As unsettled spraying weather continues, agronomists are urging winter barley growers to seize every chance to apply key T1 fungicide treatments.
Although diseases may be less obvious than usual after recent cool weather it never pays to relax, they warn.
“The T1 in barley is really important,” says Hutchinsons’ Dick Neale.
“The T2 is just a tidy up.”
Compared with wheat the crop is short-lived and never properly recovers from established diseases, explains Mr Neale.
“The flag leaf is relatively small so it’s more important to keep the other leaves clean.”
The main timing for the T1 in winter barley is first node detectable (GS31), not GS32 as in wheat, notes Masstock’s Clare Bend.
“Once disease has a grip it can be hard to control, and you can end up throwing good money after bad.
So check for that first node and be ready to go.”
ProCam’s Nick Myers agrees but points out that some crops are still quite backward.
“There’s still a bit of disease there though.
So my concern would be if people back off and we then get some really growy weather.”
In the east net blotch is the most prominent disease, says Mr Neale.
So while in other seasons eradicating rhynchosporium might be his main T1 aim he is adjusting programmes.
“We are loading up the protectant side, and from an anti-resistance point of view I’m going for Acanto Prima.”
The combination of picoxystrobin and cyprodinil offers good long-term protection against net blotch, rhyncho, brown rust, and mildew, he explains.
“I don’t expect to need a mildew eradicant at the moment, because it isn’t there.
But we’d expect to see it when we get warmer days.”
For Mrs Bend in the west and south-west rhyncho remains the key target, even though the main varieties, Carat and Pearl, have reasonable resistance.
“We have to hit it hard and early.”
Her product of choice, based on the firm’s trials, is Helix “combining the strength of the best azole, prothioconazole, with spiroxamine which gives a useful helping hand across the board of barley disease.
“If we need a strob to boost malting quality and increase the persistency we’d go for trifloxystrobin.
It’s excellent on rhyncho and we can be flexible about doses of the two components as conditions dictate.”
Fandango (fluoxastrobin + prothioconazole) performs well but lacks that flexibility, she notes.
Despite crops’ apparent cleanliness Mr Myers will be advocating fairly robust mixtures at this stage.
“We might look to reduce rates a bit if they are very clean.”
His first choice is Mobius for the synergistic effect between its prothioconazole and trifloxystrobin components.
“It gave good results in our trials last year.
“Where mildew is very active, especially in thick stands, we’d factor in a specific mildewicide.”
Talius (proquinazid) and Cyflamid (cyflufenamid) are both steps forward, though the former is solely protectant, he notes.
Where rhyncho levels are high, mixtures including strobilurins should be applied, advises ADAS’s Bill Clark.
The newer products Fandango, Proline (prothioconazole) and Tracker (boscalid + epoxiconazole) are very effective against rhyncho and net blotch and offer stem-based disease control, he adds.
“But even they will benefit from added morpholine where mildew is a problem.”