‘Primer’ for pests could bring back old chemistry
A new way of helping to kill crop pests has just been approved for use across many parts of Europe, after being licenced in the UK.
An optimised and patented primer formulation – which it is hoped will reduce the chances of a build up in resistance to chemistry – has been made by Pangaea Biosciences. This is based on sassafras oil, which has now received new registrations for use in Poland, the Baltics, Romania, and Denmark, to add to existing registrations in the UK and Czechia.
With registrations also proceeding in Brazil, South Africa, Canada, and Australia, it’s main use is in situations with resistance problems and restoring efficacy to products suffering from significant field resistance.
This patented product inhibits, or neutralises a pest’s defensive enzyme before the pesticide is applied. The primer leaves the pest in a hypersensitive state so that the concentration of the pesticide will kill even the most resistant types and it does this by deactivating the metabolic pathway (cytochrome P450) in insects, weeds and fungi which cause breakdown of an insecticide, herbicide, or fungicide.
The first registration is for the use of Booster with pyrethroids to control pollen beetle (meligethes aeneus), which is a key insect species affecting oilseed rape crops across Europe with high resistance to pyrethroids in the field.
In Europe, insecticide resistance has resulted in a 21% yield loss of rapeseed and in some cases a 70% loss with more than 60% of pollen beetle are resistant to pyrethroids and in some countries, such as Poland and Lithuania, resistance is as high as 80%. It is claimed to restore efficacy to popular pyrethroids, such as cypermethrin and lamdacyalothrin.
In one set of trials, the untreated crop had eight beetles per plant, while after a treatment of Fastac (alpha-cypermethrin) it still had seven beetles per plant. When Booster was added, the level of infestation reduces to one beetle per plant after it made the pollen beetles much more sensitive to the pyrethroid.
“This is very exciting when we consider the impact of resistance across Europe and the world,” said John Edmonds, global product development and regulatory manager for Pangaea Biosciences. “In the UK we are developing a recommendation for the use of Booster with pyrethroids for the control of cabbage stem flea beetle (psylliodes chrysocephala) – a major threat in rape in the UK and one that has often resulted in the inability to grow this crop in certain geographic areas.
“Yield losses of 10% of the national crop have been attributed to this pest alone. We are also working on other beetles such as the Asian stink bug, caterpillar species, such as diamond back moth and cotton bollworm and plant sucking insects such as whitefly and planthoppers.
“In the UK, we are plagued by weeds that are resistance to a wide range of different herbicides with different modes of action and globally there are more than 515 unique cases of herbicide resistant weeds reported. UK resistance is widespread in grass weeds such as blackgrass and ryegrass plus some in wild oat populations.
“Blackgrass is a very widespread and damaging weed in the UK in winter cereals and oilseed rape and can often be found in heavy and very competitive levels, reducing yields substantially. Recently Rothamsted Research said that herbicide resistant weeds could cost the UK £1bn a year, based on wheat yield losses of 3.4m tonnes. Booster works with herbicides exactly as it does with the pollen beetle scenario,” explained John.
It’s not a new way of treating crops, though. It was first identified by Rothamsted Research Station in the 1950s as a substance which deactivated or blocked the normal metabolic pathways of pesticide breakdown. This pathway also appears in herbicides and so it can also can help overcome weed resistance
He said that its great strength was that it could rejuvenate older chemistry and negate the need for high cost and time – reckoned to be £250m and 10 to 12 years – in developing a new chemical.
“We have optimised its formulation and understood how it works. Resistance is now a major issue in agriculture whereas it wasn’t in the 1950 to 1970s,” added Mr. Edmonds. “The ability to bring back a range of other chemistries which have all but reached their market maximum should have enormous appeal to farmers across Europe and Australia.”