Agriculture & Natural Resources
Selecting wheat varieties Source: Dr. Carl Bradley, UK Plant Pathologist; Dr. Dave Van Sanford, UK Wheat Breeder; Bill Bruening, UK Research Specialist One of the most critical management decisions Kentucky wheat producers must make in late summer/early fall is choosing which wheat varieties to grow. Even though Kentucky’s climate is extremely variable from year to year, there are several must-have traits: yield and test weight are always at the top of the list, but disease and lodging resistance are essential as well. Growers should look for those varieties with adaptation to Kentucky’s extreme year-to-year climatic variation, and it is important that growers select varieties that differ in harvest maturity so that every variety is not ready to combine at once.
In short, wheat growers can minimize risk by planting varieties that have demonstrated track records of good yield and test weight, which complement one another for disease resistance and maturity. Straw or forage yield potential might be another issue to consider. The rule of thumb for minimizing the potential loss to spring freezes is that the first variety planted in the fall should be a later heading variety, and varieties which head early should be planted last. Significant spring freeze damage has occurred in past growing seasons in Kentucky, and in general, it has been early flowering varieties planted too early in the fall that have been damaged by the freeze the most.
Selection of varieties with differences in heading dates is also important to ensure that the varieties planted are actually different and not the same genetic line licensed under different brand names. Plant height, head type, and straw or forage yield potential, can also help navigate potential branding issues among a group of high grain yielding varieties. Maturity is also important when considering disease, in particular head scab.
In years when scab is a problem, early flowering varieties may be hit hard, while later flowering types may face less pressure, and vice versa depending on the season. Although scab was not a serious problem for most growers in Kentucky in 2018, our crop is always at risk because of the prevalent rotation in which wheat is planted after corn. While no varieties are completely resistant to scab, there are now a number of varieties which have shown moderate resistance.
Under heavy scab pressure, utilization of varieties with resistance and applying the right fungicide at the proper time can dramatically minimize damage. Fungicides are great tools that can be used to help reduce scab, nonetheless, susceptible varieties can still be severely damaged in years that are favorable for scab, despite the application of a fungicide. Though multiple characteristics need to be considered, variety selection is widely recognized as the simplest and most cost effective way to maximize production profitability. The University of Kentucky wheat variety performance data is available online at http://www.uky.edu/Ag/wheatvarietytest/.