Alternative options to neonicotinoids for sugar beet growers

• Biologicals help to protect beet crops

• Plants made ‘less attractive’ to aphids

• Foliar spray to boost quality and yield

Sugar beet growers are being reminded of alternatives to help manage aphids and the threat of virus yellows this spring.

It follows Defra’s refusal to grant an application for the emergency authorisation to use the neonicotinoid-based seed treatment Cruiser SB. Manufacturers claim biological alternatives have shown promising results in trials.

Unlike Cruiser SB – which provides seed protection against the potato peach aphid and the virus yellows virus it transmits – some biological products strengthen plant cell walls and increase leaf hair density to make them less appealing to aphids.

“This approach, alongside common insecticides including Tepppeki and Insyst, has shown a significant reduction in the virus transmission,” says agronomist Mike Stoker, of  Orion Future Technologies, which makes the biological product Sirius.

Transmission

A biostimulant containing 21% bio-available silicon, Sirius has been used by UK growers since 2022 to successfully strengthen sugar beet plants against damaging virus transmission, says Mr Stoker.

“By accumulating more silicon, the plant becomes less attractive to pests and combining this with aphicides offers an attractive alternative to using Cruiser SB,” he adds.

Sugar beet losses were minimal (-0.5%) in 2019 and 2021 when Cruiser SB was unavailable, according to information published by Defra minister Emma Hardy, who is responsible for pesticide authorisations.

Losses soared to 25% in 2020 – again when Cruiser SB was unavailable – but ranged from just 0.3% to 1.7% when Cruiser SB was available between 2022 and 2024 – a level not dissimilar to 2019 and 2021.

Stronger crops

“Relying solely on seed treatments is not a sustainable way to farm sugar beet in the UK – nor has it necessarily provided the level of protection expected,” says Mr Stoker.

“There are alternatives, and concentrating on strengthening plants using naturally available solutions like silicon are sustainable and efficacious.”

Silicon is applied as a foliar spray to sugar beet at growth stage 6-8 true leaves. Once accumulated, Mr Stoker says it acts to reduce the feeding time of predating pests such as aphids.

This reduction in feeding time has been identified as an important factor in the reduction in virus transmission and has also led to healthier plants with an improved yield, he adds.

Data from multiple sources – field applications, replicated plot trials and lab studies – has demonstrated why silicon-treated crops are more resilient – and how higher silicon levels in the plant can boost quality and yield, says Mr Stoker.