The Boston Globe published an article yesterday (9/13) called "Making Your Trip Green," on options for travelers to reduce their footprints. Agritourism is mentioned on the 3rd page. The short agritourism rundown mentions New England (in passing), California, specifically Sonoma County Farm Trails, and bicycle-touring agritourism in Southern Italy, with Virginia-based Ciclismo Classico.
Kim Schneider of the Grand Rapids Press News Service also wrote an article about fall activities, with a section dedicated to agritourism. You can read it here via the Michigan news site mlive.com. It's called "Fall: Football, farms, festivals, and foliage tours." That's a lot of F's!
Michigan agritourism sites mentioned in the article include michiganfarmfun.com, which has an online guide to farmers' markets and u-pick farms, and Michigan's official travel and tourism website, michigan.org through which you can access a list of farms and mills. For apple aficionados, michigancidermill.com lists cider mills not only in Michigan but also elsewhere in the country, and apple tour routes are mapped out at michiganappletours.com.