In the absence of neonicotinoid seed treatments, this autumn, growers will be looking for different management strategies to contain the barley yellow dwarf virus (BYDV).

Whilst all cereals and grasses are affected, the biggest impact will be on barley. Symptoms are bright yellow leaves, which develop into large areas of yellowing and stunted plants.

To get the best control possible, cultural control methods will need to be understood, adapted and combined with timely pyrethroid applications, says Ron Granger of plant breeders Limagrain UK.

“The impact on yield can be significant, with higher losses coming from earlier infection, which can be as much as 2.5t/ha,” he says.

A new and exciting variety available to growers this autumn is Rafaela; a conventional six-row winter barley that carries the traits for Barley Yellow Dwarf Virus (BYDV) tolerance and Barley Yellow Mosaic Virus (BaYMV) resistance.

Mr Granger points out that it’s important to note that it’s a tolerance to BYDV rather than a resistance, which means that the variety can be infected with the virus but does not show the associated symptoms.

Ron Granger, Limagrain’s Technical Arable Manager

“Think of it as a natural plant immune system – you may still see some leaf yellowing but without the associated impact on yields – so it is a really valuable tool in the fight against BYDV.”

“However, farmers will still need to manage aphids,” he says. “Spraying in mid-October and in mid-November with pyrethroids is the best approach, as this targets both sets of aphid arrivals.”

“The virus is still circulating in the plant – the gene does not break its lifecycle but the tolerance provides a form of risk management if the weather turns and spraying is delayed.”

“The trait provides a get out of jail card, but it still needs protecting.”

However there’s more to Rafaela than its BYDV tolerance and ability to produce high yields, he adds. “It’s vigorous and early to mature, making it an ideal entry to oilseed rape, or if wanting to get something drilled whilst delaying drilling winter wheat.”

Work conducted at Agrii’s black-grass trials at Stow Longa showed Rafaela to be one of the most competitive barleys for black-grass, says Agrii’s head of agronomy, Colin Lloyd.

“In the trials, we only counted 45 black-grass ears/m2 in the Rafaela, compared to 96 ears/m2 in the best two-row winter barley, California.”

‘It’s right up there with the hybrids for black-grass competitiveness’.

“It really gets up and away – it’s quick in the spring- and this gives it the competitive advantage.”

In Agrii trials last year which were taken to harvest, Margin Over Input Costs (MOIC) were compared between barleys in this grass-weed scenario.

“Eight varieties of winter barley were drilled on the 30^th September 2018, which when taken to harvest yielded an average of 8.92t/ha, producing an average gross margin of £904/ha.”

“Of these, the best 2-row was California which yielded 9.01t/ha, producing a MOIC of £933/ha. However Rafaela out-yielded the California at 9.19t/ha, producing a GM of £954/ha – that’s a significant increase of £21/ha.”

Rafaela, Winter Barley

But compare this to winter wheat drilled right next to these plots on the same day, he adds.

“We drilled 23 varieties which averaged 5.12 t/ha with an average GM of £184 per hectare. The difference is clear, Rafaela makes money and winter wheat loses money in this earlier drilled slot in a blackgrass situation – a sobering thought.”

Limagrain continues to evaluate the best ways of using Rafaela’s genetics for on-farm performance.

“We are doing work with a range of industry partners on both naturally infected and inoculated aphid trials, and we are also testing the variety in treated and untreated insecticide trials. This will provide us with the depth of information on how and where we can fully exploit Rafaela’s exciting genetics to their full potential, says Mr Granger.

This makes LG Diablo the highest yielding spring barley variety on the AHDB Recommended List with full approval for malt distilling.

Based on its move to provisional approval 2 for brewing, if full approval for brewing is also obtained next year, LG Diablo will be the highest yielding dual-use spring barley, says Matt Shand, UK Arable Wholesale Sales Manager for Limagrain UK.

LG Diablo’s UK yield sits 2% above the current market favourites at 105% of control. Last year, LG Diablo out-performed other leading varieties such as RGT Planet and Laureate, by a significant amount in the key malting barley growing areas across the East (106%) and North (107%) regions, in fungicide treated trials.

LG Diablo’s untreated yields also sit at the top of the yield table alongside Laureate at 94% of control, and 1% over that of RGT Planet, demonstrating the variety’s very robust disease resistance profile, says Ron Granger, Limagrain’s technical arable manager.

“In terms of agronomic package, LG Diablo has straw characteristics similar to RGT Planet; medium in height (73cm) with good lodging and brackling resistance. Although rated slightly later maturing, this would not appear to have an effect regarding its high yield potential as seen in the very testing season of 2018.”

“The very high yield potential combined with a a good specific weight does mean that LG Diablo fits the bill as a good feed barley variety.”

