Understanding the Conditions that Cause Freeze Damage in Wheat

Understanding the Conditions that Cause Freeze Damage in Winter Wheat Carrie Knott and Conner Raymond In four of the last ten years, conditions that should have caused freeze damage in wheat occurred in 2012, 2017, 2020, 2021. We know for sure that at least half of these, 2017 and 2021, did not result in major freeze damage. There are also reports that producers that harvested their 2012 wheat crops had yields much greater than expected. This brings into question the validity of “the” freeze damage table that most of the U.S. soft winter wheat producing regions follow. Dr. Chad Lee has shared that it appears that “the” freeze damage table may have been developed in Texas. However, over the years most every winter wheat producing region has adopted this table. It has become clear that this table is inadequate at predicting freeze damage in winter wheat. However, most practitioners are hesitant to dismiss this table entirely because it is the only guide available to help determine when to scout wheat for freeze damage. An alternative to dismissing the table is to develop a revised table. Revising the table will require the ability to manipulate wheat growing conditions at specific growth stages. Given that we have considerable data that is being and has been compiled by Matt Dixon of UK’s Ag Weather Center, we will have weather conditions from recent freeze events that we can test within a growth chamber to isolate why and when freeze damage occurs. For example, the questions we, and many producers and consultants, have are: Is freeze damage caused only by duration of temperature? Does relative humidity have a role in freeze damage? Is wind speed important? What about soil temperature? Can it ‘buffer’ freezing temperatures near the soil level? Does the speed at which temperatures warm impact severity of damage? We would like to request partial funding to allow the purchase of a growth chamber. We have been working with Conviron, a leading growth chamber company, to develop specifications and obtain an estimate for a growth chamber to facilitate this work since January. There are specialized parameters that will make this chamber unusual, but they assure it is possible to develop, such as duration of freezing temperatures at high humidity. We are working with Matt Dixon to fully understand some of these parameters to enable us to get an estimate. Although this is a bit unusual, we were hoping to obtain feedback from the KySGGA to see if there is interest in this project and what level of funding the Board would be able to fund. We suspect the total cost for such a specialized growth chamber will be >$75,000 (possibly much greater than that). We plan to pursue additional funding sources to fully fund this project should the Board think this is a worthwhile investment. Any feedback from the Board about this project is welcome and appreciated.