Sugar beet growers have a brand-new mode of action insecticide available this spring for managing aphids carrying virus yellows.

This brings the number of different mode of action to three, in a season where farmers are forced to rely on foliar sprays in the absence of a derogation for the neonicotinoid seed treatment.

See also: Norfolk grower aims to cut soil compaction in root crops this spring

The Rothamsted Research forecast is predicting aphids to begin migrating later than usual in mid-May, with the national virus yellows forecast at 17% infection (in the absence of any control measures).

However, the British Beet Research Organisation (BBRO) has warned growers that warm and dry weather in late March and early April may pull the migration forward.

Young plants are especially at risk up to the 16-leaf stage, when the plant’s own natural resistance kicks in.

To help farmers, the British Beet Research Organisation’s AphidWatch network will go live on 1 May with twice-weekly updates available via the BBRO website.

Growers are advised to monitor their crops and deploy foliar sprays when the thresholds are one green wingless aphid per four plants up to 12 true leaves. For crops at the 12-to 16-leaf stage, it is one aphid per plant.

Sivanto Prime

The latest addition to the beet grower’s arsenal of foliar sprays is Bayer’s Sivanto Prime.

It is the first authorisation of flupyradifurone in Great Britain and Northern Ireland, which belongs to the butenolide sub-group of the nicothinic acetylcholine receptor competitive modulators mode-of-action group. 

As BBRO points out, its arrival means growers can create a three-spray programme if required, as all three can only be used once in a crop. 

• Acetamiprid (Insyst). Mode of action: Through contact and ingestion and it can be applied up to 16 true leaves.
• Flonicamid (growers can use either Teppeki or Afinto – but not both). Mode of action: Affects digestive system and it can be applied between two and 16 true leaves
• Flupyradifurone (Sivanto Prime). Mode of action: Through contact and affects central nervous system and must be applied to the crop no later than the nine true-leaf stage.

For more on virus yellows, visit the BBRO’s Virus Yellows Knowledge Hub at bbro.co.uk/on-farm/vy-knowledge-hub/