Canadian canola, cereals and pulse growers can protect their investments and help to maintain market access for everyone by carefully planning and managing their fall glyphosate applications. Glyphosate is an effective tool for pre-harvest perennial weed control but is not to be used as a desiccant.
If growers spray pre-harvest glyphosate when seed moisture content is above 30 per cent, traces of the product can be absorbed by the plant, leaving residues behind. Always wait until seed moisture content is less than 30 per cent in the least mature areas of the crop before applying glyphosate.pdf Click here to download the staging guide (1.07 MB)
Here's how to determine proper staging for your crop:
- Glyphosate should only be applied once seed moisture is less than 30 per cent. Applications made before the correct stage increase the risk of unacceptable residue in the seed.
- By waiting until 50- 60 per cent seed colour change, growers can be confident seed moisture will be less than 30 per cent. At this stage, seeds in the main stem will be green and firm to roll in the top third of the plant, mostly brown with some speckling in the middle third, and completely brown-black in the bottom third.
- Never harvest earlier than recommended. Check the product label and harvest once the crop and weeds are dry (typically 7-14 days after application) for optimal weed control.
Canola that matures unevenly can present challenges at harvest, including when it comes to fall applications of glyphosate. It is critical in variable maturity fields to wait until the least mature canola plants in the field are at less than 30% seed moisture. To learn more, you can read about timing glyphosate application on uneven fields here and watch a video of an in-field assessment here.
- Glyphosate can be applied when seed moisture is less than 30 per cent, in the greenest/least mature areas of the field. At this stage, the seed is firm and reasonable pressure from your thumbnail will leave a dent in the seed.
- Never harvest earlier than recommended; usually 7 days after application. Check the product label for the recommended PHI.
- Oats may not be accepted if treated pre-harvest – growers are advised to check with their grain buyer before applying glyphosate to oats.
- Malt barley will not be accepted if treated pre-harvest.
Glyphosate should only be applied when the seed is at less than 30 per cent moisture content in all areas of the field.
What 30 percent looks like:
- Peas: Most pods (80%) are yellow/golden brown; seeds in bottom pods are detached and rattle in pod.
- Lentils: 80% of the plant is yellow to brown. Seeds from the top third of the plant are fully-formed and firm; seeds from the bottom third are hard and tan-brown; pods rattle when shaken.
- Chickpeas: Plants are yellowed with mature pods. Seeds have changed colour and detached themselves from their pods; pods rattle when shaken.
- Faba beans: Leaves are drying down and stems are green to brown in colour; lower pods are dark brown/black.
- Dry Beans: 80-90% of leaves have been lost and 80% of pods are yellow.
- Never harvest earlier than recommended. Check the product label for the recommended PHI and use the Spray to Swath calculator at spraytoswath.ca to determine when it is safe to harvest the crop.
Note: Some customers have contract limitations on fall application of glyphosate. Talk to your grain buyers to ensure they know what crop protection products you intend to use, and to confirm that none of these products will cause concern for export or domestic customers.
Glyphosate is an effective and valuable tool, but it is under increased consumer scrutiny. By using glyphosate correctly and adhering to the following guidelines, producers can help to ensure the quality and safety of Canadian canola, cereals and pulse crops, and keep this product available for years to come.
Correct product use is just one of the ways you can protect your investment. Click here to learn how information found on the product label can help you Keep it Clean!