RAGT Seeds’ RGT Wolverine winter wheat offers BYDV resistance and competitive yields, according to Frontier trials.
Dr Cathy Hooper, technical sales manager at RAGT Seeds says RGT Wolverine’s ability to resist BYDV is clearly an exciting step forward, but farmers also need the variety to provide competitive yields in the field.
She says: “We know that sometimes varieties which offer disease resistance suffer from a yield penalty, but this is not the case with RGT Wolverine.
Both our own continuing trials and the commercial work undertaken by Frontier are proof of this.” Wolverine was launched last year and is the product of a programme of work going back 20 years to translocate and identify the Bdv2 gene in wheat.
This work has been accelerated in recent years by RAGT scientists using genetic markers.
RGT Wolverine is now on the Recommended List and RAGT has carried out trials to establish the best growing protocol, as well as working with Frontier.
“Sometimes varieties which offer disease resistance suffer from a yield penalty, but this is not the case with RGT Wolverine”
Dr Cathy Hooper
Dr Hooper says: “In the work we did at Ickleton we wanted to put RGT Wolverine under extreme pressure to see if we could ‘break it’.
The trials involved three separate drilling dates to try to replicate conditions on-farm.
“We know that one way to guard against BYDV is to drill late, but equally that is not necessarily convenient or practical for everyone.
“RGT Wolverine was planted alongside a number of other comparable varieties.
The three trials were drilled in mid-September, October and November.
The trial crops were put under extremely high aphid pressure.
There were eight separate releases of aphids into the crops and whereas normally only 10 per cent of the aphids would be infected with BYDV, in this case 100 per cent were infected.
One half of the trial was sprayed with one application of insecticides while the other half had no application at all.
“Even on rare occasions when we did see infection, the infection rate was tenfold less than normal”
Dr Cathy Hooper
“By late spring and early summer we started to see a lot of symptoms of BYDV in the early drilled crops, not so much in the October-drilled and nothing in the late drilled.
“In the early-sown crops of RGT Wolverine under this extraordinary high level of pressure, we did see the very occasional signs of BYDV.
“Bearing in mind this was a level of pressure that would never normally be seen, the variety demonstrated a very high degree of resistance.
“Furthermore, there was no yield penalty at all in RGT Wolverine, while other varieties lost up to 18 per cent of yield.” Even under conditions such as those experienced in autumn 2019, when aphid pressure remained high due to the mild weather, Dr Hooper believes that late sowing can mitigate against BYDV.
She says: “Our work indicates that delaying sowing will reduce BYDV symptoms in non-resistant varieties, but an autumn insecticide was beneficial.
RGT Wolverine is performing exactly where it matters, with good yields reported in trials Frontier’s Jim Knight says: “When it came to harvest, RGT Wolverine was one of the top performing seed crops we had.
The 190ha averaged 8.4 tonnes per hectare.
“When you put that in the context of the agricultural year that we had, those yields were well above average for all our seed crops.
We even had one grower in Kent where they were getting yields of between 10 and 13t/ha off the combine.
“Clearly RGT Wolverine is providing BYDV resistance but it is doing it as part of a package is delivering very respectable results overall.”
Dr Hooper says: “In terms of growth performance RGT Wolverine is a slow starter, but it is quick to get away in the spring and it tillers very well.” Mr Knight echoes this.
“It is more of an advantage for RGT Wolverine than we thought is was going to be,” he says, “Given the two wet autumns we have had, there is no doubt that we are going to have a reaction from growers to early drilling.
It may not be ideal from an agronomic point of view but it is understandable growers may not want to go early, and I think RGT Wolverine will suit that strategy well.” As far as national BYDV pressure is concerned, Mr Knight says it is really difficult to judge at the present time.
He says: “At the moment we have very high aphid numbers, so it is very likely we will see higher prevalence of BYDV than we have seen for a number of years, but it is difficult to be sure.
We will have to wait until April, May and June to see what happens.” He also points out that regardless of the actual BYDV pressure there are a large number of growers who use insecticides in a ‘prophylactic’ way.
He says: “I think for those growers looking at Wolverine, they can use it as a risk management tool.
It also reduces dependence on insecticides and is affordable.
With affordability a key issue, Dr Hooper explains the royalty on RGT Wolverine is administered through the BIPO system and is applied on a per hectare basis.
This means the royalty is only payable once the seed is drilled.
“In our trials an insecticide application in autumn made no difference to the visual symptoms or yield of RGT Wolverine.
However, as part of a stewardship programme and to protect the longevity of the resistance gene, in high risk areas and early sown crops we would recommend a single autumn insecticide spray “The results for RGT Wolverine were outstanding.
This is the first time we have worked with a BYDV resistant variety in Europe and it is excellent news to have our findings confirmed.
In early trials, even on rare occasions when we did see infection in RGT Wolverine, when we sent the leaf for analysis, the infection rate was tenfold less than normal,” says Dr Hooper.
RAGT is repeating the early and normal sown trials this season.
Looking to the future, she says: “We have a number of varieties in the pipeline offering BYDV resistance.
For us, the Holy Grail would be a Group One variety with both BYDV and midge resistance and I do not think we are too many years away from that.”
Jim Knight is seed business development manager with Frontier and has been involved with trials work on RGT Wolverine for some time.
He says: “My role at Frontier is as a seller of seeds rather than a trials officer, so I am coming at it from the commercial point of view.
For me the most important point about RGT Wolverine is its success as a wheat variety without taking any account of its resistance characteristics.
“The fact you have a variety which is coming in at 102 per cent of control on the Recommended List with this new genetic technology is pretty astonishing.
It means growers can take advantage of it without suffering the penalty they would get with other varieties.
It is performing so well in its own right, and this should make people sit up and take notice.
“For us at Frontier, its yield performance was the most visible thing about RGT Wolverine this year.
“We placed around 190 hectares of RGT Wolverine seed crops on behalf of RAGT.
It was spread around the country, but predominantly in the South and East Anglia which are higher BYDV pressure areas.
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