Establishment schemes that offer some level of reimbursement in the event of a crop failure are believed to cover about half of 2024-25 crop area.

Such is the threat of cabbage stem flea beetle (CSFB) and winter stem weevil and the difficulties with which they can be controlled that for many growers, oilseed rape has become a high-risk crop. The impact of this change in fortunes is perhaps best demonstrated through the gradual decline in the crop area which, for the 2025 harvest, is estimated to be less than 250,000 ha. This means the UK no longer produces enough to meet crush demand.

In recognition of the difficulties growers faced in managing CSFB and winter stem weevil, plant breeders and seed merchants introduced risk sharing schemes and investigated cultural measures that would support establishment.

Establishment schemes, whereby the grower is reimbursed either fully or partially for the cost of the seed, have proven so popular that about half of the 2025 crop area is thought to be in a scheme of one form or another. Similarly, research into the factors influencing establishment has led to the wider use of companion crops, better nutrition and variety selection, to the benefit of the grower.

The crop was often a challenge to establish well, notes Rodger Shirreff, Agrii national seed business manager, but it was the burden of CSFB that raised the stakes.

“Oilseed rape has always suffered from pest attack and difficulties in establishment, but growers had the tools and experience to cope. The loss of neonicotinoid seed treatments, however, changed the economics of production to such an extent that the only way to maintain interest in the crop was for others to adopt a share of the risk. We estimate that roughly half the crop area is in a scheme of one form or another,” he says.

The schemes vary in the extent of support and the criteria under which they can be invoked, but the principle is much the same. Importantly, crop failure is not defined as ‘by pest attack’ but can be as a result of flooding or even excessive grassweed competition.

“Terms vary, but in general, a scheme needs to be requested at the time of ordering; seed needs to be sown by 20th September and, in the event of a crop failure, a claim with proof of establishment and subsequent failure submitted by the end of October,” Mr Shirreff says.

The schemes are often variety dependant, and not all varieties are underwritten to the same extent. Some varieties are backed with a credit note for the full invoice amount, others with a credit note for a set amount and others with the offer of free replacement seed for re-drilling.

“The Agrii premium scheme offers a full money back guarantee for seed bought at the full retail price regardless of the reason for failure. Choosing which scheme best meets your needs comes down to attitude to risk and which variety best suits the situation,” Mr Shirreff says.

Exceptional varieties

Establishment schemes have helped to sustain interest in the crop while variety trials have sought to identify the varieties that best meet the grower’s situation by investigating the impact different establishment regimes have on crop growth and performance.

“Our experience is that where the crop establishes well, it will go on to perform well, but variety choice is key to overcoming CSFB issues,” says David Leaper, Agrii seed technical manager.

He cites the success of grower guides such as Agrii’s Eight-point plan to oilseed rape establishment and those like it for helping growers adapt to the threat of larvae chewing their way through a crop.

“In 2023, just 10% of the oilseed rape area sown with Agrii seed was the subject of a claim. In 2024, it was significantly less. A direct result of these schemes is the de-risking of the crop, but an indirect result is that growers have become better at establishing oilseed rape,” Mr Leaper says.

A consequence of this risk-averse attitude is a reluctance to experiment with new varieties, with growers instead choosing to stick with those that have done well for them in the past.

“Reliability is a big factor for growers. DK Exsteel, for example, is now in its seventh year and was Agrii’s second best-selling variety in 2024. It has been technically surpassed by varieties with Turnip yellow virus (TuYV) resistance but is still one of the highest yielding varieties on farm,” Mr Leaper says.

This season, Agrii will introduce the Recommended List candidate DK Exedge as a potential successor to DK Exsteel.

“DK Exedge has looked really exciting in our trials over the past two years.  It has the vigorous spring regrowth that we look for to grow away from the larval damage,” Mr Leaper says.

Establishment scheme tips the scales as OSR hangs in the balance

It is the second week in April and Charles and Philip Roberts’ DK Exsteel looks superb in the spring sunshine.

After a good start, the farm’s 85 acres of oilseed rape appear to have plenty of potential, the cousins agree.

Yet OSR is in the last chance saloon at Riggall’s Farm, following two years of heavy crop losses as a result of cabbage stem flea beetle damage.

“We’d been growing oilseed rape pretty successfully for a number of years with the (DEKALB) Ex hybrid varieties.

“We liked them because they were pod-shatter resistant, they were relatively compact and they were consistent,” says Charles.

“But as soon as the neonic seed treatments were banned, we started to struggle with cabbage stem flea beetle. We had a year or two where we had maybe not too bad a crop but the last couple of years have been a complete disaster.”

However, oilseed rape is an important break crop on the 550-acre farm at Frithville near Boston in the Lincolnshire fens.

“This is a heavy land farm. Wheat is our number one crop and oilseed rape has been our number one break crop, but it's got a question mark over it,” says Philip.

“We are very limited for break crops; in the last 25 years oilseed rape has become very important for us and if we lose it, it will leave a massive hole.”

Late last summer the Roberts cousins agreed to give oilseed rape one ‘last roll of the dice’, drilling what might potentially be their last crop between 6th and 10th September.

The deciding factor was Agrii’s establishment support scheme, under which DK Exsteel is among the varieties supported, with backing from Bayer.

“There’s a fine margin between winning and losing. The establishment scheme made the difference this season, because if the rape had failed, we knew we could recoup the cost of the seed,” says Charles.

The establishment scheme gives growers more confidence to drill oilseed rape in the face of ongoing issues with cabbage stem flea beetle and challenging weather conditions, adds Agrii seed technical specialist David Leaper.

“Over the past five years, we have run a number of successful establishment schemes to offset the risks of growing oilseed rape,” he says.

The combine will be the final judge of the 2025 oilseed rape crop and there is a way to go until harvest, but this season the Roberts’ DK Exsteel looks to be in with a fighting chance of success.