Winter barley varieties: BYDV debate in high-pressure year
© GNP Variety choice has improved for those still growing winter barley, but after such a high-pressure year, the barley yellow dwarf virus tolerance or resistance debate has reopened.
Unexpected symptoms of the disease on the first winter barley variety with a specific recommendation for resistance, Kestrel, caused some concern, despite it having resistance to three strains of the virus.
See also: Potato trials show little benefit from NUE products
With barley yellow dwarf virus (BYDV) tolerance, symptom expression in plants is not unusual.
Yields are slightly affected and while the virus can replicate in the plant and aphids can still spread the virus, it gives it some protection.
With resistance, the accepted wisdom is that aphid feeding is disrupted and the virus does not replicate, so the plant shows no symptoms and yields accordingly.
Given the very high pressure and huge numbers of aphids continuously feeding through the winter this year, the genetic trait for resistance appears to have been overwhelmed in specific situations.
“Generally, if the barley plant is healthy, it can withstand attack,” says John Miles, seed technical manager at Agrii.
“We had nutritional stresses, other viruses and earlier drilling last autumn, all of which caused yellowing.”
Ted Williams, arable seed manager and agronomist at Agrovista, says that resistance should not be thought of as immunity.
“It’s great that we have these genetic developments and they should be part of an integrated pest management strategy, but where drilling is being done early and there’s high aphid pressure you still need to be vigilant.”
He believes that there will be a switch to winter barleys with BYDV protection and points out that the tolerance trait is coming through in competitive varieties, with the candidate list showing promise.
“It first came through in six-row conventionals and can now be found in two-row feeds, such as Carpenter, Organa and Catapult. Next year we could see the highest yielding winter barley having this trait.”
Current varieties
Currently the smaller winter barley market is dominated by a few varieties – namely Tardis and Caravelle, with Kitty also finding favour for its good specific weight and strong agronomics.
All are two-row feed varieties which have performed well on-farm.
Ted also highlights Agrovista’s variety Resolute, which he describes as a winter barley for everyone.
Bred in Denmark, it has good disease resistance and lodging scores as well as a good specific weight. Otherwise, Buccaneer remains the top winter malting choice.
Newcomers for this year include UK-wide choice Catapult and Darcie, which is recommended for the East, both on a yield of 104%. Barnabus has joined the six-row hybrids with a treated yield of 108%.
“In the hybrids, we’re seeing a move away from Kingsbarn into Quantock now,” reports Ted.
Coming along are eight candidate varieties, four of which are two-row feeds that have BYDV tolerance. These include Lemuris and Blis from KWS, Caprice from Limagrain and Paquita from Senova.
“What we see with this cohort is that BYDV tolerance will be included in varieties which have plenty of other attributes to offer, putting them right in contention,” says Clare Leaman, cereal variety specialist at Niab.
All change for winter oats
New varieties coming through the system mean that the winter oat market is finally moving on from its long-term dependency on just one variety.
Two varieties at different stages of their development have joined Mascani on the AHDB Recommended List – both from Senova, Cromwell is already in the market while Rannoch is due to launch this autumn.
Cromwell, with a UK treated yield of 102% and short, very stiff straw, also has the highest specific weight and kernel content on the list. Millers are keen to see more of it.
Rannoch was added to the AHDB Recommended List for this year with a treated yield of 106% and an untreated yield of 92%, as well as a crown rust resistance rating of 7.
That means it offers a 10% yield advantage over Mascani and it is being put through a 1,000t milling pilot scheme to confirm its suitability for milling processes and added value contracts.
