Came across this today while looking for photos of sunflowers. This site contains VERY LARGE photos of different crops, such as wheat, sorghum, even bananas, and shows how they develop month by month. If you've ever wondered what a cornfield would look like in August, this is the place to look it up.
http://plato.wilmington.edu/faculty/tstilwel/Crop_Museum/living_crop_museum.htm