The bitter, deep cold that has hit Kansas this winter has producers worrying about the damage that might be occurring in wheat fields, most of which have little or no snow cover as sub-zero temperatures hit.
Kansas State University's agronomy department recently offered a update on what to consider when you are evaluating the outlook for winter-kill in wheat fields.
Agronomists say that the wheat has a better chance because cold came early and cold snaps have been frequent, allowing for good winter hardening of the crop. On the flip side, there have been significant warm-ups between cold snaps with temperatures dropping from highs in the 50s to lows in the low teens in only a day or two.
Root development helps wheat tolerate cold
Development of the root system also helps wheat tolerate cold better, agronomists say. A good crown root system and two or more tillers make them much less likely to winterkill that plants with few secondary roots and no tillers.
If soil temperatures fall into the single digits at crown level, winterkill is likely. At least an inch of snow will insulate the crown from the critical level. In the absence of snow cover, there may be potential for winterkill, especially on exposed slopes or terrace tops.
Planting depth is a factor in protecting from the cold
Planting depth also becomes critical when cold threatens. If the wheat is about 1.5 to 2 inches deep and has good contact with the soil, the crown should be protected. If planting was too shallow, winterkill is more likely.
Damage to the plants from fall infestations of Hessian fly or from winter grain mites, brown wheat mites, aphids and diseases such as crown and root rot can weaken wheat plants and make them more vulnerable to cold damage.
Plants that are killed by cold temperatures won't green up next spring. If they are damaged, they might green up but not be strong enough to survive.