PARENT SESSION
Poster Session # 21: Biogeography, Biodiversity, Populations, and Genetics.
Thursday, August 7 Presentation from 5:00 PM to 6:30 PM. SITCC Exhibit Hall B.
The effect of altered rainfall patterns on leaf rust severity in Solidago canadensis.
McCarron, James*,1, Garrett, Karen1, Fay, Phil1, Dendy, Shauna1, Alexander, Helen2, Broeckelman, B1, 1 Kansas State University, Manhattan, KS2 University of Kansas, Lawrence, KS
ABSTRACT- Altered precipitation patterns predicted by climate change models may affect the incidence and severity of plant disease in natural systems. We studied the effects of precipitation patterns on incidence of a leaf rust caused by Puccinia dioicae on goldenrod, Solidago canadensis, a common native forb in tallgrass prairie. Growing season rainfall patterns were manipulated at Konza Prairie Biological Station by reducing rain event volume by 30%, increasing the length of the dry interval between rain events by 50%, or both, using rainout shelters fitted with sprinkler systems. An unsheltered plot and a shelter irrigated at ambient quantities and intervals were the controls. We rated goldenrod plants for incidence of leaf rust for four growing seasons, and used Poisson regression in a log linear model to examine how precipitation treatments affected incidence. Goldenrod in plots receiving reduced rainfall quantity, rainfall at increased intervals, or both, had a significantly lower incidence of leaf rust in the wetter year. In other years, proximity of a primary host species was a more important factor. Both quantity and pattern of rainfall inputs may affect disease incidence in native grasslands. In addition, we are modeling the effects of climate change, in terms of predicted changes in leaf wetness duration, on the severity of leaf rust and similar diseases.
Key words: puccinia dioicae , disease, solidago canadensis, altered precipitation