The EU Commission has decided not to renew the approval of diquat based on concerns related to the exposure of bystanders, residents and birds.
Following the Appeal Committee meeting on July 12, 2018, in which no opinion was reached regarding the proposal from the European Commission to withdraw the approval of diquat, it has decided to implement its proposal not to renew the approval of the herbicide active substance in the EU.
The UK sell-out and use-up periods have not yet been confirmed by the Chemicals Regulation Division (CRD).
Mark Britton, marketing manager, Syngenta, which markets Reglone and Retro herbicides containing diquat says: “We have fought hard to defend diquat - we stand by our products and science and maintain that the withdrawal of diquat approval is not justified. Several Member States are of the same opinion, as demonstrated by the result of the July 12 vote.
“We are convinced that diquat plays a vital role in food production. Europe has unfortunately lost an important element for the competitiveness of its agriculture.”
Dr Jon Knight, AHDB head of crop health and protection says alternative desiccants have been trialled at AHDB’s Strategic Potato (SPot) Farms but not all results are available yet. “We have tried a new active that is not currently registered in the UK and should get results on that soon.
“This year is not typical and we don’t know how it will perform under different weather conditions. If it is a year before the ban comes in, we will be able to undertake more trials. As yet we don’t know the right rate and don’t know what the cost will be.”
Dr Chris Hartfield, NFU science and regulatory affairs adviser, says: “The NFU has been working hard to secure the availability of diquat for more than three years. We believe the ban is unjustified and is based on an extremely conservative, precautionary risk assessment.
“Diquat has been used safely by growers for more than 50 years. Its removal from the market will have significant implications for potato production in the UK. It is much more effective than other available alternatives.
“As well as stopping disease spread, it also allows for accurate harvest planning and helps ensure the production of high quality potatoes. It also is one of only two non-selective herbicides available to growers in the EU where no significant weed resistance has developed.”
NFU senior plant health adviser, Emma Hamer adds: “There are no like for like alternatives. Flailing has a place but has been implicated in the spread of bacterial disease and almost always needs diquat to complete the job if regrowth is to be prevented.
“Gas burners have been used but are slow and use a huge amount of energy.”
At a recent AHDB SPot farm walk, Graham Tomalin of VCS Agronomy discussed the need to consider a range of strategies when looking at alternative solutions to using diquat.
He showed how 26 varieties of potatoes planted for a herbicide trial at Somerby Top Farm, North Lincolnshire, reacted to the use of different combinations of desiccant agrochemicals, and provided insight into alternative strategies growers could use.
Mr Tomalin says a diquat ban will mean flailing will become more important with immature crops and indeterminate varieties. With canopies that are senescing, the alternatives will desiccate most varieties but this may take longer, he says.
Application quality is vital to achieving the best results from any desiccant application, says Mr Tomalin: “Coverage is very important and a combination of a slower forward speed of the sprayer, water volume and angled nozzles may all improve this.
“There are potential future alternatives to diquat, but these still need approval. Growers will need to consider the costs to benefits ratio for each option.”
Subject to approval and confirmation by CRD:
The authorisation of diquat ends on June 30, 2019.
Member States must withdraw authorisations for plant protection products containing diquat as an active substance by May 4, 2019 at the latest. (Cannot be sold after this date).
Any grace period granted by Member States must be as short as possible and will expire by February 4, 2020 at the latest. (Cannot be used after this date).