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Pest Patrol: Why are we looking at the Harrington Seed Destructor?

#PestPatrol with Mike Cowbrough, OMAFRA

The old saying “one year’s seeding makes seven years’ weeding” perfectly captures why most farmers despise uncontrolled weeds and the tens of thousands of seeds that are dispersed across their land. Fortunately a farmer-made invention called the Harrington Seed Destructor (HSD) is able to destroy more than 90 per cent of the seed produced from seven of Ontario’s most common weeds as they make their way through this Australian machine.

The HSD is attached to the rear of a combine and as the crop and any escaped weeds are harvested, the chaff and weed seeds are processed through the machine where they are ground-up. The HSD has proven to be very effective on many large-seeded herbicide-resistant weed species that Australian growers have struggled with, including wild oats and wild radish.

Figure 1: Approximate seed size of some of the weed species that were put through the Harrington Seed Destructor. photo: Supplied

Its potential as a weed control tool in North America will depend on how effective it is at controlling smaller-seeded weed species. As part of a Canadian research team, I was tasked with determining the efficacy of the HSD on seven of the most common weeds in Ontario, some of which have seeds less than one mm in diameter (Figure 1 above). The results were promising with an average of 92 per cent destruction of weed seed that passed through the HSD. For example, as a result of processing with the HSD, very few common ragweed seeds survived and germinated compared to seeds that were not processed (Figure 2 at top of page).

Now that the potential efficacy of the HSD on Ontario weed species has been determined, the next step is to test it in field conditions. For more information on the HSD, you can visit

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I would like to acknowledge Breanne Tidemann, Hugh Beckie and Neil Harker from Agriculture and Agri-Food Canada (AAFC); François Tardif and Peter Smith from the University of Guelph; and Joshua Kirsch and the staff at the Prairie Agricultural Machinery Institute (PAMI) for their assistance with this project. Partial funding for this project was provided by the Grain Farmers of Ontario, DuPont Pioneer and the Ontario Ministry of Agriculture, Food and Rural Affairs, through the OMAFRA-University of Guelph Agreement.

Have a question you want answered? Hashtag #PestPatrol on Twitter to @cowbrough or email Mike at [email protected].

Tasha Valente is a former graduate student in the department of plant agriculture, University of Guelph and is currently a research associate in the field crops unit of OMAFRA.

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