For many years now, the agricultural market has struggled to keep ahead of an ever-growing number of herbicide-resistant weeds. According to most weed scientists, these cost several thousands of dollars extra to control each year out of grower-customer pockets and can easily half crop yields if left unchecked.
Now, it looks as if fungicide resistance is beginning to rear its ugly head. At the 2017 Commodity Classic show in San Antonio, TX, the United Soybean Board announced it was expanding its Take Action program to include fungicide resistance, specifically that impact the soybean market. “Herbicide resistance is a significant issue farmers face in their fields,” said Dr. Carl Bradley, Extension Plant Pathologist at the University of Kentucky. “It’s possible that fungicide resistance is going down the same path. Now is our chance to get ahead of it before it gets too severe.”
According to Bradley, fungicide resistance in some form goes back several decades, to at least the 1980s. However, in soybeans, the first documented case of it appearing was in 2010. “That’s when the fungus that causes frog-eye leaf spot in soybeans was found to be resistant to strobilurin fungicides in Southeastern Illinois and Western Kentucky,” he said. Since that time, this particular strain of fungus has shown up in 10 other states across the Midwest. “In addition, there are approximately 20 fungus species out there right now that are showing resistance to strobilurin fungicides,” added Bradley.
Gregg Fujan, a checkoff grower-leader from Nebraska, advised ag retailers and their grower-customers to be smarter when it comes to managing their fungicide needs to avoid future issues. “To stay ahead of fungicide resistance, we can’t cut corners,” said Fujan. “If we lose the tools we have, there’s a financial risk of having diseases we can no longer control.” To keep ahead of this problem, Fujan recommended growers follow four steps – scout fields regularly, understand disease thresholds, apply fungicides only when it make sense economically, and rotate fungicide modes of action.