Oilseed rape area to shrink as growers weigh up alternatives
© Tim Scrivener Widespread abandonment of oilseed rape is being considered by growers across the country, as damage by cabbage stem flea beetle (CSFB) larvae undermine the viability of the crop.
Results from the latest CSFB survey, undertaken by the Association of Independent Crop Consultants (AICC) in conjunction with Farming Online, show that 61% of growers in England are seriously considering removing oilseed rape from their rotations this autumn.
See also: Tips for raising oilseed rape yields
This is most pronounced in the South East, where almost 90% say they have had enough, though growers in Yorkshire and Humberside and in the South West are also considering giving up.
Agronomists taking part in the survey were also asked what percentage of the crop would be affected if all those growers followed through with their plans.
AICC predicts that an “astonishing” 18% of the national crop could be dropped this autumn in response to the CSFB damage inflicted this year.
Broken down by region, as much as 25% of oilseed rape production could disappear in the South East.
Crop losses
The reasons for this are not hard to fathom.
According to the survey, which involved about 100 agronomists and covered some 84,800ha or 14% of the English rape area, over-winter crop losses have occurred across the country, but are particularly high in the South East (10%) and South West (17%).
It was no coincidence that numbers of CSFB larvae also increased in all regions, with the mild winter helping overwintering populations and encouraging further hatches.
“Considering the high levels of damage, it is not surprising that growers and agronomists alike are now questioning the validity of this crop,” said AICC chief executive, Sarah Cowlrick.
“The true impact of this pest will only be revealed at harvest, when we see the effect on yields, but we anticipate the 18% number will increase as the season progresses.”
Pressure point
The worsening situation with regards CSFB damage to oilseed rape is closely associated with the banning of neonicotinoid seed treatments by the EU in 2013 amid fears it was linked to the decline in bee populations.
Pressure on crops has grown, with the result that drillings were estimated to be down 10% nationally last autumn, while a further 5-8% of drilled crops were then ploughed up, according to United Oilseeds.
Area trader David Whyte said this was “frustrating for farmers”, but urged them not to abandon the crop.
“This season has been a perfect storm, with seed put into very droughty ground last autumn, so it never got going, and then it has been hit by flea beetle.
“But it would be an error to throw in the towel based on one bad season.”
If growers all rushed into other spring crops, such as peas or oats, that would put pressure on those markets and “not do prices any favours”.
Counting the cost of flea beetle damage
One farmer who is considering his oilseed rape strategy is Peter Lamb (pictured below), who grows 160ha of oilseed rape near Salisbury, Wiltshire, for United Oilseeds as part of a three-year rotation.
“As we approach flowering of the crop, it is becoming abundantly clear that the damage is much worse than expected,” he said.
“Plants in affected fields are twin heights, depending on whether the larvae are eating internally or not, and some aren’t coming into flower at all.”
Mr Lamb says he has been thinking about cutting his area of rape and extending the rotation.
“Rape is generally very good at recovering from things such as pigeon attack or slugs, but it is frightening when you walk out into the crop and see what effect these larvae have had.
“The dilemma is, what should we now spend on the growing costs when the yield potential has been severely reduced, and what would we grow if we dropped it.”
