The oilseed rape planted area looks on the up, with establishment lessons and advancing plant genetics taking the crop to places it’s never been before. CPM attended a Limagrain briefing in Lincolnshire in March to find out more.

by Melanie Jenkins

The trend for 2022 is very good but going further forward it looks very buoyant.

OSR can be a tricky crop to grow, but refining establishment to cope with risks and selecting varieties with the right genetics can help mitigate threats and ensure a profitable crop at harvest.

OSR plantings have gone through an evolution over the past eight years, from highs of 740,000ha in 2013/2014, to lows of 275,000ha in 2020/2021. But the trend is on the way back up with around 361,000ha planted in the 2021/2022 season, according to Andersons and Limagrain market data.

“There’s an argument for whether the 2014 area was sustainable longer term, given the one in three rotation on many farms, and it marked the first harvest without neonicotinoid seed treatments,” says Will Charlton of Limagrain. “And in an ideal situation, with a brassica the rotation should be more like one in five.

“The positive thing is we feel the planted area reached the bottom last year (2020/2021), and we think there was just 2% of the crop lost. Of the 361,000ha planted this season, we believe around 5% of the crop didn’t survive after planting.

“For next year, our current assumption is around 400,000ha will go in the ground but it could be significantly more than that. We don’t think it’ll be less than this year,” he comments.

An interesting development Will has noticed over the past three seasons is the increasing inclination towards hybrid varieties. In 2020, 46.4% of the area sown was hybrid, 37.3% was conventional and 16.3% farm-saved seed. For the current season it looks more like 63.2% hybrids, 21.8% conventionals and 15% farm-saved seed.

“Hybrids have gained a lot of traction for a couple of reasons; they’ve pulled away from many of the conventionals, are more vigorous and incorporate a range of agronomic traits.”

He also feels a lot of farmers are no longer farm-saving seed because they want to plant their OSR so early they haven’t actually combined their last OSR crop. “The pattern of earlier drilling moves earlier and earlier every year,” he explains.

“Our sense is that farmers now have a greater understanding of strategies that work in their system to get a crop established through the main risk period for cabbage stem flea beetle (CSFB) migration, and they’re trying to manage CSFB larvae through the winter, which is really positive,” says Will.

He adds that genetics have improved significantly and this has aided establishment success. “And potentially, with less overall crop in the UK there’s been a reduction in CSFB pressure but that’s anecdotal.”

The other positive is the current price of OSR. “Prices were high before the terrible situation in Ukraine, but this has pushed them even further.

“UK demand for rapeseed oil is fixed,” said Will. “Most goes into the food chain and we need all that’s crushed in the UK. Our production is no longer self-sustaining so the UK does have to import rapeseed. The trend for 2022 is very good but going further forward it looks very buoyant.”

But he warns that flea beetle hasn’t gone away. “It’s not going to be a crop for everybody to go back into and the days of 700,000ha of OSR have probably passed, but certainly 500,000ha could be conceivable going forward.”

So what lessons around establishment has Limagrain learnt?

Through its establishment scheme, which is run by partners in the seed trade, growers with Limagrain hybrids report on drilling dates and crops losses.

“Last year our scheme covered 19,000ha, so was a reasonable sample size to analyse and draw conclusions from,” explains Will.

Around 4.6% of the area was lost, with the greatest percentage of losses coming from crops sown between the middle and end of August. “During those same weeks there was a close correlation between very a dry period subsequent to drilling and crop losses in the scheme.”

The other factor was CSFB. “The risk period, according to Sacha White at ADAS, also maps in very closely with the period crops were lost,” he says.

But for those growers taking drilling ahead of the traditional third week of August window, the risk from CSFB larvae becomes higher, he says. “You may save your crop from excessive adult damage and get a well-established crop but then it’s important to look at how you mitigate and manage any larval damage. Your overall aim is to increase the branching of your crop to minimise this.”

Selecting a variety with the right genetics can have a sizeable influence on a crop’s ability to survive these pressures and achieve a grower’s aims. Limagrain aims to present growers with optimal genetics through its new fully-loaded traits programme, according to the company’s OSR technical lead, Liam Wilkinson.

Liam explains a set of traits is incorporated into all new Limagrain varieties which should provide both security and yield potential. These include turnip yellow virus (TuYV) resistance, disease resistances and pod shatter resistance. Varieties are then screened for yield potential and nothing without these genetics will make its way out of the breeding glasshouses, he says.

Looking at TuYV, Liam believes we could expect a high-pressured autumn without a real winter to check the virus. “But genetics are holding up with the loss of insecticides and there’s now no yield penalty in TuYV resistant varieties.

“TuYV resistance prevents the multiplication and spread of the virus through the plant after being infected. It’s really the foundation of integrated pest management at the moment.”

Liam highlights that in spring last year, TuYV was identified in 52% of susceptible conventional and hybrid crops and stresses this means the virus is still out there. “It’s getting harder to find as we’ve seen a switch to hybrids with resistance, but the risk is still there for those choosing susceptible varieties.”

Another key trait Limagrain has in all new varieties is pod shatter resistance. “I think it’s the ultimate level of security in a variety as this genetic trait protects against adverse weather leading up to harvest. Even passing through the crop with the header of the combine can cause significant losses,” explains Liam.

“Pod shatter resistance strengthens the bonds in the pods, making them more resilient in catchy harvests, meaning you’ve got more chance of harvesting the crop. And you can reduce volunteers – with the price of glyphosate at the moment, this probably isn’t a bad thing either,” he adds.

Limagrain’s new variety, LG Auckland is second on the AHDB Recommended list but it’s the highest yielding with a combination of TuYV, pod shatter and RLm7 resistance, said Liam. “It has good autumn establishment and quick growth, together with strong light leaf spot resistance and stem health.”

For those growers requiring more niche varieties, such as those with clubroot resistance, Limagrain is drawing TuYV, pod shatter and RLm7 resistance into these too, explains Liam. “We’re bringing the traits that were restricted to traditional hybrids to our new clubroot varieties, LG Anarion and LG Scorpion, the latter of which is coming to the market this year.”

The Clearfield sector is another area Limagrain has introduced its fully-loaded traits, the first variety of which is LG Constructor CL, he says.

Despite its focus on hybrids, Limagrain is still developing conventionals and its two new varieties for this year are Annika and Amarone, both of which include TuYV resistance, according to Liam.

Limagrain’s next focus area is stem health (see Inside Traits, page X), he explains. “We’re looking to combine advances in phoma, LLS and verticillium resistance with our fully-loaded traits.

“OSR can be a headache of a crop to grow for a lot of farmers, but genetics allow you to take as much risk out of growing the crop as possible. A lot of problems can be solved by selecting the right genetics,” he concludes.