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Harvest weed seed destruction benefits set to add up

McIntosh Son iHSD Seed Destructor

Riverina grower Andrew Alexander, Boree Creek, and Geoff Anderson, McIntosh Distribution, discuss the performance of the new vertical, mechanical Harrington Seed Destructor fitted to the Alexander’s New Holland CR9080 harvester.

Andrew Alexander thought it might be interesting having one harvester with mechanical weed seed control and one without last harvest on the family’s Riverina property. As rains prompted weed growth from earlier this year, the differences became quite stark. Andrew says where the weeds seeds were destroyed in some paddocks, there were virtually no weeds.


  • 4000ha continuous cropping program
  • Ryegrass main problem weed
  • Harvest weed seed control undertaken in most weedy areas
  • Avoids windrow burning
  • Reduces summer spraying
  • Hard weed seed areas to diminish
  • RIVERINA continuous cropper Andrew Alexander has already seen the benefits of adding mechanical weed seed control to the family’s grain harvesting operation and is now looking forward to them accruing with each season.

    The Alexanders run New Holland CR9070 and CR9080 headers for the 4000-hectare cropping program on their ‘Cypress’ property at Boree Creek, north of Lockhart, and they fitted the new vertical, mechanical Harrington Seed Destructor to the more powerful CR9080 prior to harvest last year.

    The Seed Destructor, shown to kill up to 99 per cent of weed seeds in independent testing, was predominantly used in the outer areas of paddocks near fence lines and firebreaks, which have been the primary habitat of herbicide-resistant weeds on the farm.

    After viewing the weed populations on the property from earlier this year, Andrew said having one header with the Destructor and one without certainly proved interesting.

    “In some paddocks there were virtually no weeds where the Destructor had been on the outside. There were some weeds in other areas where it had been used, but we suspected some of that came from hard seed two years ago,’’ Andrew said.

    “In paddocks where the seed was there from last year, you could see where the Destructor had been.

    “When we had summer rain, it was noticeable that paddocks were a lot greener, including with volunteers, where the Destructor had not been used. The Destructor areas were a lot cleaner.’’

    Compared with some farming neighbours, this also resulted in reduced summer spraying for the Alexanders.

    Andrew said greater benefits would hopefully be realised in coming years, once hard weed seed areas diminish.

    Andrew is the fourth generation of the Alexanders at ‘Cypress’, farming with his wife, Jacqui, and sons, Rory and Samuel, and the sixth generation is in-line to follow.

    After running a 70:30 cropping to livestock operation up until the 2018-19 drought, the family now grows canola, wheat and barley over the property’s red loams, gravelly rises and black soil plains.

    Various areas already were in a continuous cropping rotation and, similar to many farms, annual ryegrass has become the main problem weed, with developing resistance to some Group B and A herbicides. Resistance to glyphosate also has been identified, particularly along fence lines.

    Prior to investing in the Harrington Seed Destructor, spraytopping of canola and barley was carried out, although is now reduced due to the glyphosate resistance, and narrow windrow burning was undertaken for several years, however the family did not enjoy it.

    “It’s a shocking job. It’s very time consuming, it is a fire danger early and then it’s just so slow,’’ Andrew said.

    “Although when doing it, we could see the windrows were certainly collecting the weed seeds. It was cleaner between the rows, so you could see the header was collecting the seeds.’’

    He said they had closely monitored the developments with the pioneering Harrington Seed Destructor and while they also considered another harvester-integrated weed seed control system, once the new mechanical, vertical and more economical Destructor was released, it tipped the scales.

    “When it went to the belt drive and vertical mill design, it became so simple. There are no right-angle gearboxes. It’s just a shaft and a pulley. Each morning we greased a bearing on each side and that was it.’’

    Invented by Western Australian grower Ray Harrington, the Destructor is designed and manufactured by de Bruin Engineering and distributed nationally by McIntosh Distribution. The core mill technology was developed by UniSA with funding and support from GRDC.

    The system can be fitted to later model John Deere, Case IH, New Holland and Claas harvesters, with no permanent modifications required, and is designed to operate at 3000 RPM to maximise mill capacity.

    “We kept it above 3000 RPM. If it gets below, the header slows down too. The best part with the belt drive is the speed coincides with the rotor speed, which you want to maintain for the chopper,’’ Andrew said.

    “We were dubious about the belt life and thought we might snap a belt or something, but we were pleasantly surprised. We had no problem at all.

    “We did about 200 hours last harvest and we think we will get another harvest out of the mills.

    “We had some power loss with the header. It worked harder and used extra fuel, but we expected that.’’

    He said a special stone trap at the bottom of the Harrington Seed Destructor was a brilliant feature.

    “We dropped it each morning and it was easy to clean out. We never really found anything.’’

    Andrew said a rear hatch can be removed and a chute added for windrowing if desired. It also allows the ability to easily check grain losses.

    The Seed Destructors, supported in the region by the Intersales dealership group, are in limited supply Australia-wide and growers have been encouraged to lock in their “build slot’’ to upgrade their harvesters with the machines at the earliest opportunity for the 2020 harvest.

    Producers also can take advantage of the Federal Government’s recently extended $150,000 instant asset write-off under its latest stimulus package to aid their purchases.

    Growers interested in further information about the latest Harrington Seed Destructor and locking in early orders for next harvest can contact their nearest McIntosh & Son dealer.