OSR beyond the RL (1) 25-Jun-2019

Eight (42%) of the 19 varieties making-up three quarters of this season’s winter OSR plantings have never been on the AHDB Recommended List.


Interestingly too, only half of the 20 varieties on the 2018/19 RL – and none of those newly-added to the List for the season – are among the most popular varieties currently in the ground.


This is the reality revealed by the latest intelligence from the industry-leading, 400-strong Kleffmann Group WOSR AMIS® farmer panel carefully selected to be representative of British growers.

And it’s an even more dramatic position with the hybrids that make-up 11 of the 19 most popular varieties.  Of these, almost two thirds have never been on the RL.


What’s more, this pattern has been remarkably consistent over at least the past five years, pre-dating the widespread growing of the Clearfield  (CL) hybrids that have never been Recommended  but currently account for nearly 15% of total UK plantings.


So what do the best hybrid varieties have – apart from unique traits like CL – that makes them so sought after by growers, and why do so many of them fail to gain Recommended List status ?


Well, leading breeder Mathew Clarke of DEKALB should know. After all, he’s responsible for two outstanding recent grower favourites – DK Extrovert and DK Exalte – neither of which have ever featured on the RL, not to mention a whole host of other widely-grown but never Listed varieties.


“Of course, it’s satisfying seeing varieties like DK Expansion and DK Exsteel gaining official Recommendation,” he says. “But our breeding programme doesn’t lend itself to Listing simply because we don’t put gross output potential before anything else.  Instead, we select and test for a series of traits we know to be important in farm production, doing so under the most challenging conditions. Then we take forward the best-performing of these.

“Employing no fungicides on sites with the greatest disease pressures, for instance, has been our key to developing the most robust phoma and light leaf spot resistance. Drilling later than normal and into difficult seedbeds has allowed us to identify the most vigorous-establishing and fast-developing lines.  Delaying harvesting on exposed sites has been vital in securing strong resistance to pod shattering.  And testing varieties widely at lower as well as standard nitrogen inputs is enabling us to develop varieties which lose less performance when nitrogen supply is restricted.


“This approach means our varieties tend not to come top of the tree in trials geared to out-and-out yield maximisation; especially when grown in small plots and to protocols designed to suit the average. However, our parallel plot and field-scale trial work under far more typical agronomic regimes in the UK and across Europe shows they perform especially well on-farm. Which is what our whole breeding effort is geared to do.”

That this approach actually delivers the goods is clear in both the popularity and longevity of the programme’s hybrids and the fact that growers are prepared to try new varieties emerging from it in the absence of even RL candidature, simply because are Dekalb-bred.


It is also evident in the independent data on the 2018 harvest gross output of more than 65 varieties in the latest Kleffmann Group WOSR AMIS® farmer panel.  These show mainstream hybrids out-performing conventional varieties by more than 0.3 t/ha on farm. Not only this, but the 10 Dekalb ‘Ex’ hybrids being grown – none of which were on the 2018/19 Recommended List – enjoyed an even greater a gross output advantage, at almost 0.5t/ha.



To read the second part of this article, click here