Choosing the right silage corn hybrid for your operation is one of the most difficult but important management decisions you'll have to make, says Joe Lauer, University of Wisconsin extension corn agronomist.
"The second is timing harvest," he says. "It all starts with the maturity of the hybrid that you buy and the planting date, which kind of dictates when corn will be ready in the fall." Select a hybrid well-adapted for maturity, pest resistance and drought tolerance and analyze multi-location data, consistency of performance, traits and other factors. (See Don’t Gamble When Choosing Your Silage Corn Hybrids.)
Keep track of the maturity and planting date as well as when corn silks or tassels. "You can schedule your custom choppers by just counting out 43-48 days past that silk date, because that's generally when that corn field is going to be ready to be chopped." In a typical year – not like this past season – harvest usually starts when the kernel milkline is at a halfway point, usually around the first of September in southern Wisconsin.
After corn dents and the milkline starts to move, cut some plants and have their moisture content checked. “Then use a 0.5% drydown point per day to predict out when that field is going to be ready."
A field at 74% moisture, using the 0.5% moisture-loss-per-day estimate, would dry down to 70% in about eight days. At 70%, growers should start cutting if the crop is to be stored in a bag or bunker. If stored in a concrete stave silo, silage corn should have a moisture content of around 65% at harvest and at 60% if put up in an oxygen-limiting or glass-lined silo. “What you’re targeting is the storage structure; you have to fit the silage moisture to that structure,” he says.
To track moisture, some counties and universities offer silage drydown links. The University of Wisconsin’s is www.uwex.edu/CES/ag/silagedrydown.