With UK’s oilseed rape plantings potentially set to be the smallest for forty years, Chris Guest, Managing Director of plant breeder NPZ UK, joins in calls for a reboot for the crop for the benefit of UK growers and the country’s food security

“Oilseed rape can be one of the highest gross margin break crops, if not all arable crops, for growers – along with its rotational and environmental benefits,” commented Mr Guest. “Yet we see too many negative comments about the crop and these, we believe, are drowning out the sound of the positives.

“This is leading to a very one-sided picture, as the negatives are often the only ones ever seen. There are plenty of very good results and average ones to go along with the poor ones, which we all accept will also happen across all crops.

“Looking at the positives and starting with food security, oilseed rape is an important crop for the UK with its wide range of uses in food and industrial products for the primary element of oil, and then the importance of the by-product rape meal used in animal feed.

“If you look at the bottles of cooking oil on the supermarket shelf or the ingredients label on many food products, you will see just two examples of oilseed rape’s contribution to the country’s home-grown food security.

“But now, from being an exporter of rapeseed, we have become an importer – this is not good news for the UK economy or our food security.

“Turning to the equally important positive of the role of oilseed rape for growers, we have seen good results from growers this year. As just one typical example, a grower of Murray in Kent noted it had been an exceptional year with their yield equalling last year’s 4.7t/ha average across over 70ha.” 

Chris Guest notes, “we can all agree with a comment from a grower that oilseed rape can now be a high-risk crop – and it is a challenge for all breeders to do our part to support the crop by continuing to introduce varieties with improved yield, disease resistance and other agronomic benefits.

“NPZ UK are already doing our bit – the change to hybrids with their more reliable yield and high vigour underpin crop development, while the introduction of new genetics – such as the RlmS gene to reinforce Rlm7 for phoma resistance – all help growers.

“As breeders, we obviously emphasise that variety selection is key, and one of the key attributes that is being overlooked in variety selection is late season stem disease. This could be from LLS/Phoma, or Verticillium, and we are seeing yield reduction in certain market-leading varieties of up to 30% against the best of our current genetics featuring the ‘RlmS’ phoma resistance gene. 

“Pod shatter resistance can be important – but it should not be the be-all and end-all of variety selection. As our results show (and it is highly likely that official trials also show), the importance of strong stem health against late season stem disease is more important in many seasons, including the current one. Hence a proportion of any cropping area should be focussed on this – and not just on pod shatter, as is shown quite strongly in Graph 1.

(Note for Graph 1 – red dots are Ogu hybrids with POSH, grey dots are hybrids from NPZ UK and competitors without POSH)

“In gross margin terms – 30% yield reduction is a lot and can make a huge difference in the perception of the crop within the rotation from a financial angle.

“Another important factor is the choice of sowing date. We understand that many growers have moved to earlier sowing to get crops up and away from the adult flea beetle. However, from the work we have carried out with Dr. Ute Kropf of the University of Applied Sciences, Kiel in terms of OSR crop physiology, we know that these early drilled crops are too far developed before winter due to thermal temperature accumulation and are therefore already limiting their yield potential. We have been running trials looking at late sowing as we have discussed previously – and the results look very interesting.

“Graph 2 is from our internal trials at Wisbech, Cambridgeshire. In these replicated trials, we can see the large yield potential from crops sown in early and late September. For interest, drilling dates are 2^nd September for ‘normal sowing’ – much later than most growers are now drilling – and then even later for the ‘late sowing’ on 21^st September.

“Obviously this is not the golden bullet – and we need to take a balanced approach to risk management – but we would encourage growers to look at their average temperature accumulation dependant on farm location – and look for the latest safe sowing date based on historical information for 800-900°C .

“We are determined to continue our breeding work to ensure that new varieties meet the challenge and bring the oilseed rape crop back into the forefront of UK arable production,” added Chris Guest.