Look closely to assess weed size and number

Lots of crop scouts say fields don’t appear to be “greening up” that much with weeds, but once you get out and scout closely there are lots of annuals emerging, and some perennials and winter annuals are more advanced than expected. Erin Brock, CCC agronomist for the Peace region, took these photos (see below) this week. At first glance from the road, this field looks clean and ready to seed. But on closer inspection, including a look under crop residue, she discovered that a large weed population had already emerged.

Growers should take a close look at the weed spectrum and stage in each field prior to planning early season weed control. This is important information to help growers with this key decision: “Do I seed first or do pre-seed burn?” (See the next article.)

Weeds such as cleavers, which will degrade a sample and can be difficult to control in-crop when past the 2- to 4-whorl stage, are especially important to hit early with a pre-seed burnoff. Refer to product labels, company representatives or the provincial guides to crop protection for application rates based on the size and type of weeds present. Also this time of year, frost damage will impede herbicide uptake. After a hard frost, wait until daytime temperatures warm up and weeds start growing again before spraying. Again, check product labels for post-frost instructions.