Location: Grape Genetics ResearchTitle: Effects of acute low temperature events on development of Erysiphe necator and susceptibility of Vitis vinifera Author
Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/1/2010
Publication Date: 11/16/2010
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. Interpretive Summary:
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.