Questions of the Week

How early is too early for seeding?

With spring now springing, when should the canola seeder roll? Seeding early generally improves canola’s yield potential and quality, but only if the crop emerges and establishes itself with uniformity across a field and a vigorous 5-8 plants per square foot. Consider the pros and cons of early seeding, factoring in frost risk, soil temperature and type, moisture availability, flea beetle risk, seed treatment and seed placement. This Fundamentals article focuses on best management practices that improve seed survival and stand establishment. According to research from the University of Saskatchewan, an early pre-seed herbicide application can have a greater influence on crop yield than an early seeding date if weed competition is significant. (Flea beetle management tips)

How to get ahead of early season weeds?

Weeds are already off to a running start in many fields. Do you have a plan in place to manage them before they outpace the crop and steal critical moisture?  Effective early control is critical, as small weeds are easier to control and weed competition during crop emergence and early growth stages makes the biggest impact to ultimate yield. For best results:

• Scout.
• Ensure the sprayer tank is clean.
• Choose an effective tank-mix partner, both to improve the pass’ efficacy and to tackle glyphosate resistance. (Important: do not assume glyphosate resistance is not an issue on your farm.) Keep in mind some pre-seed products require moisture to activate.
• Choose the best timing: wait for weeds to be actively growing, which requires warm weather during the day and 4°C or more at night.
• Stay ahead of the drill. Early control is best and dust on weed leaves post-seeding can limit a herbicide application’s efficacy.

(Pre-seed burnoff – tips for best results) (Weed seedling ID guide) (Tips for spraying in the wind)

What is the cost of harrowing?

Harrowing and other types of tillage can be tempting both to manage residue and to help weed seeds germinate ahead of a pre-seed or pre-emergence herbicide application. However, there are many costs to aggressive soil disturbance: moisture loss, soil structure damage, seedbed variability, compaction, crusting following precipitation, disease spread and more. The benefits of conservation tillage / no-till generally outweigh any gains that tillage delivers. Rather than compromising soil structure across a whole field, focus on an effective burndown or in-crop herbicide. If absolutely necessary, “till with purpose”: target tillage to problem areas only and make as few passes as possible. (Residue management in the spring) (Seedbed preparation) (Field study: canola emergence based on wheat residue treatment)

Who should conduct on-farm trials this year? (Hint: everyone)

On-farm trials are one of the best ways to continuously improve agronomic knowledge and field-specific management practices. Some of the simplest and most beneficial on-farm trials include:

• Cultivar comparisons: try two cultivars in the same field, using long, replicated (at least 3x) randomized strips. (Note: this recommendation assumes that all growers are already following CCC’s guidance to seed multiple cultivars across a farm).
• Nutrition trials: shut off seed-placed fertilizer or trial a higher nitrogen rate on marked test strips. Assess: is there any damage from seed-placed fertilizer? What N rate pushes yield targets? (Note: every canola acre should be following 4R).
• Seedbed prep: is there a difference in weed growth or ultimate yield between harrowed and non-harrowed strips?

Record keeping is key. Remember to carefully mark where a different treatment has been applied, and keep careful notes of treatment specifics, dates and observations throughout the season. (Tips for on-farm trials)