Biopesticides may offer an answer to arable woes

In the final leg of our five-part series on sustainable arable farming, David Jones looks at whether biopesticides can answer some of the problems facing the hard-pressed growers.

For those oilseed rape growers who saw flea beetles destroy their crops last autumn, a proven biopesticide might have done the trick without any harm to beneficial bees.

An insect-killing fungus has worked against the beetles in Kenya, yet a regulatory bottleneck means it might only be available in Britain by 2020 at the very earliest.

This product is approved in countries such as South Africa and Ghana as pure fungal spores in vegetable oil and when in contact with the host, multiples within the insect before killing it.

With neonicotinoid seed treatments banned and beetles becoming more resistant to pyrethroid sprays, the fungus from the soil called Metarhizium 69 could be a panacea for oilseed rape growers.

Buckinghamshire farmer Antony Pearce is so convinced that he is searching for funding to help finance a company to bring such products to help out British arable growers.

“Our regulations are holding us back. I am looking to set up a company to bring in products which I would want to use on my farm,” he tells Farmers Weekly.

He is adamant that the product would have helped oilseed rape growers who saw their crops destroyed by cabbage stem flea beetle without a risk to the environment and with clear scientific backing.

Biopesticides, which are naturally occurring microbes, such as fungi, bacteria and viruses, are having a positive effect on crop protection in Africa and could be doing the same here, says Mr Pearce.

He is looking to use Dutch regulators to hasten approval of the product possible by 2019 and so it may reach these shore by the following year.

The testing ground for these products is equatorial Africa where up to four crops can be grown in a year giving perfect conditions for resistance to build-up, only it hasn’t.

Mr Pearce says microbes have multiple modes of action and likens them to the chemical fungicide chlorothalonil, which works on a number of sites and little resistance had been seen in over 40 years of use.

© Tim Scrivener

© Tim Scrivener

He is looking to link up with Kenyan company Real IPM (standing for Integrated Pest Management) run by Louise Labuschagne and her husband Henry Wainwright, who saw a market for these products in the flower and fresh vegetable markets of this East African nation.

She explains that the registration procedure for these products often takes two to three years in Kenya, and the African nation ironically employs European consultants paid for by the UK government to design a regulatory framework which brings these products to market much quicker and easier than in the UK.

“There is a political will by the UK government towards sustainable farming and reduced chemical use, but there is a regulatory bottleneck preventing biopesticides coming to the market,” she says.

Ms Labuschagne helped set up the Kenya-based company with her husband in 2003, with the aim of making products to protect flowers and vegetables for export. It now employs 220 staff.

“The Kenyan flower industry proved that biopesticides worked well as they have no residue problems and no interval before harvest,” she says.

Back home, Mr Pearce is interested in bringing a handful of such fungi that kill insects, biofertiliser that control diseases such as botrytis and rusts and even bioherbicides to this country.

The Kenyan group is developing a fungus which attacks a weed called striga in African maize crops, while nearer home crop consultant Niab Tag is looking at pathogens that could possibly control troublesome blackgrass.

“Mother Nature has developed pathogens for weeds such as it has done for crops. So it should be possible to find out which diseases can infect a weed,” he says.

With UK arable farming suffering from a lack of new chemical products and many others under threat from maximum residue levels (MRLs) and resistance problems, biopesticides suddenly look more interesting.

The sticking block has been the insistence of the Health and Safety Executive’s Chemical Regulation Directorate to check thoroughly on whether non-indigenous microbes will remain in the soil.

The tough long-winded regulatory process in Europe means that new pesticides can cost as much a £1m to get the regulatory green light, while in Kenya the cost can be just £20,000.

Ms Labuschagne argues these microbes are target specific so once they deal with the target they die, and as the UK government is investing heavily in sustainable farming systems so there is a need for a more pragmatic approach to biopesticides.

She adds that there is a need is to understand pests better when using biopesticides as the oilseed rape grower would need to spray at night to control cabbage stem flea beetles.

As the biopesticide used is a contact spray, it needs to land on the insects’ body to be effective, as the flea beetles only feed at night, she explains.

Another product Mr Pearce is interested in is Trichoderma asperellum which can be used as seed coating containing a beneficial soil fungus to promote healthy growth, and this could be used to control clubroot in brassicas, such as oilseed rape.

Mr Pearce, who farms about 900ha near Aylesbury and in the Cotswolds growing winter wheat, winter barley, oilseed rape along with winter and spring beans, is planning to bring biopesticides into the UK from Kenya.

He has set up Real IPM UK and, as managing director, he is searching for growers to raise a total of £600,000 to help with the registration process to bring these products to the market.

With enough growers on board, he will be able to run trials in the UK and assess what type of biopesticides farmers really need.

The market for biopesticides

Biopesticides account for 2-3% of the $51bn worldwide crop protection market, but their annual sales are growing at 16% while conventional chemicals grow at 3%.

Their popularity is driven by market demand and the regulatory pressures on conventional pesticides with fewer new products being introduced and existing ones coming under pressure.

The Kenyan flower and vegetable farms were among the first to embrace biopesticides and now in the EU high value fruit, tomatoes and cucumbers are protected by these products.

The agrochemical giants such as Bayer and BASF are snapping up biopesticide groups for hefty prices and they see them playing a part in a biopesticide-conventional chemistry approach.

The US has about 300 biopesticides available compared to only around 130 in the European Union.



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