The extreme heat, at or near 100 degrees, on May 8-10 has resulted “gaping florets” on wheat that was in the flowering stage when the heat occurred. The photo below was taken in Geary County on May 13, and the symptoms can still be seen in many fields.
The outer coverings of the floret or kernel are called the lemma and palea. The lemma is the one that has the awn at the top. Normally these plant parts cover the developing kernel until maturity. When exposed to heat stress, the florets will often become sterile and cause the lemma and palea to spread apart, or “gape,” prematurely.
There is no way to tell be looking at the anthers if they are sterile. The only way to tell for sure is to watch for kernel development. If the florets remain fertile, the kernels should develop normally. There is an increased chance of cross-pollination, however, with wheat from other fields. Wheat is normally self-pollinated.
Also, gaping florets during the pollination period can result in an increased potential for ergot to develop in the heads. Ergot is much more common in rye, which is a crop that often has floret sterility problems.