Get the most out of your herbicide application

Weedy canola thistles Nicole Philp

—Tips for windy conditions. Too windy, according to the Guide to Crop Protection, is wind above 15 km/h. A low drift nozzle to spray weeds in windier conditions is preferable to waiting longer for a relatively calm day suitable for a finer spray. More tips on spraying in wind.

—Spray within label crop stages. Crop stage window for glyphosate-tolerant canola: Seedling to 6-leaf. Liberty Link: cotyledon to early bolt. Clearfield: 2- to 7-leaf for Ares and 2- to 6-leaf stage for Odyssey Ultra and Tensile. Read more.

—When to spray uneven crop. Patchy emergence due to a few weeks of dry and then a rain, or due to reseeded crop emerging among the few original plants, has created a wide range of stages in some crops. Make herbicide timing decisions based on the stage that represents the highest proportion of plants. And rather than planning on two applications, growers may be better off spraying once at the highest registered rate when weeds that are more advanced than the crop, and with rapidly growing canola plants.

—Clean out the whole sprayer, not just the tank. Herbicide residue can be in the booms, filters and herbicide filling pump, among other places. Here are tips for proper sprayer clean out.
A Canola Digest article “Contamination station” describes how the glyphosate left in the sprayer pump was enough to damage a whole Liberty Link crop.

—New products/new registrations. Just because a product is registered in Canada for use on canola does not mean that it should be used. In some cases, key market countries may not have approved the same product or have not set maximum residue limits (MRLs) for that product. Before using a new product, check with the delivery point to make sure canola sprayed with this product will be accepted. Keep It Clean: 3 things you need to know about pesticide use