Triazoles – the active ingredient used in most fungicides for controlling septoria in wheat – should not be affected by the new pesticide legislation currently going through Brussels, according to the EU Commission.

The draft legislation seeks to introduce new “cut-off” criteria into the pesticides approvals process, and would ban products that contain ingredients that are deemed hazardous.

This would include active ingredients that are “endocrine-disrupting”.

The UK Pesticides Safety Directorate says this would hit triazoles in particular, and could remove nine of the 12 approved active ingredients from the market (see table below).

According to the PSD’s impact assessment, released in May, losing triazoles would “remove the foundation stone” of control programmes for septoria in wheat, leading to 20-30% yield losses. Increased levels of powdery mildew could reduce output another 10%.

But the EU Commission says the PSD has got it wrong and triazoles should be perfectly safe under the revised Directive.

“It is not expected that all substances listed as possible endocrine disrupters by the PSD evaluation, on the basis of the chemical class they belong to, will finally be classified as such after a scientific evaluation,” says a recent letter from director general at the EU Commission’s health directorate, Richard Madelin. “This applies in particular to triazoles.”

Exempting triazoles from the new cut-off criteria would be a major step forward, according to PSD principal agronomist David Richardson. But he urged caution.

“There is still real uncertainty as to what is actually meant by endocrine disruption, and how it will be defined in the revised Directive,” he told Farmers Weekly. “The EU Commission has given us no clear indication.”

And with the European parliament due to assess the draft regulation in the autumn, the future of triazoles hangs in the balance.


Impact of the planned directive on triazoles

Epoxiconazole – out
Metconazole – out
Fluquinconazole – out
Prochloraz – out
Difenoconazole – out
Cyproconazole – out
Tebuconazole – out
Propiconazole – out
Flusilazole – out
Prothioconazole – not assessed
Flutriafol – not assessed
Tetraconazole – OK