In the weeks leading up to the AHDB and ADAS summer open day, held on June 21 at Burley Gate, Herefordshire, septoria had started to ramp up in variety plots across AHDB’s West region.
Further south and west of Herefordshire, untreated varieties with resistance ratings of 4 or 5 had died off and the disease was moving into treated plots, despite five or six spray programmes, Mark Bollebakker, AHDB field trials senior manager, said.
Other disease levels at the Herefordshire site were relatively low, with yellow rust only being seen in Kinetic and low levels of brown rust in Crusoe.
Mr Bollebakker said: “Around the UK through the season we’ve seen septoria quite low down – we knew it was there and it wasn’t moving, but in the last few weeks it started going quite quickly and fungicides are running out of steam.
“Like last year, AHDB variety data is going to be affected this year with the presence of late septoria to a degree even in treated trials.
“We think on most sites the one year rating for septoria, which we introduced last year to keep up with the breakdown of Cougar, is going to be the rating, or it may be even slightly lower for some varieties.”
Due to the late septoria outbreak last year, Extase did very well in the West against other varieties, Mr Bollebakker added.
“When fungicides are running out of steam is when these varieties shine.
In low disease years it won’t be your highest yielding variety but last year Extase really yielded relatively well compared to other varieties.”
However, Extase does appear to have a bit more septoria than its 8 rating would suggest, and it saw a large drop in its one year resistance rating to 7.3.
Clean “Extase is good and still has less septoria than Graham, but it’s not the same as Mayflower and Theodore in terms of septoria.
“It’s probably more like a very good 7 – on some sites it’s incredibly clean still,” said Mr Bollebakker, adding it is one of the highest yielding varieties in AHDB’s data set in the South West.
KWS Palladium does not appear to be quite as high yielding as Extase but it is as clean and has a lot of other good qualities.
“We think it is the earliest variety – it has a slightly lower spec weight than Extase, but the same as Graham.
We think septoria will be a good 7 from what we’ve seen and in yellow rust areas it’s been clean this year, so we don’t expect its rating to change much.”
Because of seed availability issues, no Mayflower was drilled at the demo site last autumn, but Mr Bollebakker expects it to gain good traction in the West due to its very good septoria rating.
“Mayflower is a bit lower yielding for a Group 2 in the East, but it gets better the further west you go.
It’s extremely good on septoria, good on yellow rust and probably slightly better than the others on brown rust.”
Group 3s and 4s are where the biggest changes to septoria ratings are being seen due to many of them having Cougar parentage and older varieties being weaker in this area.
New Group 3 varieties such as KWS Guium and KWS Brium do not have Cougar parentage but their septoria ratings are on the lower side.
“For Group 4s, I think Saki is probably the worst of the varieties affected by Cougar septoria.
The one-year rating is 5.1 and I wouldn’t be surprised if it went the same way as Barrel, which is disappointing.
“For newer varieties, RGT Bairstow doesn’t do so well the further west you go, but RGT Stokes has produced very high yields in the West.
It is weak on lodging, but it reacts well to PGRs; its spec weight isn’t the highest.
All soft Group 4s come with a weakness at the moment.”
However, there are some new and interesting varieties among the hard feeds, Mr Bollebakker said.
“KWS Cranium came on the list in the years we had to late drill trials.
It’s a really good late driller and this affected the Recommended List data.
In more normal drilling years it’s not as high yielding, and it’s quite late maturing.
Spec weight is okay and septoria-wise it’s a low 6.
In the East there might still be a space for it.”
Good performer Gleam is also not so popular in the West due to its lower septoria rating but in the East it’s a very good performer, he said.
“It’s getting slightly weaker on all diseases but it’s such a consistent performer.
It’s a good variety in both [early or late] situations and it performed particularly well last year, achieving 105%.”
Graham remains the stronghold in the West, compared to the East Anglia, where it behaves like a different variety, Mr Bollebakker said.
“Here, this should still be your mainstay.
For septoria it’s still at the better end.
It may go slightly down but it’s still good.
We’re also seeing more yellow rust but it’s not dropping like a stone and it will still be better than Gleam.
On brown rust it’s always been a bit weak.”
Alongside Mayflower, Theodore remains best for septoria resistance but its spec weight of 73.8kg/hl is too low for many, said Mr Bollebakker.
“Its brown rust rating will not stack up this year, partly because it’s still so green.”
Meanwhile, Costello remains a consistent performer in the West.
“It’s not exciting necessarily yield-wise but the further west you go it goes towards 102%.
Septoriawise it’s more fixed and it has good yellow rust resistance with seedling resistance.
It does get brown rust though.
Maturing slightly later than Graham, it has a great spec weight and is a consistent performer.”
For Costello growers, new variety KWS Dawsum might tempt them.
“It’s done pretty well all over the UK, but Dawsum’s yields have really stood out at 106% in the West and 107% in the South West.
It’s a Costello Kerrin cross and it’s for the people that grow Costello, but giving significantly higher yields.
It has an excellent spec weight of 79.5kg/hl and good lodging at 7, similar to Gleam.
It’s a +1, so slightly earlier than Costello.”
For septoria, Dawsum sits between Graham and Costello and is expected to achieve a rating of around 6.1-6.2.
“This isn’t what you’d want ideally but it’s still better than Costello.
If you’re happy to grow those sort of ratings it’s definitely one to have a look at.
It should yield 6-7% more than Costello based on our three years of data.
This is a real yield jump that we don’t normally see.”
Two other new hard feeds offer good septoria resistance, including Champion with its 8 and LG Typhoon with a 7.
Mr Bollebakker said: “Champion is a bit taller, but it reacts well to PGRs.
It’s good on yellow rust but spec weight is still not great.
However, it’s an incredibly high yielder and based on just South West data it achieves 108% and 107% as a second cereal.
From what I’ve seen this week, it’s like Extase.”
LG Typhoon’s yield is a little lower and its yield didn’t improve as it moved west, said Mr Bollebakker.
“It’s excellent for yellow rust and septoria at 7.
We do see some septoria but the rest of the leaf stayed really nice and dark green.
This variety has a really nice look to it.”