FHB May Be Severe in Kentucky this Year

Wheat across central and west Kentucky (which makes up the bulk of the wheat acres in the state) has been in various stanges of flowering since early last week. Many fields are currently at full anthesis or slightly beyond.

As we all know, it has rained a lot over the past 5-8 days across much of the state. This wet weather, as well as temperature and humidty conditions, have resulted in a moderate to high FHB risk across most of central and west Kentucky. The windy weather before it started to rain, and now the rain, has greatly hindered fungicide applications aimed at Fusarium head blight suppression. Some spraying was probably possible on Monday and Tuesday of this week, but the current storm system moving through the state will effectively eliminate the possibility of ground spraying for today (Wed), probably tomorrow, and maybe into Friday-Saturday. Aerial application will also be challenged. The bottom line is that most wheat fields in the state will be highly vulnerable to FHB. By time spraying is possible again, it will be too late to spray most fields due to label restrictions. Plus, from a practical perspective, once infection has occurred, fungicides (which are not that good against FHB in the first place) are of little value.

I rarely prognosticate epidemics, but it seems that nothing is in our favor, and everything is pointing towards an significnat FHB episode in the state. Fields that were in full flower early last week may escape significant infection since they were beyond the most susceptible infection stage by the time the rains began. Likewise, crops that have yet to flower, may escape infection. But the acres that fit either of these two scenarios is rather small compared to the whole.

If it is any consolation, remember that when FHB pressure is high (such as I believe it is right now), fungicide-treated crops can still be severely impacted by both FHB and DON. That is, only 30-50% suppression can be expected when fungicides are applied under the best of scenarios. One final point. Some may be thinking that they wish they had sprayed while their crop while it was still heading out, but before flowering. Doing so would have provided little benefit against FHB due to the limitations of fungicides against FHB and the fact the new tissue that emerges after application would be (for all practical purposes), unprotected.

I am sorry to have to predict this gloomy situation. We will know how accurate my words are by mid-May. That is about how long it will take for FHB symptoms to be expressed.