While still mostly in the research phase in the U.S., the approach known as harvest weed seed collection (HWSC) has become a standard practice among many Australian grain producers.
In a recent post on Australia’s WeedSmart website, Cindy Benjamin reports that it is now considered the “holy grail” of the country’s key tactics aimed at dealing with resistant weeds in the nation’s countryside.
By 2014, some form of HWSC already had been implemented on over 40% of Australian’s grain farms “and adoption is expected to increase to 80% by 2020,” Benjamin reported.
Currently, 6 HWSC approaches are used in Australia – “all of which have been invented, adapted and adopted by Australian farmers,” Benjamin notes. Each system separates chaff and seeds from the straw or pulverizes chaff and seed before it leaves the combine.
Among the approaches:
- Depositing a narrow line of chaff and seed behind the combine for burning or composting.
- Collecting chaff with a cart towed behind the combine and then dumping the chaff outside of the field for burning, composting or feeding to livestock.
- Pulverizing chaff and seed with a mill, either built into the rear end of the combine or towed behind the combine.
That last approach, which several U.S. universities are evaluating, destroys over 95% of the weed seed that make it to the mill. It also eliminates crop seed that could germinate as volunteer plants later.
While grinding weed seed requires a steep investment in equipment, it has gained plenty of traction.
“Most agree that the ultimate HWSC tool would complete the weed seed control in one pass at harvest, retain all stubble and nutrients and not require any follow-up work such as marketing hay or burning chaff,” Benjamin specifies.
And, she adds, a pair of machines meet those requirements now – the iHSD (Integrated Harrington Seed Destructor) and the Seed Terminator. Both are in commercial operation in Australia.
While some “teething problems” might be expected with new technology, the machinery is being evaluated on an international basis, /Aside from work in the U.S., the Seed Terminator has been in trials in Canada and the iHSD is being evaluated in France.
So far, both machines completed around 200 hours of work “without a hitch,” Benjamin writes. A group of Australian farmers surveyed after the 2017 harvest “suggested” that both brands achieved over 95% reduction in seed viability.”
The approach isn’t without disadvantages, she adds. Mills can choke in certain situations and also sustain damage from sand or soils the combine collects. Some reduction in harvest progress might be expected, too.
She goes into more detail about costs for these systems and also covers general costs and operating parameters.
Related articles on this site:
- Resistant Weed Seed As Livestock Feed? Ask The Australians
- Arkansas: Ramping Up Australian Weed Seed Destructor Evaluations – Video
- Weed Seeds: 6 Ways Australians Keep Them Out Of The Bank…