David Gadoury's Presentation on Grape Powdery Mildew

I found a great presentation on powdery mildew given by Cornell's Senior Research advisor, David Gadoury from the Department of Plant Pathology at the New York State Agricultural Experiment Station in Geneva. This presentation was given on April 4, 2011 and is posted on the Oregon Wine Research Institute website. The presentation, including a 15 minute question and answer period is approximately 1 hour long.
The link is here (I found that the slide portion of the presentation took a little while to launch so you just need to be a little patient):
Everything You Always Wanted to Know About Grape Powdery Mildew and Several Things you Really Need to Forget
Some interesting points that David Gadoury makes:

• The cleistothecia is the overwintering body. They mature on the leaves and are deposited by rain into the grapevine bark crevices where they overwinter. There are some impressive images made using scanning electron microscopy to show this maturation.
• The susceptibility of the fruit to powdery mildew is a consequence of inoculation during pre-bloom, bloom, or shortly after bloom. After that period has passed, the fruit acquires an ontogenic resistance to powdery mildew. Gadoury mentions that this ontogenic resistance to powdery mildew may be related to the appearance of a Germin-like protein. Spraying during this time, up until 3-4 weeks post bloom, is absolutely critical for clean fruit at harvest.
• There are beneficial mites called Tydeid mites (Orthotydeus lambi) that have been shown to feed on powdery mildew colonies. These mites are killed by the usual spraying regimes including sulfur. The strobilurins are much less harmful to Tydeid mites, but there is resistance showing up in powdery mildews.

Here is the lifecycle of powdery mildew:

This was a really eye-opening presentation for me. I hope you can find the time to view it. You will find that it is well worth it.