Evidence of the freezing temperature causing damage to winter rye has just started to become visible in recent days (Photo 1). Affected florets have bleached appearance. When you pull back the glumes you will see that the anthers halted development and have not been extruded/pushed out. Neither are any kernel developing in these pale white florets.
|Photo 1 - Frost damage on individual spikes of rye. Notice the pale, bleached glumes of the affected florets and the absence of extruded anthers.|
I suggest that you contact your crop insurance agent if you have multi-peril crop insurance on your winter rye as this frost damage may fall under the adverse weather conditions cause of losses.Source : umn.edu