Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 4/1/2006
Publication Date: 6/1/2006
Citation: Li, Y.H., Windham, M.T., Trigiano, R.N., Fare, D.C., Spiers, J.M., Copes, W.E. 2006. Epidemiology of Powedery Mildew on Flowering Dogwood in Tennessee. Phytopathology 96:S186.
Technical Abstract: Powdery mildew, caused by Erysiphe pulchra (syn. Microsphaera pulchra) is an important disease on flowering dogwood (Cornus florida) in the Eastern United States. Temporal progress of powdery mildew on flowering dogwood cultivars with different levels of resistance was investigated in the field in 2004 and 2005. Disease onset was observed in late-May, followed by a rapid increase in disease severity until early- to mid-August. Thereafter, disease severity increased slowly. Using nonlinear regression analysis, disease progress curves were fitted to logistic models (R(^2) > 85%) and absolute rates and y(max) derived. Standard areas under disease progress curves (sAUDPC), absolute rates and y(max) were significantly different (P < 0.05) among dogwood cultivars in both years. Cultivar ‘Karen’s Appalachian Blush’ consistently expressed higher resistance with lower values of sAUDPC, y(max) and slower absolute rate in both years compared to a susceptible line of variety ‘Rubra’ and moderately susceptible cultivar ‘Cherokee Daybreak’.