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Spring and Winter Canola: Other Problems

Author: OMAFRA Staff
Creation Date: 01 March 2002
Last Reviewed: 01 March 2002
Agronomy Guide > Pub 811: Spring and Winter Canola >Other Problems
Excerpt from Agronomy Guide for Field Crops (Chapter 8)
Order OMAFRA Publication 811: Agronomy Guide for Field Crops

Table of Contents

  1. Frost and Hail Damage
  2. Herbicide Injury
  3. Winterkill
  4. Cross-Pollination of Herbicide-Resistant Varieties
  5. Plugged Tile Drains
  6. Updates on Spring and Winter Canola: Other Problems
  7. Related links...

Frost and Hail Damage

Canola seedlings can recover from a light spring frost if the growing point is not damaged. If hail removes both cotyledons or the stem is broken below the cotyledons, plants usually do not survive. A uniform stand of 10 plants/m2 (1 plant/ft2) will have a yield that is 90% of a full stand.

If hail occurs during vegetative growth, yield loss will be dependent on the amount of leaf area destroyed. Yield loss will equal approximately 25 % of the leaf area destroyed. Stem bruising and breakage will result in higher losses.

If hail occurs during flowering, plants can compensate by developing secondary clusters and new branches (see Table 8-4, Percentage Yield Loss Due to the Destruction of Branches During Flowering in Canola). Yield losses will be highest when hail occurs during late flowering and during pod fill.

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Table 8-4. Percentage Yield Loss Due to the Destruction of Branches During Flowering in Canola1
% Branches Lost Days From First Flower
-7 0 7 14 21
Percentage Seed Yield Loss
10 0 0 10 10 10
20 0 0 13 20 20
30 0 0 12 29 30
40 0 0 12 32 40
50 0 0 14 36 50
60 0 0 18 42 60
70 0 0 24 50 70
80 0 5 31 60 80
90 0 12 40 71 90
100 0 20 51 84 100

1Research conducted in Western Canada. Canola Council of Canada, 1994.

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Herbicide Injury

Canola is highly susceptible to phenoxy herbicides. Clean spray equipment thoroughly before using on canola.

Winterkill

Winter canola is less winter-hardy than winter wheat in Ontario. Winterkill is most common in March and April after winter canola loses its winterhardiness, begins to grow and is then damaged by a reversion to extremely cold temperatures. Winterkill can also result from a lack of winter snow cover, prolonged periods of ice cover and desiccation by winter winds, resulting in reduced stands of winter canola. If the damage is severe enough (75% kill), the crop may not be salvageable. However, if 30% of the stand remains, with healthy plants evenly distributed across the field, the crop will compensate adequately.

Cross-Pollination of Herbicide-Resistant Varieties

If varieties with different herbicide-resistant traits are allowed to cross-pollinate, the result may be volunteer plants with multiple resistance traits in subsequent crops. Separate fields planted to varieties resistant to different herbicides by a minimum of 175 m. This isolation will reduce the occurrence of field-to-field crossing.

Plugged Tile Drains

Sporadic problems with winter canola roots entering tile drains requires further investigation.

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Updates on Spring and Winter Canola: Other Problems

No updates available at this time.

Related links...

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