PLAINVIEW, Minn. — Late-planted crops in the ground are growing concerns over harvest in southern Minnesota. 

"What’s easily said is that crops are late," said David Kee, director of research for Minnesota Soybean. "We’re in a precarious situation with an arctic frost that could do us severe damage, but a late frost and we’d be in pretty good shape."

Kee and several University of Minnesota extension educators have been traveling from county-to-county on a plot tour as harvest looms around the corner for corn and soybean growers.

The consensus at the Sept. 3 field day in Postdam was similar that made at previous stops. Crops in southern Minnesota are showing signs of shutting down, not flowering or producing more pods.

What soybeans need more than anything right now are heat units, said Kee, which come from days with higher average temperatures and nights that stay in the 50s. Heat units push crops to the next development stage.

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"If we can get more of that, we’ll fill pods," said Kee.

The time crunch to harvest was expected by farmers across the state who had to get their crops planted later than normal. A couple weeks more in the ground can make all the difference for crop yields, said Kee.

In bin-buster years like 2016 and 2017, he said crops got in the ground the last week of April and first weeks of May. This year, most crop got planted in the last weeks of May and into mid-June.

"We’ve got a long history knowing that puts us against the wall," said Kee. "We’ve got to have good rain and we’ve got to have good sunshine."

Race to mature before a killing frost

According to Kent Thiesse, farm management analyst and senior vice president at MinnStar Bank in Lake Crystal, Minn., the biggest challenge for corn and soybean growers this year is getting crops to mature before a killing frost brings the growing season to a close.

The average first frost date in southeastern Minnesota is Oct. 15, said Thiesse.

It seems growers are going to need every one of the days up to then to be ideal.

The Southern Research and Outreach Center in Waseca reported that as of Aug. 28, growing degree units (GDUs) were down 5 percent from the average. The research center in Lamberton, Minn., reported a similar drag in GDU.

According to Lizabeth Stahl, extension educator at the University of Minnesota, corn is at least one stage behind average this year. That could result in reduced kernel quality and harvest issues, she said, along with the potential for more ear molds, ear drop, stalk rot and/or stalk lodging.

To see when the state's corn might reach physiological maturity this year, Stahl recently ran the Growing Degree Day Decision tool on the Midwest Regional Climate Center website, which uses weather data to predict crop development. Using a location in Martin County, the tool calculated the average first freeze to come on Oct. 13.

Storage, moisture concerns 

The earlier the frost the more likely crops will need to be dried before storage, said Kee. That comes at a significant cost to farmers, depending on which crop they have and how much of it they have to dry.

How long crops will be stored is price dependent, said Kee, and farmers will sell for what they can turn a profit on. If they can't profit, they'll hold onto it.

Kee said from 2005 to 2015, a large amount of storage capability was built by the farming industry.

"Back when prices were good, farmers invested in storage for years like this," said Kee.

At physiological maturity, moisture content of corn runs from 28 to 35 percent, according to Stahl.

She said for safe storage up to six months, aerated corn grain should be no more than 15 percent moisture and no more than 13 percent moisture for storage longer than that.

"One message is clear, we should be prepared to handle wet corn this fall," said Stahl.

Kee said there’s a limited amount of on-farm storage that should be considered because after it’s filled, crops have to be stored in fields. Farmers can save money on drying costs by having crops dry in the field, but crops stored outside degrade quickly, he said.