Mechanical Harvest Goes Global

These days, fruit and nut growers of all stripes are looking for any edge when it comes to reducing costs and improving efficiency. In addition, increased scrutiny over immigration and the industry’s traditional labor supply has increased the interest among growers in advancements in mechanical harvest.

Because of the interest, the International Symposium on Mechanical Harvesting of Fruits and Nuts was hosted at the Citrus Research and Education Center in Lake Alfred, FL, in April. The gathering brought in 151 leading academics from around the world to discuss the latest development in mechanical harvest. Representation from Australia, Argentina, Brazil, Chile, Japan, South Africa, Spain, and the U.S. were in attendance.

The three-day event featured presentations on fruit and nut harvest, capped off by a field trip to see mechanical citrus harvest in action and a visit to a Mosaic phosphate mine.

“Over a year ago, the University of Florida/Institute of Food and Agricultural Sciences (UF/IFAS) Mechanical Harvesting Team felt like we had a real opportunity to exchange information with the major worldwide players in mechanical harvesting of fruits and nuts,” says Jim Syvertsen, UF/IFAS Horticultural Sciences. With this idea, Syvertsen and his colleagues organized the April gathering.

Labor Driving Change

Nobuyuki Iwai, UF/IFAS, presented a study on how immigration reform and citrus harvest mechanization are creating a world of uncertainty for growers. He noted that estimates show that more than 70% of Florida’s farm laborers are unauthorized.

With an increased push for reforms like stricter border enforcement and E-Verify, the state’s citrus growers have expressed growing concerns over labor availability and increasing harvest costs. Between this concern and increased costs due to diseases like HLB and canker and increased competition, growers are looking for any edge possible.

Iwai said that mechanical harvest could be part of the edge that growers are seeking. However, mechanical harvest of citrus in Florida remains low, estimated at only 7.1% of the total crop. Part of his research has been comparing the costs of traditional hand harvest versus different methods of mechanical harvest. His work shows that mechanical harvest is a less expensive means of gathering fruit for processing oranges.

Other presentations focused on work to commercialize an abscission agent for use on orange trees to compliment mechanical harvest. The lack of an agent partly accounts for the low rate of mechanical harvest. Mark Trimmer, with AgroSource, presented the status of his company’s work to register the abscission agent CMNP, which has been identified as the best alternative for use in citrus.

Some of the attributes that make CMNP attractive are it reduces mature fruit detachment force (FDF) by 75% or greater within three to four days of application and there is no leaf or blossom drop or FDF reduction observed in immature fruit. In addition, there are no adverse effects on return yield from repeated annual applications and juice quality (Percent acid and Brix) were not impacted by CMNP.

Another big negative from orange juice processors has been the amount of debris coming with mechanically harvested fruit to the juice plants. Trimmer says multiple studies show that CMNP is the answer to the debris issue. In fact, some studies show mechanically harvested citrus using CMNP came with equal or even less debris than hand harvested fruit.

Trimmer added that AgroSource has the license rights to develop, register, manufacture, and commercialize CMNP. He noted that there are a huge number of hurdles that must be cleared with EPA to receive registration for this product or any other product for that matter.

The product was submitted to EPA for Section 3 registration and tolerance in January 2011. Trimmer says EPA is actively reviewing the submission.

Future Of Innovation

Many of the presentations during the Symposium were forward looking at how entire production systems of fruits and nuts might be changed with mechanical harvest being a key component of those changes.

Dan Guyer and Mollie Woods, both from Michigan State University, presented “Revolutionizing Cherry Production Systems” during the event. Their study has focused on how automation of cherry production can help growers address the challenges of the day and remain economically viable.

Their research is looking at futuristic, higher-density approaches to planting tart cherry orchards. The system would encourage smaller plant types and allow over-the-top canopy shaking harvest machines. The researchers looked at several harvesters including the Korvan from OXBO. It is a commercial blueberry harvester without any modifications made. The results were positive using these spindle/tine shakers. They noted fruit removal was very good except for strictly horizontal branches and fruit quality was very good with high grades.

Matthew Whiting, Washington State University, presented his study on tree fruit architecture of the future. His vision involves cherry orchards of the future that are highly trained and upright, which make them good candidates for mechanical harvest.

He calls his system upright fruiting offshoots (UFO) production, which applies a systematic approach to pruning and training plants and facilitates a precision canopy and crop management. This system allows for high input efficiency and minimizes the environmental footprints of the orchard of the future.

The key to the system is the tight, upright fruiting walls which facilitate the addition of new technologies including mechanical harvest. Trees are planted at 45-degree angles and then trained on a trellis laterally to fill the spaces in between each plant.

Getting Together Again

Syvertsen says the International Symposium On Mechanical Harvesting of Fruits and Nuts was a huge success, bringing together some of the best minds and ideas on this area from around the world. “The attendees agreed that a meeting of this scope should be held again in three years,” he says. “Researchers from Washington State University have volunteered to host the next International gathering.”

To view all the presentations from this year’s symposium, visit http://www.crec.ifas.ufl.edu.