Hammering chaff makes mash of weed seeds

The Australian-designed multi-stage hammer mill is mechanically driven, unlike its hydraulically driven competitor

Another harvest weed-seed smasher is being rolled out to Australian producers and may be available to Canadian growers as soon as next year.

The Seed Terminator is a multi-stage hammer mill that can be retrofitted to a range of Class 7, 8 and 9 combines.

“We call it the colour blind approach,” said Nick Berry of Seed Terminator.

“We are trying to commercialize it without having any preference of colour machine. We’ve put it on John Deere, Case and New Holland machines at this stage. We have some plans for Claas and some Massey machines potentially.”

Another machine designed to manage weed seeds discharged out the back of combines, the Harrington Seed Destructor, was originally developed in 2007 by Australian crop producer, Ray Harrington. It is not sold in Canada on a large scale.

Berry said there are major differences between the two technologies.

“Basically, the only thing that is similar is that it mounts onto a harvester and kills weed seeds. The mill technology is totally different,” he said.

“As well, the drive system is mechanically driven rather than a hydraulic drive. So, obviously, that saves a lot of power and cost compared to dealing with hydraulics.”

Canadian farmers may be able to buy the Seed Terminator next year if the limited commercial release in Australia goes well this year.

Last year nine prototypes of the Seed Terminator were installed and tested in nine combines to assist the company’s research and development.

“We had a harvest trial last year during the Australian harvest and learned a lot, and now we’re going into limited production this year in Australia and hopefully full scale next year,” Berry said.

The company was founded in the middle of last year when it developed its multi-stage hammer mill that it says kills more than 90 percent of weed seeds.

“It leverages what has been known about hammer mills for a long time, is that they kill weed seeds in a pile of chaff. But until the multi-stage hammer mill, it didn’t really have the capacity to mount onto a harvester,” Berry said.

The straw is separated with a baffle arrangement in the combine, and only the chaff is fed through the Seed Terminator.

“If you end up with too much straw in it (the mill), it could potentially plug up, but that’s more about how you set up this baffle arrangement than anything,” Berry said.

The mill draws power from the combine, and because it takes a lot of energy to kill weed seeds in a mill, its efficiency was a top priority.

In addition to having a direct drive as opposed to a hydraulically powered unit, the Seed Terminator’s efficiency is improved by its trademarked Aero-IMPACTTM, which the company totes as a low-turbulence impact technology that uses aerodynamic efficiency.

“When you are dealing with these high speeds in this type of mill, you end up generating a lot of turbulence, which is hot air that is wasted energy basically…. So with our air impact technology, we try to reduce the amount of turbulence that is needed but still get the impact that is needed,” Berry said.

The air impact technology uses the airflow caused by the mill to suck material off of the cleaning shoe and help capture ejected material.

“Because you have all the suction, it’s actually pushing out a huge amount of air on the exit. That means you can direct the airflow and get a pretty good spread. Because the material is all smashed up it actually blows around anyways,” Berry said.

He said the company installed a Seed Terminator into a 16-year-old Class 7 John Deere 9760 STS and it worked well, suggesting the efficiency of the product.

Seed Terminator is currently testing the power requirement of its harvest weed seed destroyer.

“We built two test stands and one more is on the way. One of them is going to be all about testing the power-to-kill relationship with different settings. And we’ve got a torque transducer so we are going to button down that number (power requirement),” Berry said.

The ability of the Seed Terminator to destroy a broad spectrum of weeds is unknown. However, the South Australian Grain Industry Trust has recently committed funding to test the machines efficacy on a broad range of weed seeds, Berry said.

Seed Terminator is committed to keeping its product below the $100,000 mark, while the integrated Harrington Seed destructor costs approximately $160,000.

Berry said how much time it takes to install the Seed Terminator depends on the combine being fit because some modifications are necessary. But he said installation usually takes about two days.

“Basically, it just mounts onto the hitch of the harvester and it is belt driven from the side of the machine.

“It’s a very quick job to remove the machine once it’s installed. You can literally put it on tractor forks or blocks and have it off in half an hour,” Berry said.

The Seed Terminator does not, however, have to be removed if a growers doesn’t want to use it in a certain crop because operators can simply bypass the mill by taking off the shoots that feed it and then run the combine as usual.

Canadian weed scientists have said harvest weed-seed control with such a machine could become an essential strategy in the fight against the development of herbicide resistant weeds.

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