After a stretch of warm weather, an unseasonable cold front is set to hit Minnesota in the coming days, with many Minnesota counties south of St. Cloud in Freeze Watches/Warnings into the weekend.

Bruce Potter, an integrated pest specialist with the University of Minnesota, says farmers should be aware of the potential freeze damage to soybeans.

“Many of us have been through this before,” he said. “Most often things work out just fine for soybeans.”

Potter says Minnesota Extension agronomists will provide more information if things take a turn for the worse. In the meantime, he offered some points for growers to consider:

• Unlike soybeans, the growing point of emerged corn is still below the soil surface and protected from frost;
• Soybeans that have not emerged (including hypocotyl crook) will be OK;
• Soybean injury or death from freezing temperatures is more likely in low areas;
• Soybeans in the cotyledon stage are more freeze-tolerant than later stages;
• Temperatures will likely need to drop below 32 F for soybean seedlings to be killed. In an NDSU study, 50% of seedlings were able to tolerate temperatures as low as 24 F for a short time. In this same study, peas were similar to soybean, edible beans were less tolerant and alfalfa were more tolerant to frost areas; 
• Soil moisture, soil type and previous crop residue can influence freeze tolerance.
• Plants with a live growing point remaining can survive;
• Plants frozen below the cotyledons will be dead;
• Yield loss will be related to stand loss and soybean compensate well for reduced stands;
• You will need to wait several days to adequately assess stand loss.