Any grower walking oilseed rape crops in April would be forgiven for thinking they need hardly bother with a combine this summer. And yet this notoriously unpredictable crop produced the goods, with above average yields in trials at least.

“I have no idea where the average farm yield is going to come in this year – I would guess below the five-year average at 2.5-3t/ha,” says David Neale, crop marketing manager at Agrii. “But within that, there are 5t/ha crops that were drilled early into good conditions and established well.”

There were also disastrous crops that were muddled into poor seed-beds, failed, and were redrilled in the spring. “One Wiltshire grower pulled out 30% of his winter rape, and what was left still looked awful,” says Mr Neale. “But it ended up yielding well – if there is any sort of root, it’s amazing how some of these crops will pull through.”

However, anything shallow rooted was hit hard by the hot June weather, and did not yield well. “Rapeseed is a lazy rooter, so it needs every encouragement to get it going,” he says. “Subsoiling to break the plough pan and create a good root line definitely helps – but this autumn has demonstrated the importance of rolling the ground afterwards to retain the moisture.”

For more on this: See all of the articles on High 5 OSR yields

Thankfully, crops suffered from very little pest or disease pressure this year – but farmers must be careful not to grow rape in a tight rotation, warns Mr Neale. “And don’t assume you’re safe from phoma and light leaf spot, because they are travelling across the country very rapidly.”

One of the biggest issues that limits rape yields is drilling it at a high seed rate. “You only need 40 seeds/sq m for hybrids and 50 for conventional varieties – as soon as you get much above that you will cap yield potential.” Anti pod-shatter is also becoming an important factor in minimising field losses, he adds.

Seed quality has been generally reasonable this year, with oil contents ranging from 41-45%, says Richard Elsdon, technical manager at United Oilseeds. “However, we’ve had more admixture in samples than for a long time, with several samples having as much as 5-7%.”

This was down to the slow establishment and difficulty of applying post-emergence and spring herbicides, particularly on heavy soils. But while crops were very slow and variable in ripening, there have been surprisingly few problems with red and green seeds this year, he adds. “Growers were very aware of the potential problem, and were patient with combining only the ripest parts of the crop.”

But a potential knock-on effect of last year’s wet autumn has been the number of growers who drilled their crop very early this season, warns Mr Elsdon. “Mother Nature did the plant growth regulation last year, and crops stood from start to finish, which helped them to reach their potential. But some crops are already very forward, which could be difficult to manage; growers should look at applying a growth regulating fungicide, such as metconazole, before it’s too late.”

With the high soil temperatures and warm autumn, the window for drilling is still just about open, and farmers have plenty of varietal choice. “In terms of mean gross output there is really nothing to choose between the top dozen varieties, so growers can concentrate on selecting varieties with the plant characteristics and disease resistance that suit them best,” says Simon Kightley, oilseeds variety specialist at NIAB.

Based on the four-year mean, there is a good mix of hybrids and conventional varieties at the top of the list, as well as some promising candidates, he adds.

As part of the Yield Plateau project, NIAB identified October, December and April as key growth stages; with a warm October, cold but dry and bright December, and warm, dry and bright April most conducive to high yields, says Mr Kightley.

“We didn’t have any of that in 2012-13, so thought we were on for possibly record low yields. But flowering was a month late, and very prolonged; and the summer weather was very good, so we ended up with a very good average yield.”

New series: High 5 Barometer farmers

Farmers Weekly’s highly successful High 5 OSR Challenge enters its third year this autumn, aimed at helping growers consistently achieve 5t/ha or more by teasing out the secrets of growing these high yielding crops.

Achieving a 5t/ha average remains the holy grail for most OSR growers and the High 5 OSR Challenge, in association with Dekalb, has over the past two years brought together the latest advice and tips, from top experts and 5t/ha growers.

“As a key OSR breeder, we are delighted to extend our involvement in this important initiative into a third year,” says Will Miller, product manager at Dekalb. We hope to help growers across the country secure more consistent and reliable as well as higher outputs from their winter oilseed rape.

In this year’s High 5 OSR Challenge, we will be following two 5t/ha growers throughout the coming season, reporting on how they go about getting a High 5 crop in 2013-14.

Starting next month, the new series will include regular updates on their crop, outlining what they have done in recent weeks plus what they are planning in the coming weeks. Look out for the four updates

• 11 October: Harvest and establishment
• 15 November: Autumn development
• February 2014: Canopy management
• August 2014: Harvest results

To keep up to date or catch up on the latest advice and tips, visit our High Five OSR Challenge webpage at www.fwi.co.uk/highfive.

In addition, regular updates on crop progress and planning will be provided throughout the season by growers and agronomists in
other parts of the country at
www.osrgrowersclub.dekalb.co.uk

Meet the growers

Andrew Gloag, Busby House, North Yorkshire

Andrew Gloag was the Farmers Weekly Arable Farmer of the Year in 2009 and farms around 1,450ha including winter wheat, oilseed rape and barley plus beans. He is currently planning 300ha of oilseed rape and his average yield in 2011 was 5.48t/ha.

Tim Goodman, North Hill Farms, Salisbury

Tim Goodman is the manager of the Wilton Estate’s 1,400ha of arable cropping, with a planned 400ha area of oilseed rape for 2013/14, mainly following winter and spring barley. His average yield in 2011 was at 4.5t/ha.