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Canola growers reminded to avoid malathion

July 31, 2009 – In this summer of mixed conditions, the Canola Council of Canada reminds  growers that the use of malathion, be it in stored canola or the bins in which it will be stored, is not registered and could reduce exports to countries with residue restrictions.

August 5, 2009  By Canola Council of Canada

July 31, 2009 – As canola growers prepare for harvest, the Canola Council of Canada (CCC) reminds them to keep the insecticide malathion far away from bins slotted for canola storage this fall.


Malathion is not registered to treat bins that will store canola or to control insects in stored canola.



"Using malathion on canola seed or in canola storage bins will result in detectable levels of malathion residue because malathion has a strong attraction to the oil in canola seed," says Arvel Lawson, CCC manager of Crop Production. "Consequently, malathion can move into canola seed from storage bin walls."


Every country that buys Canadian canola sets limits on pesticide residues, and exceeding those limits can mean rejected shipments and increased monitoring, says Lawson. Because of Canada’s bulk grain handling system, every load of canola delivered needs to meet the requirements of all our export customers.


Last year Canadian canola seed exports amounted to over $3.1 billion and detection of residues could cost the industry, including farmers, millions of dollars in business.


If a bin has been treated recently with malathion, it should not be used for canola storage this fall because a minimum of six months must pass before a malathion treated bin can be used to store canola.


Lawson advises using proper harvest and storage management to keep canola seed insect-free:

  • Adjust combine settings to harvest sound seed and to minimize chaff and weed seeds in the sample.
  • Chose bins in good condition and sweep out thoroughly before harvest; make sure the bin is free of chaff, seeds and foreign material.
  • If considering a bin treatment, a registered diatomaceous earth product can be used to treat empty bins but should never be used directly on canola seed as the product will not be effective.

"If the canola you are putting into the bin is sound and reasonably free of chaff, volunteer cereal or weed seeds, foreign material, and stored product insects of concern, the canola should store well and remain insect-free if kept below 15°C and 8 percent moisture."


For more information on proper canola storage and keeping canola Export Ready, go to



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