June 11, 2014 – Issue 10

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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…


  • Four the week

    Spray drift from a canola field can be deadly to neighbouring crops.

    Sock it to wind. A little wind is OK, but take measures to reduce drift (shown above). Herbicide timing is more important that waiting to achieve full coverage from a fine spray.

    Flea-ing to the stems. In windy and cool conditions, flea beetles may duck for cover and feed on stems. Take a look. This hidden damage can be costly.

    Recede from reseeding. A thin stand will “usually” provide a greater economic return that a crop reseeded in June — although some conditions apply.

    Bore into boron. Canola needs boron, but this essential micronutrient is not a miracle cure for all that ails. Applied boron rarely provides an economic response for Western Canadian canola.


  • Map of the week

    We have two maps from AAFC’s Drought Watch site showing rainfall as a percent of normal. The top map is for the week of May 27-June 2 and the second is for June 4-10. Quite a difference.

    Precip May27-Jun2,14
    Precip Jun4-10,14
    Legend precip


  • June 11 Quiz

    Filling the sprayer small

    Here are the questions:

    1. Growers have two key considerations when it comes to spraying — good coverage and drift management. What two objectives below will help you achieve good coverage while also reducing the drift risk?

    2. Which situation is most likely to provide the greater economic return for a herbicide spray?

    3. The best conditions for spraying herbicide are?


  • Tips for spraying in wind

    Herbicide drift injury on canola. Drift can be costly on your own farm and especially awkward and costly if it carries to a neighbouring farm.

    How do you spray weeds in a timely fashion when every day seems too windy? Too windy, according to the Guide to Crop Protection, is wind above 15 km/h. But we know that some operators will go with winds of 20 km/h and maybe a bit above. Here are tips to improve performance and limit the drift risk in wind…


  • Spraying on cool, cloudy days

    Cool cloudy day

    Applications made when cool cloudy days follow cool nights will result in lower or slower herbicide efficacy than applications made in warm sunny days. Cloudy days don’t provide the photosynthetic activity required for many herbicides, including Group 10 glufosinate.


  • Wind drives flea beetles to feed on stems

    Flea beetles can move lower in the plant on cool, cloudy days. Damage to stems can be more costly than leaf damage.

    High winds may force flea beetles off leaf tops and down to leaf undersides and leaf stems. Stem feeding could make the flea beetle situation worse, since it takes just a few bites on a stem to nip off a whole cotyledon or sever the stem. Stem feeding, if it’s happening on a lot of plants, has a lower control threshold than the 25% damage recommended for leaf feeding.


  • Canola recovers from early hail

    Early season hail rarely has an impact on canola yield potential. Hailed seedlings usually come back very well. If hail breaks off both cotyledons or snaps the stem, these plants usually do not survive. But even in these severe cases, while individual plants may die, a whole canola crop is fairly resilient to early season hail when it comes to overall yield potential.


  • Nutrient essentials: Boron

    Interveinal chlorosis is typical of boron deficiency.

    Canola needs a little bit of boron, and most Canadian Prairie soils have enough to meet this demand.


Canola Watch