Multiple Modes of Action Deter Fungicide Resistance, Too
Resistance isn’t just limited to herbicide-resistant weeds. Any control measure aimed at a pest can be rendered ineffective if it is repeated again and again.
Biotypes of a soybean disease, frogeye leafspot, have resisted strobilurin fungicides (Headline, Quadris, Evito) in states including Arkansas, Illinois, Kentucky, Tennessee, and Missouri. One way to forestall resistance is to use a fungicide with multiple modes of action.
That’s the story behind that Xemium fungicide brands that contain both strobilurin and SDHI inhibitor modes of action. It’s also provided impetus for companies like BASF to research newer compounds.
“It increases our vigilance to look for mixtures with additional modes of action to make sure we are not destroying very valuable (current) chemistries by using them with just a single mode of action,” says Markus Heldt, president of BASF’s crop protection division.
Heldt said at last week’s BASF annual press conference in Limburgerhof, Germany, that BASF is developing future chemistry to complement currently used fungicides. The company annually screens over 100,000 compounds in the fungicide area, he says.