2024-06-14
Depending on where you farm, pre-seed herbicide application time could still be weeks away, so there is still time to think about how to maximize your pre-seed herbicide application this year.
When is it too cold to apply? Pre-seed application can be challenging due to variable weather conditions, products will performance best when temperatures are consistently warm, when weeds are actively growing with new green leaves and new growth emerging from the center of the plant, and there is low risk of frost.
Below are some temperature requirements and guidelines for pre-seed application:
Apply early or wait? If you have been dealing with a particularly problematic field, or problem weeds such as kochia, Russian thistle, narrow-leaved hawk’s-beard, or other hard to kill weeds, consider delaying your pre-seed herbicide application to allow these weeds to germinate, be in a better stage for application, or for the weather to improve, which will increase the probability of getting better control prior to seeding. Some products also have after seeding application options but be careful – once the crop is emerged it can be controlled by your pre-seed herbicide, so check the label thoroughly before considering a post-seeding application.
Maintain recommended water volumes. It is important to maintain your water volumes for pre-seed application, as many weeds are likely small, plus growth may be slower due to cool temperatures. This is especially important if you are applying a contact herbicide where coverage is critical to maintain performance.
Follow label recommended application rates and weed staging. As with water volume, application rates are important to maintain performance. Do not cut back rates as performance can be reduced. If weeds are not emerged or are already past the recommended stage for application, product performance may be reduced.
Contact or systemic herbicides – which is better? For some crops, you can choose either contact or systemic herbicide options. Both have strengths and weaknesses. Contact herbicides usually act quickly, but only control the part of the plant on which they were sprayed, so lots of water and warm sunny temperatures are important. Contact herbicides usually have little residual activity, so they are well suited for sensitive crops such as pulses or canola. Systemic herbicides are absorbed by the plant and taken into the root system for complete control, but rely on good growing conditions for best control, so cool conditions are not ideal. Depending on the product they can have residual activity, so they are often best suited for cereal crops. Contact and systemic herbicide combinations can sometimes be better than either product alone. For comparison, the chart below lists common pre-seed herbicide groups. The most common herbicide groups for pre-seed are 2, 4, 6, 9, 13,14 and 15. It can be confusing – if you are not sure how to choose a product, contact your AgraCity representative and they can help you choose the best products this year.
The Mode of Action, Site of Uptake, and Symptoms of Different herbicide Groups
Information in this chart courtesy of Saskatchewan 2020 Guide to Crop Protection
AgraCity Pre-Seed or Reduced Tillage Products
AgraCity can help. AgraCity has a complete line-up of pre-seed products for every acre on your farm. Just go to AgraCity.com. or call AgraCity at 1-833-832-7637and one of our agronomists can help you find the best performing, cost competitive product for all your acres this year.