History of Mechanical Citrus Harvesting
1990 to 2008
Trunk Shake & Trunk Shake Catch Harvest Systems
Several companies developed trunk shake catchframe harvest systems & 2 companies developed monoboom trunk shakers. In general, these trunk shake catchframe harvest systems consisted of 2 self-propelled units (each with 1 operator) & operated in the 2-row bedded groves in South Florida. The shaker unit operated in the ditch middle with a deflector frame that diverted fruit to the receiver unit on the opposite side of the tree or row. The receiver unit operated in the middle on top of the bed & initially conveyed harvested fruit into 10 box containers, tubs or flexible containers. Later designs conveyed the collected fruit into a towed, bulk fruit storage trailer. When the trailer was full, the fruit was dumped into a standard goat truck for delivery to the roadside tractor trailer. The harvesting units were mounted either on rubber tires or rubber tracks, with rubber tracks offering a traction advantage for towing the bulk storage trailer & when driving through muddy &/or difficult ditch conditions. When it could be arranged, the most economical configuration was usually 1 goat truck to service 2 harvest systems for a total of 5 operators/drivers.
FHI - Before the FDOC harvesting program was underway, Fruit Harvesters International (FHI - Alva, FL) demonstrated in 1994 that their newly designed trunk shakers could achieve orange removals in the 90% range. They worked independent of the FDOC & were the first company to introduce trunk shake catchframe mechanical harvesting systems in 1993 (2-1). Eventually they had 10 systems (See Photo A, Photo B, Video A, Video B), each with 2 self-propelled units on rubber tracks. Lateral conveyors on the receiver unit moved the collected fruit to a longitudinal conveyor which delivered fruit to the towed, fruit storage trailer For these systems (or any other shake catch system) to operate effectively, the trees had to be skirted (lower tree limbs removed). Growers resisted tree skirting because of concerns of cost & lost fruit yield. Growers were also concerned about the long term yield effects of trunk bark damage & root exposure resulting from the vigorous shaking of the trunk shaker. Laborers were required to follow the mechanical harvesters to glean fruit remaining in the tree & on the ground, which was estimated to be 10 to 15% of the yield. FHI declared bankruptcy in the 1990-2000 season.
Compton – Under a 1995 FDOC contract, Compton Enterprises, Inc., CA, built a trunk shake catchframe mechanical harvesting system for the 1996-97 season with the units mounted on rubber tires (See Photo A, Photo B, Video A, Video B). Commercial trunk shakers manufactured in California for the tree nut & fruit industries generally achieved inadequate orange removals (70-80%). Compton’s shaker head was redesigned similar to Drs. Brown & Whitney’s suggestions, in which increased unbalanced mass, wheel diameter & eccentricity for larger displacements at lower frequencies, removed 63 to 98% of the oranges. Fruit removal was directly related to trunk displacement. Design of the first receiver unit used a longitudinal pan near the trunk line which dumped collected fruit onto an adjacent longitudinal conveyor. Because of the pan width & low skirting height, dumping the fruit in the pan onto the conveyor was found to be difficult without sometimes moving the receiver unit away from the tree row line. The receiver was redesigned to incorporate lateral conveyors to move the collected fruit to the longitudinal conveyor (See Photo, Video). During the 1997-98 season, ~ 20,000 boxes of oranges were harvested & field tests (2-2) showed 84 to 95% of the oranges were removed shaking 5 to 10 s per tree with machine capacities up to 10 t/h. Compton continued to promote the harvest system for sale/lease until the 2000-01 season when he discontinued development/promotion without a sale or lease.
Coe – Independent of the FDOC, Coe Orchard Equipment Manufacturing (currently at Live Oak, CA) began development of a system in 1996. They worked with Barron Collier Co. in Immokalee & formed Coe-Collier Citrus Harvesting LLP. Each self-propelled unit was mounted on rubber tires (See Photo, Video). It was probably the best known trunk shake catchframe harvesting system with the higher harvesting capacities. As many as 15 of these harvest systems were manufactured & harvested 6500 acres in various groves including Barron Collier during the 2001-02 season. These systems continued to operate in later seasons. However, only a few of these systems remained in operation in the 2006-07 harvest season & Coe Orchard Equipment Co. discontinued manufacturing them.
FMC - Also independent of the FDOC, FMC Food Tech (Lakeland, FL) began development of a trunk shake catch harvest system during the 2001-02 season. Their units were mounted on a prime mover (rubber tracks) provided by another manufacturer (See Photo A, Photo B, Video A, Video B). The harvest system was leased to US Sugar Corp. in their groves South of Clewiston, but development ceased during the 2005-06 season when apparently machine reliability & hiring reliable machine operators were problems.
Orchard Rite – This was a monoboom trunk shaker without a catchframe. Stackhouse Brothers Harvesting (Hickman, CA) brought a self-propelled, monoboom Orchard Rite (Orchard Rite Inc. Ltd., Yakima, WA) trunk/scaffold shaker (See Photo, Video) to Florida during the 1999-2000 season. It was used to shake fruit onto the ground for pickup by manual harvesters. No tree skirting was normally required to use this shaker & it could be used effectively on larger, taller, nonuniform trees which were incompatible for catchframe use. Some of the shaker heads were outfitted with long clamp pads that could be inserted into the tree canopy for scaffold or limb shaking when short or inadequate trunk height prevented effective trunk shaking. For fruit removal, the shaker operator would normally back the machine down the middle between 2 adjacent tree rows, shaking the trees in both rows. This procedure minimized the problem of running over fruit which had been shaken off the trees. A few of these shakers operated through the 2001-02 season when they were no longer used because of the general preference for pull behind continuous travel canopy shake machines.
OMC – The FDOC provided funding for OMC (Orchard Machinery Corporation, Yuba City, CA) to develop a monoboom trunk shaker (See Photo) for field testing during 1995-96. This shaker was handled & operated through dealer Pat Rosales, Orchard Grove & Machinery Corporation, Albany, GA. After Mr. Rosales’ untimely death, OMC discontinued development of the shaker.
Referenced Articles
2-1 A Review of Citrus Harvesting in Florida
2-2 Field Test Results with Mechanical Harvesting Equipment in Florida Oranges
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