By Scout Nelson
Farmers across North Dakota are encouraged to inspect their corn and soybean fields for frost and freeze damage after the first fall cold snap from September 5 to 7.
Weather stations in the state recorded temperatures near or below 32 degrees Fahrenheit, with some locations dipping into the upper 20s for several hours.
Agronomy experts recommend checking fields about five to seven days after a frost to see full damage. Tissue that looks green soon after freezing may already be dead but not yet discolored.
Cold air often settles in low areas, so farmers should look closely at swales and drainage spots for the most severe injury.
Corn is highly sensitive to prolonged freezing. Damage depends on how cold and how long temperatures stay low, as well as the crop’s stage of growth.
At the R4 soft dough stage, a killing frost can reduce yield by up to 55 percent, while a light frost may cut yields by 35 percent. At R5 dent stage, losses range from 25 to 40 percent. By R6 black layer maturity, yield loss is minimal even after frost.
Soybeans also face risk if frost hits before maturity. Plants at the R5 beginning seed stage can lose 75 to 80 percent of yield, while those at full seed R6 can lose 20 to 40 percent.
Once soybeans reach R7 beginning maturity, yield losses fall to 0 to 5 percent, and fully mature R8 beans are unaffected.
Experts advise leaving frost-damaged soybeans in the field to dry and ripen naturally before harvest. Seed coat color varies with drying conditions; sunny, dry weather encourages a normal golden color, while cold, wet weather may leave beans with a green tint that elevators may discount.
By checking fields promptly and understanding growth stages, farmers can make smart harvest and marketing decisions to protect yield and crop quality.
Photo Credit: gettyimages-chrisboswell
Categories: North Dakota, Crops, Corn, Soybeans