The Scottish Farmer

Miravis Plus spray performs in trials

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AHDB have published their trails into crop spray Miravis Plus from Syngenta which shows that the product has useful activity that can help farmers manage several major diseases in wheat and barley.

Miravis Plus (Syngenta) contains the active substance pydiflumet­ofen (also known as Adepidyn technology), which was approved for use in Great Britain by the Health and Safety Executive (HSE) earlier this month. It is a succinate dehydrogen­ase inhibitor (SDHI) fungicide.

The product has been tested under code in winter wheat and winter barley trials for several years, as part of the AHDB fungicide performanc­e project.

ADAS’ Jonathan Blake, who works on the trials, said:

“We test products under code so we can release independen­t performanc­e data as soon as approval for use has been granted.”

To maximise di‰erences between treatments for each target disease, the fungicide performanc­e cereal trials use high-risk locations, highly susceptibl­e varieties and one spray timing. As a result, the trials provide a tough test for fungicides and yield di‰erences recorded may not be seen in commercial situations.

A particular strength of the trials is that they reveal the relative performanc­e of fungicide products. The dose-response curves on the AHDB website have been updated to show how Miravis Plus compares to the other products tested in these trials.

Wheat fungicide performanc­e

IN the wheat trials, Miravis Plus has been tested against septoria tritici since 2019 and against brown rust and fusarium since 2020.

Against septoria tritici, Miravis Plus is highly active in both protectant and eradicant situations, performing comparably to or better than existing standards when applied at or above a half-label rate, with the result remaining consistent over the trial years.

Single-spray average yield responses in septoria trials (over the last three years) indicated that

Miravis Plus increased yield by 0.4 t/ha compared to Peqtiga (fenpicoxam­id), the next most e‰ective solo active, when compared at a full-label dose.

NIAB’s Stuart Knight said: “Against brown rust, Miravis Plus has demonstrat­ed useful activity when applied on its own, and it will add to the e—cacy of products it is partnered with. However, it is not as active as other SDHIs, such as Vimoy (isoflucypr­am,

Iblon), Elatus Plus (benzovindi­flupyr,

Solatenol) or Imtrex (fluxapyrox­ad).”

On fusarium, the trials are inoculated and mist

nd irrigated at flowering to ensure high disease pressure. The doserespon­se graphs indicate that it has excellent activity when compared with the azole standard Proline (prothiocon­azole).

Barley fungicide performanc­e

IN the barley trials, Miravis Plus has been tested against ramularia, rhynchospo­rium and net blotch, with good results against all three diseases, reports SRUC’s Fiona Burnett.

Against ramularia, Miravis Plus has consistent­ly shown much stronger control over three seasons of testing compared to the previously leading product Myresa (mefentrifl­uconazole), which was itself more e‰ective than the other long-establishe­d standard prothiocon­azole. This is particular­ly good news for growers, who have grappled with ramularia control recently because of fungicide-resistance issues.

Against rhynchospo­rium, Miravis Plus is highly active in both protectant and eradicant situations. It has consistent­ly performed as well as or better than existing standards, such as prothiocon­azole, Imtrex (fluxapyrox­ad), Ascra

Xpro (bixafen + fluopyram + prothiocon­azole) and Myresa (mefentrifl­uconazole). On average, Miravis Plus increased yield in the rhynchospo­rium trials by 0.3 t/ha (over the last three years) compared to Imtrex (fluxapyrox­ad), the next most e‰ective solo active, when compared at a halflabel dose.

Against net blotch, Miravis Plus gave consistent­ly better control than the existing azolebased standards (listed above). It was also notably better than the other straight SDHI in trial, Imtrex (fluxapyrox­ad).

Resistance management

MIRAVIS Plus is an SDHI and is limited to one applicatio­n per crop. To prevent or slow resistance, SDHIs should be alternated with applicatio­ns of fungicides with di‰erent modes of action and used in tank-mix with an e‰ective partner from a di‰erent mode of action group. This is in accordance with the FRAG-UK guidelines.

Miravis Plus is authorised for use in winter and spring wheat, barley, oats, rye, triticale, spelt and durum wheat. It can be used up to and including growth stage 65 for barley and oats, and growth stage 69 for other cereals.

 ?? ?? Against septoria tritici, Miravis Plus is highly active
Against septoria tritici, Miravis Plus is highly active

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