Malting barley growers need to be careful in their choice of fungicides when responding to mounting disease pressure, as one SDHI product has yet to be approved by maltsters.

One of a group of new fungicides – Adexar – is so fresh from testing that although it has received approval from the Chemicals Regulation Directorate, it has not gone yet gone through trials to get on to the recommended list with the organisation that represents brewers, the British Beer and Pub Association.

“Unfortunately Adexar is just too new – it hasn’t had the chance to get through our approvals process and consequently it’s not on the brewers’ recommended list,” explains Ian Slaiding, R&D manager for Campden BRI, the company responsible for testing any chemicals used in malting and brewing.

“Obviously with fungicides, the biggest danger in the brewing process is upsetting the yeast – we have to ensure there is no residual effect that could impact on that.”

For a new product to pass through the approval process, samples of grain from crops treated with the chemical (and untreated) are evaluated at every stage of the malting and brewing process, right from germination rates through to the final taste of the beer. Understandably this can be a lengthy process, says Dr Slaiding.

Although new, Adexar has already proved a popular choice because of its ability to deal with a broad range of pathogens including rhynchosporium, net blotch, brown rust and ramularia.

“It’s basically a technicality that means Adexar hasn’t yet got on to the recommended list with the BBPA,” says Peter Hughes, BASF’s cereals fungicide product manager.

“Unfortunately, we’re unlikely to get approval for the use of Xemium products this year in malting crops, but plenty of growers looking to bolster their control programmes in feed barley and wheats are using them.”

As wet weather intensifies disease pressure, all is not lost for malting grain producers, he adds.

“Boscalids such as Tracker in combination with a pyraclostrobin will give good disease coverage.

“Prothioconazole-type products tend to be the backbone of barley fungicide programmes at both T1 and T2, but it’s not healthy to be too reliant on just one group of chemistry, especially with resistance issues in mind. That’s why agronomists are keen to try and use this latest SDHI technology.”

Independent Yorkshire agronomist Patrick Stephenson is urging growers to carefully consider their options.

“Some people may well have planned to include Adexar in their control programmes without realising it couldn’t be used on crops destined for malting.

“It would tend to be employed later in the season at T2 so growers need to find alternatives well before then. Other SDHIs like Siltra Xpro and Bontima or a combined prothioconazole and fluoxastrobin such as Fandango will provide good protection, too.”

Actives

• Adexar – epoxiconazole + fluxapyroxad

• Bontima – cyprodinil and Isopyrazam

• Comet – pyraclostrobin

• Fandango – fluoxastrobin and prothioconazole

• Siltra Xpro – bixafen and prothioconazole

• Tracker – boscalid and epoxiconazole