United Kingdom
April 25, 2025

The launch of a new hybrid oilseed rape variety with resilience to cabbage stem flea beetle (CSFB) promises a big step forward in helping growers overcome one of the biggest challenges to growing the crop.

LG Avenger is the culmination of almost a decade of work by breeders Limagrain Field Seeds, and is the first to be commercially available in the UK with the LG CSFB Resilience characteristic.
 

Florentina Petrescu OSR Product Manager LG UK
 

“LG Avenger is the result of our new methods of breeding oilseed rape varieties, which consider all limiting factors for crop development, including the threat from CSFB,” says Florentina Petrescu, Limagrain UK OSR Product Manager.

“It is the only variety with LG CSFB Resilience on the 2025/26 AHDB Recommended List, alongside many other valuable characteristics, including high yield, pod shatter resistance, high oil content and a very good disease package, including a light leaf spot rating of 7 and sclerotinia tolerance.”
 

Ron Granger – Arable Technical Manager LG UK
 

The introduction of LG CSFB Resilience is the latest in a long line of developments that have helped improve yields in LG’s ‘fully loaded varieties’, Arable Technical Manager, Ron Granger adds. Other features include TuYV and pod shatter resistance, Sclero-flex technology (Sclerotinia tolerance), and the N-Flex nitrogen efficiency trait.

“Limagrain has been at the forefront of OSR breeding for the past decade, and we remain fully committed to the crop, despite the reduction in the UK area witnessed over that time.”

CSFB has been a big factor in the declining area, which has fallen by around 500,000 ha from its peak in 2011/12, to approximately 235,000 ha this season, he notes. Defra figures show average yields for England have also fallen over the past decade, from 3.9 to 2.7 t/ha, although in Scotland, where CSFB is not yet a major issue, yields have risen, reflecting varietal improvements, he says.

“There are success stories where growers are trying new things, and going forward, there needs to be a change to the traditional practices to make OSR succeed. Variety choice is part of that.”

What is CSFB Resilience?

Mrs Petrescu describes LG CSFB Resilience as “a novel genetic approach that tackles CSFB at key crop stages, as part of an effective integrated pest management strategy on farm”.

Resilient varieties feature a series of characteristics that make them better adapted to escaping damage during two crucial periods in the autumn and spring, so it is not just about a single genetic trait, she says.

These characteristics include:

1. Strong autumn dynamic growth to help developing crops escape the early “shot holing” damage caused by adult flea beetles feeding on cotyledons and first leaves, which can result in significant leaf loss and complete crop failure in extreme cases
2. Rapid stem elongation in the spring to improve the plant’s resilience to damage caused by larvae mining into petioles and stems
3. A capacity in some varieties (e.g. LG Avenger) to limit the number of larvae that develop within the stems – the exact reasons for this are still being identified
4. Reduced CSFB larvae damage severity – e.g. stunted, bushy plants.

Reducing the severity of CSFB damage has a direct benefit on final yield, Mrs Petrescu adds. Indeed, AHDB research suggests one additional larvae per plant can cost 50-70 kg/ha in lost yield.

Feeding damage by adults and larvae has other implications too, such as increasing the entry points for disease, uneven flowering and variable pod maturity. Varieties with LG CSFB Resilience, such as LG Avenger, therefore also include characteristics like pod shatter resistance, and a strong disease profile to help mitigate these risks, she says.

Independent backing

CSFB is a major issue in many other European countries, including France, where CSFB resilience has been a characteristic on the French Recommended List for the past six years. Independent data from the French equivalent of AHDB (Terres Inovia) puts LG Avenger as one of the highest rated varieties for resilience on this list.

This backs up three years’ worth of Limagrain Europe assessments in 2022-2024, where LG Avenger significantly outperformed the sensitive control variety and came close to the most resilient control, LG Aviron.
 

“Oilseed rape ticks so many boxes as a break crop, both in terms of gross margin, inputs, equipment required, workloads, and agronomy. But in order to grow oilseed rape successfully, growers may need to think differently about how they do it.”

Limagrain UK has produced a white paper covering the work behind the resilience trait and how to optimise it as part of an IPM programme. Visit http://bit.ly/42nP6dV

No silver bullet

While varietal resilience is a welcome addition to the toolbox needed to tackle CSFB, it is no ‘silver bullet’ and must be used as part of an integrated pest management strategy, built around 10 key areas:

1. Rotation/proximity to the previous year’s OSR crop – adults emerge from OSR stubbles for up to six months after harvest, peaking in mid-September. Risk is often higher in crops grown close to a previous OSR crop, although work is ongoing to identify how far adult CSFB can fly. Cultivation of the previous oilseed rape stubble straight after harvest has shown to significantly reduce the number of adults emerging from the soil through the autumn
2. Variety choice – grow hybrids with CSFB Resilience and consider regional performance
3. Companion/trap crops – growing a companion crop (e.g. buckwheat, berseem clover) can help to disguise emerging OSR from CSFB. Leaving long stubbles from the preceding crop can also help
4. Seedbed preparation – good seed-to-soil contact and soil moisture retention are key to rapid establishment, so drill by conditions, not date. Consolidate well and avoid cultivations that may dry the soil out too much before drilling
5. Crop establishment – consider all ways to boost establishment, such as placing nutrition close to seed
6. Weather forecasting – key to determining drilling conditions
7. CSFB monitoring to assess risk – stem larval sampling is simple and cheap to do on farm
8. Record keeping – drilling dates, conditions, pest numbers, yields, etc
9. Evaluate the effectiveness of management practices
10. Insecticide application – use only where necessary once thresholds are met, but recognise that widespread resistance means pyrethroids may have little impact on CSFB, and may damage beneficial populations
11.  

Website: http://www.limagrain.co.uk

Published: April 25, 2025