Topics for the Week

Is it time to swath?

The optimal time to swath to maximize canola’s yield and quality is when at least 60% of seeds show colour change on the highest yielding parts of the plant (usually the main raceme but watch side branches in hormone-imbalanced plants and plants compromised by hail). The only way to assess the right time to swath is by walking fields and cracking open pods: seeds may have already turned in fields with green plants, or they may be very green in pods that appear dry. When in doubt about timing, odds are good that it’s still too early. Many fields would benefit from additional patience at swathing. Not all shatter-resistant products are equal – talk to a seed dealer about how best to rank operations based on shatter loss potential (and shatter loss rating where applicable). Avoid swathing in heat. (Hail damaged pods and swath timing) (Swath later for higher yield)

Prep the combine now for successful canola in 2023

Managing cereal residue well this fall is key to preparing the seedbed for an optimal canola plant stand next spring. Now is a great time to check the combine’s spread patterns, then adjust vane angle, cut height and spread width to optimize residue spread’s uniformity across the entire cutting distance. Ensure chopper blades and stationary knives are sharp, and review how environmental conditions can impact spread (pay especially careful attention to wind speed and direction while combining). Ideally, a correctly calibrated combine may eliminate the need for secondary residue management passes.
(The combine can influence stand establishment) (Impact of preceding crop on canola) (Combine basics) (How to reduce combine loss)

Remember to stop, stretch & disease scout at swathing

Swathing is an excellent time to disease scout efficiently and effectively: take the opportunity to learn from the crop to improve management in future years. While driving through the field, be intentional about stopping to scout periodically, both in average-yielding and notably above- or below-average areas. When evaluating plants that are prematurely ripe, ask: was blackleg control effective? Did sclerotinia break through? Is clubroot resistance holding up (and are there any clubroot-prone patches that need a top-up of lime to increase soil pH)? If any disease symptoms are challenging to identify, if you’d like to improve your long-term management of sclerotinia and/or to maximize blackleg resistance efficacy via race identification, send samples to a lab for analysis. Disease testing is free in both Saskatchewan and Manitoba. (Choose the right cultivar for each field) (Disease scouting pre- and post-swathing)

Pest update: keep scouting

Canola may no longer be as susceptible to certain types of insect feeding (lygus bugs, for example, generally can’t chew into toughening pods). However, pest challenges are not yet over. High temperatures in many areas over the last week, especially in regions that received some moisture, will likely boost populations of certain problem insects. Late-seeded crops are at highest risk of damage.

Diamondback moths continue to be a significant issue in some fields. Because they cycle in as few as 21 days, their population can explode seemingly overnight. Spray insecticide only after first considering natural predation and the required spray-to-swath interval. Grasshoppers are widespread but are causing largely cosmetic damage in most fields, though spraying is occurring in some fields. No products are currently registered for crickets, which have recently been noted feeding on canola pods alongside multiple other food sources. Peeled back pods in ripe areas and/or along field edges may, in fact, be the work of birds rather than insects. (Late season insects and pre-harvest intervals) (Insect guide – crop protection 2022) (Potential changes to diamondback moth thresholds)