OSR additions show strength in depth
High yielding hybrid and conventional oilseed rape varieties were added to the East/West and North oilseed rape Recommended Lists last week, but only one is considered to be a breakthrough, as Louise Impey discovers
While there are now more varieties in the top yield bracket to choose from across both lists, it could take a couple of seasons before the true yield rankings emerge, points out NIAB TAG’s oilseeds specialist Simon Kightley.
Added to that, lodging and stem stiffness remains a controversial area, he believes, as the number of seasons where little or no lodging occurred has influenced the ratings.
“The best advice is to be wary of any variety with a 7,” he summarises. “The 2012 growing season showed us that varieties at that level can be susceptible to lodging.”
For independent agronomist Peter Riley of Prime Agriculture, growers in England with a high phoma burden will be disappointed with the latest recommendations, with one exception.
“Quartz, from KWS, is a new conventional variety for the East/West region, with a 9 for stem canker,” he reports. “It also offers relatively early maturity.”
He can see it being grown where there is a high proportion of oilseed rape in the rotation, and in phoma “hot spots”. “It will still need fungicides, but it should give some leeway.”
Mr Kightley agrees. “Quartz is relatively short, it has excellent stem canker resistance and it’s exactly the type that growers want. They’ve been after a Castille replacement for some time.”
The other new conventional variety for the East/West is Rivalda, also from KWS. Higher yielding than Quartz, at 103%, it came back into contention after missing out on recommendation last year.
“Rivalda is clearly on a par with DK Cabernet for yield,” points out Mr Kightley. “However, it’s a bit weaker in the straw.”
None of the three new hybrids, Marathon, PT211 and Avatar, have managed to topple PR46W21 for yield, which stays on the top at 106%. “It’s been so consistent. If you’re a hybrid fan, it has really justified its place on the farm.”
Marathon, from DSV, with a gross output of 105%, is a shorter hybrid. “It’s got superior standing ability,” continues Mr Kightley. “It’s interesting, as the very big, vigorous hybrids haven’t been taken up by growers.”
But its 3 rating for stem canker is at the minimum standard, confirms HGCA RL manager Simon Oxley. “We haven’t seen any improvement in stem canker resistance with any of the new hybrids.”
PT211, from DuPont Pioneer, has a 5 for stem canker, while Avatar, from LSPB, has a 4. Both varieties are 104% for gross output.
“PT211 just has the edge for disease resistance and has been consistent. It also has a UK recommendation. Avatar offers a slight earliness advantage,” summarises Simon Kightley.
North list
Three new conventional varieties and five new hybrids feature on the North list.
After a couple of years of insufficient information, the Recommended List has now caught up with itself, confirms Dr Oxley, who adds that more money is now being invested in trials in the region.
But Dr Kightley’s concern is that a 6 rating for light leaf spot has now swept in, which is the minimum standard for varieties grown in Scotland. “None of the new varieties get higher than a 6 for light leaf spot.”
All of the conventional varieties – Anastasia, Boheme and Pendulum – are high yielding and have good resistance to lodging, notes Dr Oxley.
“Anastasia is the highest yielding, at 106 for gross output.”
The five new hybrid varieties – PT208, Raptor, Shot, PT211 and DK Expower – demonstrate high yields and good lodging resistance, he continues. “But they don’t offer a step up in yield over Compass.”
Troy: A Breakthrough?
Troy, a semi-dwarf hybrid variety from DSV, joins the East/West and the North region lists as a specific recommendation.
With a gross output of 102% in the East/West, it puts the semi-dwarfs right up in contention, notes Mr Kightley, who describes it as the highlight of the season and a breakthrough variety.
“It’s right up there, within 4% in the East/West region, and almost at the top in the north with a gross output of 105. It’s short, manageable and people will want to grow it.”
While its disease resistance isn’t anything to shout about, with a 4 for stem canker and a 6 for light leaf spot, its height and stiffness make it easy to spray, he points out.
Peter Riley remarks that there was more lodging in rape crops this year than for some time. “So the stem stiffness and short height of Troy will be attractive.”
Barry Barker of Agrii agrees that Troy looks good. “These types are getting better and their different growth habit offers management advantages, especially at harvest.”
He believes growers will want to know if the semi dwarfs are as vigorous as others. “Do they give the ground cover that’s required?”
DK Imagine CL
The first Clearfield variety has been described, rather than recommended, as it is a specialist variety.
DK Imagine CL has tolerance to the imidazoline herbicides, explains Dr Oxley, giving it potential advantages and disadvantages in a farm situation.
Used in conjunction with Cleranda herbicide, it can help growers deal with certain weed problems, he says. “It’s very niche and advice should be taken before it is introduced into the rotation.”
