Cornell Vegetable MD Paper: In High Tunnels, Diseases Are What You Make Them. Great overview of ways to reduce disease in your high tunnel, and possible problems you might encounter! http://vegetablemdonline.ppath.cornell.edu/NewsArticles/HighTunn.htm
Managing Diseases of Organic Tomatoes in Greenhouses and High Tunnels. Good overview from the national eXtension website. http://www.extension.org/pages/18337/managing-diseases-of-organic-tomatoes-in-greenhouses-and-high-tunnels#.VKeXMHv3gzw
Not sure if folks up here have dealt with this, but just in case – a paper from Cornell on Winter Aphid Management for winter greens in high tunnels. http://cvp.cce.cornell.edu/submission.php?id=261&crumb=greenhouse_and_tunnels|greenhouse_tunnels
From American Vegetable Grower in 2012, 20 practices to reduce disease in your high tunnel – Zero Disease Tolerance in High Tunnels. (compiled by Cornell University) http://cvp.cce.cornell.edu/submission.php?id=109&crumb=greenhouse_and_tunnels|greenhouse_tunnels
From the Minnesota High Tunnel Production Manual for Commercial Growers: Plant Diseases in High Tunnels: Their Pathology and Control (PDF). Originally from Pennsylvania State University. http://hightunnels.cfans.umn.edu/files/2012/11/13-Diseases.pdf
High Mowing Seeds blog post on Disease Prevention in High Tunnel Production. http://www.highmowingseeds.com/blog/disease-prevention-in-high-tunnel-production/
Maine Organic Farmers and Gardeners Association (MOFGA) fact sheet on Garden Weeds (PDF). Not high tunnel specific, but helpful nonetheless! http://www.mofga.org/Portals/2/Fact%20Sheets/FS%2006%20Garden%20Weeds%20web.pdf
University of California Integrated Pest Management Online Natural Enemies Gallery. http://www.ipm.ucdavis.edu/PMG/NE/
Pacific Northwest Insect Management Handbook online. http://insect.pnwhandbooks.org/
Alternative to chemical pesticides and other pest information from the Pesticide Action Network. http://www.pesticideinfo.org/Alternatives.html
Resource Guide for Organic Insect and Disease Management (order online - $20) from the Maine Organic Farmers and Gardeners Association (MOFGA)