Long-term spring OSR grower reveals his approach
© MAG/Richard Allison Graham Bell has grown spring oilseed rape for more than two-and-a-half decades, and, with the right approach, is achieving higher margins than the winter crop it replaced.
While spring OSR is a niche crop in the UK, the spring-sown version accounts for two-thirds of global area and has earned its place at Cormaddie Farm near Dumfries.
Graham explains that spring OSR is part of an eight- to nine-year rotation, usually following spring beans, which are used as protein source for the farm’s 300 suckler cow herd.
See also: Analysis: Signs of cautious optimism for oilseed rape?
The beans can come off late in November, so spring OSR’s relatively later drilling gives ample time to get fields cultivated before drilling the following spring.
And based on his experience, he is surprised more farmers don’t grow it, especially given the problems many are seeing with establishing and overwintering the autumn-sown crop.
Farm facts
Graham Bell, J and T Bell, Cormaddie Farm, Dumfries
Graham Bell © MAG/Richard Allison
- 400ha mixed farming operation
- 160ha arable cropping
- Cropping consists of winter wheat, winer barley, spring barley, spring beans and spring OSR
Spring OSR summaryÂ
- Plays a key role in the rotation after beans
- Despite lower yields than winter OSR, margins are higher as it is cheaper to grow
- Modern hybrids establish quickly and produce consistent yields
- Avoid overwinter problems with winter crop like pigeon damage
Yields
Graham has achieved yields as high as 3.4t/ha, with the average over the years of about 2.5t/ha.
Although the spring crop is typically lower yielding than the winter one, costs are lower resulting in better margins, typically 10% above winter OSR.
Graham explains that both fertiliser and spray costs are half that of the winter-sown crop and there are reductions in herbicide and trace element costs, too.
This year, Graham is growing 14ha of Lumen as he looks to build up his area, having grown over 30ha of spring OSR in previous years.
He explains that the temporary reduction is due to clubroot issues, the result of growing a lot of vegetables in the 1960s and 1970s.
Establishment
Graham normally drills the crop from 20 April to 1 May when soil temperature is above 6C.
Land is ploughed and power harrowed before planting with a combination drill. Fields then get a final pass with the Cambridge rolls to give good seed to soil contact.
One key factor is that seed-beds need moisture and Graham has found it is not advisable to drill into dry soil.
© MAG/Richard Allison
A pre-emergence herbicide Sultan (metazachlor) is applied after rolling, as a flush of weeds can be an issue, particularly if conditions are wet after drilling.
Crops will receive 185kg/ha of a nitrogen + sulphur product shortly after drilling, as OSR loves sulphur.
This is followed by 125kg/ha of muriate of potash, as potassium is another key nutrient for optimal growth.
Pest control
Cabbage stem flea beetle can be a challenge, and Graham sprays the crop up to three times with Decis (deltamethrin) to control the pest.
Graham explains that the beetle comes in from the hedgerows as the crop establishes, especially in a dry summer.
Although it requires three sprays it is a relatively low-cost insecticide.
Pollen beetle can also be a problem, so a single spray is used at the green bud stage if above the threshold.
For disease, the relatively short growing season means phoma and light leaf spot are not a problem.
Graham opts for a mid-flowering fungicide to manage sclerotinia (check), typically azoxystrobin.
Harvest
The crop is harvested 20-28 September and this has been pretty consistent over the years.
Graham adds that it is an easy crop to harvest due to being shorter than its winter cousin and there is not the same volume of material going through the combine.
Expert growing tips
DSV is a key breeder of spring OSR, with four out of the five varieties on the current AHDB Descriptive List.
Sarah Hawthorne, marketing and arable sales manager at DSV UK, offers some pointers for growing a successful crop.
Sarah Hawthorne © DSV
Good establishment is essential and grower should aim to drill in the best conditions possible to ensure rapid and even emergence.
She says it is always better to wait for optimum seed-bed conditions rather than sowing early.
For fields that are overly wet and cold, they should be cultivated before sowing to ensure the topsoil can warm up and dry out before being drilled.
Spring oilseed rape plants develop fewer branches than winter-sown varieties, so need to be compensated for with a higher plant density.
Ideally, growers should be aiming for between 60-80 seeds/sq m, depending on soil conditions and sowing date.
Soon after sowing, an early application of 80-100kg/ha of nitrogen fertiliser is recommended, and this should be followed by a further 40kg/ha at stem elongation.
Like winter oilseed rape, the spring-sown crop has a high demand for sulphur and boron.
An early application of 20-30kg/ha of sulphate is a good idea and 300-400g/ha of boron is needed before flowering.
Adequate P, K and Mg also need to be provided to maximise yields.
The same herbicides used for winter oilseed rape are suitable for spring crops.
For fields with high volunteer pressure or difficult to manage weeds, there are clearfield options including the new variety Cocktail CL.
However, the biggest challenge for the spring crop is insect pests.
Cabbage flea beetles must be monitored after sowing and their feeding damage can look similar to cabbage stem flea beetles, so growers need to be careful.
When feeding exceeds more than 25% leaf area, a pyrethroid insecticide is recommended.
Pollen beetle can also be an issue and growers should be on the lookout for these as soon as buds become visible.
They are a bigger threat to spring sown crops than winter ones as the beetles migrate to the spring crops after the winter crops have flowered.
Growers need to be vigilant and take appropriate action where needed.
Finally, plant growth regulators are not usually required and, generally, use of inputs is lower than with winter oilseed rape crops.
Being cheaper to grow than winter OSR helps offset the lower yields likely to be achieved.
Why spring OSR?
Newer varieties that deliver consistently high yields combined with a greater understanding of the crop’s management are making spring OSR an increasingly attractive option for UK growers.
Variable establishment from challenging autumn and winter periods is largely avoided, and while yields of 4-5t/ha might be a stretch, 3.0t/ha should be a realistic target for many growers.
With lower growing costs and the current high prices, DSV says that means it’s a crop capable of delivering a healthy margin in most areas of the country.
