A rain event predicted for later this week has prompted croppers in the state's north to prepare to battle emerging Feathertop Rhodes grass, typically a summer weed but now confirmed to effectively germinate in winter.
Grains Research and Development Corporation has supported research that shows that the weed germinates across a wide temperature range of 10-40 degrees Celsius. University of Queensland weeds researcher Bhagirath Chauhan said early trials proved a number of separate FTR populations from different origins could germinate in temperatures as low as five degrees Celsius.
At Moree, cropper Dan Reardon has dealt with the incursion for the past five years and while the drought provided farmers with an opportunity to get on top of summer grasses, this season will show resilient varieties like FTR can return with a vengeance. He recommends the use of group B pre-emergent herbicide Flame, containing imazapic, as a way to control the weed but warns against annual use as it impacts barley in particular.
"I mix it up," he says, noting that his camera sprayer has made a massive difference in controlling the weed. Beyond chemical the only other solution was full cultivation of affected paddocks but a farmer would need to bank on winter rain to make hat program work.
Mr Reardon's agronomist Brad Cogan recommends the pre-emergent Dual Gold, with the active ingredient S-Metolachlor, and a number of paddocks are being sprayed this week with the herbicide ahead of Friday's rain event.
Escaped weeds will be targeted with a double knock glyphosate/paraquat and as a last resort they will be hit with Gramoxone with Sharpen (with Saflufenacil) for broadleafed weeds.
On the coast near Tabulam Kendall Dowley has struggled with FTR for the past three years and finds Verdict with a wetting oil works well in controlling the weed in his summer soybean crops.
Weed specialist Mark Congreve from Independent Consultants Australia Networkis leading a new GRDC project focused on communicating and extending FTR research and said widespread rain during February and March across northern NSW resulted in major germinations of FTR.
"Research has also shown that one of the most effective tactics to manage FTR in fallow is to have a residual herbicide down before late winter or early spring rainfall and rising temperatures trigger large germinations.
He suggested growers consider using Dual Gold (Group K) for single or split applications in fallow, which can be useful where a planting date for summer crops is not certain. The use of Balance (Group H) is a useful option for summer fallow control where the paddock is going back to chickpeas or winter cereals next year.
