THE rather uncommon combination of a Shelbourne stripper front and chaff decks for cereals has provided useful harvest weed seed collection for Ungarra continuous cropper Jamie Phillis.
Having tried various methods of harvest weed seed control on his 1750 hectares on the Eyre Peninsula, Mr Phillis has seen promising results from fitting chaff decks to his header during the past two harvests.
"I've been through the different methods of harvest weed seed control over the last 10 years, including windrow burning to chaff lining to chaff decks," he said.
"Windrow burning indeed collected everything, but also burnt everything - all the residue that I was trying to preserve.
"Chaff lining worked well, capturing only the chaff faction - which contains most of the weed seeds - but where the chaff was deposited didn't suit me quite so well with a disc seeder.
"Therefore, I decided if I was getting a compromise on my wheel tracks, and in my chaff line, I might as well put the chaff on the wheel tracks.
"I felt that I needed some sort of harvest weed seed collection and that was the most minimalistic way apart from a mill."
Operating under a controlled traffic farming system, chaff was sieved off the header on all crops, split onto two conveyor belts and deposited onto wheel tracks where it is left to break down.
Mr Phillis said the traffic on the two chaff deck lines hastened the breakdown of weed seeds. The main weeds he is targeting are ryegrass and brome grass, with barley grass and wild oats harder to capture successfully.
"When chaff lining, in one row, chaff is purely left to rot, but with the chaff deck in a controlled traffic scenario you're also getting that traffic over those chaff deck lines, so that's where I felt it had a better fit in our system," he said.
"It's basically left to rot but I feel that process is quickened by having traffic over it as well, especially those that have the sprayer pass.
"In my previous system with the chaff line that didn't get disturbed, it was still sitting there four years later.
"With a disc seeder also, it doesn't get disturbed at all, whereas this breaks it down that bit quicker because of the traffic over it."
While Mr Phillis did not do much summer spraying in 2018-19 due to the dry conditions, he could see his new system having the potential to reduce dust during that phase in future - due to driving over a chaff component rather than a bare wheel track.
"We did target the wheel tracks with extra chemical because of the potential seed burden," he said.
"The chaff deck system and RTK GPS gives us the ability to just spray the wheel tracks.
"Because you know where the weed seeds are, you can have a plan for them, whether it's extra chemical or another method of control."
UNCONVENTIONAL SYSTEM GARNERS RESULTS ON EP
UNGARRA cropper Jamie Phillis said an unusual aspect of his system was the use of a Shelbourne Reynolds stripper front on his cereal crops.
"The system of collection is the same but the tool used to collect that at the front is slightly different," he said.
"A stripper front gathers only the grain, heads, and husks, leaving basically 100 per cent of the straw standing.
"This improves the performance of disc seeders, due to less hair-pinning of chaff and stubble into the ground, maximises ground cover with all residue kept standing, and can double harvester capacity.
"People tend to think a stripper front doesn't collect weed seeds but I've certainly noticed useful collection, with green chaff line rows after germination, so it has obviously collected the seeds and dropped them into those rows so that's encouraging."
A conventional Draper front is used for Mr Phillis' other crops, which include lentils, beans and the occasional canola and lupin crop.
Chaff decks are still used with the Draper front on these other crops and Mr Phillis said only small modifications were required if he wanted to return to the standard harvester configuration.
Mr Phillis said his system was providing good weed seed collection and he would continue to use it until impact mill technology became more affordable and was perfected.
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