T1: A crucial time for disease control on wheat

Winter wheat crops have come through the long winter and are now beginning to advance. However, the recent harsh weather has left its mark and there is already high disease pressure.

The T0 fungicide, generally a Bravo type, will reduce disease pressure. However, it is the T1 (leaf 3 emerged) fungicide application that will set the foundation for disease control this season.

The three key disease targets at T1 are obviously Septoria, but last year’s experiences indicate that Yellow Rust must be factored in on susceptible varieties; Eyespot is often a threat also.

The core fungicide at T1 will be a SDHI/triazole mix and must deliver an appropriate balance between curative, preventative and persistent activity against all three target diseases.

ELATUS™ ERA

ELATUS™ ERA – a combination of the novel SDHI active SOLATENOL™ and the triazole, prothioconazole, was introduced to the market last year by crop protection company, Syngenta.

Syngenta’s Billy Cotter said: “ELATUS™ ERA delivered on the promise it had shown in trials in previous years. Growers used it very successfully across all three cereal crops – wheat, barley and oats. While the product is restricted to one application per crop per season, growers reported very positive experiences where they used it at either T1 or T2.”

Cotter explained: “On winter wheat in particular, our experience tells us that T1 is the preferred timing for ELATUS™ ERA. The SDHI component, SOLATENOL™, has an excellent balance between curative, preventative and persistent activity to deliver the optimum performance on all three key diseases, particularly Septoria.”

Septoria- most damaging at T1

ELATUS™ ERA has performed exceptionally well in recent trials, particularly where Septoria is the target disease.

In independent trials, where single label rate doses of SDHI/triazole mixtures were applied, ELATUS™ ERA consistently delivered top level control and yields against the disease.

This consistent, high level of performance against Septoria can be attributed to its balance between curative, preventative and persistent activity.

Re-emergence of Yellow Rust

Some popular varieties developed high levels of infection last year from the re-emerging disease, Yellow Rust. Cotter said: “Yellow Rust is a very damaging disease and when left uncontrolled, its yield reducing effects can be even greater than Septoria.”

There have been a limited number of trials undertaken on Yellow Rust in Ireland. However, in the UK where they face significant Yellow Rust challenges, SDHI fungicide SOLATENOL™ has been reported as the highest performing against Yellow Rust.

Eyespot – often present and damaging

There are differing views as to the prevalence and importance of Eyespot in wheat. However, it is often present in crops and in some seasons can be quite damaging. Prothioconazole is well recognised as the leading triazole for Eyespot reduction and support from the SDHI component in mixture fungicides can be expected.

Cotter explained: “We had a lack of trials data to demonstrate the efficacy of ELATUS™ ERA on Eyespot when we launched the product in 2017. In our Septoria trials last year, we asked the researchers to do an Eyespot assessment at the end of the season.

The data indicates that when ELATUS™ ERA is used as a T1 in programmes it delivers a 60% reduction in Eyespot incidence.

Getting the best results

Wet weather disease pressures are likely to be high, therefore the temptation to reduce fungicide rates on wheat should be avoided.

Chlorothalonil containing products like Bravo will be an essential addition to spray tanks at the key timings in wheat disease control. Where ELATUS™ ERA is used at T1 or indeed at T2, Syngenta recommends the addition of Bravo at 1.0L/ha.