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United States Department of Agriculture

Agricultural Research Service

Research Project: IMPROVING GRAPE ROOTSTOCK AND SCION PEST AND DISEASE RESISTANCE

Location: Grape Genetics Research

Title: Effects of acute low temperature events on development of Erysiphe necator and susceptibility of Vitis vinifera

Authors
item Moyer, Michelle -
item Gadoury, David -
item Cadle-Davidson, Lance
item Dry, Ian -
item Magarey, Peter -
item Wilcox, Wayne -
item Seem, Bob -

Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 1, 2010
Publication Date: November 16, 2010
Citation: Moyer, M., Gadoury, D., Cadle Davidson, L.E., Dry, I., Magarey, P., Wilcox, W., Seem, B. 2010. Effects of acute low temperature events on development of Erysiphe necator and susceptibility of Vitis vinifera. Phytopathology. 100:1240-1249.

Technical Abstract: In both warmer (e.g., South Australia) and cooler (e.g., Fingerlakes, New York) viticultural regions, the pre-bloom increase of foliar powdery mildew incidence is unusually slow. Because both experience relatively cold nighttime temperatures (e.g., > 4 deg C) in the period before bloom, we hypothesized that cold temperatures either increased host resistance via abiotic stress responses, and/or negatively impacted existing powdery mildew colonies. We showed that 2-8 deg C treatments pre-inoculation for 2 hours are sufficient to inhibit fungal penetration through induction of host resistance, even on susceptible cultivars of Vitis vinifera. However, this induced resistance is transient, peaking at 24 hours post-treatment. Cold treatments also slow fungal development post-inoculation by increasing hyphal mortality. Accounting for the observed effects of acute low temperature exposure may help improve forecasting of powdery mildew epidemics, particularly early in the growing season.

Last Modified: 7/23/2014
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