Yeast Rot in Blueberries Major Problem in 2020

Clint Thompson Fruit, Georgia, Top Posts, Vegetables

A sporadic blueberry disease caused significant problems for Georgia producers in 2020.

Though management options are non-existent with yeast rot, Jonathan Oliver, University of Georgia (UGA) assistant professor and small fruits pathologist, believes timely harvesting and handling of ripe fruit will help minimize instances in 2021.

Photo by Clint Thompson/Shows Jonathan Oliver talking about yeast rot during the virtual Southeast Regional Fruit and Vegetable Conference.

“It was a major problem for our rabbiteye growers. Kind of the last half, maybe the last three-quarters of the rabbiteye harvest, at least in southern Georgia, seemed to be affected by it significantly. It probably is weather and condition dependent,” Oliver said.

“We had a lot of warmer weather right before we had the problem, and we had a lot of rainfall. It seems to be something of a problem when fruit is already either overripe or damaged in some way. Some of the weather conditions I think led to some of those problems. That’s why it was kind of an issue last year.

“It sporadically can be an issue in other years as well. It was a real big issue right at that one critical time last year, unfortunately, for our growers.”

Environmental Conditions

Warm, wet or humid conditions likely favor the growth of the fungus. There was a rapid shift to warmer overnight temperatures in Georgia in mid-to-late May. It went from the mid-50s to mid-70s very quickly. Also, there was a huge rain event that contributed as well. Alma, Georgia received 2.3 inches on May 22.

It is a secondary or weak pathogen that colonizes fruit surfaces and wounds. This causes the fruit to collapse and take on a wet, slimy appearance. Soft, splitting rot were common, and samples that were sent to the diagnostic lab were infested with yeasts.

Economic losses were significant. Harvested fruit was rejected and packing lines shut down early.