Topics for the Week

Don’t let weeds get a running start

GET ON TOP OF THOSE WEEDS: scout, then spray. Early weed control always offers the best ROI and gives canola a competitive advantage. Spray sooner rather than later even if not all weeds have emerged.  (Weed control strategies for each HT system).
Short on herbicide? Know your water quality and check the label to see if an adjuvant to improve herbicide performance is an option. Herbicide applied at less than the label rate can lead to reduced efficacy and increased risk of resistance. A better option when herbicide supplies are tight may be to identify the weediest fields or problem patches and apply the correct rate in those areas first, then work backwards as herbicide supplies allow. (Spraying tips for tough conditions)

Slow-starting spring = buffet for flea beetles

Now is the time to scout aggressively for flea beetles. A cool spring to date means canola has been slow to grow, which makes it significantly more vulnerable to flea beetle damage. A few fields are already being reseeded due to feeding; many others are at or past the economic threshold. (The flea beetle spray decision: 8 steps)
Insecticidal seed treatment only provides good flea beetle protection for the first few weeks after seeding, especially in moist soil. If the crop has not reached the 3-4 leaf stage by 3-4 weeks post-seeding and flea beetles are still actively feeding, keep an extra-careful watch for feeding to pass the 25% action threshold.

Seeding at last!

Many fields in Manitoba, eastern Saskatchewan and the Peace region are finally dry enough to seed – hooray! However, big challenges remain: crusting, well-established weeds, nutrient losses and more. Despite the late date, careful seeding is as critical as ever. To give the delayed crop its best chance to reach maturity, target the higher end of the 5-8 plants/ft2 recommendation to achieve a higher density plant stand.
Fortunately, canola suffers a less significant drop in yield potential from delayed seeding than many other common prairie crops. Still, keep realistic yield expectations (approximately a 10-20% yield decrease) along with balanced nutrition in mind when making fertilizer decisions: apply enough nutrients to meet the crop’s needs without overapplying. Manitoba Agriculture soil fertility specialist John Heard recommends that growers who are unsure of nitrogen carryover levels apply an extra 50-100lbs to a nitrogen-rich test strip to guide decisions on a top-dress application.

Why are plants missing?

The only thing worse than seeing that a seeder mis-seeded, that fertilizer burned seedlings, or that disease or pests ate into an emerging crop is not catching the problem at all. While assessing emergence and determining the causes of misses won’t necessarily fix patchy emergence this year, it can help inform crop management … and might decrease the chance of the same issue happening in another year.
Start scouting as soon as canola starts emerging, with final plant counts at the two- to four-leaf stage. Watch for misses, atypical uniformity, and weak plants. The Canola Calculators can help guide counting, and this list can help identify what may have caused missing plants. Crop insurance deadlines for reseeding are nearing. (Plant population: How to count? Why low?)