A significant increase in numbers of aphid vectors combined with earlier flights and rising numbers of volunteers has increased risk of potato virus, according to Graham Tomalin of VCS agronomy.
Defra/APHA inspections carried out in 2019 resulted in nearly double the level of downgraded crops compared to 2018 due to persistent virus and SASA inspections in 2019 revealed the highest level of mosaic virus within inspections since 2000, he said.
“With the loss of many insecticide actives it is essential extensions of the approvals of mineral oils are achieved to maintain standards. We don’t have approval to use them at the levels we need.
“We also need further assessment of the effects of non-persistent virus on specific newer varieties.”