Susceptible peach varieties make bacterial spot disease a problem that continues to linger for growers in the Southeast.
That was a message that Phil Brannen, University of Georgia Cooperative Extension plant pathologist, presented during last week’s Southeast Regional Fruit and Vegetable Conference.
“A lot of the varieties that people really want the fruit from are susceptible. Unfortunately, that’s the reality. We do have some resistant varieties or at least some that are much more tolerant of this disease, but those are the ones that don’t have the color that you might want because they’re going to the market and stuff like that. That’s where we run into issues,” Brannen said.
Why are Varieties so Vulnerable?
He added that most of the varieties that producers in Florida, Georgia and Alabama are using originate out of the breeding program in California. But those varieties are grown and developed under much different environmental conditions than in the Southeast.
“They’ll have beautiful peaches. They’ll be very colorful and all the things that the market would demand. That’s great, but they breed these in a dry environment in California. They don’t have bacterial spot because they’re basically growing these things in the desert. They use irrigation under the trees in order to keep them alive,” Brannen said.
“For California, this is not an issue or not a major issue. But you take those same varieties from those breeding programs and say we want those because they produce a beautiful fruit and that’s what we want and you bring them here, they have never been developed in the presence of these diseases as far as their breeding program. Then all of a sudden you realize, ‘Wow, these are really susceptible to bacterial spot.’”
What is Bacterial Spot?
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.
Producing peaches in the Southeast can be tricky for growers. They understand that consumers are used to buying certain peaches that exhibit certain traits. That’s why producers are content with growing varieties that are vulnerable to bacterial spot disease.
“There’s two things that sell peaches and neither one of them really have to deal with taste. Taste is variable based on the acidity and sweetness you have in the peach. People like taste based on what they like. The color is strictly a visual type of thing. A lot of people really love a red color or a lot of blush on a peach. You can take a peach that’s very yellow and it would taste maybe better than that red peach. But people are still going to seek that color,” Brannen added.
“The second thing is size. People want a large peach. A smaller peach will taste just as good, maybe better. But people want a large, red luscious peach. That’s what the market demands. That’s what we’re trying to provide.”