Delaying oilseed rape planting and using biostimulants could prove an effective strategy against cabbage stem flea beetle, according to trials.
Work carried out on RGT Black Moon and RGT Paparazzi by Orion FT has shown plants treated with silicon biostimulants Deneb and Sirius had wider stems, sustained less damage and had a higher plant count.
“Using vigorous, fast establishing hybrids that are better suited to late drilling is becoming more popular, however, the threat of CSFB doesn’t diminish entirely for those looking to delay,” says Orion’s research and development agronomist, Kate Finlayson.
“Our trial shows that OSR treated with silicon established thicker and wider stems and a thicker cuticle, making the plant less appealing to CSFB.”
Reducing pressure
Planting later can reduce larval pressure by delaying emergence until after adult CSFB have laid their eggs. This, combined with cooler conditions, has helped growers to slow beetle damage.
But with the threat still apparent, Orion’s trial shows taking a biological approach can improve plant resilience and reduce reliance on chemical treatments.
“Planting later increases the risk that plants won’t establish fast enough to endure early cold weather. Biostimulants can mitigate this by helping OSR to take up more nutrients faster,” explains Kate.
“Whereas silicon helps to improve the nutrient availability in OSR, enabling the plant to establish faster with stronger stems and deeper seeking roots.”
Combatting slugs
She highlights that it’s not just CSFB damage that silicon helps with either. “We’ve carried out similar trials with slugs which also saw a significant reduction in plant damage. By making OSR stronger, it helps to toughen and thicken the cuticle and increase leaf hair density. It also increases phytoliths in the plant which make it less attractive to insect herbivory.”
For those planning to plant OSR later, the risk of CSFB is lower, but focusing on plant health to see the crop establish fast enough is still a challenge, believes Kate.
“Planting late is becoming as a good strategy in the UK, but OSR establishment can be boosted by biostimulants to help fight against pests and to stand up to cold and challenging growing conditions,” she concludes.
