May 13, 2015 – Issue 9

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  • Help for the reseeding decision — scenarios

    Thin stand small

    When growers have canola stands of fewer than 4 plants per square foot — due to low seeding rates, poor seed survival, insects, crusting, frost, wind, etc. — they grapple with the question whether to reseed. An established canola stand with as few as 1-2 plants per square foot generally has higher economic potential than if were to reseed that crop in June. This population is far below the minimum 4-5 per square foot required to meet yield potential, but a thin stand seeded early has greater economic potential (considering yield, quality and cost of production) than an adequate stand that doesn’t get established until mid to late June.

    However, reseeding may be the better option if…


  • How to assess frost damage on young canola

    Frost on vol canola 2 Ward

    After a frost, it can take a few days to accurately determine how many plants survived, and whether the stand is still uniform. Be patient before making any decisions. Check the whole crop the day after a frost and then again 3-4 days after a frost to assess the situation.


  • May 13 Quiz — Weed control

    Cleavers spring Orchard

    Test your knowledge on weed control under cool, frosty conditions.


  • Early weed control in cool or frost conditions

    Weedy field pre-seed Nicole

    Early weed control with lower efficacy is generally preferable to no control at all or late control with higher efficacy — as long as weeds are present and not frost damaged.


  • Big cleavers need pre-seed control

    This is an extreme case of runaway early season weeds. These should definitely get a pre-seed burnoff, probably at least a week earlier. Source: Ken Sapsford
    Winter annual cleavers are reported in high numbers in some fields. These need to be sprayed before seeding to prevent them from getting really large and near impossible to control with in-crop label rates. The pre-seed window provides an opportunity to hit these large cleavers with rates needed for control.


  • Slow emergence and seed treatments

    Seeding into warmer soils speeds up emergence and makes it more uniform

    Slow canola emergence due to cool soils can increase the risks from seedling diseases and from flea beetles.


  • Check fields at emergence, then again a week or two later

    Cutworm scouting step 3: Identify insects found. This is a cutworm. The nominal threshold is 25-30% lost plants in a field or confined area.

    Growers will learn a lot from two field checks during the first few weeks after emergence. Scout fields 5 to 10 days after seeding when canola starts to emerge, looking for early threats. Then go back again two to three weeks after seeding to assess the stand.


  • Seeding depth in dry soils: Early May versus late May strategy

    In areas with dry top soil conditions, growers often wonder whether to seed deeper to chase moisture. This approach differs based on the date and typical rainfall patterns.


  • Economics of a high canola seeding rate

    Seeding canola JONWhetter small

    Achieving 7 to 10 plants per square foot can mean some high seeding rates for seed with large thousand seed weights (TSW). Therefore, going much above 6 lb./ac. is not generally recommended — regardless of TSW. The better agronomic strategy is to put effort into increasing seed survival rather than invest in a higher seeding rate.


  • Seed-placed fertilizer safety

    The safest method for seed-placed fertilizer is to put nothing with the seed. However, with low-medium soil test results, it’s often beneficial to put ammonium phosphate with the seed at a safe rate, and put all other fertilizers in a band away from the seed row.

    Table 1. Safe rates of seed-placed N


  • Clubroot resistance breakdown confirmed over a wide area in Alberta

    Erosion of clubroot resistance is showing up in fields across central Alberta. Recent research by Alberta Agriculture and Rural Development (AARD) and the University of Alberta (U of A) has confirmed the continued spread, with multiple virulent pathotypes suspected. Some fields risk losing their ability to grow canola profitably until new genetic solutions or other […]


  • Road trip to canolaPALOOZA


    What do sclerotinia, cotton candy, drones, and unicycles have in common? They will all be part of canolaPALOOZA, June 23 at the Lacombe Research Centre in Alberta.


Canola Watch