Unseasonably cold weather over the Memorial Day weekend have some producers concerned about frost damage to their wheat crop. Some are even thinking about abandoning their wheat fields under the assumption that all is lost. Indeed, temperatures were as low as 30-35F in some areas and a few frost-damaged spikes are beginning to show up in some fields; however, is the problem severe and widespread enough to justify abandoning your crop? Before you make a decision, here are a few things to consider:
1. Your concerns may be justified since wheat is most sensitive to frost damage during the heading and flowering growth stages, since freezing temperatures at these stages may lead to sterility. However, if pollination has already occurred, your crop may be safe since, as the developing grain is less sensitive to cold temperatures. You can tell by opening a few florets at several locations across the field and examining the grain. The presence of healthy, greenish-white, developing grain is a good sign. Injured kernels are usually shriveled and whitish-gray in color.
2. Did it get cold enough for long enough? Did temperatures drop below 30F for two or more hours? At the current growth stage, frost damage tends to be most severe when flowering-heads are exposed to temperatures of 30F or below for at least two hours.
3. Heads with extruded anthers does not necessarily mean that your crop is still at the sensitive flowering growth state. Anthers may still be seen hanging from the heads during early grain fill. So, double check your growth stage. Remember, wheat is less sensitive to frost at the early dough stage than at the flowering stage.