A DEPARTMENT of Agriculture and Food WA (DAFWA) trial into herbicide applications in oats has shown good tolerance for a wide range of mixes, including trialling the off-label use of trifluralin.
Speaking at the Australian Fodder Industry Association (AFIA) conference in Perth last week, DAFWA research officer Georgie Troup presented the findings of the trial conducted at Katanning last year.
At last year's AFIA conference DAFWA was asked to test various herbicides due to a lack of information about the impact various herbicides had oat yields, including trifluralin, which is currently not registered for use in oats.
The trial is part of a larger project to support growers by increasing profit from oat production by 10 per cent through variety specific agronomy support for recently-released varieties Williams and Bannister, and for new lines being released by the National Oat Breeding Program.
Herbicides tested in the trial included pre-seeding treatments of Diuron, TriflurX (trifluralin), Dual Gold (s-metolachlor) and Terbyne Xtreme (terbuthylazine); Glean (chlorsulfuron) at two to three leaf stage, Aptitude (metribuzin and carfentrazone), MCPA amine, MCPA LVE, Paradigm (halauxifen and florasulam), Lontrel (chlopyralid) at three to four leaf stage and Amicide Advance 700 (2,4-D) at five to six leaf stage.
Varieties trialled were Carrolup, Kojonup, Williams, Bannister and the breeding line WA02Q302-9, which will be released later this year.
"The aim of the trial was to identify herbicide sensitivities of recently released oat varieties and reduce the potential for hay losses due to herbicide damage," Ms Troup said.
She said almost all varieties tolerated all the herbicide mixes with "good crop safety margins".
"A good crop safety margin means that the variety tolerated an application at maximum label rate and above label rates well," she said.
"A low crop safety margin for a herbicide means the variety tolerated the maximum label rate but higher rates resulted in significant yield loss.
"Only one variety, Kojonup, showed a low crop safety margin for the mix of 2.4L/ha Terbyne Xtreme and 4L/ha TriflurX mix."
Ms Troup said a low crop safety margin implied that when spraying under less than optimal conditions, herbicide damage and significant yield loss could occur.
"For example, this can happen when overlapping herbicides, spraying under wet conditions and when plants are under stress."
She hoped the research would provide some confidence to hay growers when using dual-purpose varieties.
Ms Troup also encouraged people to download the DAFWA My Crop Oats application to assist in diagnosing and overcoming crop constraints.
"The diagnostic tool in the app quickly diagnoses a range of possible constraints based on what you can see in the paddock," she said.
"It contains an extensive image and factsheet library for 66 in-crop constraints, helping accurate diagnosis of constraints and detailed management solutions.
"The type of constraints include a broad range of disease, pest, nutrient deficiencies, herbicide damage and other management and environmental production issues."
