The work is part of a project supported by the North Carolina Plant Sciences Initiative (PSI), bringing together researchers from horticulture, computer science and engineering to develop non-destructive imaging technology that could eventually improve orchard management, reduce labor costs and increase crop value for apple growers across the Southeast.

The NC State University project team includes Chenhan Xu, an assistant professor of computer science; Edgar Lobaton, a professor of electrical and computer engineering; and Tom Kon, associate professor of horticultural science and apple specialist at the Mountain Horticultural Crops Research and Extension Center in Mills River.

“Crop load management is the intentional removal of flower buds, flowers, and/or immature fruit and is arguably one of the most important annual management decisions for apple growers,” Kon said. “In most years, apple trees produce an excessive number of fruit, and over 70 percent must be removed, or ‘thinned,’ to optimize crop value, enhance fruit quality, and ensure consistent cropping.”

Decisions about which flower buds, flowers, or fruit to remove can carry long-term financial consequences for growers.

“One bad decision or outcome can reduce orchard profitability for multiple years,” Kon said.

The interdisciplinary research team has developed a prototype system using radio frequency imaging technology similar to what is used in airport security scanners to see inside fruit and buds without damaging them. Researchers believe the system could help predict if an apple bud is reproductive, meaning it contains flowers, or vegetative, meaning it does not have flowers and may develop into a branch. The technology could also tell farmers if the apples will fall off or persist during early fruit development.  

“Radio frequency imaging could also be useful to estimate the water content, dry matter content, and other characteristics of these structures,” said Kon.

These insights could eventually help growers make more precise decisions throughout the growing season, beginning with dormant pruning.

“Crop load management starts with dormant pruning,” Kon said. “During pruning, growers can reduce the number of flower buds and subsequent cropping potential. While this is an effective and beneficial practice, it is quite difficult to execute with precision and accuracy.”

Kon noted that growers currently cannot accurately identify flower buds through visual evaluation alone, creating uncertainty during a process that directly impacts yields and profitability.

“If successful, this technology could be used to improve pruning practices and help growers reach consistent yield targets,” he said.

The research also addresses one of the industry’s most pressing operational challenges: labor. Chemical thinners are commonly used to remove excess immature fruit, but growers often must wait nearly two weeks before visible signs indicate whether the treatment worked. By that point, the ideal application window may have passed.

When chemical thinning treatments are unsuccessful, growers must rely on hand thinning, a labor-intensive and expensive process that can cost between $1,000 and $2,000 per acre.

“Therefore, it is critical to provide apple growers with quick and accurate technologies to determine chemical thinner responses,” Kon said.

The long-term implications for North Carolina agriculture could be significant. Apple production in Henderson County alone contributes an estimated $18.5 million annually, and crop load management decisions can create a difference of $5,000 to $10,000 in crop value per acre.

“The development and commercialization of non-destructive technologies to improve orchard management decisions in modern orchard systems would be of great value,” Kon said. “In the long-term, these technologies could help improve worker efficiency, reduce labor inputs, increase crop value, and help reduce food waste.”

The project also reflects the increasingly collaborative nature of agricultural innovation in North Carolina. Kon said the PSI played a key role in bringing together researchers from different disciplines who otherwise may never have worked together.

“This work and collaborative partnerships would not have occurred without the support of the NC Plant Sciences Initiative,” Kon said.

Kon explained that the collaboration began during a PSI workshop designed to connect researchers and extension professionals around pressing agricultural challenges.

“I sat down at a table with several colleagues that I had never met before and was given the task of developing a project idea that would address a critical research priority for our stakeholders,” he said. “This interdisciplinary project team and concept would not have been assembled otherwise.”

Although the PSI is based in Raleigh, Kon emphasized that its reach extends across the state, including Western North Carolina’s agricultural economy.

“NC PSI's impact and collaborative opportunities extend from the mountains to the coast,” Kon said. “I am incredibly grateful to be a small part of this team and am working with some truly brilliant scientists as part of this project.”

Learn more about the NC Plant Sciences Initiative at cals.ncsu.edu/psi.