FINE-TUNING curative spray timings to manage septoria in wheat has shown that prevention is better than cure.

As the choice, scope and efficacy of curative fungicides comes under increasing pressure – both in terms of their effectiveness due to potential resistance, and their availability due to regulatory pressures – wheat growers should consider the application of a T1.5 treatment to ensure leaf 2 is adequately protected from septoria, according to product manufacturer, Adama.

Andy Bailey, its fungicide specialist said the most effective way to control septoria is to prevent infection in the first place. “This means ensuring each newly emerged leaf is protected prior to the first infection period – in essence, before the first spores land on the leaf and germinate,” he argued.

“Whilst leaf 3 and the flag leaf (leaf 1) are routinely protected with well-timed applications at T1 and T2, respectively, leaf 2 often goes unprotected at its emergence, with growers relying on the subsequent T2 application to give kickback curative activity against any existing latent infection. This puts leaf 2 at significant risk to infection progressing beyond chemical control, especially if the T2 application is delayed.”

Growers should consider the concept of ‘leaf layering’ – applying protection to each new leaf as it emerges – to ensure optimum protection of ‘at risk’ crops. For Leaf 2, this means applying a T1.5 treatment at GS33 to treat the fully emerged leaf.

“The first choice of active ingredient for any T1.5 treatment, where septoria is the driver, should be a multi-site such as folpet,” he added. “Folpet will provide good levels of contact protection against septoria, and can be mixed with a strobilurin to protect against the threat of rust, or an azole/morpholine if active rust is present.”

In addition to controlling septoria and activity against rust, folpet also takes the pressure of resistance off azoles and SDHIs: “Like other multi-site fungicides, folpet affects several different metabolic sites within a pathogen,” said Mr Bailey.

“This gives it a low risk of resistance, with modelling work predicting that the addition of folpet to the tank-mix could theoretically extend the fully effective lifetime of medium to high risk fungicides. For example, the fully effective lifetime of epoxiconazole could have been extended from 8-16 years, with the lifetime of pyraclostrobin going from 4-8 years.”

He said that field trials and septoria strain analyses conducted in 2014 also showed the addition of folpet to an azole stopped the selection of resistant septoria strains. Similar results were also seen in 2015 trials carried out on SDHIs.

“With the current arsenal of fungicides having a reduced curative capacity, using folpet will not only ensure the crop remains cleaner for longer, but also take the pressure off subsequent application timings,” he said.

* Folpet is available as Arizona (500g/l folpet SC) as a flexible mixing partner and Manitoba where it is co-formulated with 50g/l epoxiconazole plus 375g/l folpet SC).


Adama has added 14 new fungicides, herbicides and insecticides to its crop protection portfolio following the approval by the European Commission for its parent company, ChemChina’s buyout of Syngenta.

As a condition though, Adama has had to divest some products from its portfolio. Under the agreement, Adama gets a portfolio of 14 crop protection products – nine fungicides, three insecticides and a herbicide.

Included in the deal is eight isopyrazam (IZM) based fungicides, plus a triazole based product.