All four Emergency Authorisations submitted by AHDB for Vydate 10G have been rejected by HSE, meaning it’s essential for growers to swiftly assess alternative methods of soil pest control this spring. Charlotte Cunningham reports.

This follows the decision not to re-authorise Vydate for sale, distribution and use in the UK beyond 31 Dec 2020 and means that growers of potatoes, carrots, parsnips, onions, garlic and shallots can no longer use it.

Manufacturer Corteva Agriscience has advised that all full, part full and empty Vydate 10G Ecolite containers should be returned to suppliers by 15 Apr, to allow sufficient time to meet the 30 Apr deadline for removal of Vydate 10G from the market.

Vydate has been the industry standard for PCN control in short-season potato crops and for suppression of free-living nematodes in potatoes, carrots and parsnips.

Its loss will affect around 20% of the GB potato area according to Scottish Agronomy’s Eric Anderson.

He says that growers will need to assess alternatives swiftly and he advises weighing up product performance, the capital cost of application equipment and use period, together with the practicality of application.

“In elevated PCN situations, Nemathorin 10G applied overall will give the most consistent result and can be applied through the granular application equipment growers already have.”

Minimum growth period

But Eric says growers must note the restriction that Nemathorin treated potato crops must be grown for a minimum of 17 weeks before being desiccated or lifted green top, whichever comes first.

“Those considering a switch to Velum Prime would be well advised to go for in-furrow application at planting to expedite application through existing equipment i.e. Team applicators.”

Eric finds this configuration preferable to either an application system mounted to the same tractor as the tilling machine, or a conventional boom sprayer applying in advance of the bed tiller.

Another option is NEMguard PCN, a granular biocontrol formulated from garlic extract marketed in the UK by Certis Europe.

The company’s 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.”

In carrots Root Crop Consultancy’s Howard Hinds has gained experience of NEMguard DE granules commercially since the critical shortage of Vydate in 2015 and 2016 left growers with no alternative.

He says: “Performance of any nematicide depends on the season and conditions and we have seen a similar reduction in fanging from Nemguard in some seasons as from Vydate.

“Good soil moisture is required for its activity so in a dry spring irrigation is something growers need to plan for.

“Recently approved for carrots and parsnips, Velum Prime is the other option and on high risk FLN sites using these two different modes of action may be necessary,” Howard concludes.

Vydate alternatives

Product (active substance) Crops Activity / target
Nemathorin 10G (fosthiazate) Potato PCN and spraing
Velum Prime (fluopyram) Potato, carrot and parsnip Suppression of nematodes and reduction of fanging
NEMguard PCN (garlic extract) Potato Reduction in PCN populations
NEMguard DE (garlic extract) Carrot and parsnip Reduction of nematode damage