This week's early frost could significantly damage Minnesota's soybean and corn crops, according to a state agronomist who thinks soybean yields could be down 10 percent on average.
Early frost crop damage tends to happen in isolated pockets, but University of Minnesota agronomy professor Seth Naeve said that doesn't appear to be the case this time.
"It was a freeze and a hard frost across the entire state, so the impact gets cranked up," Naeve said.
The premature freeze was aggravated by late planting. Wet spring weather meant some farmers got their crops in a couple of weeks late, meaning some corn and soybeans aren't as mature now as they normally would be. So they're more susceptible to freeze damage.
Naeve estimated that Minnesota soybean farmers may have lost 10 percent of their crop, though he cautioned that's an early estimate. Losses will vary by region.
Gene Stoel, chairman of the Minnesota Soybean Research & Promotion Council, said that in the area where he farms -- Murray County in southwestern Minnesota -- soybean farmers might lose 5 percent to 30 percent of their yields.
Stoel, who also grows corn, said area corn farmers might lose 5 percent to 20 percent of their yields. "We really won't know the extent of the damage until we get the combines out into the fields."
Minnesota is the nation's third-largest soybean producer, and its fourth-largest corn grower.
Jeff Coulter, a corn agronomist with the U's Extension Service, said much of Minnesota's corn crop was damaged by frost on Thursday. As much as 25 percent of the state's corn harvest might see a yield loss of 10 percent.
Still, arid conditions over the last 4 to 6 weeks in much of Minnesota have accelerated crop maturity, Coulter said. The more mature a crop is, the less damage frost does to it.
"I don't think we will have very big losses," said Greg Schwarz, a farmer near Le Sueur and president of the Minnesota Corn Growers Association. Still, he noted that farmers who got their corn in late because of wet weather are at risk.
The freeze issue isn't simply about yield, but corn quality. With a freeze, the husks of corn that's not fully mature can tighten. The kernels then may not dry properly and may be more susceptible to mold or fungus, Schwarz said.
Soybean quality can also suffer from a premature frost. Immature beans, which haven't yet yellowed, are less appealing to processors and therefore can command lower prices at the elevator, Naeve said.
The early freeze also affected crops in northern Iowa, eastern North Dakota and western Wisconsin, according to Bloomberg News.
Mike Hughlett • 612-673-7003