Tree Fruit Growers Move Toward Automation

Tree Fruit Growers Move Toward Automation

High-Density Orchard


Note: The cover story of American/Western Fruit Grower’s April issue featured growers and researchers in Pennsylvania who are involved in a Penn State University Conservation Innovation Grant (CIG) project to develop growing systems that will allow greater orchard mechanization and labor efficiency in the near future. This story highlight some of the technology that is part of this transition to mechanization, and how the state’s apple industry responded to changing market trends in order to make this happen. Much of the information for this article comes from a “Specialty Crop Innovations: Progress and Future Directions” report published by Penn State Extension.

Until recently, nearly three-quarters of Pennsylvania’s apple crop was destined for the processing market. However, as the industry moves toward more fresh-market production, this transition has required a greater focus on fruit quality and getting full production in a quicker period of time.

Increased productivity, however, comes at a cost. High-density orchards require supplemental tree support that adds greatly to their initial investment. Average establishment costs for a high-density block in the Mid-Atlantic region are between $8,000 and $10,000 per acre compared to traditional low-density systems that cost $2,500 to $3,000 per acre to establish. Early and significant yields — a key benefit of high-density production — are critical in achieving maximum economic return and expedited payback in these systems.

The investment is well worth it, however, especially when it comes to future savings in labor. “Transitioning to uniform, high-density orchards will put growers in the best possible position to take advantage of new labor reducing technologies as they are developed,” says Matt Harsh, a fruit and vegetable grower in Smithburg, PA.

A New Orchard Blueprint

While it is a well-known and generally agreed-upon principle that smaller trees require less labor because they require less pruning and minimize ladder use, few high-density training systems were developed with labor efficiency in mind, and fewer still to facilitate the use of labor-saving mechanization. In fact, Jim Schupp, associate professor of pomology at Penn State’s Fruit Research and Extension Center, has declared at several industry meetings the past few years that fruit growers need to rethink their planting systems and make them more compatible with the potential benefits that mechanized orchard technology can provide.

A few years ago, tree fruit researchers at a fruit production workshop developed a “blueprint” of a successful intensive apple system (the blueprint includes dwarfing rootstocks and high tree density; quality nursery stock; supported canopies; single rows of tall narrow canopies; a canopy shape that complements natural tree form; minimal pruning; and minimal branching structure). In order to be economically productive, the orchard needs to achieve high light interception without creating dense areas in the canopy. Over time horticulturists found that when an orchard system is entirely within the reach of a person on the ground, one of two bad things happens: Either the canopy is productive but too dense, causing a loss of fruit quality, or the canopy is too small, causing loss of yield. The solution has been to increase canopy volume without condensing the canopy by growing the tree taller, while keeping it narrow and orienting the rows in a north-south direction wherever possible to minimize cross-row shading.

According to Schupp, these narrow fruiting wall systems can provide several advantages:
• The tall narrow tree wall is horticulturally sound, and its biological efficiency surpasses the performance of most existing systems.
• Sunlight and labor have the same reach. With narrow canopies, you can address both problems of light distribution and platform labor reach simultaneously.

Once this blueprint was established, the next step was to develop the Conservation Innovation Grant (CIG) project, covered in the April issue of American/Western Fruit Grower. The CIG plantings are evaluating the effect of two high-density apple growing systems on productivity, fruit quality, and labor efficiency. The trees are being trained to form either a continuous tree wall, or a cone-shaped canopy with discrete gaps in the tree tops. Labor efficiency between the two systems is being compared using both ladders and a mobile platform. The large number of CIG trials and the relatively large size of the plantings will also provide adequate space for evaluating additional labor saving technologies developed through two USDA Specialty Crop Research Initiative (SCRI) projects funded in 2008. By blending this research into the CIG demonstration project, researchers hope to increase the visibility of the results and speed industry adoption of new practices as they develop.

To watch videos of Jim Schupp, as well as Pennsylvania fruit grower Bruce Hollabaugh, discussing how CIG plantings will benefit the apple industry,.

To learn more about the technology being developed for these systems, go to the next page of this story.