Fruit Growers See New Technology, Orchard Design at Field Day

Ayleen Stellhorn
Southcentral Pa. Correspondent

BIGLERVILLE, Pa. — Participants in the 2009 Grower Field Day, held at the Penn State Fruit Research and Extension Center last week, had one goal in common: the search for the perfect fruit tree.

“We’re close,” said James Schupp, Department of Horticulture. “But we’re not there yet.”

Fruit growers started the day in a pre-program workshop on orchard mechanization and automation, which was co-organized by Penn State Fruit Research and Extension Center (FREC), Penn State Cooperative Extension, Carnegie Mellon University, and the USDA Agricultural Research Service. After lunch, three one-hour sessions were offered on a rotating schedule.

Schupp, who opened the session on orchard automation, told his audience that the driving force in orchard management is shifting from biological efficiency — as seen with the incorporation of dwarf trees — toward technological advancement. 

“It will still be about efficiency,” he said, “but we’ll be bringing the benefits of advances in communication, mechanization, computers, and cameras to an agricultural setting,” he said.

Schupp is also seeing a trend toward narrower trees, continuous tree walls, and less space between rows.

“We’ll need to match our orchard designs to the capabilities of the machinery,” he said.

As an example, he pointed out a nearby test orchard of vertical axis, cone-shaped apple trees that were planted in 2005 with 4 to 6 feet between the trees and 15 feet between the rows. The orchard supports between 500 and 700 trees per acre.

In contrast, he showed a 2009 planting of trees in a continuous tree wall that numbers about 1,200 per acre. They were planted 3 feet apart with 12 feet between rows.

“Ten years ago, I would have thought that planting was too tight,” he said. “With new technology, we can manage close spaces more effectively.”

A second component of the orchard automation workshop focused on new machines that are currently being developed and tested, including a string thinner and a drum shaker thinner, presented by Tara Baugher, of Penn State Cooperative Extension.

The string thinner can be adjusted to thin blooms of perpendicular V, conical, or open center trees and was found to reduce hand thinning by 30 to 60 percent and yield fruit in higher size categories by 35 to 40 percent, Baugher said.

The drum shaker thinner, originally used in orange groves, will thin at the green fruit stage. The first two years of research here were conducted in a block of pillar peaches with a narrow canopy. Baugher noted that limb damage and poor maneuverability led them to develop a more maneuverable machine with smaller rods and head that is better suited for more delicate fruit.

“It can’t do as much with bloom thinning as a string thinner,” she said, “but together they look like a good combination.”

Baugher expects the design of the drum shaker thinner to be refined again, with the next generation to be fitted on the front of a tractor instead of a stand-alone machine.

“We are continually tweaking to refine its use for this region’s needs,” she said.

A final component of the orchard automation workshop introduced the idea of pairing cameras and computers with machines. Paul Heineman and Jude Liu of Penn State and Yang Tao of the University of Maryland researched the development of robotics that simulate the thought processes and motions of humans.

In the human approach, a person would see a branch, determine which blossoms to remove, and then remove those blossoms by rubbing the branch.

In the mechanized approach, a camera would take a picture of the branch, a computer would evaluate the image and determine which blossoms to remove, and a robotic arm and finger would remove the blossoms.

Additional workshops during the afternoon discussed advances in sustainable/organic fruit production and hot topics in fruit research.