The liquid version of tri-allate has gained a spring wheat label recommendation to assist growers with grassweed control.

Available as Avadex Factor, the liquid formulation now aligns with the granular form – Avadex Excel 15G – which has full label approval for wheat and barley for both autumn and spring drilling.

“The new label recommendation for Avadex Factor is particularly beneficial for growers who don’t have access to a granule applicator,” says Gowan’s Hank King. “Wild oats, a key grassweed target in spring-drilled cereals, are highly susceptible to tri-allate. It also does an excellent job on blackgrass, ryegrass and bromes, that we typically witness in winter crops.”

Herbicide resistance

According to Hank, another consideration when assessing options for wild oat control is herbicide resistance. Resistance to ACCase and ALS chemistry is known to be present in UK wild oat populations, but there’s no known resistance to tri-allate, which also brings a different mode of action to herbicide programmes.

Winter wheat

Farmers intending to sow winter wheat varieties with a low vernalisation requirement, such as Skyfall, should be mindful of the end of January cut-off for them to be classified as winter wheat according to pesticide labels, adds Hank.

“Most other pre-emergence herbicide options have a reduced rate for spring crops. However, the label rate of Avadex Excel 15G and Avadex Factor is the same for the autumn and spring. This gives farmers the flexibility to sow when the conditions are right and not have to worry about changing herbicide recommendations, potentially compromising control,” he explains.

Spring cropping

In situations where spring crops are replacing failed autumn drillings this season, care is required where tri-allate has been used, advises Hank. “Where tri-allate has been applied in the preceding autumn, oats shouldn’t be planted within 12 months, but spring barley can be safely planted.”

Growers considering more niche market spring crops are advised that Avadex Factor also has Extension of Authorisation for Minor Use (EAMU) approval in spring linseed, canary grass and corn gromwell, while Avadex Excel 15G has EAMUs for spring linseed and canary grass.