August 13, 2014 – Issue 19

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  • Four the week

    PHI insecticides

    No rush. The ideal swath timing for yield is when canola is at 60% seed colour change on the main stem. For large plants with many branches, even this may be too early for seeds in side branches to reach the firm green stage.

    Patch work. Patchy canola is a pain to harvest, and there is no good answer in terms of when to swath except to say that later is probably better to give more seeds time to fill.

    Lygus, part IV. We’ve been talking about lygus for weeks, but they keep hanging on. This week’s key points: They can’t penetrate firm seeds or mature pods and by now pre-harvest intervals are a management factor.

    Phinal countdown. This is crunch time for pre-harvest intervals (PHI), with many products dropping off the availability chart as we get closer to canola cutting time. Take the quiz to test your PHI skills.


  • Map of the week

    This map shows the percentage of land impacted by excess moisture in the spring.

    Dark blue areas had 50% of acres impacted by excess moisture this spring. That would explain a lot of patchy crops.


  • August 13 Quiz

    Less than 7 days PHI

    How well do you know the concept of “pre-harvest intervals”? Take the quiz and find out…


  • Swath timing tips

    The ideal swath timing is when 60% of seeds on the main stem are showing some colour change from green to brown. Colour change is considered any amount of yellowing or browning on the seed. To determine ideal swath timing, fields need to be walked and pods need to be cracked – remember you are looking for seed colour change, not pod colour change.


  • Avoid swathing in heat: green risk, yield risk

    swathing canola

    Swathing canola when temperatures are hot can cause two potential problems for the crop:

    1. Rapid dry down due to hot conditions does not give the green-clearing enzymes enough time to reduce chlorophyll levels in the seed, and green counts can be elevated.
    2. Very dry pods can shatter if swathed on a hot day.


  • Hail bruising and pod shatter

    These white spots on pods and stems are hail damage. These plants and seeds should be fine, but more intense hail could have damaged and bruised seed.

    Hail can cause seeds inside pods to bruise. This bruising can also cause pods to shatter prematurely, although the shatter tendency depends on the extent of hail. If only a few bruises, shatter loss should be minimal. However, if bruising occurs on more than 25-30% of the pod, and the spots turn white or brown, shattering is likely to occur. When those pods will shatter is difficult to predict.


  • A harvest option for thin patchy canola

    wind blown swaths

    The ideal canola crop for straight combining is thick and well-knitted with even maturity. However, a case can be made for straight combining very thin crops with uneven maturity.


  • Top 10 reasons for patchy fields — August 2014

    seeder issue Brackenreed small

    We have reports of lots of patchy uneven canola fields this year. Here are our top 10 reasons, in no particular order….


  • Lygus spraying with harvest near

    Adult lygus bug on canola pod. Credit: Beth Hoar

    Lygus bugs are still at high numbers in some regions, mostly in Alberta. If sweep netting shows high lygus numbers, here are five considerations before spraying…


  • PHI reminder


    Many canola fields are within 5 to 10 days of swathing, which limits the choices for insecticides based on pre-harvest intervals. Here are the pre-harvest intervals for insecticides registered for insect control in canola. Try the interactive PHI tool at


  • Damage ID

    canoladiagnostictool small

    To identify a problem, start with careful scouting. Use this checklist and then move on to the Canola Diagnostic Tool.


  • Take check strips to yield

    Check strip flag small

    A check strip is a good way to assess if a new product or technique works and, if it does work, whether it provides a return on investment. Effective analysis requires taking these strips to yield and comparing them.


  • Clubroot in North Dakota

    A severe case of clubroot has been found in a canola field in North Dakota, near the Manitoba border. This suggests the disease has been in the area longer than expected. It also confirms expectations that environmental conditions in Manitoba are suitable for clubroot. Close scouting is advised for growers in Manitoba and Eastern Saskatchewan, especially canola fields close to the North Dakota border.


Canola Watch