OSR growers advised to tackle flea beetle with early nutrition

Oilseed rape growers are being advised to apply a nitrogen-sulphur combination, once conditions allow, to boost spring growth and strengthen defences against pests like cabbage stem flea beetle.

Will Oliver, Warwickshire arable farmer and Basis-qualified agronomist, explains that properly nourishing OSR crops at this crucial growth stage is key to unlocking their full potential.

“By getting a first dose of nitrogen and sulphur on the crop as soon as conditions allow, you ensure that the plant has the resources it needs to kickstart growth,” he explains.

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He explains that a well-nourished OSR plant has a much better chance of withstanding any stress caused by challenging spring conditions and will be much better able to grow away from pest damage.

Growing OSR for the first time in five years himself, Will has selected Avenger, a variety marketed as flea beetle resilient.

He plans to get a first dose of nitrogen and sulphur on the crop – drilled in early-mid August – as soon as the ground is travelable, and highlights the importance of timing.

“The key is not to delay that first nutrition pass – you want to get it on before the crop starts to elongate too much,” he explains.

“If you wait for perfect conditions, you could miss the window. By then, the crop might already be stressed, and it will be much harder for it to recover if hit by poor weather or pressure from CSFB or other pests.”

Sulphur and nitrogen

To simplify nutrient management, Sam Leadbeater, UK and Ireland sales manager for fertiliser company OCI Global, recommends using a compound fertiliser that provides both nitrogen and sulphur in a balanced formulation.

“At this point in the growth cycle, sulphur supports healthy vegetative growth, helping the OSR plant establish a strong foundation for future yield potential,” he says.

“Sulphur is also crucial for protein synthesis and oil production in OSR crops, especially during the reproductive stages.

“It enhances nitrogen use efficiency (NUE), ensuring that nitrogen is utilised more effectively within your crop.”

Split doses

Sam Leadbeater encourages farmers to apply fertilisers in split doses to match OSR’s growth stages and changing nitrogen uptake requirements.

“Split doses help match the crop’s needs as it moves into the spring growing period, while also reducing the risk of leaching or over-application, which can lead to excessive vegetative growth and lodging later in the season,” he adds.