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.

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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.”

The Scottish Farmer: Against ramularia, Miravis Plus has consistently shown strong control Against ramularia, Miravis Plus has consistently shown strong control

To maximise differences 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 differences 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 effective solo active, when compared at a full-label dose.

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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 efficacy 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-irrigated at flowering to ensure high disease pressure. The dose-response 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 effective 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 effective solo active, when compared at a half-label dose.

Against net blotch, Miravis Plus gave consistently better control than the existing azole-based 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 different modes of action and used in tank-mix with an effective partner from a different 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.