Aaron Vague and James Jess in the trial plot at Lake Bolac.
In the southern cropping region’s high rainfall zone (HRZ), an important question needs to be answered: how can harvest weed seed practices be adopted to reduce soil weed seed banks to address herbicide resistance?
And more specifically, how can growers get weed seeds into the header?
Southern Farming Systems (SFS) is answering these questions through its Grains Research and Development Corporation-funded HRZ harvest weed seed control (HWSC) project.
Paddock-scale trials will demonstrate to growers the suitability and effectiveness of a number of HWSC measures, using commercial equipment to highlight the potential of these management practices to complement large scale trials.
Trial plots have been established at SFS’s Lake Bolac site in western Victoria and in Tasmania.
SFS project lead Aaron Vague, who is conducting research at the Lake Bolac site, says there are two main aims to the project.
“Firstly, we want to focus on how we can change crop maturity and crop physiology to match the requirements to be able to use harvest weed seed techniques,” Mr Vague said.
“Then, we can go into the paddock, use the big machinery, talk to the famers and actually refine how those techniques are going to be worked into their system, and how beneficial to profit and economics they’re going to be at the end of the year.”
According to James Jess from Western Ag, the management needs to be an integrated approach.
“That’s the way I put it to my clients. It’s not going to be one thing that’s going to get you out of the woods – it’s got to be a combination of good techniques,” Mr Jess said.
“The key to profitable farming is to get the weed seed management under control so you can get profitability across the whole farm.
“If you have gaps in the paddock or slug patches that have managed to get through, that’s where the ryegrass really persists and gets going, and suddenly you get big areas in a paddock that blow out, and it can be very detrimental to your bottom line.”
The other key question for growers to consider is whether or not it’s possible to manipulate the physiology of the target weed, so it can be fed into the harvester.
“What we’re trying to do is synchronise the maturity and growth of the crop you’re growing, and also of the weeds you’re trying to control,” Mr Vague said.
“If you get a wheat crop that might be over a metre tall, your ryegrass is now over a metre tall. So what if we perhaps either sow later, or use a different crop cultivar, just to try and get that weed seed at a different level, change its physiology, and then allow that to feed through the header and put it in a useable form.”
The project aims to measure the suitability and efficacy of reducing weed seed bank numbers across a range of weed species and crop types.
Regional best management agronomy will be implemented for other control measures as standard across treatments to deliver a functional package to the southern HRZ.
More information on the project can be found in the Harvest Weed Seed Control YouTube video at https://www.youtube.com/watch?v=RrvQQYqSmdE.
Aaron Vague, Southern Farming Systems
0439 005 071
Sharon Watt, Porter Novelli