All four Emergency Authorisations submitted by AHDB for Vydate 10G have been rejected by HSE – so growers must swiftly assess alternative methods of soil pest control this spring.

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

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

This useful product 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.

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,” said Mr Anderson.

But, he said, 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, ie Team applicators.”

Mr Anderson said this configuration was 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 said: “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 said: “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,” Mr Hinds concluded.

Vydate alternatives:

Vydate alternatives

Vydate alternatives