A weekly report prepared by the staff of the Ministry of Agriculture, Food and Rural Affairs (OMAFRA). If you require further information, regarding this report, call the Elora Resource Centre at 519-846-0941. Office hours: 8:30am to 4:30pm.
For technical information, call the Agricultural Information Contact Centre at 1-877-424-1300 or visit the OMAFRA website: www.ontario.ca/omafra.
OMAFRA FIELD CROP REPORT – FALL WEED MANAGEMENT TIPS
Many farmers have witnessed the value in applying herbicides in the fall to perennial weeds.
Often they will see a reduction in the population the next year and a delay in their shoot emergence. This allows the planted crop to have an advantage.
Unfortunately weather conditions around the time of application can be variable and can influence a herbicide’s effectiveness. Here are “top tips” to make the most of the application window.
1. Choose the most effective products, rate and tank-mixes for the perennial weed that you are targeting.
2. Apply when air temperatures are above 8C for a minimum of two hours after application. It is best to apply during late morning or mid-day so the targeted plant is taking up glyphosate during the heat of the day.
3. After a frost, wait two to three days before evaluating weed growth and if the target plants look fine and air temperatures are above 8C resume applications.
For example, milkweed is sensitive to frost. It would not make sense to apply glyphosate since its leaves are unlikely to absorb any herbicide.
Alternatively, dandelion and wild carrot would not be affected by the same frost event and one could resume fall applications based on the condition of the leaves. Improved control of Canada thistle into the next season has been demonstrated when herbicide applications were made after the first frost.
4. Wait a minimum of 72 hours after application to perennial weeds if you want to till the soil. The longer that you can wait after application before making a tillage pass, the more the herbicide will translocate within the plant and do a more effective job controlling the species.
For the full article visit fieldcropNews.com/2017/10/omafra-field-crop-report-october-5-2017.
