Keith, fyi.
ran across this article yesterday from MSU.
Potato late blight confirmed in Michigan
posted on June 25, 2010 09:34
Willie Kirk, Plant Pathology
Potato late blight was reported and has been confirmed in St. Joseph county in one field near Nottowa on Monday, June 21. With the thunder storms and heavy rains that have occurred in the state in recent days, it is important to be extra vigilant when scouting fields for late blight. Particular attention should be paid to pivot tracks and other such lanes created by farm machinery.
For further information on measures that should be taken when late blight is observed, refer to the Late Blight Extension bulletin. This bulletin is also available as a high quality downloadable .pdf file from http://lateblight.org. You can also get updates as texts sent to your mobile phone if you subscribe to Twitter, sign up link available also on the web site.