Multisite protectant fungicides have an important role to play in protecting existing chemistry and prolonging its useful life, as well helping to manage disease levels earlier in the season.

According to Neil Paveley, crop protection lead at ADAS, making fungicide programmes more robust means using mixture partners from the start and maximising the use of multisites, as they help to slow down selection for resistance.

“With septoria in particular, it’s important to look after all the chemistry that we’ve got. We know there’s been a decline in azole activity and that the pathogen is continuing to evolve, so the early warning signs are clear.”

Alternatives to adding a mixture partner with a different mode of action, such as folpet include either increasing the dose or the number of sprays, or splitting treatments. 

“But work has shown that all of those actions increase selection pressure and will drive resistance development faster. So using more sprays against septoria isn’t a sustainable solution,” says Mr Paveley.

His advice ahead of the new spraying season is to build mixture products into programmes from the outset, use multisites throughout and limit the number of azoles to T1 and T2.

“Consider alternatives when you’re targeting septoria or rusts at T0 and T1.5,” he says. “We need to maintain azole efficiency – both for its contribution to disease control and its ability to help protect other chemistry. That’s why the multisites are so important.”

There’s no doubt that cereal fungicide programmes are becoming more protectant, with greater emphasis being given to the earlier timings, reports Clare Bend of Agrii.

“Taking control early on helps to support the loss of curative activity from the azoles,” she says. “It’s a ‘prevention is better than cure’ approach and it should begin before fungicide decisions with variety choice and seed treatment use.”

As well as their stewardship role in early sprays, multisite protectant fungicides bring a yield improvement from their disease control contribution, she notes. “So their inherent disease activity is beneficial too.”

That was very evident last year, she adds, with responses to T0 sprays averaging 0.8t/ha.

Paul Fogg of Adama, the crop protection manufacturer behind the development of folpet, describes the multisite protectant as a backstop and believes that fungicide programmes should be built around it.

“We need to adopt a disease management approach, rather than disease control,” he says. “It’s all about making best use of protectants at T0 and T1, and reducing the disease pressure at later growth stages.”

This is where folpet, sold as Phoenix, which is more than just a resistance management tool, comes in, he continues. “It adds to disease control, doesn’t affect the uptake of the partner product and has been shown to increase the lifespan of the single site active that it is mixed with.”

Dr Fogg reminds growers that many of the fungicide tools at their disposal don’t work as well as they used to. “That needn’t be a problem. Building disease control programmes around protectants puts the grower back in control.”