Potato growers will enter the 2026 season without access to mancozeb, as industry efforts to obtain emergency approval for its continued use have been halted.
GB Potatoes has confirmed that it will not proceed with an Emergency Authorization (EA) application for the fungicide following technical discussions which concluded that any approval would bring little material benefit to growers.
The decision follows plans for the use of mancozeb to be discontinued in the UK at the end of the 2025 season, raising concerns about epidemic control amid rising disease pressure and risk of resistance.
GB Potatoes said the EA had assessed all possible routes to support growers through the transition, including whether to allow limited use of mancozeb on potato crops in 2026.
GB Potatoes chief executive Scott Walker said the option had been considered in detail. “Following the announcement that the use of mancozeb will be discontinued in the UK at the end of the 2025 season, GB Potatoes has considered the feasibility of proceeding with an emergency authorization (EA) application to allow its continued use on potato crops,” he said.
He said such authorization could have helped with resistance management. “Had the EA allowed the use of mancozeb for the 2026 season, it would have provided significant benefits for resistance management amid increasing pressure from late blight resistance,” he said.
A small technical group was formed with support from Horticulture Crop Protection Ltd to develop potential applications and liaise with the Health and Safety Executive (HSE) on approval requirements.
Pre-application discussions also took place with license holder UPL, which GB Potatoes said were constructive.
However, this process turned out to have significant limitations. “It has become clear that any authorization will be limited to one use of mancozeb per crop in order to meet HSE risk assessment requirements,” Mr Walker said.
This restriction made the proposal unfeasible, he said. “Such a restriction would not be commercially viable given the need to introduce additional management requirements,” he said.
Agronomists participating in the discussion also advised that the benefits would be minimal, concluding that “a single application would provide very limited resistance management benefits.”
As a result, GB Potatoes has decided not to proceed. “It is with great regret that the decision has been made not to proceed with the application for emergency authorization for mancozeb,” Walker said.
He said all possible avenues had been considered and thanked the HSE, Horticulture Crop Protection Ltd and a number of industry experts for their time and input.
The results mean growers are preparing for the 2026 season without the use of fungicides that have long played a role in resistance management, increasing their reliance on residual chemicals and alternative disease control strategies.
