With warnings of another potentially high risk season for aphid-borne viruses on the cards, cereal growers are being urged to think carefully about insecticide choices to protect crops and beneficial insects.
“Ultimately, it’s about choosing the right product for the situation,” says ProCam agronomist Martin Hoggard. “Where we have valuable crops to protect, we need to look carefully at the options available and make decisions based on the unfolding season, the crop’s value and potential, and the wider farming and environmental situation.”
Martin doubts lambda-cyhalothrin has the persistency to control the aphid vectors of BYDV, so he will look to esfenvalerate after good results against a “prolific” aphid population in some crops last season.
Esfenvalerate’s persistency delivers the necessary level of aphid control without impacting beneficial predators, and comes at a sensible price, he says.
Esfenvalerate has a completely different chemical structure to other pyrethroids, which gives it several distinct advantages, says Aliona Jones of Sumitomo Chemical.
These include longer persistency, superior rainfastness and photostability, better repellency, higher activity at lower loading of active ingredient, and, crucially, a kinder environmental profile for predatory and non-target insects, including ladybirds, ground beetles, lacewings and predatory bugs, she says.
“It’s not selective, but it can be used in a targeted way to control aphids effectively. It also offers one of the most favourable profiles for certain beneficial insects among commonly used aphid insecticides, in cereals and a broad range of label-approved crops.”
Esfenvalerate works in three ways; knockdown, ingestion and repellency, she continues. “By deterring pests going towards the plant in the first place, they don’t have to come into contact with the active during application or ingest it.”
At the highest dose rate approved for autumn use (165ml/ha), esfenvalerate can last up to six weeks in certain conditions, potentially allowing for some cost savings to be made compared with needing repeat applications of other insecticide chemistry, she notes. Applying fewer insecticides also helps to protect populations of beneficial species.”
