Attention Blueberry Producers: Diseases to Consider This Time of Year

Clint ThompsonBlueberries, Florida

By Clint Thompson

The calendar says it’s the end of November, which means it is prime time for Florida blueberry producers to manage potential disease buildup in next year’s crop.

Phil Harmon, professor and Extension plant pathologist at the University of Florida Institute of Food and Agricultural Sciences, highlighted a few that growers should be mindful of this time of year.

“It’s a time when a lot of diseases are showing. Plants get tired and start losing their leaves. We’ll see those affected by phytophthora root rot, they will color up early,” Harmon said. “It’s not a great time to control that disease, but it’ll let you know that it’s happening by making those plants turn red before others around them that are not affected by root rot.

Stem blight is one where the stress and end of the season, we’ll see some of those that have been affected by stem blight for the last year aren’t growing as vigorously, they will start to flag and die this time of year. Even though the disease has been active the last six months over the summer, it shows itself in the fall. It’s not a great time to control other than identifying those diseases when they’re there, making appropriate plans for phytophthora root rot prevention and rouging plants, ripping them out and burning them that have stem blight or other diseases.”

Rust Disease

Blueberry rust is a fungal disease that can defoliate blueberry bushes, leading to plant death. Florida Evergreen growers should be vigilant in protecting their crop.

“We’re getting late enough in the year now where guys in South Georgia, even here in North-Central Florida, have stopped spraying. We’ll see a lot of rust come in and start to defoliate, as we naturally defoliate moving into December, hopefully before bloom. The exception of course is with our evergreen production, whether that’s in high tunnels further north or if it’s down south of the I-4 corridor,” Harmon said. “Where we have Evergreen, we have to be vigilant on rust; use our fungicides and prevent a big inoculum load from building up and carrying over into the fruiting stage; post-bloom and cause a lot of problems for us.”