Selecting Wheat Varieties
Carl Bradley—Extension Plant Pathologist
Bill Bruening—Research Specialist
Dave Van Sanford—Wheat Plant Breeder
Kentucky wheat producers have a critical decision to make at this time of year: choosing the wheat varieties that they will plant this fall. Year to year climate variability means that certain traits may be more important in some years than in others, but there are always several “must have” traits. Yield and test weight are at the top of everyone’s list, but disease resistance, early maturity and straw strength are essential as well.
It is important to select well adapted varieties that demonstrate stable performance over years of testing. While early maturity is important for double-cropping, growers should select varieties that differ in harvest maturity so that all of the wheat is not ready to combine at once. Risk can be reduced by selecting varieties that have demonstrated track records of good yield and test weight, in varied environments.
Growers with an interest in straw or forage yield should pay particular attention to those data in the variety bulletin.
The risk of spring freeze can be high in Kentucky but can be minimized by following this rule: late flowering varieties should be planted first in the fall, and varieties that head early should be planted last. We have observed that in years with severe spring freeze damage (e.g. 2012), early heading varieties planted too early in the fall have been most damaged by the freeze. Selecting varieties that differ in heading date will also help growers avoid planting two varieties that are actually the same genetic line licensed under different brand names. Other traits such as height, head type and straw or forage yield potential, will also help growers avoid these potential branding issues.
Maturity is also important when considering head scab or Fusarium head blight. In some years with heavy scab pressure, early flowering varieties may be hit hard; in other years, later flowering varieties may face more intense scab pressure. Though scab was not a serious problem for most growers in Kentucky in 2019, our wheat crop is always at risk because the fungus that causes head scab (Fusarium graminearum) is abundant in Kentucky.
There are no varieties that are completely immune to scab, but a number of agronomically productive varieties with moderate scab resistance can be found. To minimize the risk of serious losses to head scab, growers should plan to use varieties with demonstrated resistance and be ready to apply the right fungicide at the proper time if conditions favor scab during the window when infection can occur. While fungicides can be an effective tool to reduce losses from head scab, susceptible varieties can still be severely damaged in years with heavy scab pressure in spite of a timely 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. Although head scab generally was not a major problem for Kentucky farmers in 2019, ratings were made at one location, and data were collected for leaf and glume blotch through the UK Wheat Variety Testing trials.
Results of the 2019 UK Wheat Variety Testing trials, as well as results from past years, are available at http://www.uky.edu/Ag/wheatvarietytest/.