Ear Fill

Once the corn has committed to the size and number of ears it will produce, the only change the plant can make if growing conditions worsen is the number of kernels that will be filled on the ear. If conditions stay ideal, the big ear gets all of its kernels filled and makes the type of corn we like to sell. If lack-of-moisture or high-temperature conditions begin to put the plant under stress, it will concentrate its efforts at the bottom of the ear, aborting the kernels at the tip. Remember, the corn is interested in making the greatest number of healthy kernels. It will produce 350 plump, healthy kernels not 700 half-filled, withered ones. In fact, if stress occurs late enough in the process, the plant may actually begin to relocate moisture from already-filled tip kernels toward the bottom of the ear. This makes those tip kernels appear shriveled, as if not "fresh" but it is merely a way for the plant to ensure healthy viable seed to reproduce.

Before any kernel can be filled, it must first be pollinated. This occurs when the pollen from the tassel falls onto the silks of the ear. Each kernel has a silk attached to it, which serves as a transportation route for the pollen. If something interferes with this process such as insects eating the emerged silks, for example, some or possibly all of the kernels will go unpollinated and fail to develop into plump sweetcorn kernels. Instead, the cob will just remain flat where the kernel would have been. Pollination has a short window to occur, and is dependent on ample moisture (rainfall) to happen successfully.  If it fails to pollinate during this window, it won't.  One thing to keep in mind: pollination of the corn you are buying occurred three weeks ago.  The weather we have now may be substantially different than it was three weeks ago.