Australian machine will be tested on prairie soil

Harrington Seed Destructor, which destroys weed seeds at harvest, will be studied under Canadian conditions

Researchers continue to explore how destroying weed seeds at harvest could tackle the growing problem of herbicide resistant weeds in Canada.

Agriculture Canada has bought a Harrington Seed Destructor, a pull-behind unit from Australia that pulverizes weed seeds when combining.

Though the department has yet to take delivery, University of Alberta grad student Breanne Tidemann is exploring how effective a seed destructor might be in Canadian conditions.

“(At $205,000), it is not a cheap machine, but they are still developing it,” Tidemann told the Agronomy Update in Lethbridge Jan. 21.

Developers are working on a combine-mounted seed destructor that could be cheaper and require less horsepower and fuel when in use.

The real question is whether such a unit will be effective in Canadian conditions. Early research shows it might be useful against cleavers and volunteer canola but less so for wild oats.

For starters, weeds must produce seeds at a level accessible to swathers and combines, which is 15 centimetres off the ground.

“If they’re produced lower than that, you can’t collect them without putting the equipment at major risk of damage,” said Tidemann.

Weeds must also retain their seeds at harvest if the seed destructor is to be effective.

The researchers tested wild oats, cleavers and volunteer canola in wheat and fababean plots at Lacombe, Alta., St. Albert, Alta., and Scott, Sask. Three farmer fields in the Lethbridge region were also examined.

Tidemann said those weeds are No. 2, 3 and 6, respectively, in terms of abundance in Western Canada. Wild oats and cleaver are also resistant to several herbicide groups.

The research found that the seed destructor would effectively destroy most cleaver and volunteer canola seeds at harvest but wild oats generally escape.

“The retention does not look good for something like harvest weed seed control.”

Wild oat retention was worse in farmer fields than on test plots, “which means an even worse story for wild oats in terms of seed retention.”

However, field observations showed the seed destructor might be useful against Persian darnel and lamb’s quarters.

Tidemann said there was some variability at test sites, which he attributed to differences in heat, precipitation, environmental factors and weed-crop competition.


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