With late crop development this year, we still have a lot of crops to walk. One excellent tool is the Corn, Soybean, Wheat and Alfalfa Field Guide – newly updated and in a new format this year will help with this chore. The Field Guide is available on OSU Extension’s eStore for sale, and may be ordered from county Extension offices as well.
This link is to the store for the hard copy version: http://estore.osu-extension.org/productdetails.cfm?PC=2845; the price is $12.50.
Many use their droid or iPad in the field and there is a digital version available now too: http://estore.osu-extension.org/productdetails.cfm?PC=2841, for $10.