Farmers Weekly’s regular update on the key pesticide label changes and potential implications to help you stay on the right side of the law.

Use up Austral Plus-treated cereal seed by spring 2020

Cereal seed treatment Austral Plus is now entering its use-up period and growers with any treated seed on farm should ensure it is drilled by the end of spring 2020.

Containing the insecticide tefluthrin and the fungicide fludioxonil, Austral Plus has been relied upon for many years for reducing damage caused by wheat bulb fly and wireworm and controlling seed and soil-borne diseases in wheat, barley and oats.

However the product has failed to gain re-approval from the European Commission (EC) due to its potential toxicity to mammals, and sales of the product ceased on 31 August this year.

See also: Why more on-farm trials are needed to fill applied research gap

Syngenta’s seed and seed treatment sales manager Samantha Brooke says it represents a blow for growers, particularly those drilling spring cereals into high-risk wireworm situations.

“Although there are other [insecticide seed treatment] products available for use in the autumn, [Austral Plus] is the only one that can be used in the spring, so it will have a big impact,” Mrs Brooke explains.

She says there is a good volume of product currently within the supply chain, which has a 12-month use-up period ending on 31 August 2020.

However, as the product is typically used on late-drilled cereals after roots – where wheat bulb fly risk is high – or in the spring, in reality, the window for use is much smaller.

“We are advising our customers to use stocks up this autumn or in spring 2020,” she adds.

Looking ahead, the pyrethroid seed treatment Signal 300 ES (cypermethrin) will offer an alternative to Austral Plus in autumn- or winter-sown crops of wheat and barley sown before 1 February.

Rob Adamson, technical specialist for UPL UK & IE, says the product is recommended for both wheat bulb fly and wireworm control and has a comparable activity to the tefluthrin in Austral Plus, but with improved operator safety and a low-dust profile.

The product also has a recommendation for control of frit fly, for which there has been no foliar chemical control option since the withdrawal of chlorpyriphos in 2016.

“Having an additional qualified recommendation for Signal and the control of frit fly is a real win for growers and provides the one opportunity to safeguard against this pest,” he adds.

Another tefluthrin-based seed treatment, Force ST, which is used to control the soil pest complex in sugar beet and fodder beet, is unaffected by the withdrawal of Austral Plus in cereals and was recently re-registered until 2027.

Look out for application timing change on Axial label

Growers using the popular grassweed herbicide Axial Pro (pinoxaden) should note a minor change to its label after it came through the regulatory re-approval process.

Axial Pro is an acetyl-CoA carboxylase (ACCase) inhibitor herbicide used to control wild oats and ryegrass in wheat and barley.

Sales of “old label” Axial Pro with MAPP number 18275 ceased on 31 August 2019. The replacement “new label” Axial Pro has the MAPP number 19010.

Unlike the old label product, which could be used during the autumn and up to GS41, new label Axial Pro cannot be used before 1 February, and up to growth stage 41.

Syngenta told Farmers Weekly there was very limited use of pinoxaden before spring, but those who chose to do so must ensure they applied the old label product.

Any supply had to be on farm by 31 August 2019 and must be used by 31 August 2020.

New autumn grassweed herbicide approved

Bayer has gained approval for a new autumn residual grassweed herbicide product, Alternator Met.

It contains the two active ingredients in grassweed killer Liberator – flufenacet and diflufenican – with the addition of metribuzin, an active most familiar to potato growers who use it as a pre-emergence option.

The product can be used pre- or post-emergence in winter wheat or winter barley in one of two ways, shown in the table below. A 6m aquatic buffer zone must be observed.