Minnesota soybean harvest is approaching in southeast Minnesota, but wet weather and late-season disease questions could delay progress, according to a University of Minnesota Extension crops educator based in Rochester.
Ryan Miller said early-maturity beans in the region have already shed most or all of their leaves, while longer-maturity varieties are still turning. A forecast calling for 2 to 3 inches of rain this week could slow fieldwork. Miller noted that operating heavy equipment on saturated ground is not advisable.
“We’re pretty normal, I would say. We may be a week or so ahead of schedule, maybe two, depending on where you’re at,” Miller said. He added that fields west of Rochester toward Interstate 35 have run ahead all season, and the Waseca area could be as much as two weeks early.
Minnesota soybean harvest pace and conditions
The latest U.S. Department of Agriculture Crop Progress report released Monday, Sept. 13, reflecting conditions the prior day, showed 1% of Minnesota soybeans harvested. That compared with none at the same time in 2025 and 2% for the five-year average. Nationally, harvest was slightly ahead of average at 6%, compared with a 3% average and 5% last year.
Weather has varied across the region. Areas north of Rochester through Goodhue and Dakota counties were very dry this summer. Counties along the southern tier were dry for an extended stretch before heavier rains arrived, Miller said. With limited late-season precipitation in parts of the area, he is cautious about yield prospects.
“We were a little drier than I like, so I don’t know if we’ll have super impressive yields,” he said. “I don’t think it’ll be an absolute disappointment. I mean, the crop looked pretty good.”
Stress, drought and uneven field appearance
Miller said a normally maturing soybean field yellows evenly before leaves dry and drop. In dry conditions, leaves can roll to conserve moisture, creating a silvery cast across fields. Without rain, plants on hilltops and coarser soils tend to die first, with dead patches forming and expanding. The U.S. Drought Monitor released Thursday, Sept. 10, reflecting Sept. 8 conditions, reported 94% of Minnesota was abnormally dry or worse.
Disease can also cause localized patches of early plant death, Miller said, though those often stay confined to areas within a field.
Red crown rot surveillance continues
Miller submitted plant samples this season to test for red crown rot, a disease that has been identified with increasing frequency in the North Central region. He said the pathogen was detected this year in Wisconsin, across the river from Winona County. Asked whether it has been confirmed in southeastern Minnesota, he said, “Not in this part of the state yet, as far as I know.”
Dean Malvick, a University of Minnesota plant pathologist, said on an August episode of Extension’s Strategic Farming Field Notes podcast that red crown rot was found in one southwestern Minnesota field a year earlier and is likely present in additional fields. He noted that leaf symptoms can resemble sudden death syndrome and brown stem rot. Red crown rot typically shows reddish discoloration at the soil line, while brown stem rot turns the stem pith brown.
Miller said the pith in his samples appeared healthy, suggesting they were not brown stem rot, though lab results were still pending. “It is quite a yield-limiting disease where it does occur,” he said. Malvick added that labs prefer plants that are not completely dead, which makes late-season sampling more difficult. Miller said future surveys may need to begin around the second week of August, which Malvick noted is when sudden death syndrome often emerges.
Pest pressure and insecticide options
Soybean aphids did not reach the treatment threshold of 250 per plant in fields that Miller scouted in southeast Minnesota, although he said some fields elsewhere in the state were sprayed. He noted that pyrethroid insecticides, once a low-cost option, are no longer effective against soybean aphids due to resistance. Remaining products cost about twice as much as generic pyrethroids, and there are fewer choices.
“It’s not like weeds where there are lots of options. There are really just a handful with insecticides,” Miller said.
Soybean growers concerned about disease pressures can find additional background on surveillance and management in why soybean disease detection must happen before symptoms.