Managing GM Canola on the Farm

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Managing GM Canola on the Farm
Dr. Christopher Preston CRC for Australian Weed
Management and University of Adelaide
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GM Canola What Might it Do For You?

• In Canada
• Easier and better weed control
• Used in weedy fields to clean up
• Manage herbicide resistant weeds
• Increased profit due to
• Increased yield
• Lower costs
• Reduced fuel consumption
• Assisted move to no-till

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TT Canola has a Yield Penalty
From Robertson et al. 2002 Australian Journal of
Agricultural Research 53 643-651
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Hybrids

• 70 of canola grown in Canada is hybrid
• In Canada, hybrids yield up to 30 higher than
  open-pollinated varieties
• Cytoplasmic male sterility and the triazine
  resistance trait are both maternally inherited.
  This is why we currently have no TT hybrids

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Hybrids Improve Weed Control in Canada
Open pollinated

In Vigor Hybrid
Photos John ODonovan
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Potential Negative Impacts of GM Canola

• Adventitious presence
• Seed dispersal
• Pollen movement
• Management of volunteers
• Herbicide resistant weeds

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Gene Flow Between Canola Crops
Resistance in sink fields
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Honeybee Behaviour in Canola Crops

• Sprayed flowering canola fields with fluorescent
  dye
• Collected bees from the treated field and the
  adjacent field separated by a road 24 h later
• At full flowering 2 - 4 of bees marked with the
  dye were in the adjacent field
• When flowers were sparse, 19 of bees marked with
  a dye were in the adjacent field
• Model simulations suggest canola out crossing
  between fields will be low and will be influenced
  by hive number and when hives are placed

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Worst Case Scenario Predicted Spread by
Honeybees
Effect of field size
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Out Crossing to Weeds

• Out crossing between canola and wild radish
• Planted herbicide resistant wild radish in
  susceptible canola and vice versa
• Tested seed of susceptible species for resistance
• Tested 52 million seedlings
• Found 2 hybrids, 1 in 26 million frequency
• Hybrids are self pollinated and have low seed
  dormancy

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Herbicide Resistant Canola Volunteers

• A problem in Canada in the early days of GM
  canola use
• Examined canola seed banks in South Australia
  across 3 years.
• No germination of seed from 2.5 years after
  harvest

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Selection for Herbicide Resistance

• Glufosinate is a low risk herbicide not used
  anywhere else in the rotation
• Glyphosate is also a low risk herbicide, but is
  already used extensively in the rotation

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Glyphosate Resistance Risk Factors

• Intensive use of glyphosate
• No other effective herbicides
• Little or no tillage

A. Storrie
R. May C. Preston

• Assess glyphosate risk before growing Roundup
  Ready Canola
• Take action to reduce risk

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Glyphosate Resistance in Australia
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Stewardship and Crop Management Plans

• A requirement as part of the license
• Access to the technology will require an
  accredited agronomist
• Requirements regarding
• Where the crop can be grown
• Management of seed
• Management of herbicides
• Management of volunteers
• Adverse effect reporting
• Audits of areas sown and CMP implementation

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Managing GM Canola on the Farm

• Decide whether Roundup Ready or InVigor canola
  suits your farming system
• Use the canola to maximise weed control potential
• Dont plant Roundup Ready canola in high risk
  paddocks
• Manage canola volunteers
• Use a herbicide other than glyphosate for
  knockdown weed control in the year after Roundup
  Ready canola
• Monitor crops for potential glyphosate resistant
  weeds and stop seed set