These stages have some really fun names. As we mentioned, the first stage is called "the Silk Stage," or "Silking." The next two stages, "Blister" and "Milk" are when the kernels are fertilized and the embryo grows in size (becoming a blister on the cob), turns yellow, and develops a milky interior. 

During the "Dough" stage the starch inside the kernel becomes thick and paste-like. "Dent" is Stage R5, and the kernels at the tip of the cob begin to dry down and dent in. The plant still has significant moisture content in R5, but as it moves into the final stage, R6 or "Physiological Maturity," it dries and hardens. All the starches have been pulled back into the cob at this point, and the kernels are left filled sugar and develop their final coloring.  

Here is one of our farmers, Edward, harvesting his hybrid corn in the "Dent" stage, which he will put away as silage-- good feed for dairy cattle in the Winter.  Recently, the American Grassfed Association also recognized it as an acceptable feed for grassfed beef, even though it has some grain in it.  The concept behind silage is that the corn is cut when it is still quite moist (R5) and put into an airtight environment where anaerobic bacteria break down the cellulose and make the nutrients more available to the animals.  It's kind of like sauerkraut.