Plenty of winter wheat varieties were added to the AHDB Recommended List at the end of last year,  but their yellow rust resistance ratings may have suffered already, following an unexpected outbreak of the disease.

Confirmation that Yr15 major gene resistance has broken down means that almost 60% of the UK wheat area is currently in varieties that are now affected by yellow rust, and many of the newcomers are also showing susceptibility to the disease.

See also: Why leafhoppers are an emerging threat to potatoes

That makes decisions on varieties for this autumn’s drillings more difficult, say experts, who stress that it’s a complicated picture and that growers should think about how to manage their risk.

New race

Niab plant pathologist Dr Aoife O’Driscoll says: “There is a new race out there and it has overcome the Yr15 resistance gene.

“But we’ve had plenty of warning throughout the season and we do have fungicides that will control it.”

The jury is still out on where it came from, she adds. “It may have arrived from another country – we know it’s been found in Denmark and Ireland – or it could be a locally evolved race.”

Planting a susceptible variety knowingly means planning to deal with it, says Niab regional agronomist Patrick Stephenson, who highlights that the number of spray days may not be the same next year.

“Given the popularity of some of the varieties affected, there will be seed supply issues if certain varieties are shunned.”   

Agrii seed technical manager John Miles points out that while Yr15 has done much of the heavy lifting up until now, a variety’s susceptibility is determined by its full genetic package.

As that’s made up of both major and minor genes, it’s worth finding out more about a variety’s make-up, as not all have been affected equally, he advises.

Tricky varieties

“What’s important now is for growers to understand whether there are varieties that have become too hot to handle,” he says.

John reminds growers that septoria is the main disease concern in most years. He puts brown rust second on the worry list, with a creeping weakness across the board.

“Brown rust is more tricky for agronomists, but it’s septoria that can cost you money.

“Yellow rust is behind these and can be controlled more easily, but it’s fair to say that it’s given us a nasty surprise this year and that’s when we’ve had plenty of spray days,” says John.

He advises farmers to get the most up-to-date figures from their seed suppliers on yellow rust ratings and to be aware of those that are now susceptible to both brown and yellow rust.

“There isn’t a great appetite to go back to the high input, high output days of Santiago-type varieties,” he believes.

“Yield is the main driver, but higher disease control costs aren’t going to be relished.”

Group 1

The Group 1 category of breadmaking varieties is changing at long last, says Clare Leaman, cereals specialist at Niab, with two new varieties attracting plenty of interest.

The long-standing line-up of Zyatt, Skyfall and Crusoe all have known issues with either yellow or brown rust, so most growers are looking to move on or balance that risk, she reports.

Cheer, which was recommended in 2024, doesn’t offer more yield at 96%.

“Cheer has a 6 rating for septoria and an 8 for yellow rust, but there does seem to be more yellow rust in it this year than its rating suggests,” says Clare.

The new Group 1 choice for this year is Vibe, which sits between Zyatt and Skyfall for yield on a figure of 98%.

Vibe has a good untreated yield of 89%, continues Clare, and a yellow rust rating of 8 has not been impacted at all this season.

“It has a protein level of 13.2%, which puts it up there with Crusoe.” 

Three millers in the east of the country have already confirmed that they are happy with Vibe.

Group 2

There are five new additions in the Group 2 sector, vying with popular existing choices which already have market opportunities.

Arnie tops the category, with a treated yield of 106% and both yellow rust and septoria ratings of 7.

New to the Recommended List, it has been described as a game changer, bringing feed variety level yields to this category.

“It seems to be a safe 7 for yellow rust and it has a good specific weight,” says Clare. “It will largely be grown as a feed wheat and should feature strongly this autumn.”

Equipe is another newcomer in this sector, with the highest untreated yield and export potential. Clare believes it is an Extase-type, with relatively early maturity and good protein.

Otherwise, Newbie and Shergar are also in the running, with both showing their best performance in the North.

Goldfinch offers resistance to barley yellow dwarf virus and orange wheat blossom midge, but comes with a lower yield and weaker straw.

“It’s good to see this technology coming to the market,” she says.

“Until a contract comes along for a Group 2 variety, it’s a feed choice,” says Patrick.

“We now have too many of this type – if they have low protein figures, it’s going to take too much nitrogen to make it worth chasing a premium.”

Established choices Extase, Palladium and Mayflower are having mixed fortunes this year, reveals Clare, with Mayflower succumbing to yellow rust despite its 9 rating.

Palladium is also carrying a bit more disease than expected, but does have milling homes.

Group 3

Bamford set a new standard in the Group 3 sector last year, bringing yield and marketing options, although many grew it as a feed wheat.

It’s another variety which is carrying a bit more yellow rust than its 7 rating indicates.

New this year to the biscuit-making group are Solitaire and Flute, both with high yields, orange wheat blossom midge resistance, and the same marketing flexibility as Bamford, including distilling.

However, yellow rust has been found in Solitaire, confirms Clare, who has concerns about its straw strength with its 5 and 6 ratings for lodging resistance.

Both Flute and Solitaire have 5 ratings for brown rust, she notes.

Group 4 soft feed

Hexton is the newcomer in the soft feeds, with a UK treated yield of 105%. As with others in this category, it is later maturing, but has given exceptional performance in the North at 111%.

“Hexton is a contender in a big pool of high-yielding soft varieties, including the Group 3s,” says Clare.   

John sees a place for it too. “We like what it has to offer and it’s early drilling figures are of interest, especially as it has distilling approval.”

Others are Redwald, the highest yielding variety in this sector, and Blackstone, which has been impacted by yellow rust. Redwald’s straw strength is a watch point, they warn.

Group 4 hard feed

The hard feed wheats have been most impacted by yellow rust, where those heavily reliant on Yr15 have collapsed in style, warns Patrick.

As a result, the Recommended List will include a bracketed yellow rust figure for this year, as well as the three-year mean figure. and he urges growers to look at the one-year rating.

“It will flag up where to use a T0 and get on top of the disease before it takes hold, so that the high yields that these varieties offer are unaffected,” says Patrick.

The new, very high-yielding choice, Scope, is one which will see its yellow rust rating fall, he predicts, possibly down to a 4. “Forewarned is forearmed.”

Otherwise, Scope offers stiff straw and a septoria rating of 6.5, points out Clare.

Existing choices Champion, Beowulf, Dawsum and Typhoon are all reported to be impacted by yellow rust, with some being worse than others.

John suggests looking at their brown rust scores to help determine risk and consider whether they can be looked after.

“If they are now susceptible to both diseases, then you need to decide if that matters.”

Clare advises growers to keep up-to-date as the yellow rust situation will continue to evolve.

“Don’t be complacent and balance the risk as far as possible with a good selection of varieties.”

Old-timer Graham is holding up well, she adds. “It’s been consistent and is not affected by yellow rust.”