To Keep it or Re-Seed it?
In the last Wheat News Plus article “Hitting the SWHEAT Spot” discussed management strategies to achieve the desired plant stand to provide optimal yield potential for your winter wheat crop. But now since the snow has melted on most of the wheat fields across the province, was the rate you planted last fall the same rate that survived the winter?
I have received a few questions regarding termination already because the stands look thin. The short answer for now is that it is too early to tell. Winter wheat is a unique crop in that the decision to terminate and successfully establish another crop can be left quite late. Once the plants break dormancy and they start greening up, then stand assessments can start. Leave the termination decision as late as possible to give the wheat crop a fighting chance.
The concern is not so much with the early well established wheat but rather the later planted small wheat. Especially if areas of the fields were marginal during planting and seeding depth was reduced to get it out of the ground quick. These areas could experience more frost heaving and winter kill due to limited root growth. Clay soils are more affected by frost heaving compared to sandy soils. I would look at these areas first to perform stand assessments then move to other areas to get the whole picture.
Three factors that should be considered when making termination decisions are plant health, uniformity of plant distribution, total area of field affected. Looking at the chart below, you can have stands as thin as 7 plants/ft of row and still have 90% yield potential. However, if the plants are not evenly distributed and look unhealthy and or frost heaved, the yield potential could be significantly less.
When making replant decisions, it is imperative to look at the bigger picture. How does the rest of the field look? Do the poor spots represent 60% of the field or 5%? Try not focusing on just the poor areas (I know that is hard). The good areas could have 20 plants/ft of row with 100% yield potential. Using an aerial photo/drone image can help create a better image of the actual percentage of the field that is damaged.
If you are unsure about a stand and you are on the fence of keeping or terminating, my recommendation would be to give it a small shot of nitrogen as soon as the fields are fit to drive on. Continue to monitor the fields during April and early May. Unless the field is a complete write off, manage the wheat as if you are keeping it. If you wait until May and no nitrogen has been applied and keeping it is the right strategy then yield potential will be lost because the crop has likely starved for N during that time.
Keeping wheat in the rotation is extremely important. Whether you are in the market for straw or follow a strict crop rotation, terminating a field is not an easy decision. I realize no one wants a poor crop however; it is more than likely that the whole field is not terrible so make the best out of the good areas.