Harvest Healthcheck for OSR
A Harvest Healthcheck of oilseed rape crops and stubbles can give an early indication of the success of control strategies, as well as an indication of potential risks facing the new season crop this autumn.
Norfolk iOSR grower, Chris Eglington, reported his precision drilled crop has remained remarkably clean and even all season, to the point that this season, for the first time, he decided not to desiccate any of the acreage. However, to mitigate any risk of a delayed harvest, he has applied a podstick treatment across the whole area.
In Northamptonshire, Ian Matts (above), opted to glyphosate most, but not all, areas – focusing on green tramlines or under trees, again with podstick on shatter susceptible varieties. Unlike Chris - who only grows conventional varieties - most of Ian’s crop next year will be hybrids, with the exception of some Elgar too. For him disease resistance has a high influence on variety selection, along with yield and gross output.
Further south, in Berkshire, Joe Dilibero (top of page), plans to grow Exalte across most of his oilseed rape area next year, having had good results again this season – producing an extremely consistent crop with just one autumn and one flowering fungicide spray.
Can you spot cankers?
The legacy of last autumn’s Phoma can be clearly evident in oilseed rape crops at harvest. The effect seen is typically stunted plants with thin main stems and far fewer branches that have died off early – with all the implications for a reduced yield, warns Syngenta Technical Field Trialist, Tom Clark.
Look closer on stems or trash of harvested stubbles and there is often evidence of cankers developed on the stem base of crops, typically displaying a key characteristic of the black speckled dots around the canker. Breaking open the stem will reveal a decaying mush, which can be easily differentiated from Sclerotinia if there are no black sclerotia evident within the stem.
“Last season’s infection will inevitably have an impact on yield this harvest. But it also poses a serious risk for the new crop in the autumn,” warns Tom.
“Old crop cankers, on the surface or mixed in with the stubble trash, will be the source of infective spores to attack new plants over the autumn," he advised.
" Rain events over the autumn trigger continuous further spore release from old cankers and repeated infection events.”
For more information and growers' exoperiences, visit the Arable Farming iOSR website: