Temperature fluctuations can result in winterkill or freeze injury to soft red winter wheat. Cold
temperatures without snow cover for protection can cause damage to the crown of the plant
resulting in winterkill or injury. Plants with three to four leaves and well-developed roots are
most likely to survive. Winter wheat plants survive the winter by hardening during the late
autumn and early winter as temperatures gradually become cooler.
Extreme temperature fluctuations can cause heaving of small plants in late winter and early spring. Heaving is most like to occur in poorly drained soils. Wheat is at the greatest risk of spring injury if warm temperatures have caused it to break dormancy and are followed by freezing temperatures. Damage this time of year may occur over large areas of the field, but are usually most severe in low areas where cold air settles.
Wheat plants killed by cold temperatures will not green-up in spring and have a bleached tan appearance. Winterkill is usually most evident on hilltops and other unprotected areas. Wheat plants damaged by cold temperatures will have a soft, mushy, brown crown and secondary Roots will have died off. These plants may green-up in spring, but plants will not thrive and eventually die. Often this is a result of root and crown rot that infect the damaged crowns.
Count the number of plants per square foot to determine if the stand is adequate to keep or if planting to a different crop is the best option. Ideally, the stand should have 24-28 plants per square foot. However, a stand with 15-18 plants per square foot still has 75-80% of the yield potential of the ideal stand.
For more information contact Valerie Tate, agronomist for MU Extension at email@example.com or call 660-895-5123. MU Extension programs are open to all.
Valerie Tate is an agronomist for MU Extension.