Did This Week’s Low Temperatures Injure Nebraska’s Wheat?
|How low did it go? Following is a sampling of low temperatures April 14-15. On both days, all lows across the state were below freezing, according to State Climatologist Al Dutcher.|
Winter wheat producers are asking this question as they survey their fields and continue to wait for an extended spring warm-up.
Winter wheat that had not started to joint could suffer damage to the existing foliage. This damage will be evident almost immediately. At this stage the growing points would still be protected by the soil and should not be injured. The exception would be if the soil is very dry, has cracks, and is exposed to the wind. Dry soil cools down six times faster than moist soil.
Very little, if any, of Nebraska's winter wheat was at the joint stage when the coldest temperatures hit. This contrasts with 2012 when, by the week ending April 15, the USDA NASS Nebraska Weather and Crops Report reported 38% of the winter wheat was jointed. The average crop growth stage for the week ending April 15 is 6% jointed. (See 2012 CW article.)
For more information see the UNL Extension publication, Freeze Injury to Nebraska Wheat (EC132).
Extension Western Nebraska Crops Specialist
Figure 1. How freezing temperatures injure wheat at various growth stages. Winter wheat rapidly loses hardiness during spring growth and is easily injured by late freezes. (Graph adapted from A.W. Pauli for UNL Extension EC132, Freeze Injury to Nebraska Wheat.)