Penn State: Are drones the future of tree fruit production?

by Jeff Mulhollem

UNIVERSITY PARK, Pa. — A team of researchers in Penn State’s College of Agricultural Sciences is addressing the growing interest among tree fruit growers in Pennsylvania and the Northeast in adopting drone-based spraying systems for high-density apple and peach orchards. The Northeast Region of the Sustainable Agriculture Research and Education Program and the Pennsylvania Department of Agriculture recently awarded the team two grants to support the work.

“Many farmers are seeking alternatives to traditional air-blast sprayers, which experience frequent breakdowns and inefficiencies,” said team leader Shanthanu Krishna Kumar, assistant professor of tree fruit. “A survey of growers last year revealed that 95% were eager to explore drone spraying technology, citing increased efficiency, labor savings and improved soil health as key benefits.”

The project will include a series of field trials and demonstrations to optimize drone-based spraying systems for high-density fruit orchards. Image Credit: Penn State. Creative Commons

Pennsylvania ranks among the top producers of apples in the U.S., with over 14 million bushels harvested annually, highlighting the significance of efficient spraying in this sector, Kumar noted. He explained that growers like the ability of drones to spray at night, which offers advantages such as reduced wind speeds and lower risk to pollinators. Additionally, they see drone spraying as a more viable option for irregularly shaped and steep orchard sites that are less accessible to traditional equipment.

Despite the potential benefits, farmers have expressed concerns about drones maintaining optimal water volumes and spray coverage, as well as whether drone-applied growth-regulating chemicals crucial for managing crop loads in orchards will be as effective, Kumar added. The research team will focus on those aspects in the study.

“Farmers also seek more information on maintenance, troubleshooting and the cost-effectiveness of drone technology,” Kumar said. “This project aims to bridge these knowledge gaps and support growers of all sizes, in adopting sustainable and efficient spraying.”

The project will include a series of field trials and demonstrations to optimize drone-based spraying systems for high-density fruit orchards. Credit: Penn State. Creative Commons

The project will include a series of field trials and demonstrations to optimize drone-based spraying systems for high-density fruit orchards. High-density apple orchards, for example, have many fruit trees per acre, typically exceeding 180 trees, to maximize yield and production. These orchards use dwarf trees, specialized pruning and tree-training systems to achieve early fruit bearing.

These trials will focus on determining appropriate water volumes, flight parameters and the efficacy of plant growth regulators applied with low water volumes. A side-by-side comparison of drone spraying with traditional air-blast sprayers will provide critical data on spray coverage and economic viability.

The researchers aim to produce best-practice guidelines for drone applications from their work, helping farmers adopt this technology while reducing chemical use, labor costs and environmental impact, Kumar said. Eight growers across Pennsylvania will host on-farm trials, providing real-world insights into the technology’s effectiveness.

Outreach efforts by the researchers will include workshops, field days, webinars and video tutorials, as well as Spanish-language programming. The team will share their findings through industry publications, presentations at conferences and local meetings. The project also will offer guidance on securing funding opportunities for farmers interested in adopting drone spraying systems.

“By addressing farmers’ concerns and providing accessible, practical solutions, our project aims to promote widespread adoption of drone-based spraying technology, leading to more efficient, sustainable and economically viable fruit production in the Northeast,” Kumar said.

Long He, associate professor of agricultural and biological engineering, is co-principal investigator on the project, and Penn State Extension educators Daniel Weber and Maria Gorgo-Simcox are team members.

The grant from the Northeast Region of the Sustainable Agriculture Research and Education Program is $200,000. The PA Ag Innovation Grant from the Pennsylvania Department of Agriculture for purchase of a drone to use in the research is $19,000. The researchers also will use the drone to experiment with scanning fruit trees for precision nutrient management.

This research is part of the College of Agricultural Sciences’ Technologies for Agriculture and Living Systems (TALiS) initiative, a unique, holistic approach that balances the need for increased food productivity and efficiency with a dedication to conserving vital living systems. It envisions a future where advanced technologies help create sustainable, resilient agricultural systems interconnected with the living systems that sustain them.