Warm winter weather and the impacts to winter wheat stands
The beginning of winter 2020-21 has been warmer than normal. Recent weeks have seen some areas of Alberta reaching temperatures greater than 10°C for multiple days in a row. How does this impact winter survivability of winter wheat? Will the wheat break dormancy and die off? Will pooling water from snow melt drown the plants and starve them of oxygen?
In short, it’s too early to know for sure. There is no research data to indicate survivability risk of winter wheat due to warm weather. Just like any crop, summer or winter, there are numerous factors that will affect the crop’s survivability potential when stress occurs. Crop stage, available moisture, residue, seed health, disease presence, fertility, variety, and more will all affect a plants ability to survive external stresses.
In addition to this, no action can really be taken at this point in the crop’s life. Until we reach early spring and can begin assessing plant stands, it is a waiting game.
“We need to remember that winter wheat is grown all the way from the tree line to Texas. Somewhere along that line there are what we would view as “unseasonably warm temperatures” and the winter wheat doesn’t die,” says Paul Thoroughgood, regional agronomist with the Western Winter Wheat Initiative (WWWI).
Even though it’s both hard to tell what the impact will be and not much can be done at this point, there are a few things to keep in mind:
- Winter wheat has a history of looking poor during winter and early spring, while making surprising come-backs. In other words, don’t worry about what things look like now. Wait until spring when appropriate plant stand assessment can occur.
- If you have more than a few quarter sections of winter wheat and you are concerned about survivability risk, create a plan to determine where you will source seed in case the spring assessment of your winter wheat crop indicates the crop needs to be terminated.
- Walk away from the field and set yourself a reminder in early March to assess the field. If it’s still snow covered at that time, delay until the snow cover diminishes.
- Even in the spring, a winter wheat crop can give the impression the plants are dead or dying. A spring assessment is a good way to assess winter survivability. A link to how to conduct spring survivability can be found here: https://www.growwinterwheat.ca/growing-winter-wheat/spring-assessment/. Questions regarding spring assessments can be answered by the contract agronomist with the WWWI in Alberta, Monica Klaas. She can be reached at firstname.lastname@example.org.
- Target spring plant populations should be around 30 to 40 plants/ft-2. If your spring plant stand is significantly lower than this, it may still be worth keeping as indicated by research by Lafond and Gan, 1999. This research demonstrated that plant stands of 13.3 plants/ft-2 can still provide 91.6% of the yield that 30.4 plants/ft-2
For more information regarding winter wheat production in Alberta or the Prairies, refer to the following resources:
Winter Wheat Production Manual