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NEMguard DE authorised for use in sugar beet against free-living nematodes and reduction of Docking disorder

Following work by BBRO, manufacturer Ecospray and distributor Certis Europe, authorisation for NEMguard DE in sugar beet has been issued by the Health and Safety Executive.

Image of untreated and treated sugar beet plants
Five untreated roots suffering from FLN damage (left), mean fanging score 3. Five grown with NEMguard DE 10kg/ha from an adjacent strip (right), mean fanging score 0.6.

NEMguard DE is a granule formulation containing 450 g/kg garlic extract which is applied at drilling via a granule applicator.

Docking disorder is the name given to the symptoms of free-living nematode (FLN) damage characterised by stunted plants, root fanging and reduction in root size. It is named after a village in the north-west of Norfolk where the condition was first recorded and caused by FLN Trichodorus spp. & Paratrichodorus spp. (stubby root nematodes) and/or Longidorus spp. (needle nematodes). FLN damage is usually more common on light sandy soils and is more severe in years with heavy rainfall in the spring.

In fields with a history of Docking disorder yield losses were minimised by the use of nematicides, such as Vydate (oxamyl) which is no longer available. BBRO has sought alternative options for protection. In conjunction with manufacturer Ecospray, three in-field strip trials were established in 2021 to test NEMguard DE against Vydate, and untreated controls, on FLN vulnerable sites. Following these trials in 2021, a year with perfect conditions for FLN, BBRO are confident that NEMguard DE worked as well as Vydate for FLN management.

Roots were carefully hand lifted from 2m2 sampling areas and scored between 0 (no fangs) and 4 (severely fanged and damaged). The photo below shows root fanging from one field site near Thetford, Norfolk. As it was a small strip trial, data cannot be statistically compared, but the trend shows that NEMguard DE resulted in much better root quality than untreated controls. This should result in significantly greater recovered yields when mechanically harvested.

  • The recommended application rate for NEMguard DE is higher than that of Vydate. BBRO suggest you use 10kg of NEMguard DE/ha in 2022, which they believe will provide adequate protection of your crops. This rate may be refined over time and could reach up to 20kg/ha (the maximum on-label dose) as research continues in the coming years.
  • It is difficult to establish accurate damage thresholds as weather conditions have a significant influence. Soils can be sampled for FLN, with Trichodorus populations more than 1000/litre of soil or with Longidorus populations in excess of 100/litre of soil, indicating risk of damage. On land with a history of FLN damage, the use of a nematicide is usually worthwhile.
  • Granule applicators will need to be serviced, modified, and calibrated ready to distribute NEMguard DE for drilling 2022. For more advice on servicing and calibrating applicators visit the NEMguard DE product page.

More information on using NEMguard DE for sugar beet can be found here.