The Florida Department of Citrus has identified the need for an alternative to the current hand-harvesting method for fresh-market citrus crops. Last year, several forums and technical meetings were held in Florida to discuss the need for and feasibility of a program to research and develop an automatic fruit harvester (AFH) system.
Dr. Thomas Burks, assistant professor, Agricultural and Biological Engineering Department at the University of Florida, has been appointed research leader for the citrus AFH robotics program. The goal was to establish a program to develop a robotic system capable of picking fresh market citrus and late-season Valencia oranges. However, after discussing the scope of harvesting needs with state fruit associations and the USDA, a broader scope for horticultural crop automation has emerged.
Foreign migrant workers represent the majority of hand-harvest laborers for the citrus, apple, avacado, peach, nectarine, pear, and plum industries. These industries are even more vulnerable to an unpredictable labor supply since Sept. 11. If there are fewer workers allowed into the country, the tree-fruit industry will experience a traumatic, economical setback.
Recent changes to free-trade markets and the threatened removal of import tariffs have caused U.S. producers of labor-intensive crops to lose market share due to higher U.S. production cost than those of developing (low-wage) countries. Additionally, per-unit labor costs have increased as a result of rising hourly wages, new labor regulations, additional worker benefits, and higher recruiting costs. A federal program to supply foreign workers is only a temporary solution, because unit labor costs are projected to increase by about 30% under such a program.
If the industry maintains the status quo for labor productivity and production cost, it appears they will be forced to downsize until they supply only smaller, high-priced, selective markets. This scenario would be a disaster for horticultural crop states in the United States where the production, packing, and processing infrastructure has been developed. Consumers will continue to purchase food, but U.S. growers would lose their share of the U.S. and world fruit markets. The tree-fruit industry must improve labor productivity and reduce the cost of production if they hope to remain competitive in local and world markets.
There have been several robotic tree-fruit harvesting efforts during the last two decades. In each case, projects were terminated due to low crop recovery (i.e. 75%) and low picking rates (slower than the hand picker) which did not increase labor productivity, economically justify the cost of the equipment, or reduce production cost. As a result of past, failed attempts, the Florida program has recognized that a robotic application, with as many complex design issues as fruit harvesting, requires technological expertise from multiple disciplines. Scientists and engineers from academia and the robotic industry indicate that there have been sufficient advances in sensing technologies, machine vision, computing capabilities, manipulator design and performance to justify a renewed effort in robotic fruit harvesting. However, there is not an off-the-shelf solution to several technological aspects of the AFH system. Although the technology has improved, a significant development program is required to integrate and implement a production-ready AFH system.
Compared to the 65-75% removal efficiency of past harvesters, we expect to successfully remove 92-95% of the fruit. Significant improvements in past sensing technologies must be realized. It is not likely that a single sensor will be able to achieve this level of improvement. However, several state-of-the-art sensor types and multiple sensor implementation scenarios offer significant improvement over past performance.
Common industrial robotic manipulators are available which appear to have cycle rates capable of meeting the AFH performance criteria. However, they are constructed for factory floor applications and are thus too heavy and bulky for a mobile application like the AFH. Smaller platforms may be necessary when developing harvesting systems for other tree fruits.
New technologies must be developed and implemented to modernize the U.S. horticultural crop industries so they become highly competitive in free-trade markets and are not dependent on a large, seasonal workforce. The appropriate course of action is to invest in research and development to create new, reliable production, harvesting, packing, and processing technologies that enable high labor productivity and low unit cost, and deliver high-quality, safe food products to both domestic and international markets.
We are actively seeking funding from several statewide and national sources to kick off a $7-10 million horticultural crop automated harvesting research program. Additional general research funding should also be made available for a broad range of automation research in production agriculture as a whole. A program of this magnitude will require a unified voice from the agricultural community, which not only identifies the need for such a program, but also demonstrates a willingness to participate in the development programs financially and through active lobbying efforts.
This effort will require U.S. horticultural commodity groups, academic and technical communities uniting to identify and integrate the technologies to produce a dependable harvesting system. Controlling system market costs will require that similar technology applications be adapted where possible.
We need federal support and funding to successfully produce automated harvesting systems. We need to identify all the horticultural associations and appropriate state and federal agricultural research agencies that would support a national AFH program. Contact your U.S. Senators and Congressmen to express the need for alternate harvesting and your support for a national AFH research and development program. It is important for the horticultural industry to unite around a national program.
Thomas Hardy, a consultant with the Florida Department of Citrus, can be reached by calling (850) 265-4914 or e-mail tchardy@bellsouth.net.
