1. Downy Mildew Robert Fairchild VWT 35

2. Introduction Serious grape pest since mid-1800s. Prevalent in warm areas with early spring rains/high humidity Economic impact depends on the grape growing region. Plasmopara viticola

3. Description of Pest/Weakness  Over-winters as Oospores in moist soil.  May over-winter as mycelium in buds or leaves that persist through winter.  Requires water for initial spread Photo from http://stcoemgen.com/2013/06/03/downy-mildew-2/

4. Biology of Pest  Disease Cycle Photo courtesy of http://maryam2230.blogfa.com/post-91.aspx

5. Damage Caused/Monitoring  Symptoms  Signs Photos of my Cabernet Sauvignon

6. Management  Cultural Control  sanitation  Mechanical and Physical  None identified  Biological  None identified  Chemical  Bordeaux blend (Cu & S blend)

7. References  Bettiga, L.J. (Ed.). (2013). Grape Pest Management, (3 rd Ed.). Berkeley: University of California Press.  Dicklow, M.B., (2013). Downy Mildews of Ornamental Plants. Retrieved on 4/22/2014 from https://extension.umass.edu/floriculture/fact-sheets/downy- mildews-ornamental-plants  Evert, R.F. and Eichhorn, S.E., (2013). Raven Biology of Plants, (8 th Ed.) New York: W. H. Freeman and Company.  Hoffman, U., (2008). "Optimization of downy mildew (Plasmopara viticola) control "in organic viticulture with low copper doses, new copper formulations and plant strengtheners, results of 20 years of on farm research"- In: Proceedings of Ecosostenible-wine; INCAVI - Jornades techniques internationals - Villafranca Penedes  Ontario Ministry of Agriculture and Food staff, (2012). Publication 370 - Guide to Greenhouse Floriculture Production: Chapter 8 - Major Greenhouse Diseases. Retrieved on 4/20/2014 from http://www.omafra.gov.on.ca/english/crops/pub370/pub370ch8.htm#fig84.  Winkler, A.J., Cook, J.A., Kliewer, W.M., & Lider, L.A. (1974). General Viticulture. Berkeley: University of California Press.

8. Questions?