ATHENS — A multidisciplinary team of agricultural experts from the University of Georgia is working to determine the causes of and solutions to postharvest quality issues that have hit Georgia blueberry growers hard in recent seasons.

Funded by the UGA College of Agricultural and Environmental Sciences Office of Research and Cooperative Extension, the project will address "significant issues" with fruit quality, particularly in rabbiteye blueberries, one of the two main types of blueberries grown in the state.

“We primarily have two types of blueberries grown in Georgia, the southern tallbush varieties and the rabbiteye varieties, with the rabbiteyes being harvested later in the growing season,” Jonathan Oliver, fruit pathologist and assistant professor in the CAES Department of Plant Pathology, said. “Some of our rabbiteye growers and packers have reported problems with the quality of the fruit. Growers spend a lot of money and time preparing for harvest, and when your fruit arrives at lower-than-expected quality, it can have a huge impact on your bottom line.”

In 2022, the total value of the Georgia blueberry crop was $348,7 million, making blueberries one of Georgia's top 10 agricultural commodities.

According to the study proposal, blueberries are known to be susceptible to post-harvest injury, which causes the fruit to soften or split during harvesting, handling and storage. Because the fruit appears to be growing and ripening properly on the plant throughout the growing season and even during harvest, discovering a reduction in fruit quality after harvest is an unpleasant surprise for growers.

“When this happens, the packer has to either reject the load or send it to processing instead of the fresh market,” Oliver added. "We as a team are looking at this issue to try to understand factors that may be involved, whether it's disease, horticultural practices or environmental issues that may be contributing to what growers are seeing in the field."

The research team also includes Angelos Deltsidis, assistant professor of postharvest physiology, and Zilfina Rubio Ames, UGA Extension small fruit specialist and assistant professor in the CAES Department of Horticulture.

By approaching the problem from three perspectives: plant diseases, post-harvest handling, and cultivation practices, the multidisciplinary team increases the likelihood of finding a solution.

“Postharvest physiology includes management practices; horticulture covers the practices that growers have now and how that affects the quality of the fruit; and plant pathology looks at disease and possible causes,” Ames said. “Blueberries are the highest value fruit crop in the state of Georgia, so it is critical that we find solutions for members of our industry.”

The team began the research by collecting samples from the 2022 crop and conducting laboratory studies on post-harvest transport and storage to determine how fruit quality changes over time after harvest. Further studies will be conducted at the Georgia Blueberry Research and Demonstration Farm in Alma and in partnership with growers.

Additional studies will examine factors affecting pollination, fruit set, and development; cultivation practices; the potential benefits of more frequent harvest schedules and the impact of mechanical harvest on quality.

“We are looking at the entire process from start to finish, from planting to post-harvest, to see what the different factors may be that are causing this problem that growers are having,” Oliver added. "This is detective work."

For more information on research at CAES, visit caes.uga.edu/research .