This year, conditions at seeding posed many challenges to growers which caused delayed and/or uneven emergence. This has resulted in fields which are now displaying differences in maturity.
As growers begin to make their pre-harvest weed control plans, the Canola Council of Canada is issuing an important reminder that glyphosate application must be carefully timed to protect the quality and marketability of canola crops.
In all fields, including those with variable maturity, it is critical to wait until seed moisture content is less than 30% in the least-mature areas of the crop before applying glyphosate. Applications made before the correct stage increase the risk of unacceptable residue in the seed. When making your assessment, here’s what to look for:
- By waiting until 50 to 60% seed colour change in the least-mature areas of the field, growers can be confident seed moisture will be at less than 30%.
- 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.
In addition to glyphosate timing, crops that mature unevenly can present other challenges at harvest. Here are some important things to consider:
- Swathing remains the best and least-risky option to manage uneven maturity.
- If time allows, leaving a pod shatter tolerant variety to dry down naturally can be a suitable, cost effective option to swathing and pre-harvest applications.
You can read more about these harvest options in this Canola Watch article.