Most farmers were at least two weeks late planting this year's corn crop. Shown is a partly flooded field near Anderson, Iowa. (The Minnesota Star Tribune)

The silver lining of a wet spring and delayed planting has been a rally in corn prices, and prices may rise more this Friday.

July corn futures on the Chicago Board of Trade have risen by nearly a dollar since early May to nearly $4.50 a bushel. Farmers are locking in prices for December 2020, and watching closely for data on acreage and grain stocks set to be released at week's end that will give investors a better picture of how much corn is out there, and could lift prices further.

"We needed a disaster to reduce the huge oversupply problem, and Mother Nature gave us the wettest spring on record," said Al Kluis, a commodity broker in Wayzata.

Corn and soybean planting was about two weeks late in Minnesota and much of the Midwest. Some 20% of the Ohio corn crop was unplanted as of Sunday, and almost one in 10 acres of corn hadn't been planted in Illinois, Indiana, Michigan and Missouri, according to the U.S. Department of Agriculture (USDA).

Corn prices, which had been in a five-year slump, flourished with the delayed planting, rising to their highest level since June 2014.

But farmers are mostly holding off on selling their stored grain until the USDA releases its market-moving grain stocks and June acreage reports on Friday.

"Most producers are sitting there waiting for the government to come out with their crop reports," said Doug Albin, a farmer near Clarkfield, Minn.

Albin said farmers are optimistic prices will increase further after the release, because they can't help but be influenced by what they see in their "backyards." In Albin's area, some farmers couldn't plant half of their corn because the ground was too wet. That makes him think the reports on Friday might paint a more dire picture of the coming harvest and drive up corn prices.

"Whether it's going to have a $4 or a $5 in the front of it, nobody knows," he said, referring to the price of corn per bushel.

A lot of farmers, Albin said, are using the recent upswing in corn prices to hedge on their 2020 crop, locking in December 2020 contracts for 5%, 10% or 15% of their expected crop that year.

For farmers, it's another set of calculations on a moving set of figures. While prices have risen, corn needs time to mature and dry before the harvest, and most farmers in Minnesota will reap a smaller harvest than usual in 2019.

"We're going to be short this year," said Jim Kanten, a farmer in Milan, Minn.

He said he's sold about 1,000 bushels of corn from storage in part to check on the condition of the grain in his bins, but he's holding onto the bulk of his corn in storage.

"I'm waiting a little bit to see where the prices go," he said.

Zach Rada, a farm business management instructor at Ridgewater College in Willmar, Minn., said the price increase and poor corn crop will be close to a wash for many farmers unless prices keep rising. But he has seen trucks full of corn lined up at the Bushmills Ethanol plant outside Atwater.

"I can't speak to every day but you see lines there, and you don't usually see that in the summer," Rada said. "The corn is moving right now."

U.S. corn prices are high enough that imports from Brazil are likely to start hitting the southeast and southwest U.S., said Kluis, the commodity broker, and despite the lower yields many farmers in the Midwest face this year, the higher prices should give farmers breathing room.

"Even if you only have 80% of yield potential you are now looking at a profit, and you're also looking at 2020 hedging in a modest profit," Kluis said. "The outlook has changed dramatically in two months."

Adam Belz • 612-673-4405 Twitter: @adambelz