Opinion: Farming’s approach to fungicides needs a rethink

Selecting wheat fungicides can be as complex as deciding what coffee to order in Starbucks.

Whatever happened to white with one sugar?

Be it latte, cappuccino, Americano, flat white, 1%, or semi skimmed, there is more choice and Brits are buying a lot more coffee than we were 20 years ago.

The same is true of wheat fungicides. More choice and more often.

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Ian Pigott farms 700ha in Hertfordshire. Ian is also the founder of Open Farm Sunday

Different chemistry, timing, tank mixes, pack size and formulation, advertising influence, incentives, invitations to watch the men’s final at Wimbledon (I wish) all need to be considered. And apparently the more you spend, the greater the yield benefit and, most importantly, the return to the farmer.

This bang-for-your-buck hype is then carefully folded like a meringue mixture among the advice. Advice that is given by experts in plant health, nutrition and agrochemicals.

Climate of fear

However, objective disease and risk management plans have become blurred by a subliminal messaging that creates fear. But if you don’t spray… we need to protect… in case… we might get… what if. The agronomists inclination is to err on the side of caution. More spend, definitely. Less risk, perhaps. Good practice, absolutely not, in my opinion.

A four- or even five-spray fungicide programme is commonplace on many arable farms.

UK wheat yields have plateaued since 1984. Fungicide programmes have more than doubled over the same period.

In 1984, fungicides were applied at growth stage 32 and maybe again at flag leaf. Is this outdated or are timings denoted with a letter and a number (T0, T1, etc) much sexier and easier to sell? Phones and software successfully use the same marketing methodology.

When strobilurins succumbed to widespread resistance due to reckless overuse, the advice for new SDHI chemistry was to use carefully and with caution. But this didn’t result in fewer applications. No, the answer has been greater diversity in tank mixes.

Fungicides may be keeping plants greener longer, but with yields plateauing, it is apparent we are either measuring the wrong metrics or not understanding the drivers of plant health and yield.

Soil health

At what point is the health of the soil microbiome considered when these recommendations are made?

The soil and its microbiome is made up of millions of tiny bacteria and fungi. It is a living organism, sometimes referred to as the stomach of plants. Fungicides protect plants against the very thing we are trying to promote in the soil.

We are obsessed with the costs and outcomes of spray programmes. Where is the science that measures the yield in relationship to the health of the underlying soil microbiome?

Kings College London professor of genetic epidemiology Tim Spector has written compelling papers on the importance of a healthy gut microbiome to human health.

He also heads the British Gut Project. His research shows overwhelmingly that overuse of antibiotics and poor diet can be attributed to a 30% decrease in microbes in our bodies. But as well as killing off good bugs, they allow bad bugs to flourish. The consequence is obesity, increased illness and reduced well-being.

The parallels between soil health and gut health are blindingly apparent. We know that routine antibiotics use is bad practice in humans and animals and can lead to resistance, greater build-up of disease and reduced vigour.

So why on earth are routine prophylactic fungicide programmes acceptable for our crops?