What Makes a Growers’ Favourite OSR ? 08-Jun-2017

Of the 87 mainstream winter OSR varieties commercialised in the UK in the past 15 years, an industry-wide study reveals that less than 10% achieved a level of success over several seasons that would quality them as grower favourites.

What did they have that the overwhelming majority lacked ?  This is the sixty four thousand dollar question that would really help growers see the wood for the trees in the veritable forest of varieties vying for their attention these days.

“That’s what we wanted to explore by using the data on certified seed variety estimates we compile annually with inputs from all the main breeders and seedsmen,” explained Agrii seed technical manager, David Leaper responsible for the study.

“Our analysis shows that almost 100 ‘double low’ winter OSR varieties have been introduced and taken-up to any reasonable degree commercially since 2002. From an average of less than five a year in the first five year period, no one will be surprised to learn that the rate of introductions has accelerated markedly to average nine a year in the most recent five years.

“Excluding specialist HOLL, HEAR, Clearfield, semi-dwarf and other specialist varieties with clear market share limitations left us with a total of 87 mainstream ‘double lows’. Of these just 27 achieved a certified seed market share of at least 5% and 13 a share of at least 10% in one or more years.

“Although some of the newest varieties have clearly not reached the end of their commercial lives and could achieve greater relative success than this analysis suggests, the number of varieties gaining at least 10% of the market in any year has clearly declined over the years,” he observed.

“While nine varieties introduced in the five years to 2006/7 achieved this degree of success, just two introduced in the five years to 2011/12 and 2016/17 did so in each case. This is almost certainly due to the larger number of varieties being marketed, not to mention the recent decline in plantings.”

Drilling down more deeply into the figures, the Agrii study shows that 20 of the 27 most successful varieties gained a certified seed market share of at least 5% in two or more years, rather than declining – often very rapidly – after a single year of use.

More revealingly, only eight achieved a level of consistent success that would qualify them as clear grower favourites – a market share of at least 5% for four or more years (Figure 1).


Figure 1: Varieties introduced from 2002 achieving a certified seed market share of at least 5% in one or more years

Source: Industry estimates compiled by Agrii 2002/3- 2016/17


David Leaper accepts that basing the analysis on certified seed figures under-estimates the area of pure lines grown each year. However, he sees it as the only fair way to compare all varieties on the same basis.

He also points out that certified seed sales are almost certainly also a better reflection of the actual value growers place on varieties, demonstrating their willingness to continue investing in them rather than merely sticking with them to secure farm-saving economies.

Interestingly, the eight grower favourites that stand out are equally divided between pure lines and hybrids. What’s more, they’re exactly the ones most of those familiar with OSR over the years would put on their immediate ‘top of the crops’ list – starting with Winner, Castille and  ES Astrid, moving though all-time favourite, Excalibur, then onto DK Cabernet, DK Expower, PR46W21 and most recently DK Extrovert.


Of the three varieties yet to peak in certified seed sales terms, David Leaper identifies DK Exalte as the most likely to join this list given its current position and relative youth in the market.


So what exactly is it that these varieties have provided above all the others available over this time ?  The highest gross output is clearly one factor. However, it’s certainly not the only one – or even the most important.  

After all, only three of the eight favourite varieties have topped the Recommended List and five have never been in the top three on the RL.  Indeed, the most recent grower favourite –
DK Extrovert – has never even been on the List. Nor has the most promising newcomer,
DK Exalte.

In contrast, no less than five RL toppers and a host of varieties that have at one time been within the top three on the List do not figure amongst the clear grower favourites.

“Recommended List testing shows almost every modern variety is well able to deliver high gross outputs in small plot trials,” noted David Leaper.  “To deliver consistently above average performance under commercial farming conditions, however, our research underlines the importance of a number of vital traits alongside high output.

“In particular, winter rape crops have to be resilient enough to cope with stresses like later-than-ideal sowing, less-than-ideal seedbeds and spray timings, persistent pest problems and, increasingly, extreme weather variations.

“In our experience, this means they need to develop rapidly in both the autumn and spring, be as resistant as possible to phoma and light leaf spot, and stand-up well through to harvest with minimal seed shedding.

“In performance terms, the varieties that do so invariably seem to come out at or near the top of the large scale trials we run across the country under typical farm regimes. They’re also proving much more popular and, crucially, longer-lasting with our growers. That’s why our Master Seeds portfolio is based firmly on varieties selected for a combination of traits that goes well beyond gross output.”

Responsible for no less than five of the eight grower favourites over the past 15 years, this view is shared by Dekalb breeder, Matthew Clarke of Monsanto who stresses that output is only one of the characters  he selects for in his OSR breeding.

“Our breeding programme relies on  untreated screening and trials and, as well as employing genetic markers for key traits,  we select varieties at a range of sites which put them under particular environmental pressures,” he explained. “That way, we only pick the best performing of the varieties that survive on the basis to take forward.

“As a result, our varieties seldom top official trials and, in some cases, don’t even get on the RL (which currently only tests varieties under a high input regime). However, it also means we only bring forward varieties we are confident have the right genetic balance for the greatest resilience in commercial growing.”

Foremost among the traits other than gross output Matthew Clarke considers central to a grower favourite OSR are vigorous establishment, phoma stem canker and light leaf spot resistance and resistance to pod shattering.

“Vigorous establishment to four true leaves is a trait we’ve always prioritised in varieties that suit earlier drilling as well as those better able to deal with sowing well into September,” he pointed out. “This makes them better able to deal with difficult seedbeds, lack of moisture and early slug and insect attack, reducing the risk of crop failure under all but the most challenging conditions.

“RLM7 phoma stem canker resistance gene supported by high levels of poly-genic resistance is also important in getting crops through those first few critical months as cost-effectively as possible. And allied to strong light leaf spot resistance, it provides the greatest spraying flexibility, not to mention economy.

“As well as dramatically reducing yield losses from bad weather in the run-up to harvesting, the pod shatter resistance trait that is now incorporated into most of our varieties is giving growers the confidence to delay desiccation to take advantage of the longest possible pod fill and oil accumulation too,” Matthew Clarke added.

“Our traits package is all about improving agronomic flexibility and reducing risk; things  growers have clearly been voting for with their feet in their variety choice.”


Favourite OSR Characteristics


The extent to which factors other than gross output are actually being valued by growers is underlined in the Winter OSR Attitudes and Intentions Study undertaken by CPM this spring.

When we asked directly, ‘What for you makes a favourite OSR variety’ the overwhelming majority of responses we received from the 250-plus participating growers across the UK listed three or more characters. And high yields and oils were not the most important.

Top of their priority list by a clear margin ahead of gross output was vigorous early growth and reliable establishment, with disease resistance in third place just ahead of consistent performance, and ease and security of management and harvesting. Other characteristics identified by many were rapid spring growth, good standing ability, early maturity (Figure 2)


Figure 2: What for you makes a favourite OSR variety ?




Current Grower Favourite Views

Vigorous establishment, rapid autumn development, consistent performance, strong phoma and light leaf spot resistance, early spring growth and pod shatter resistance are the key characteristics appreciated by those growing DK Extrovert for at least three seasons.

These particular attributes of the most recent grower favourite where apparent in a recent straw poll of Openfield growers with nearly 900 ha of the variety currently in the ground. 

The fact that three quarters of those involved in the poll consider DK Extrovert to be better than their previous favourite and the same proportion are not looking to move on from the variety yet, underlines its continuing value in commercial practice despite never have been included on the Recommended List.



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