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Taking control of a late seeding season

Read Time: 10 minutes

By Amy Dering April 20, 2018

You can’t change the weather, but you can make the best of it

The calendar says it’s the middle of April, but outside it looks more like the beginning of March. There is still snow covering the ground, and night-time temperatures are staying below zero. It’s not ideal, but with a few modifications, you can still have a successful seeding season.

Weed control

Before we can talk about seeding we need to set up for success by controlling weeds. It’s possible that we could see higher than normal weed populations in 2018 because many areas during 2017 were so dry, weeds in the seed bank were unable to germinate. When it comes to choosing your pre-burn products, a tank-mix partner with systemic properties (eg. Blackhawk®) added to glyphosate is a good option. If a contact tank-mix partner (eg. Heat LQ®), is being used it is important to use the registered water volume for proper coverage. Pre-burn products with residual control, such as Korrex™ II, could also be a good fit to control flushes of weeds in the early spring before wheat crops.

Herbicides work best on young, actively growing weeds when night-time temperatures stay above 5°C and day-time temperatures are above 10°C with sunshine. Herbicides could be slower acting if the temperatures stay cool and weed growth is slow. Consider the temperature and the size of the weeds when making your pre-seed herbicide choices.  

Phosphorus fertilizer

When seeding into cool soils, you’ll want to evaluate your phosphorus rate to ensure enough is available to the crop. Even if the soil is warm enough for germination (see Table 1), phosphorus availability could be significantly reduced. It would be ideal to have temperatures a few degrees higher than the minimum temperature required for germination at the time of seeding. Waiting for warm soils and increasing your phosphorus rate by a few pounds per acre will ensure enough is available to the crop. In a normal year, approximately 30% of the phosphorus applied becomes plant available.  One could assume more phosphorus will be available in soils with higher organic matter because the phosphorus binds less tightly to organic matter than it does to minerals such as clay.

If you are considering increasing your phosphorus levels be mindful of the seed safe rates of P2O5. Mosaic’s MicroEssentials® products including MicroEssentials S10™, S15™, and SZ™ are good sources of phosphorus with the benefit of improved seed safety.

Seeding rate

This spring may call for higher than normal seeding rates. Since we’re starting off cool, we can expect higher seedling mortality. Increasing your seeding rate can combat mortality due to frost, disease, or insects, and ensure proper plant populations. Consider bumping up your seeding rate by 5-10% to account for  less than ideal conditions. 

According to the Canola Council of Canada, the most important thing when it comes to seeding rates in any year is to use germination, vigor, thousand kernel weight (TKW), and disease presence to choose your ideal seeding rate.  

We are all anxiously waiting for spring’s arrival, but we can use this wait time to prepare for the crop season by planning the best crop and pesticide rotations, along with seed and fertilizer rates to maximize the effort put into each field.  

If you’d like to talk through your options for adjusting your spring plans, contact your local Cargill agronomist. We’re always ready to look at your situation and recommend a strategy that will work for you.


Blackhawk is a registered trademark of Nufarm Ltd. Heat LQ is a registered trademark of BASF SE. Korrex II is a trademark of Production Agriscience Canada Company, Dow AgroSciences and Pioneer and affiliated companies or their respective owners. MicroEssentials, S10, S15, and SZ are trademarks of The Mosaic Company..

MicroEssentials is a registered trademark and SZ is a trademark of The Mosaic Company.

Amy Dering

Amy earned her Bachelor of Science in Agriculture from the University of Saskatchewan in 2016. She then joined the industry, but always made sure she was close enough to help out on the family grain farm. Amy’s favorite parts of being on Cargill’s Agronomy team are the opportunities to expand her knowledge of insects, diseases, and weeds, as well as the possibilities to try new products and practices with growers.