Regenerative agriculture systems can be used to minimize fungicide dependence, but will not exclude them completely.
While most producers who have embraced regenerative agriculture aim to reduce inputs, there will be occasions when they will need to be used for good results, agree experts and farmers.
It is also increasingly recognized that it is important to combine all available tools in a disease control strategy.
Cultural and chemical
How they come together will depend on the system, site and season – with actions then being tailored to the situation, says Stuart Knight, Crop and Agronomy Director at Niab Tag.
He stresses that cultural techniques are just as important as chemical techniques.
“Growers cannot rely on fungicides, especially as we are losing key active ingredients and seeing performance decline among others.
“Any farming system, whatever it is, will fail if it depends too much on one element. “
In the case of fungicides, it’s very difficult to regularly grow high-yielding wheat crops without them, as Kent farmer and consultant Andy Howard discovered, especially when the system is in transition.
Mr. Howard distinguishes between the types of fungicides that could be used and the way they are used.
He believes foliar fungicides are still needed on many regenerative farms, but seed treatments are less appropriate.
“After promoting soil biology for the benefits it brings, we don’t want to negatively impact it by using treated seeds,” he says.
The experience of a farmer
As early as 2016, Mr. Howard set himself the ambitious goal of reducing inputs by 50% over five years on his farm, while maintaining production.
At that time, he found it easier to cut down on fungicides than herbicides and cut fungicide spending to around £ 45 / ha this year.
His approach was to start with biology and nutrition, before introducing fungicides.
This season that means he didn’t need a T0 or a T1, but he did use a reasonable T2 and a low rate T3.
Howard also points out that using too much nitrogen makes it difficult to reduce fungicides.
“Excess nitrogen causes disease and puts stress on spraying. These scenarios make it difficult to use fungicides as a last resort, not the first, which it should be. “
While genetics have a role to play in reducing pesticide use, her advice is that they need to be used in the right system.
“We know they’ll break down if they’re not part of a whole-farm approach – so we shouldn’t expect them to save a bad situation. “
He adds that using high levels of fungicides promotes the development of disease resistance, so he reduced the rates, with the help of biology and nutrition.
“The appropriate dose changes as the system evolves and matures. We have been able to reduce rates successfully, so we are now looking to reduce the frequency of spraying. “
Spring crops and intercrops – both of which are grown on his farm – require much less intervention. A bean / oat mix reduced the amount of rust in the beans by up to 75%.
“Mixing varieties is another opportunity,” he says. “They are an inexpensive way to provide diversity and have been very successful on a number of farms, both in terms of increasing yield and reducing disease levels.”
Andy Howard’s top tips for reducing fungicides
- Start with the basics – start by looking at your floors
- Study techniques such as variety blending, nutrition and intercropping, to reduce disease susceptibility and introduce diversity
- Try new approaches on small areas
- Scale up to 10 ha to assess the approach
Niab’s Stuart Knight points out that there are unnecessary fungicide applications on farms, both in terms of the level of product in the mix and the use of additional top-up sprays.
“It’s about matching the spray to what’s in front of you. The insurance mindset will need to change with lower input approaches. “
Regarding spray rates, he says high doses will select resistant strains of septoria.
“High rates cost money, so it’s important to be appropriate. Also, remember that whatever fungicide regimen you use, timing is critical to achieving good disease control. ”
What about biostimulants?
Don’t be tempted to swap one cost for another when you wean yourself off fungicides, warns Syed Shah, a regional agronomist in Niab.
There are alternatives, such as widely marketed biostimulants, many of which have a positive physiological effect on the crop, but few have shown a difference in yield in trials, he says.
However, they cannot be used to control major leaf diseases once they have been identified in a crop, he cautions.
“If you have yellow rust or septoria to control, right now you need a fungicide. In contrast, biostimulants and other biologics usually need to be applied before the onset of the disease because they work differently.
He agrees that nutrition is important for a healthy plant, and recommends growers focus on what is needed before cutting inputs.
“Sometimes you have to use fungicides. The direction of travel is clear – reducing inputs is on everyone’s radar and it can be done. But don’t be in a hurry if the time is against you.
Stuart Knight, Crop and Agronomy Director at Niab Tag, Syed Shah, Regional Agronomist at Niab, and Andy Howard, Farmer and Consultant from Kent, spoke at the Groundswell event on June 22-23, 2021 in Lannock Manor Farm, Hertfordshire.