Sub-freezing temperatures in the northern third of Minnesota late Thursday and early Friday may have damaged crops, particularly wheat and soybeans, that were just starting to emerge from the ground.

Agronomists in Minnesota and North Dakota on Friday quickly arranged an online seminar for farmers in the two states to assess the effects of the overnight temperatures that fell into the 20s and 30s.

The lowest temperatures were in northeast Minnesota, with Cotton, about 45 miles north of Duluth, falling to 19 degrees, a record low. In Bemidji, the overnight low was 24, also a record. In Crookston, in northwest Minnesota, it was 37, lowest temperature for the date in a decade.

Farther south, temperatures in the upper-30s and low 40s may simply have wilted leaves on soybeans and corn.

"It's that upper third of the state, give or take, where it did get cold enough to cause issues," said Jared Goplen, an educator with the University of Minnesota Extension. "The funny thing with cold temperatures is the effects tend to be so specific. You can see problems in some areas of a single field and not in others, depending on where that cold air sat."

On the Minneapolis Grain Exchange, spring wheat prices rose on the perception that the cold weather hurt the first major crop of the year. Before the cold snap, spring wheat was growing well ahead of the five-year average, with 93% of the state's crop emerged.

"It's impacting the wheat the most, but some of the corn and beans could be a little damaged from that," Chuck Shelby, president of Risk Management Commodities, told Reuters.

Soybeans were also more likely to be damaged than corn because the growing point of soybean plants is already above ground, while the growing point of corn plants is still below the surface, Goplen said.

Earlier in the week, the U.S. Department of Agriculture reported that half the soybeans and three-fourths of the corn planted in Minnesota had emerged. Because of generally good weather for the last two months, the state's farmers were well ahead of five-year average in planting all the major crops.

University and extension researchers were gathering information from farmers as they were able to get in fields later Friday. Some reported seeing leaf damage, but that may not necessarily indicate a dead plant. In a worst-case scenario, sub-freezing temps may have killed the plants and will force farmers to buy new seed and replant.

"I don't think we got cold enough that we're going to have widespread plant death, but there may be some areas that need to be replanted," Goplen said.