Clearfield oilseed rape growers can test out the encouraging findings of two years of NIAB-TAG and other trials on limiting cabbage flea beetle damage with a companion crop of white mustard for themselves free of charge this autumn.
In a special initiative by leading OSR breeder Dekalb, one hundred 1ha packs of the country’s most popular Clearfield variety, DK Imperial CL carefully blended with white mustard seed are being offered to growers at no cost for planting alongside their chosen DK Clearfield crop this season.
The blend packs are being made available through Dekalb merchants on a one-per- customer, first-come-first-served basis with simple guidelines on their use and a protocol for feedback on their performance.
“Alongside our own European work, the NIAB-TAG trials clearly identify white mustard as the most promising OSR companion to combat flea beetle attack,” pointed out Dekalb marketing manager, Deryn Gilbey.
“Under intense pest pressure in a Cambridge trial last autumn, the only plots to survive were the ones including white mustard. Remarkably, these showed almost no evidence of crop grazing damage.
“Equally, under relatively low CSFB pressure at Morley noticeably reduced grazing was recorded with the white mustard treatment compared to the OSR alone or with other companion mixes.
“At the same time, however, more crop backward development at flowering recorded with this treatment at Morley – attributed to early competition from the mustard’s particularly rapid autumn growth – was identified as a clear concern by NIAB-TAG,” he noted.
“We see the Clearfield system as an ideal technical solution here. As well as allowing crops to be grown without any possible check to establishment from either pre-em herbicides or SU residues, it means the white mustard crop can be reliably eliminated – along with other competitive weeds and any non-CL volunteers – with an early post-emergence Clearfield herbicide spray.”
The Dekalb initiative is designed to validate initial work on white mustard as a flea beetle- deflecting companion crop on a field scale under different conditions and across a range of locations.
In parallel to the wider studies planned by researchers in the coming season, the breeder sees feedback from a substantial number of growers with flea beetle concerns taking advantage of its offer helping to establish how valuable the technique can be in commercial practice.
“In the absence of neonicotinoid seed dressings, we know that getting oilseed rape away as rapidly as possible is vital in combatting flea beetle problems,” Deryn Gilbey stressed. “This puts a premium on the Clearfield system in general and our vigorous-establishing, fast-developing CL varieties in particular.
“We need to understand the extent to which white mustard is effective in attracting flea beetles away from oilseed rape on a field-scale. If it does this reliably enough it could make all the difference in allowing crops to continue being grown in areas where the pest has massively increased establishment risks in recent years.
“As well as being a valuable way of further countering the early crop risk from adult beetle grazing, of course, diverting egg-laying to companion plants that are then destroyed early could help reduce future infestation pressures.
“We look forward to making the findings of our work with growers available widely ahead of 2018 planting to provide the industry with the best possible companion cropping guidance on countering the flea beetle challenge,” he concluded.