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iOSR growers techniques to tackle CSFB

Agronomy Issues
Georgina Wood
Georgina Wood reports trials at the iOSR Focus Site in Suffolk have provided an insight in to some techniques to help growers mitigate the effects of CSFB

Direct drilling and higher seed rates have been two key learns from trials on the iOSR Focus Site this season, reported Georgina Wood. “We also demonstrated the huge impact of barley volunteers due to moisture competition in such a dry season,” she advised.

“Growers that have moved to more OSR establishment after hybrid barley, typically to optimise timing to avoid peak Cabbage Stem Flea Beetle activity, should take note to target vigorous volunteers early to prevent any check in OSR establishment.”    Volunteer control in OSR

Jeff Bradshaw agreed that, in his experience, direct drilling OSR, along with diammonium phosphate (DAP) down the spout, had been highly beneficial last autumn in the dry soil conditions, with fewer problems with slugs and less issue with CSFB.

However, he remained aware that, in a wet winter, the need to get water away from oilseed rape roots is essential – so the technique is only suitable for where soil conditions and structure allows.

He was also surprised by Georgina’s iOSR Focus Site trials that showed sowing under a covering of straw that helped to retain moisture was significantly more successful than with bare stubble, when previous experience would indicate slug pressure would prove too high.

Undercover growth

Georgina Wood also reported that companion crop trials had proved successful, with planting in conjunction with mustard showing up to 58% reduction in CSFB larvae in the OSR – although the pressure was such that it still left significant numbers in each plant.

“Where the OSR was sown in the row with the companion crop we had seen significant competition from the mustard that impacted on the OSR, especially in the dry season,” she added.

“But planting in between the OSR rows had less effect. However, we still struggled to control the mustard without significant frosts.”

A late drilled crop of OSR that had shown real promise with good plant numbers going into the winter, had been repeatedly decimated by pigeon feeding, and resulted in little or no crop at flowering, she added.  

Hybrid vigour

For Cambridgeshire grower, Ian Lutey that has been a switch to growing all hybrid varieties. “We used to grow a mix of conventional and hybrids on more difficult or later sites,” he recalled.

“Now we look for the hybrid vigour initially for establishment, but more importantly in the spring to get the crops away and build a good structure canopy.”

When selecting varieties, Ian (below) now puts as much emphasis on the growth habit and health of the variety - including rooting vigour - as he does the yield figures from the Recommended List.

Ian Lutey

It was noted among all the iOSR growers that sticking with varieties that had shown to work for individual farms and systems was proving more successful than constantly changing with the list.  

Read more from the latest iOSR group:

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