Stronger activity against key barley disease threats – rhynchosporium, net blotch and ramularia – is the benefit of fluopyram approval in barley, claims manufacturer Bayer.

Ascra (prothioconazole + bixafen + fluopyram) is approved for one application per season for both winter and spring varieties. Independent and Bayer farm trials – with its Forward Farmer group –delivered mean yield responses of 0.3 t/ha in winter barley varieties and 0.2 t/ha benefit in spring varieties, compared to the previous 'standard', Siltra (prothioconazole + bixafen).

The company also claimed improved protection against rhyncho and net blotch, compared to Revystar (mefentrifluconazole + fluxapyroxad) and equal ramularia control.

Importantly, Ascra also has full MAGB approval for malting varieties and a cut-off date of GS61, ideal for those targeting premium markets. “Often the ideal ramularia timing for spring crops is GS49 (first awns visible) and fortunately both Siltra and Ascra can be used here,” said Bayer’s Greg Hanna.

Ascra has been in trials with SRUC and Prof Fiona Burnett felt it was particularly useful in net blotch and rhyncho situations. She puts this down to the higher loading of SDHI. “We’ve seen a slight slide in SDHI performance against net blotch resulting in higher rates being needed to maintain control. Ascra’s high SDHI loading is bolstering activity,” she noted.

For ramularia control, she considered the best options are Ascra, Siltra and Revystar, although she advised that control was largely based on their azole components. Also, she welcomed news that there was no shift in the efficacy of prothioconazole, given that it is the cornerstone of most barley programmes.

In SRUC spring barley trials, Ascra was shown to give a slight uplift in yield over Siltra, which could be down to physiological properties. “We know that plant stress is a factor in ramularia infection, so any benefit in plant health is helpful," she said.

"Much of the SDHI family have these additional properties, which we saw with strobs. Also, research has also shown that healthier plants photosynthesise more efficiently.”

Dr Tom McCabe, of Teagasc, agreed that Ascra’s SDHI loading was a benefit in barley disease control programmes. He considered rhyncho the major winter barley threat in Ireland and throughout much of the UK. Polycyclic disease crops can be exposed to multiple infections and research had shown that this trash-borne disease can be spread by infected seed.

There’s probably no better place than Ireland to test fungicides for wet weather diseases and Ascra proved a consistent performer in Teagasc winter barley rhyncho trials, with yield responses of 0.3 t/ha over Siltra and Revystar.

He said Ascra was also flexible, suiting both key timings but particularly useful as a winter barley T1 application. “Barley is a sink capacity crop, so ear numbers are vital for yield. The T1 is all about tiller protection and retention," he pointed out.

"That SDHI loading is also giving an uplift to net blotch control, and with a good dose of prothioconazole it is effective against mildew too."

But he added that Siltra was still performing well and the addition of fluopyram was giving growers more options. Also, he wasn’t opposed to prothioconazole being used twice in winter barley programmes, but would be if used at the T0. Then he would prefer to see cyprodinil or spiroxamine applied.

Bayer’s Scottish technical manager, Grant Reid, welcomed the approval of Ascra in barley. “Barley genetics have got better in recent years, but we don’t have any equivalent to Extase in barley varieties. Its septoria rating is also matched with good scores for rusts, mildew and fusarium.

“Of 27 recommended winter barley varieties, just six get a score of seven for rhyncho and of these, all are rated below six for net blotch. In spring varieties, only four have a rhyncho rating of six or better. Fortunately, Ascra is a very strong all-round fungicide delivering effective control across the spectrum,” he concluded.