All four emergency applications for the use of Vydate (oxamyl) in 2021 potato, carrot, parsnip, garlic and onion crops have been rejected by the Health and Safety Executive.
However, the Chemicals Regulation Directorate (CRD) has agreed to extend the expiry dates for the disposal and storage of Vydate 10G until April 30, 2021. The application for sugar beet is still to be determined.
The emergency application was made for the 2021 season, following an announcement that Vydate would not be reauthorised for use beyond December 31, 2020.
All full, part-full and empty Vydate 10G Ecolite stock should now be returned to distributor suppliers by April 15. This will allow sufficient time for the supply chain to meet the April 30 deadline for removal of stock from the market.
This decision leaves potato growers with just one remaining granular nematicide for the control of potato cyst nematode (PCN) – Nemathorin (fosthiazate) and the liquid nematicide Velum Prime (fluopyram).
Growers making the switch from oxamyl to Nemathorin need to be aware of a number of differences in the products, says Syngenta technical manager Michael Tait.
“The same equipment can be used for the overall application of granules, however it must be fitted with Nemathorin-specific rotors or cartridges and calibrated to accurately deliver the 30kg/hectare application rate for PCN. Nemathorin cannot be applied in-furrow.
“Incorporation to a consistent depth across all soil types and conditions is important, as Nemathorin is relatively immobile in the soil profile – which helps to achieve the good levels of PCN control,” he says.
“If field conditions change, check the incorporation depth and adjust accordingly.”
Crops cannot be desiccated or harvested for at least 119 days after application.
Nemathorin is also approved to reduce the damage caused by problematic potato soil pests, wireworm, and free-living nematodes (FLN) responsible for the transmission of spraing. Another option is NEMguard PCN, a granular biocontrol formulated from garlic extract.
Certis’ Neil Beadle says: “Nemguard can help reduce nematode damage in potato crops and can be applied using the same rotors/cassettes currently in place for Vydate application. The operator simply recalibrates to deliver the correct dose.
“It also has no harvest interval, so fits short duration crops well.”
Parsnip growers have also been offered a lifeline for the control of FLN following the loss of oxamyl. The liquid nematicide Velum Prime can now be used on parsnip crops after AHDB Horticulture was granted an extension of authorisation for minor use in the crop.