Growers should adopt new SDHI fungicides for their disease control and yield responses, while any physiological benefits from them should be viewed as adding to the robustness of the products, Bill Clark, director of Broom’s Barn Research Station said.

“You can’t ever get the yield response from triazole fungicides that you can with SDHIs. It doesn’t matter how cheap epoxiconazole gets, you will never get to the level you can with the new chemistry. So you have to adopt this chemistry.”

The yield responses from providing good disease control would be much more consistent than any responses from physiological effects on the plant, he stressed.

All SDHI fungicides produced physiological effects in crops, he pointed out. “These are real effects. They increase photosynthesis directly, they have effects on photosynthesis through keeping stomata in the leaf open longer, have effects on rooting, and that effects water uptake and nitrogen availability.

“But you won’t get yield responses from physiological effects every year, in every crop. You have to look at the robustness of these products. Part of the benefit from physiological effects is how it adds to the consistency of these products. They are the icing on the cake.”

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