Oilseed rape varieties with specific oil profiles could offer growers significant opportunities, providing any yield disadvantage over conventional varieties can be minimised, says Velcourt.

At this year’s Cereals Event at Nocton, Lincolnshire (14-15 June), the company is demonstrating five different OSR varieties:

Pure line (Castille), hybrid (Excalibur), a new hybrid semi-dwarf (CWH-81) and specialist oil varieties (HEAR candidate, Helico and a High Oleic Low Linoleic candidate MSP-12).

“The most exciting is definitely the new generation of varieties called HOLLs,” says technical director, Keith Norman.

“Oil from these varieties does not degenerate with high temperatures or frying, therefore caterers don’t have to replace frying oil – which clearly has some big advantages.”

Like semi-dwarf varieties, HOLL types have the added benefit of being up to 20cm shorter than conventional varieties, which can reduce lodging risk and improve harvesting efficiency, he adds.

“One of the biggest constraints with oilseed rape is getting it into the combine – up to 0.3t/ha of the crop’s potential yield can be lost getting it into the combine, so semi-dwarf varieties might be one way of increasing throughput, forward speeds and reducing losses.”

Current HOLL varieties typically yield 10-15% below conventional types – a deficit which is just covered by the price premium available, he notes.

While new varieties such as Monsanto’s Recommended List candidate MSP12 could potentially reduce the yield gap to around 5%, there is still some way to go for conventional breeding, he says.

“There could be a way forward though – the government may start to change its thinking on Genetic Modification if a need for a specific type of oil arises eg for pharmaceuticals or health benefits.”

Monsanto’s Geoff Hall acknowledges that yields of current HOLL varieties like the company’s Splendor, are around 10% below conventional varieties, but says the gap is getting narrower as breeders develop new varieties.

In addition, health concerns surrounding the high levels of trans fatty acids found in conventional hydrogenated vegetable oils are likely to boost demand for healthier HOLL-types, he says.

“This autumn we could see HOLL varieties accounting for more than 2% of the total oilseed rape area (about 10,000ha), but there’s potential to take up to 10-20% of the total rape market.”

Trans fatty acids are already a big issue in the USA, where some snack companies already label products as “trans fatty acid free” and new labelling requirements are likely to come into force across the EU within the next two years, he adds.

“There is definitely a market there that wants these varieties.”

But specialist oils will not be suitable for all growers, due to the high seed purity requirements, Mr Hall suggests.

“Crushers don’t want anything that spoils the sample.

Any farmers coming into oilseed rape for the first time should think carefully about HOLL varieties, while others will need a good rotational break and pay special attention to controlling [non-HOLL] volunteers and weeds.”

Ideally volunteer contamination should be less than 2.5%, which equates to under one per square metre, he notes.

Mr Norman agrees.

“This may influence how often oilseed rape can be grown in the rotation and what other crops can also be grown.

In some cases you may need to use virgin oilseed rape ground, or possibly leave a five-year gap between rape crops.”

For many growers this is not a realistic option and he believes much closer oilseed rape rotations (eg every other year) are a better way of spreading costs.

“Before we can do this however, we need to find out why oilseed rape on virgin soil yields up to 1t/ha more than crops in a close rotation.

It could possibly be a root effect (similar to take-all in wheat), but we need more work to find out what’s going on in the soil and what treatments are effective.”

paul.spackman@rbi.co.uk