Pesticide changes this March growers need to know

Two changes to pesticide labels plus the need for farmers to keep on top of their spray store stock ahead of a spate of withdrawals next year are the key messages in the latest edition of Pesticide Watch.

One of the key changes means linseed growers now have another option for managing grassweeds, as tri-allate gains limited approval.

Farmers are also reminded to monitor stocks of some pesticides carefully, as withdrawals next year could result in left-over stock that cannot be legally used next year. 

Liquid grassweed killer gets green light for linseed

A liquid formulation of the herbicide tri-allate has gained an Extension of Authorisation for Minor Use (EAMU) for winter and spring linseed crops.

Granular tri-allate product Avadex 15G already has an EAMU for pre-emergence use in winter and spring linseed, helping to control blackgrass, bromes, ryegrass and wild oats.

See also: Sussex grower switches wheat variety to trim fungicide spend

As spring sowings start in mid-March, herbicide options have been bolstered by the addition of Avadex Factor, a capsule suspension formulation of tri-allate that can be applied pre-emergence only.

The EAMU specifies a maximum total dose of 3.6 litres/ha, and a statutory 6m drift-reducing technology buffer zone around watercourses must be adhered to.

A contractor is needed to apply Avadex 15G granules, so being able to use the liquid formulation could see growers reap the benefits of tri-allate for grassweed control, at a reduced cost.

It can also be tank mixed with other herbicides such as Callisto (mesotrione) to boost broad-leaved weed control, most notably brassica weeds charlock and runch, both of which are difficult to control in oilseed rape.

As with any EAMU, growers should obtain a copy from the CRD website or NFU before use, and application of the product is at their own risk.

Keep on top of expiring chemical store stock this spring

With sprayers about to get busy for the spring, now is a good time to identify any chemical stock that is set to expire during the next 12 months and use it legally ahead of its cut-off date.

There is a spate of agrochemical product approvals set to expire in early 2020 and although this seems a long way off, not using them up during this cropping cycle may cause compliance issues.

One example is the onion fungicide Unicur (fluoxastrobin + protioconcazole) with the Mapp number 14776. The product carrying this Mapp number can’t be used beyond 31 January 2020.

If the product has not been used in the summer, it cannot be used before the expiry date unless the business grows over-wintered onions.

There are also issues surrounding products that have moved from one approval holder to another for commercial reasons, such as an acquisition or divestment.

The sulfonylurea herbicides Accurate (metsulfuron) and Accurate Extra (metsulfuron + thifensulfuron) have switched from Headland Agrochemicals to Nufarm.

Accurate (Mapp 13224) and Accurate Extra (Mapp 14167) will expire on 31 January 2020, but cannot be used before 1 February in the year of harvest and existing stocks need to be used up this spring.

There are a number of other similar examples in the Chemicals Regulation Division (CRD) database, highlighting the need to keep an accurate record of what is coming in and out of the chemical store and to ensure products are used within dates set out in each approval.

A Rural Payments Agency or assurance scheme inspection could uncover these issues, possibly resulting in penalties or fines.

Withdrawal timeline revealed for Mocap

In early March European regulators published the final report on the non-renewal of the granular insecticide and nematicide Mocap (ethoprophos), which outlines the timeline for its withdrawal.

Sales of the product will be permitted up to 21 September 2019 and any stocks must be used by 21 March 2020.

Nick Badger, potato portfolio manager at approval holder Certis, says the 2019 planting season remains unaffected by the withdrawal, but availability for the 2020 season is currently under review and will be communicated in due course.