Karen Lewis demonstrates demonstrates a handheld mechanical thinning tool during a Washington State University field day. Photo by Geraldine Warner

Karen Lewis demonstrates demonstrates a handheld mechanical thinning tool during a Washington State University field day. Photo by Geraldine Warner

New technologies that will allow orchardists to grow fruit more efficiently and deliver a better product to the consumer are becoming available. Below are five technologies that you can use now.

1 New chemistries

Two plant bioregulator products that are having an important impact in the industry are Apogee (prohexadione calcium) and the sprayable MCP product, Harvista. Apogee is a tool that reduces vegetative growth of trees by blocking the -synthesis of gibberellins (hormones that promote -elongation of cells). Treated trees produce shorter shoots with shorter internodes.  Benefits include better light penetration in the canopy and less need for pruning. This has allowed orchardists to more successfully develop and manage simple, narrow, and productive canopies in apples.

The active ingredient in Harvista is MCP (1-methyl-cyclopropene), which has been used for more than a decade as a postharvest treatment to maintain fruit quality, and is now available as a preharvest spray. MCP blocks the fruit’s receptors to ethylene, the ripening hormone. Applied before harvest, it can slow down fruit maturity and slow firmness loss in storage, though it is not considered a replacement for postharvest MCP.

As overall production and yield per acre increase in Washington State, tools that can be used to manage physiological maturity will become more important. Being able to manipulate maturity somewhat allows growers and field staff to better manage harvest, target markets, and manage inputs such as labor, tractors, bins, and warehouse services. Anything we can do during harvest to ensure that we pick fruit at its peak for the intended storage or target market is a must try.

2 Fruit handling

From receiving to loading trucks, the packing side of the industry has invested in available technologies and streamlined the handling of the fruit. This is critical as the fruit volume continues to increase. Dr. Ines Hanrahan of the Washington Tree Fruit Research Commission cites both defect sorting and sophisticated inventory systems as two of the newer technologies used in fruit handling.  Defect-sorting technology results in a better product in the box and is beneficial to all sectors from tree to truck because detailed defect sorting minimizes oversorting and undersorting. Defect sorting will be listed right next to CA (controlled atmosphere) storage and MCP in the record books.

Mechanical aids

Harvest-assist systems, platforms, and other tools that can help improve efficiency  and productivity in thinning, pruning, harvesting, and other orchard practices are becoming more available.

We have more opportunities than ever to seriously evaluate mechanical thinning, mechanical pruning, and mechanical harvest-assist. I would not have said this three years ago. This is a new day for mechanization in Washington State.

The equipment industry is delivering well-designed, robust, and reliable equipment to mechanize orchard practices. There are six different commercially available harvest-assist machines in the field this season—some working day and night. Last year there was one. In addition, sickle-bar mechanical pruners appropriate for modern apple and cherry plantings are commercially available. Mechanical thinning tools include handheld and tractor-mounted string thinners. Both have been proven to be effective tools in apple and cherry and should be considered for crop load management strategies that include bloom thinning. These aren’t your dad’s 12-foot monster blades or big, old, rope thinners.

Mechanization of these orchard tasks may be new to us, but we have only to look around the world to know that these tools are a viable option. This is not rocket science. We have the systems, we have the tools—we just need to make a mindful study of the application and work diligently on the integration. While it is true that these mechanical solutions will not work in the vast majority of our bearing orchard acres, most will work in most newly established blocks. Growers need to put opportunities for mechanization near the top of the list as they design and develop new orchard blocks.

4 Decision-aid systems

With increasing demands on their time and management skills, growers and field staff are relying on Internet-based systems to help them make management decisions in the areas of horticulture, crop thinning, pest management, or water management. The Washington State University Decision Aid System (DAS), and the WSU Ag Weather Network (AWN) are two systems that represent the best of what is required to meet the evolving needs and possibilities when developing, operating and delivering a decision-aid system. These systems have the winning combination of validated models and robustness. Everyone in central Washington, and I mean everyone, can access reliable data 24/7/365 on multiple devices.

These user-friendly, site-based decision-aid systems equip consultants and growers with timely information and allow them to be better at what they do day in and day out. It is all about making the best informed decisions.  It’s not always about getting the task done more efficiently, it’s about getting the task done and done on time. It would be difficult to be a consultant in Washington and not have DAS and AWN information. At the very least, you would not be very competitive.

5 New genetics

Genetics and plant material need to be included in all technology discussions. The number of varieties and rootstocks available to apple and cherry growers has grown tremendously in the past several years. Growers have the opportunity to select the best rootstock-scion combination for their site, giving them a head start at delivering a top quality product to their target market.

It gets very exciting when public breeding programs work with industry to release new varieties, like WA 38, SnapDragon, and RubyFrost apples. The soon-to-be named WA 38 is genetically equipped to reach its full potential when grown in the high-light, high-heat, and cold-winter climate of central Washington. We are on a path where site mitigation for hail, heat, cold, sun, shade is the becoming the new normal. It is a leap forward when you make breeding selections using criteria that would minimize (though not eliminate) some types or the amount of mitigation.

Great advances have been made in rootstock cultivars with selection emphasis on productivity, yield efficiency, disease and pest resistance, tolerance to extreme temperatures, and ease of nursery propagation. Rootstock breeding and field evaluation are critical to the industry’s long-term health. There are so many people from the public and private sectors working hard to develop and field-test new material. A tip of the hat to all of them because we benefit when we have a wide range of superior products to meet the diverse demand from an increasingly diverse population. The opportunities for delivering a repeatable excellent eating experience for consumers are much greater now. It’s a win-win for everyone along the chain from tree to table. •


Karen Lewis is Washington State University Extension specialist with the Center for Precision and Automated Agriculture.