DESTROYING weed seeds via their harvesters was always going to be a natural progression for the Boultbee family near York - they were just waiting for the latest integrated weed seed control systems and technology to mature.
The Boultbees have been practicing harvest weed seed control (HWSC) since the turn of the century, using chaff decks and chaff carts in more recent years to mainly target annual ryegrass, brome and wild radish weed seeds.
Andrew and Marjorie Boultbee have been continuously cropping areas of their home property and leased land in the Avon region since the early 1980s.
The cropping program generally follows canola-wheat-wheat or canola-barley-barley rotations, as well as growing hay, on soils ranging from loams to lighter land and some tamma country.
Their three children, Briony, Ben and Kate, were home from university to help with the last harvest.
The family also runs about 3000 Merino and crossbred sheep confined to grazing areas.
Mr Boultbee said they ran into herbicide-tolerant weed populations many years ago and so were early adopters of HWSC to ensure weed pressures did not dictate cropping rotations, as well as to achieve good weed control on the leased land.
"We haven't burned on a broad scale for 20 years, so that took one of the weed control tools away," Mr Boultbee said.
"We started with chaff carts and then put weed seeds in tramlines with the chaff decks, but we were always heading toward destroying weed seeds.
"We were just waiting for the Seed Destructor to become vertical and reliable."
The family had the new vertical, mechanical Harrington Seed Destructor (iHSD) installed on each of their two John Deere S680 headers by McIntosh & Son at Wongan Hills prior to last harvest.
Invented by Western Australian grower Ray Harrington and independently shown to kill up to 99 per cent of weed seeds, the Seed Destructor is designed and manufactured by de Bruin Engineering and distributed nationally by McIntosh Distribution.
The core mill technology was developed by the University of South Australia 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 3000rpm to maximise mill capacity.
"We looked at everything and we saw the Seed Destructor as a more reliable system,'' Mr Boultbee said.
"It needed to be vertical, otherwise you compromise your cut height protecting the unit from rocks, and hydraulics are expensive and unreliable.
"We have done so much with chaff carts and have seen that unreliable machines can compromise your harvest time, so it's why we needed to choose the best option.
"Everything off the sieve goes through the mill, so with the horizontal system, if you put a knife guard through the mill, you have to rebook your holidays and spend $10,000.
"With the vertical Seed Destructor, you have a sump (stone trap), so you have got a sporting chance to catch it.
"Some of the rubbish you find in the sump of the Seed Destructor, you wouldn't want it going through the mill.
"We are used to having the fronts on the ground, at beer can height or less, and travel at 8-8.5 kilometres per hour maximum to limit damage.''
The Boultbees were also able to check grain losses when required and were pleased with the wearability of the Seed Destructor mills after about 550 harvest hours.
"The wear was pretty even and they made it through harvest in our system," Mr Boultbee said.
"I think they would do about 600 hours and we are quite comfortable with that considering what we have heard.
"We thought we would be lucky to get through the season, because of the total hours required to finish harvest.''
Mr Boultbee said machine support during the harvest from McIntosh & Son had been great and they would look to streamline a couple of aspects of the Destructors for next season.
"It was very nice not having chaff heaps to deal with or it sitting in rows from the chaff decks," he said.
"Chaff carts were good at the time and had a great fit for sheep.
"There is valuable nutrition coming off the sieve and we prefer to have that material back on the paddock.''
Mr Boultbee said once the HWSC "lever'' was pulled for weed control, it was also important to be employing all other weed management strategies, as it was just another selection process.
The Boultbees croptop their canola and, similar to the benefits gained from their hay program, they swath barley to capture any weeds that may shed or lodge early.
"Research has suggested weeds lose about 1pc of seed a day from a certain point, so if it takes 40 days to get to a crop and there's already been a bit of wind, that's a fair bit of harvesting of weed seeds by nature," Mr Boultbee said.
Despite possibly sacrificing some yield, thicker and taller crop varieties with greater vigour are preferred to increase crop competition.
In areas with high weed burdens, an east-west seeding orientation is followed to provide a shading effect in the inter-row, further discouraging weeds.
Crops are also sown into the previous year's inter-row for more even soil throw, incorporating pre-emergent herbicides evenly without the effect of bulldozing root systems.
Meanwhile, growers can now take advantage of an early order program announced on the Harrington Seed Destructors to upgrade their harvesters with the machines and effectively beat price rises during 2021.
Growers interested in further information about the vertical, mechanical Harrington Seed Destructor can contact their local dealer.
