Most years, freeze injury to winter wheat is not a big concern in Ohio. However, wheat freeze injury was identified in several fields in the southern portion of the state where wheat was flowering during the May 2 and May 3 freeze events. In Piketon, Ohio, the air temperature was ≤30°F for four hours and reached a low of 27.2°F on May 3 (https://weather.cfaes.osu.edu/).
Previously, Dr. Carrie Knott from the University of Kentucky found severe damage to winter wheat when temperatures were ≤30°F for four hours and reached a low of 28°F, with yield losses ranging from 60 to 85% (Knott, 2020). (Video summary of Dr. Knott’s research on wheat freeze damage: https://www.youtube.com/watch?v=xAOBKJoiZ5k&t=148s). Freeze injury at flowering can cause sterility, embryo death, or complete loss of the spike. In a controlled environment study at Ohio State, there was a 19% reduction in seeds per head when the temperature dropped to 27°F for 15 minutes (relative to plants held at 40°F) when wheat plants were flowering (Alt et al., 2020).
It is extremely challenging to assess fields for freeze damage because of variability across the field and within the wheat head itself. When scouting fields, check low areas where freeze damage is most likely and compare to higher areas. Look for discolored heads, awns, and spikelets. Portions of the head may have small or missing seeds (Figure 2). Examine spikelets from the top, middle, and bottom portions of the wheat head as flowering is asynchronous. It is possible only a portion of the head is damaged, depending on which part of the head was flowering at the time of freeze. Affected kernels may appear small, shriveled, or fail to develop entirely. If you suspect freeze damage, make sure to have your field assessed by a crop insurance adjustor before deciding next steps.
Wheat fields that were at earlier growth stages (e.g., heading but not yet flowering) at the time of the freeze event on May 3 are showing mostly normal flowering development so far, suggesting they may have avoided the most severe injury seen at flowering. On May 11, wheat at the Western Agricultural Research Station was flowering, with the female portion (stigma) white and feathery. The male portion (anthers) were yellow. Figure 1 shows a wheat spikelet with normal development.
Figure 1. Potential freeze damage to winter wheat, 2026. Photo credit: Gigi Neal, OSU Extension.
Figure 2. Dissected wheat spikelet showing the male (anther) and female (stigma) reproductive structures from normal wheat spikelet. From FactSheet: https://ohioline.osu.edu/factsheet/anr-93
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References:
Alt, D.S., Lindsey, A.J., Sulc, R.M., and Lindsey, L.E. (2020). Effect of temperature on survival and yield components of field-acclimated soft red winter wheat. Crop Science, 60, 475-484. https://acsess.onlinelibrary.wiley.com/doi/10.1002/csc2.20087
Knott, C. (2020). Estimated winter wheat yield reduction following spring freeze events in field conditions. Crop, Forage & Turfgrass Management, e20080. Available at: https://acsess.onlinelibrary.wiley.com/doi/10.1002/cft2.20080
Lindsey, L., Alt, D., and Lindsey, A. (2020). Freeze symptoms and associated yield loss in soft red winter wheat. Ohioline FactSheet ANR-93. https://ohioline.osu.edu/factsheet/anr-93
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