightly overlapping bracts with deeply pigmented clefts. `Jean's Appalachian Snow' has large, strongly overlapping bracts with non-pigmented clefts. The three powdery mildew-resistant cultivars will be entered into an existing breeding program with `Appalachian Spring', a cultivar released by the Tennessee Agriculture Experiment Station and resistant to dogwood anthracnose, in an attempt to produce trees that are resistant to both diseases.
William E. Klingeman, David B. Eastwood, John R. Brooker, Charles R. Hall, Bridget K. Behe, and Patricia R. Knight
A survey was administered to assess plant characteristics that consumers consider important when selecting landscape plants for purchase. Visitors to home and garden shows in Knoxville and Nashville, Tenn.; Detroit, Mich.; and Jackson, Miss., completed 610 questionnaires. Respondents also indicated their familiarity with integrated pest management (IPM) concepts, pest control philosophy, recognition of flowering dogwood (Cornus florida) pests and diseases, including dogwood powdery mildew (Microsphaera pulchra), and willingness-to-pay a price differential for a powdery-mildew-resistant flowering dogwood. Fewer than half of the respondents in any city indicated familiarity with IPM, although they were familiar with organic farming and pest scouting components of an IPM program. Willingness-to-pay was relatively consistent across all four locations. The uniformity of average tree premiums, which ranged from $11.87 in Jackson to $16.38 in Detroit, supports the proposition that customers are willing to pay a substantially higher price for a landscape tree that will maintain a healthier appearance without the use of chemical sprays. Factors affecting consumer demand for landscape nursery products and services can be paired with consumer awareness of IPM terminology and practices to create an effective market strategy for newly developed powdery-mildew-resistant dogwood cultivars.
Robert N. Trigiano, Alan S. Windham, Mark T. Windham, and Phillip A. Wadl
; Ranney et al., 1994 ), the fungus Erysiphe (sect . Microsphaera ) pulchra (syn . Microsphaera pulchra ) is now recognized as the cause of annual epidemics in Tennessee ( Klein et al., 1998 ) and throughout the United States ( Li et al., 2009
Lauren Fessler, Amy Fulcher, Liesel Schneider, Wesley C. Wright, and Heping Zhu
1970s, dogwood anthracnose [( Discula destructiva ) Redlin] became a threat that grew over time ( Daughtrey et al., 1996 ). Eventually, dogwood anthracnose and dogwood powdery mildew, the disease caused by Microsphaera pulchra (syn Erysiphe pulchra
Margaret T. Mmbaga, Lucas M. Mackasmiel, and Frank A. Mrema
579 Mmbaga, M.T. 2002 Ascocarp formation and survival and primary inoculum production in Eysiphe (Sect. Microsphaera) pulchra in dogwood powdery mildew Ann. Appl. Biol. 141 153 161 Mmbaga, M.T. Sauvé, R.J. 2004a Evaluation for multiple disease