By Clint Thompson
Persistent rainfall has led to certain diseases being more prevalent in peaches in the Southeast this year. Phil Brannen, University of Georgia Cooperative Extension fruit disease specialist, emphasized that bacterial spot has been most concerning, especially in susceptible varieties.
“We’ve had more bacterial spot on varieties that are susceptible to it than we’d like to see,” Brannen said. “That’s been probably the worst of it.”
Bacterial spot is a sporadic leaf-spot disease that can cause defoliation in certain cultivars. Spots can also appear on the fruit, causing damage and leaving fruit unmarketable.
Brannen said peach producers operate on a strict spraying schedule, between 7 and 10 days. They will spray for the disease, and then approximately a week later will spray again, though the fungicides aren’t totally effective in a rainy summer.
“The only thing we have that we can do is to spray low rates of copper, use oxytetracycline, and neither one of those are particularly great when it’s really wet. We will definitely see more bacterial spot in a wet year like this,” Brannen said. “Peaches that are not susceptible to bacterial spot are doing fine. But where we do have bacterial disease, it’s been problematic. They’re spraying like crazy, but it’s mainly certain cultivars.
“If we had not had a good spray program, we would have lost the entire crop. That’s how bad that would be. In a year like this, with the amount of rain that we have had, it can be real bad. That’s why fungicides are important.”
Fungal diseases, on the other hand, have been managed successfully this year.
“The spray programs we have on the fungal side, even though it’s been that wet, we really don’t have that much showing up; as far as peach scab or brown rot. Commercially, we just have really active fungicides,” Brannen said.