In Kansas, when is winter wheat most likely to suffer freezing injury?

Winter wheat is most susceptible to freezing injury after the jointing stage through the flowering stage in spring due to the plant's physiological development. As winter wheat progresses through its growth stages, it becomes increasingly sensitive to environmental stressors, particularly temperature fluctuations.

During the jointing stage, the plant is beginning to form its reproductive structures which are critical for yield. If temperatures drop significantly at this time, it can lead to damage to these structures, adversely affecting yield potential. Furthermore, once the plant reaches the flowering stage, it is even more vulnerable to freezing temperatures. If a freeze occurs during flowering, it can result in severe damage to the developing kernels, leading to additional decrease in yield and quality of the harvested wheat.

In contrast, during the tillering stage in late fall and the dormant stage in the middle of winter, winter wheat is generally more resilient due to its biological adaptations for surviving cold weather. While still needing protection from extreme temperatures, the plant’s growth processes are not as critical at these times, allowing it to withstand colder conditions. Thus, it is during the late spring stages that freezing temperatures pose the greatest risk to winter wheat.