Weed management moves to a whole new level when you add the word ‘integrated’. This is the driving force behind the WeedSmart Big 6 approach, which suggests that growers implement as many of these six key tactics as possible into their crop management programs.
Herbicide resistant weeds might not be widespread in Central Queensland yet, but all the indications are that the problem is flying just under the radar. Following the discovery of the world’s first population of glyphosate resistant sweet summer grass near Emerald, random weed surveys have since confirmed glyphosate resistance in both feathertop Rhodes grass and fleabane samples collected in the region.
Members of the Central Queensland Grower Solutions Group have been working hard to build an integrated weed management system that suits their farms. In doing so they are ticking off many of the ‘Big 6’ tactics each season. These tactics are summarised as:
Crop and pasture rotation
Double knock to protect glyphosate
Mix and rotate herbicide groups
Stop weed seed set
Harvest weed seed control
In August last year, twelve Central Queensland growers attended the 2018 WeedSmart Week in Narrabri as part of a 6-day fact-finding tour through southern Queensland and northern NSW, delivered by the CQ Grower Solutions Group.
Kurt Mayne and Scott Becker were among the group, and this year they are backing WeedSmart Week in their own backyard of Emerald, Queensland. This practical and thought-provoking event also has the solid backing of the CQ Grower Solutions Group, a joint initiative of GRDC and Queensland Department of Agriculture and Fisheries (DAF).
Rolleston grain grower, Kurt Mayne returned from the study tour with a realistic view of the risk of herbicide resistance and a firm commitment to getting himself on the front foot before it starts to impact on the profitability of his business.
“One of the stand-out tools that we saw being used very effectively was optical sprayer technology,” said Kurt. “When I returned from the tour last year, I purchased a WeedIT sprayer to prolong the effective life of the chemistry that we currently have available.”
CQ grain grower, Kurt Mayne is impressed with the benefits that have come with the addition of an optical sprayer to his weed control program. Kurt will be part of an expert panel at WeedSmart Week in Emerald to discuss the pros and cons of this technology.
“In our farming system it is hard to incorporate pre-emergent herbicides in the fallow because that can restrict our opportunity cropping options. The optical sprayer makes fallow weed management much more effective, and when that’s combined with pulses in the rotation we are able to keep on top of grass weeds like feathertop Rhodes grass, which was getting increasingly difficult to manage.”
With WeedSmart Week being held for the first time in Central Queensland, Kurt is looking forward to the opportunity to hear how other growers are contending with herbicide resistance in weeds and how different ideas and technologies could be implemented in the region. Kurt will be part of the spray technology discussion panel at the forum on 13 August.
Farming near Moura, Scott and Kelly Becker are keen to trial harvest weed seed control as a possible addition to their weed management program. Being fully aware of the impact herbicide resistance could have on their family farming business, the Beckers have been proactive with chipping out small patches of feathertop Rhodes grass in sorghum.
“We are planning our cropping program four or five years ahead, mainly to manage stubble cover and to rotate herbicide modes of action,” said Scott. “We have incorporated most of the WeedSmart Big 6 tactics to keep weed numbers low and think that chaff lining could be a useful way to contain any weed seeds produced in-crop.”
Keeping weed numbers low is high priority for Scott Becker, Moura, who is keen to find a practical harvest weed seed control option suited to CQ farming systems and weed spectrum.
“It’s a numbers game when it comes to weed management and the only way we can win is to be doing everything possible to keep numbers low and prevent seed set where possible,” he said.
Hayley Eames, Department of Agriculture and Fisheries development extension officer said the CQ Grower Solutions project has been delivering a range of extension activities aimed at addressing production constraints around five key themes, including integrated management of hard to control weed species, since 2015.
“Herbicide resistance is ever increasing in Central Queensland and although individual weed control tactics are quite well understood in the region there needs to be more integration of control measures,” she said. “Growers have relied on rotation from summer to winter crops and from cereals to pulses and this has worked well for a long time. There is scope to include other strategies though, such as strategic use of pre-emergent herbicides and harvest weed seed control.”
DAF is supporting WeedSmart Week in Emerald as a rare opportunity for local grain and cotton growers to focus on managing the looming threat of herbicide resistance in weeds. The 2.5-day program will begin with a 1-day forum at the McIndoe Function Centre, Emerald on 13 August. The following day will be filled with a bus tour to farms around Emerald where growers have put in place integrated weed management programs to minimise the impact of herbicide resistance on their businesses. The final part of the program is a half-day tour of the SwarmFarm Robotics base at Gindie on Thursday 15 August to see and discuss cutting-edge technologies such as optical weed sensing for spraying and chipping, robots and emerging ‘green-on-green’ spray sensors.