AHDB's application for emergency authorisation of Vydate has been rejected by the Chemicals Regulation Directorate (CRD).
The nematode treatment will no longer be available to growers of carrots, parsnips, onions and potatoes, following the unsuccessful application.
The CRD has, however, agreed to extend the expiry dates for the disposal and storage of Vydate until 30 April 2021.
All full, part-full and empty Vydate 10G Ecolite stock should be returned to distributor suppliers by the 15 April.
AHDB said this will allow sufficient time for the supply chain to meet the 30 April deadline for removal of Vydate stock from the market.
The emergency application was made for the 2021 season, following an announcement that Vydate would not be re-authorised for use beyond 31 December 2020.
AHDB, with support from Vydate manufacturer Corteva, applied for the approval to provide limited use for this season.
Joe Martin, Crop Protection Senior Scientist, said: “We made the emergency application following the product’s non-renewal, due to the lack of alternative control products now available to growers.
"We’ll continue to work with manufacturers to seek new options for the industry.”