Farming feature: Farmers cut back oilseed rape crop in response to insectide ban

An infestation of cabbage stem flea beetle larvae on an oilseed rape crop in East Anglia

An infestation of cabbage stem flea beetle larvae on an oilseed rape crop in East Anglia - Credit: Matthew Usher

The European Union (EU) imposed a restriction on neonicotinoid seed treatments in December 2013, but the row over whether the ban was justified rages on.

Field of oilseed rape at Thorndon, near Eye

Field of oilseed rape at Thorndon, near Eye - Credit: Archant

Environmental campaigners point to scientific studies indicating the treatments, which are coated onto the seeds, have serious, harmful effects on bees and other pollinating insects, while farmers argue there has not been enough data from realistic field trials for a fully science-based decision to be made.

Farmers are concerned that the ban leaves their crops vulnerable to infestations from pests such as cabbage stem flea beetles which hit a number of UK farmers around August/September last year when OSR crops were establishing - and it’s thought, as a result, growing areas could drop dramatically this year.

The pests can be very damaging to these very young crops, and OSR growers in Essex and Suffolk say they had to spray their crops, sometimes multiple times, in order to save them from further attacks.

Last autumn was the first season that neonicotinoid seed treatments were not available to protect emerging winter oilseed rape (OSR) seedlings from damage by cabbage stem flea beetles (CSFB).

Guy Gagen, chief arable crops adviser for the National Farmers’ Union (NFU) said: “Sadly I think there will be less oilseed rape grown nationally, in particular in East Anglia, because the risks that farmers are facing are increasing all the time.

“It is not just about seed treatment, it is about general control – and we are starting to see resistant populations as well. The more simple, straightforward insecticide we could have used is now not effective in large parts of East Anglia. That has only emerged in the last couple of years and, again, is stacking the odds against the farmers.

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“Those campaigning claiming to be representing the interests of pollinators tend to dismiss agriculture as not being relevant at all. They say farmers should just grow something else.

“But OSR is a very important crop economically, and for the whole agricultural system. It is very versatile and produces an oil used in a multitude of products from mayonnaise and salad cream to biofuel. Also, some people forget that most of what is harvested is used as animal feed, at a time when we import a lot of the animal proteins we use.”

John Collen, who farms at Gisleham, near Lowestoft, and sits on the national National Farmers’ Union (NFU) crop board, said: “Without question, people are looking to take I would suggest 30% of the OSR crop out.”

He successfully combated his own flea beetle infestations with about three spray treatments, but is hopeful that in the near future an alternative coating will be available for the seeds which will make it easier to establish than present rules allow.

However, for various reasons, including its usefulness in combating blackgrass and rye grass problems, he would continue to grow around 1,000 acres of the crop. The margins were “poor”, he said, but so were the margins on other possible alternatives, he reasoned.

“Growing it is relatively simple, but establishing it it far from simple. It’s a very, very easy crop to lose at establishment,” he said.

Robert Raven, who farms at Henstead, near Wrentham, is cutting his OSR growing area by about 30% from 30 to 40ha to about 20ha this year.

His crop was hit by flea beetle which he had combated successfully with spray treatments.

“The result of the ban is we had to do a lot more spraying,” he said. A lot of farmers had been “badly affected” by flea beetle outbreaks - although his treatments worked, he said.

“The acreage across Europe is right down compared to where it was last year,” he said. “We depend on this stuff for our cooking oil and our biodiesels.”

Many farmers see OSR as having rotational benefits and find it to be a useful break crop.

Mr Raven argued that the neonicotinoid seed treatment only affected the soil it was touching, whereas spray treatments, by their nature, were much less discriminating.

“What we now have to do is to spray in the field which is a less targeted method,” he said. “Without the seed treatment we then have to spray up to three times and a lot of people take more than that. That’s a blanket treatment that’s going to affect all the insects in the field.”

Meanwhile, Andrew Blenkiron, who manages the Euston Estate, in west Suffolk, said: “We are stopping growing it completely.”

Part of this was down to the flea beetle challenge, he said, but other unconnected factors were involved. He felt the neonicotinoids ban was a mistake as there were lots of challenges to getting a healthy OSR crop established.

“You can apply loads and loads of insecticide which is loading the environment up with more chemical than a bit of seed dressing,” he argued.

But John Haynes, of MJ and SC Collins at Matching Green, Hatfield Heath in north Essex, said he would be sticking with the crop and his 400ha growing area - in spite of a huge increase in pesticide bills last year to control a big outbreak of flea beetle which hit 75% of his crop. He faced an extra £26,000 insecticide bill to control the pest.

“I think we were pretty much in the epicentre of a substantila flee beetle population which caused us a lot of damage and aggravation through not having the neonicotinoid seed treatment. The flea beetle always present, we just noticed it a lot more this year,” he said.

However, he was taking a long-term view and staying with it for the foreseeable future. “OSR is a very important crop for us and I think it would be foolish to have a kneejerk reaction. The crop actually fits in time wise to our calendar and I’m pretty gott at growing it,” he said.