How to protect both beneficials and crops this autumn
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 as well as 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.”
This autumn, he will be looking to use esfenvalerate (as in Gocha and Sumi-Alpha), as a key tool for managing the risks from Barley Yellow Dwarf Virus (BYDV), following good results against a “prolific” aphid population in some crops last season. “Lambda-cyhalothrin is used extensively by cereal growers throughout the UK, but I’m not convinced it will provide a long enough period of control of the aphid vectors of BYDV, so I’ll be incorporating Gocha instead, to ensure the new season’s crops are properly protected,” he explains. Esfenvalerate’s persistency and longer period of activity delivers the necessary level of aphid control without impacting beneficial predators, and comes at a sensible price, he adds. Esfenvalerate has a completely different chemical structure to other pyrethroids, which gives it several distinct advantages, says Aliona Jones, Technical Demand Creator for Sumitomo Chemical in the UK & Ireland. 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 says. Applying fewer insecticides also helps to protect populations of beneficial species. Furthermore, this persistency, even in the warmer conditions increasingly being experienced in the UK, comes despite needing a lower amount of active ingredient per hectare than other pyrethroids at higher rates, she notes. “It’s a very low amount of active that needs to be used to form an effective dose, which is something that’s becoming increasingly important across the industry, both in the UK and elsewhere.”
Indeed, esfenvalerate has just been re-approved in the Netherlands, a country known for its stringent rules around crop protection products.
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Kind regards
Niamh Tye
Park House
28 High St, Little Bytham
Lincs
NG33 4QX
Source: press release issued by Siafu.