The liquid form of a key herbicide has gained a spring wheat label recommendation, offering farmers another option for tackling grassweeds in the spring crop.

With large areas of spring cereals expected after a wet autumn and winter, the label extension of Avadex Factor (tri-allate) is welcome addition to the herbicide options.

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“The new label recommendation for Avadex Factor is particularly beneficial for growers who don’t have access to a granule applicator,” says Hank King, UK and Ireland business manager for Gowan.

“Wild oats, a key grassweed target in spring-drilled cereals, is highly susceptible to tri-allate, but don’t forget that it will also do the excellent job on blackgrass, ryegrass and bromes that we typically witness in winter crops.”

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 is no known resistance to tri-allate, which also brings a different mode of action to herbicide programmes.

Spring rates

Most pre-emergence herbicide options have a reduced rate for spring crops. However, the label rate of granular and liquid forms of Avadex are the same for the autumn and spring, Hank says.

“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. 

In situations where spring crops are replacing failed autumn drillings this season, care is needed where tri-allate has been used, he advises.

Where tri-allate has been applied in the preceding autumn, oats should not be planted within 12 months, but spring barley can be safely drilled.