New Year's Resolutions for Managing Weeds

It's that time when some of us resolve to do things better in the New Year. Here are some suggestions that may help to improve weed management:

1. I hereby resolve to learn more about which weeds are causing problems. Scouting for weeds is an important part of pest scouting, but weeds often get missed when looking for insects and diseases. Plan to assign the extra time in April, May and June when weeds are emerging to take a separate trip through the field looking for only weed seedlings. A weekly weed walk may be needed during this critical period, and in some cases twice a week. Note if weeds emerged before or with the crop, as these weeds are the most competitive ones.
2. I hereby resolve to learn more about how to identify weeds. For many of us, this may mean investing in a hand lens to help see the small identifying features of weeds. For seedling broadleaf weeds, you need to be able to see the cotyledon, or the first leaves that emerge, which are often a different shape than the mature leaves. You need to be able to see if they are in an opposite or alternate arrangement on the stalk. For weeds in the Smartweed family, like Lady's-thumb and buckwheat, you need to be able to see the ocrea, which is a sheath of tissue where the leaf connects to the stalk. For grasses, you need to be able to see the auricle, which wraps from the leaf blade slightly around the stem. You also need to see if there is a ligule, which is the fringe of tissue on the leaf blade where it folds away from the stem. Once you've learned these four terms - cotyledon, ocrea, auricle and ligule, you've already kept your resolution!
3. I hereby resolve to keep better records about my weed problems. Winter is the time to make field maps, which is the easiest way to track weeds. Although we know there will be weeds in every field, we don't know which species and in which part of the field they will be located. If a map is handy when you are out scouting, you can draw circles showing the weed patches, and jot down which species and how dense they are.
4. I hereby resolve to be more proactive with new weed problems. Buying some equipment like a hand sprayer or a wick wiper is a good investment. Plan to charge the wick wiper with glyphosate in the spring, and keep it ready when you find new weed patches. Put together a collection kit in a small cooler for plants that you don't recognize. We receive our best specimens when the roots have been loosened with a hand trowel, then the entire plant is placed first in a paper bag, then inside a larger plastic bag, and kept in a cooler with an ice pack. Add a pen or magic marker to note date and place and you're ready for the season.
5. I hereby resolve to use a stale seedbed to reduce my weed pressure. For crops that are planted in late May or early June, the stale seedbed technique can drastically reduce the annual weeds in your crops. Plan to start early as soon as the land is fit. A stale seedbed is set up with either a killed cover crop, or with early tillage to encourage a flush of weeds. A burndown by either herbicide or flaming is done immediately before planting. The key is to plant directly without disturbing the soil, which gives your crop a head start on any late emerging weeds.
6. I hereby resolve to get the newest edition of Publication 75, Guide to Weed Control. The 2008 edition is now available from your local OMAFRA offices, or by calling this toll-free number 1-888-466-2372, or from our website ontario.ca/crops. Look for the updated version on our website soon as well. This is a good investment for only $15 + GST (which is now only 5%!).

If you follow these 6 suggestions, you are already well on your way to a more successful weed management program in 2007. There are many variables that we can't control like rain, temperature and wind conditions, so if we prepare for those we can, we're starting the New Year off in the right direction.

Learn more

• Guide to Weed Control, OMAFRA Publication 75