Can Drones Offer a Faster, More Precise Way to Measure Blackberry Flowering?
Study develops system to measure flower density with camera-equipped drone
By John Lovett – Feb. 6, 2026
DIGITIZING NATURE — Akwasi Tagoe, left, and Cengiz Koparan examine an aerial image taken with a drone and filtered through a system they developed to quantify blackberry flowers and vegetation. (UADA photo)
FAYETTEVILLE, Ark. — For blackberry breeders, white and pink flowers on blackberry plants are more than something to admire; they are a key measure of productivity.
However, getting an idea of how many flowers are on the plants can be time consuming and subjective, which results in data inconsistencies. What if a drone could do it with a camera?
That’s the question agricultural engineers at the Arkansas Agricultural Experiment Station are trying to answer in collaboration with the department of horticulture. So far, they have proven the concept.
Cengiz Koparan, assistant professor of precision agriculture technology, worked with Akwasi Tagoe, a graduate student in the department of agricultural education, communications and technology, to develop a system for measuring flower density using a camera-equipped drone. They call the measurement the flower-to-vegetation ratio, or FVR for short, which was validated by comparing the results to human counts.
“Now we can quantify flower coverage and vegetation coverage with a standardized measurement,” said Koparan, who works in the departments of agricultural education, communications and technology, and biological and agricultural engineering. “We also now know the flowers produced per given vegetation for a specific variety. It gives us a little bit more insight about the phenotype.”
A phenotype refers to the set of characteristics of a plant variety observed under specific environmental conditions.
Although the task may appear simple on the surface, there are multiple layers of complexity woven into the project of decoding natural phenomena with digital tools. Overcoming that complexity required rethinking how drone imagery could be processed and interpreted.
“We sought to turn drone imagery into actionable data for growers and breeders,” Tagoe said. “By quantifying flowers and canopy growth using an open-source software, and subsequently computer vision, we look forward to moving from manual counting to scalable, real-time decision support that improves yield prediction and agricultural systems management.”
Flower power
While it was known that flower density and vegetation coverage are important indicators individually for identifying plant characteristics, including yield potential, Koparan said the combined FVR measurement was developed out of necessity based on how flying drones “see” the varying landscape.
“Our goal is to produce a drone navigation planning system that will allow farmers to just push a button and the drone will do the rest,” Koparan said.
The same concept is being applied in Koparan’s lab to instantaneous mapping of soybean crop injury, plant vigor and biomass estimation of corn, weedy rice detection and mapping for robotic weedy rice management.
An eye in the sky
In their proof-of-concept study, it was found that the images could be used to estimate floral initiation and timing, which offered insights for planning crosses and potentially forecasting harvest periods for growers.
Koparan and his collaborators published the results of their proof-of-concept use of drones to quantify blackberry flower coverage in the journal AgriEngineering in November 2024. The American Society of Agricultural and Biological Engineering also published their work as a conference paper for the 2025 ASABE Annual International Meeting in July 2025. Koparan noted that additional results, including work on yield prediction, are in the works.
A co-author of the studies was Margaret Worthington, director of the Arkansas Fruit Breeding Program for the experiment station and an associate professor of fruit breeding and genetics for the department of horticulture.
Other co-authors included Alexander Silva Cordoba, a Ph.D. student in the department of horticulture; Aurelie Poncet, formerly an assistant professor in the department of crop, soil and environmental sciences; Dongyi Wang, an assistant professor in the departments of biological and agricultural engineering and food science; and Donald Johnson, a University Professor in the department of agricultural education, communications and technology.
The departments of agricultural education, communications and technology, crop, soil and environmental sciences, food science, and horticulture are in the Dale Bumpers College of Agricultural, Food and Life Sciences at the University of Arkansas. The department of biological and agricultural engineering is in the College of Engineering.
Ground truthing
The next step in this research for Tagoe is looking at the relationship between yield data and the flower counts per research plot. If the correlation between yield and flower count is high, Worthington said she could use the data to better select the best genotype to enter replicated yield trials and increase the chances of finding a “winning cultivar.”
“I’m excited to see how this method correlates to our yield data, and I hope that we would eventually be able to predict yield potential on hundreds of selections based on an index of flower number and berry size,” Worthington said.
To learn more about the Division of Agriculture research, visit the Arkansas Agricultural Experiment Station website. Follow us on 𝕏 at @ArkAgResearch, subscribe to the Food, Farms and Forests podcast and sign up for our monthly newsletter, the Arkansas Agricultural Research Report. To learn more about the Division of Agriculture, visit uada.edu. Follow us on 𝕏 at @AgInArk. To learn about extension programs in Arkansas, contact your local Cooperative Extension Service agent or visit uaex.uada.edu.
About the Division of Agriculture
The University of Arkansas System Division of Agriculture’s mission is to strengthen agriculture, communities, and families by connecting trusted research to the adoption of best practices. Through the Agricultural Experiment Station and the Cooperative Extension Service, the Division of Agriculture conducts research and extension work within the nation’s historic land grant education system.
The Division of Agriculture is one of 20 entities within the University of Arkansas System. It has offices in all 75 counties in Arkansas and faculty on three campuses.
Pursuant to 7 CFR § 15.3, the University of Arkansas System Division of Agriculture offers all its Extension and Research programs and services (including employment) without regard to race, color, sex, national origin, religion, age, disability, marital or veteran status, genetic information, sexual preference, pregnancy or any other legally protected status, and is an equal opportunity institution.
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