Good seed corn quality is something you know when you see it. You open a bag and find lots of foreign material, misshapen and broken kernels, and you know you don't have quality. But getting quality seed can be harder than recognizing it.
It starts with having the right equipment to process corn, and then operating it correctly. First, of course, it must be harvested gentler and dried on the ear. Sorting for off-types often happens when corn comes in from the field as it heads for the drying bin. These off-types would produce what are often known as rogue plants.
Once off the cob, grading and cleaning become paramount. Warner Seed Farmers, near Dayton, Ohio, use both mechanical sorters and an electronic color sorter. The color sorter consists of cameras that capture an image of each kernel. The idea is to detect infirmities, such as a tiny crack, that wouldn't be detected otherwise, and that can't be caught in the grader.
Once detected, a puff of air is automatically triggered by the brains of the color sorter. It's enough to knock the undesirable kernel out of the system. It may not a good kernel out too, but that doesn't appear to be a huge problem with their machine, Dan Warner says. It typically doesn't have a lot of extra, good kernels sorted out with ones that need to be removed.
The neat thing about the color sorter is that it can be set to your specifications, Warner says. If you want to really zero in and knock out more kernels, you narrow the specifications to be allowed. If you can live with kernels having slightly more variation, then you can widen the range. Kernels are ejected by the puff of air depending upon when the cameras say they are out of the desired quality range.
Once seed is sorted and graded, it's treated. All seed corn receives certain treatments. More are coming all the time. Warner relies on an expensive but effective seed treater machine to coat kernels evenly.
Then the corn is bagged. A germination tag is placed on each bag. Even for seed coming from storage from a previous year, it must be retested by law. In Indiana it must be 95% germination or higher. If not, the company is required to inform the buyer that it tests below that level.
This should be a good year for high germinations test results, based on early results so far, Warner concludes.