Published on 01/20/23

CAES researchers examine blueberry quality issues for Georgia producers

By Maria M. Lameiras
Close-up of rabbiteye blueberry branch with ripe berries
While blueberries are known to be susceptible to postharvest injuries, resulting in fruit softening or splitting during harvest, handling and storage, UGA researchers are trying to figure out why some crops experience greater losses.

A multidisciplinary team of University of Georgia agriculture experts are working to determine causes and solutions to postharvest quality problems that have hit Georgia’s blueberry growers hard in recent seasons.

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

“We primarily have two types of blueberries that are grown in Georgia, Southern highbush varieties and rabbiteye varieties, with rabbiteyes having a later harvest in the growing season. Some of our rabbiteye growers and packinghouses have reported issues with fruit quality,” said Jonathan Oliver, fruit pathologist and assistant professor in the Department of Plant Pathology at CAES. “Growers put in a lot of money and time into preparing for harvest and when their fruit comes in at lower quality than they expect, it can really impact their bottom line.”

In 2022, the total value of Georgias blueberry crop was $348.7 million, making blueberries one of Georgias top 10 agricultural commodities.

According to the study proposal, blueberries are known to be susceptible to postharvest injuries, resulting in fruit softening or splitting during harvest, handling and storage. Because the fruit appears to be growing and ripening properly on the plant during the growing season and even at harvest, discovering reduced fruit quality after harvest is an unpleasant surprise for producers.

Interior photo of a mechanical blueberry picker
One facet of the study will determine the impact of mechanical pickers on postharvest blueberry quality.

When this happens, the packinghouse has to reject the load or they have to send it to processing instead of to the fresh market,” Oliver added. ”We as a team are looking at this issue to try to understand the factors that may be involved, whether it is 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 in postharvest physiology, and Zilfina Rubio Ames, small fruit specialist with UGA Extension and assistant professor in the CAES Department of Horticulture.

By approaching the problem from three perspectives — plant disease, postharvest handling, and growing practices — the multidisciplinary team increases the likelihood of finding a solution.

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

The team began the research by collecting samples from the 2022 crop and performing lab studies on postharvest transportation and storage to determine how fruit quality changes over time after harvest. Further studies will be performed 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; growing practices; the potential benefits of more frequent harvesting schedules; and the impact of mechanical harvesting on quality. 

Were looking at the whole process from start to finish — planting to postharvest — to see what all of the different factors might be that are leading to this issue that the growers are having,” Oliver added. This is the detective work.”

For more information on research at CAES, visit

Maria M. Lameiras is a managing editor with the University of Georgia College of Agricultural and Environmental Sciences.