THE PRESSURE on herbicides in terms of the threat of weed resistance is going to continue to grow and the cropping sector needs to be continue to push to try and find alternative modes of weed control.
That was the stark message from a University of Sydney researcher addressing the Victorian Farmers Federation (VFF) grains conference earlier in the year.
"Trying to alleviate the impact of resistance means we desperately need alternative technologies not just new herbicides," said Mike Walsh, a specialist weed researcher based at the University of Sydney's Narrabri campus.
Dr Walsh said there was a lot of work being done on weed identification using sensor technology and emerging concepts such as the Swarm Farm idea where a number of small drones are sent out to the paddock to target spray weeds or the Bilberry system which recognises individual weed species.
"It is coming along, but it is not easy and not quick."
He said there were also other concepts, such as laser or microwave weeding which had been demonstrated as concepts but needed further work before they would be able to be used economically on a commercial scale.
In the shorter term he said harvest weed seed control (HWSC) options continued to prove popular.
"From chaff lining right through to HWSC machines such as the Harrington Seed Destructor and the Seed Terminator, there is really good interest in the farming community in bringing down weed seed numbers after harvest.
"This in turn has a really good impact in cutting down weed numbers the following year."
He said there had been strong interest in the milling system, which was spurred by weaknesses in other systems, such as grazing of chaff lines leading to increased ryegrass germination.
Dr Walsh said with so many options available in the space he would like to se independent testing, especially in machines utilising a milling system to crush weed seeds.
In terms of in-crop control, he said there were two key areas for researchers to focus on.
"Both are in the period after crop emergence we need to look at the early post emergence when the new crop is competing against weed species in order to get established and then slightly later on at the late post-emergence period," Dr Walsh said.
"The critical thing is that we have to be able to control a lot of weeds in a short period of time and to have concepts capable of controlling the bigger and more robust weeds."