Feb 13, 2023

Tart cherry research targets innovation

A multidisciplinary team of researchers at Utah State University (USU) and Michigan State University (MSU) are investigating more efficient ways to manage the state’s tart cherry crop, which yields sales between $7 million-$21 million annually.

The study team is using $1.97 million over 4 years from the U.S. Department of Agricultural Specialty Crop Research Initiative. About 18 months into the study, the group’s goal is to help growers tackle issues such as drought, pests, low yield and soil health.

By using soil maps, estimated yield maps and canopy imagery, project lead Brent Black and team members at USU and MSU are pinpointing ways growers can optimize irrigation, nutrition and canopy management for the orchards that are already established.

Black, professor in USU’s Department of Plants, Soils, and Climate and Extension fruit specialist, has more than 30 years of experience researching crop management. Michigan and Utah are the top two U.S. tart cherry producers, respectively.

As the use of drones infiltrated the fruit production world, Black began to investigate new technologies to improve production in orchards through precision management.

The task was to determine the best option for tart cherry production, Black told an audience at the Northwest Michigan Orchard and Vineyard Show in mid-January in Acme, Michigan.

“Would the benefit justify the cost? Maybe a different level of technologies would be more appropriate for tart cherries than what we have been seeing in apples,” he said.

Black looked at technology used by growers of agronomic crops such as corn and soybeans that mapped various parts of the field to determine certain qualities. That led to an objective to map orchards for variability, including soil characteristics (texture, nutrient holding), tree characteristics (tree size, canopy volume and density) and yield. Another research area involved diseases and pest distribution.

 Using drones, sensors and other tech

Technologies being investigated are drones, satellite images and vehicle- or sprayer-mounted sensors.

Another study approach mapped orchard variability, including soil characteristics, Black said.

Looking at the relationships between the different maps that can be generated included matching soil characteristics to the canopy/volume/density, yield potential and root distribution, and examining fertilizer placement, to determine where its use provides the best results.

“Another issue is canopy density and pest distribution,” he said. “If our canopy’s too dense, that’s where we first see powdery mildew, spider mites and some of the other pests that we deal with.”

Determining what those relationships are can lead to management interventions. One component of integrated pest management is knowing when to take action.

“We can maybe set thresholds for canopy densities regarding some of these other inputs, enabling us to be more efficient in how we’re managing our orchards,” Black said.

The approach could also include variable rate irrigation for improved water relations, and encourage less fertilizer leaching. Pruning timing could also benefit from variable rate management by identifying a threshold for light interception in managing pests, for example. Orchard removal management could be improved by use of the technologies.

“In recent years, some foreign countries have been importing cherries below the cost of production, and that’s put a real strain on the industry,” he said. “This whole project is looking at ways we can help growers better manage their crops and increase their profitability and efficiency.”

The project includes research into different methods of more efficiently collecting crop data, including ground-based and ATV-mounted sensors and drones.

Alfonso Torres-Rua, professor in USU’s Department of Civil and Environmental Engineering and member of the AggieAir UAV research program, is a collaborator on the project.

“Using sensors mounted on drones has the potential to collect hundreds of thousands of data points much faster than sending scouts out on foot or by ATV to monitor conditions in the orchard,” Black said.

Data from sensors on the ground and drones will create three-dimensional pictures to analyze orchard characteristics such as canopy density, soil health and disease and pest outbreaks.

“Drought strain and disease outbreaks cause changes in the way light is absorbed and reflected by the orchard,” Black said. “Using drone-mounted sensors, we hope to detect these differences and make targeting problems areas faster and easier.

Study could guide decisions to replant, wait

Matt Yost, USU assistant professor of plant science and Extension agroclimate specialist, is focusing on developing tools that help growers make site-specific efficient irrigation plans suited to their orchards. Grant Cardon, professor of soil science and USU Extension soils specialist, is studying the effects of different inputs and cultivation practices.

Orchards have a typical life span of roughly 30 years, so growers often face the decision of whether to replace or continue cultivating an orchard. Black and his team will use this research to help growers evaluate the health and profitability of older orchards. At least eight orchard blocks of varying ages are being studied to help growers decide when to switch to a new crop or begin again.

Marion Murray, USU Extension integrated pest management specialist in the Department of Biology, is guiding student research assistants in collecting and analyzing pest data.

The project’s team includes USU graduate students Christina Lilligren, Kurt Wedegaertner and Anderson Safre; the latter two also presented information during the NW Michigan session.

“This project is an excellent example of the innovations that are going into the farming industry,” Black said. “Some people tend to think of farming as an old-fashioned pursuit, but engineering and science and highly technical skills are really needed in agriculture. It’s an exciting field to be in right now.”

— Gary Pullano, FGN senior correspondent

Photo: A precision orchard management project research team is composed of Utah State University’s Matt Yost, Alfonso Torres-Rua, Brent Black, Marion Murray and Grant Cardon. Not pictured are Michigan State University team members Todd Einhorn, Bruno Basso, Nicki Rothwell and Molly Woods. Photo: Utah State University