To add insult to injury, Wisconsin, Minnesota and northern Iowa growers with hail-damaged cornfields in late July have been advised to grow sorghum-sudangrass as a replacement, says Dan Undersander.
“Don’t,” pleads the extension forage agronomist with the University of Wisconsin.
“That’s about the worst thing to plant now. You would get no tonnage, it only grows when the temperatures are above 80 degrees, and we’ll be past that in about two weeks,” he warns.
Undersander estimates that thousands of acres in the three-state area have been hit by hail. Some fields will be assessed as total losses. In many, corn was broken off at the ear and stopped growing.
“The first thing to do is talk to your crop adjustor,” he advises, to make sure you get paid for the value of the lost forage or grain. Then look at the nutrient value of the crop if you were to disk it down. For silage, harvest the remaining forage as the whole-plant moisture dries down, and make sure it’s at the correct moisture for ensiling. Lower stalks and leaves will ferment if harvested at 60-70% moisture – depending on storage type – producing a low-quality silage good enough for heifers and dry cows.
If the damaged corn isn’t harvestable and you need forage, the best crop to plant this late in the game is oats, the agronomist adds. “It has the most tonnage, and it will grow in cooler temperatures.” Oats planted during the first two weeks of August can be expected to yield 1-2 tons/acre dry matter in southern Wisconsin and less farther north, according to a release by Undersander and fellow Wisconsin agronomists Joe Lauer and Shawn Conley. Other small grains will yield less because they won’t head.
Corn planted the first of August can be expected to yield about 0.7-2.8 tons/acre dry matter in southern Wisconsin. Those were the yields of corn planted Aug. 1 in 2005-06 when killing frosts hit in October of those years.
Another option for damaged fields: growers could prepare them for winter wheat production, the agronomists suggest.