LG Diablo has a very good specific weight, which is important in the malting industry as malting is a volume-based process and low specific weights cause reduced throughput in the processing plants, points out Mr Shand.

“So growers with low specific weight parcels will incur penalties if specifications are not met, particularly in times of over-production.”

“Its hot water extract is a similar level to that of Concerto – a trait that helped Concerto to become a benchmark variety. Again it’s about meeting the needs of the market as a high hot water extract is heavily desired by the end user in order for them to achieve higher sugar extraction rates from the malt and the ability to create more alcohol – and offers this.”

“Now that the variety has been given the green light by the industry for distilling, we believe that LG Diablo will fulfil the requirements of both grower and end users to become a key variety in the spring barley sector in the next couple of years”

LG Flynn and LG Mountain offer growers two high yielding 2-row feed winter barley varieties, with differing desirable agronomic characteristics.

For growers looking to make the most of the opportunities offered by winter barleys, there are two new varieties available this autumn, from the very successful Limagrain UK barley breeding programme, that launched ‘California’ over five years ago.

LG Flynn and LG Mountain offer growers two high yielding 2-row feed winter barley varieties, with differing desirable agronomic characteristics – it’s important that growers choose the right variety for their situation on-farm.

LG Flynn offers growers agronomic attributes of good straw strength and disease resistance, combined with a very high specific weight – all key qualities of a ‘classic’ feed barley.

The variety also carries the valuable attribute of resistance to Barley Yellow Mosaic Virus (BaYMV).

In AHDB Recommended List 2019/20 trials across all regions, LG Flynn has performed consistently, producing high yields for both treated and untreated trials.

Its UK fungicide treated performance is 104%, against 103% for KWS Orwell, and 6% over KWS Cassia, at 98%. The variety also offers a strong disease resistance package, with a 6 against Rhynchosporium and a 6 for Net Blotch.

“The stand out attribute of LG Flynn is its high specific weight; at 69.8kg/hl, it has one of the highest specific weights available and is similar to KWS Cassia with low screening scores,” explains Limagrain UK’s senior barley breeder, Mark Glew.

“We know that farmers like to grow big, bold samples, and like with wheat varieties, good specific weight in barley would appear to be more robust, especially in times of stress or erratic weather patterns,” says Ron Granger, arable technical manager for Limagrain UK.  

Specific weights for barleys were starting to drop in newer varieties, compared to older varieties. This came about as breeders’ drove to produce ever higher yielding varieties, unfortunately at the cost of grain quality.“

*LG Flynn and LG Mountain buck a trend, offering a combination of both high yields and high specific weight.

LG Mountain is one of the highest yielding 2-row feed barley varieties available, with a good all-round disease resistance profile, combined with early maturity and BaYMV resistance.

“This is a barley that represents a significant step forward in yield for 2-row barley varieties, over other commercial varieties we are really pleased with the consistency of yield over seasons and regions, and in treated and untreated trials – particularly in the east and north,” says Mark Glew.

LG Mountain has good grain quality attributes, with a very good specific weight of 68.9kg/hl – similar to KWS Glacier.

LG Mountain has an earlier maturity (-1) than LG Flynn (+1), which is valuable for growers looking at getting an earlier harvest for WOSR establishment.

“This earlier maturity, combined with a good specific weight, should also give growers confidence for securing yield potential in stressful seasons of drought, as seen in summer 2018,” says Mr. Glew.

Q. What is BYDV and what are its effects on winter barley?

Barley Yellow Dwarf Virus (BYDV) is an infection transferred by aphids which causes yellowing of plants. The symptoms are seen in the spring, when the leaf tip starts to turn yellow, gradually spreading to the base of the plant. Infected plants may be severely stunted and do not come into ear, remaining dwarfed at around 3 inches, eventually killing it. This results in devastating yield loss.

Q. How can breeders help growers reduce the risk of BYDV?

Insecticides are currently used but chemical restrictions, such as the ban of neonicotinoid seed treatments, are increasingly limiting the options available to growers for chemical control.  Fortunately, breeders have identified a gene called YD2 which provides effective varietal tolerance.

Tolerant varieties still become infected by the virus, but the plant shows none of the detrimental symptoms and associated yield losses of non-tolerant varieties.

Breeders can select for varieties with BYDV tolerance by using marker selection and the introduction of new varieties with BYDV tolerance is the number one priority for winter barley breeders. Rafaela winter barley comes from the Limagrain Belgium breeding programme and offers high yields with BYDV tolerance.

Q. How can BYDV be best controlled?

Using an integrated approach of choosing varieties with genetic BYDV tolerance, alongside correctly timed insecticide sprays will provide the best level of protection. The real value of varietal tolerance is that it protects the plant throughout the year, so if you can’t get on the land in the autumn to spray, the genetic tolerance will protect the plant in the same way as neonicotinoid seed treatments previously did.