Advanced Trellis Methods and Mechanical Harvesting for Grape Tomatoes

Advanced Trellis Methods and Mechanical Harvesting for Grape Tomatoes

Summary

Grape tomatoes are tough when compared to cherry tomatoes and the market for grape tomatoes is the fastest growing segment of the tomato market. The labor involved in harvesting can be a huge challenge both as an expense and in simply getting enough labor. In a proof of concept trial in 2008, it became apparent that grape tomatoes showed some promise as a machine harvested crop through shaking and sorting later in a cool location out of the sun.
Three trellis systems were installed on the Penn State Southeast Research and Extension Center (SEAREC) and at the Dickinson College Farm. Each system was planted with 2 varieties of non-determinant red grape tomatoes. These systems were showcased at on-farm meetings at both sites with over 155 growers participating in meetings. While the trellis systems still require some modification, the shaker apparatus worked very well. Growers at both meetings offered their advice on how to improve the system. There is little doubt that specific varieties of grape tomatoes show great promise in being able to be shaker harvested.

Objectives/Performance Targets

• -Develop farm-ready, economical, trellis system(s) for grape tomatoes that can will work well with simple shaker apparatus.

  -Develop an inexpensive shaker apparatus for tomato vines that is accessible to small farmers.

  -Create presentations, demonstrations and publications to encourage the adoption of this technology should it prove workable.

Accomplishments/Milestones

In 2009, we installed 3 trellis systems at both the Penn State Southeast Research and Extension Center (SEAREC)Manheim, PA, and at the Dickinson College Farm, Mt Holly Springs, PA. Trellis systems: 1) Standard upright “I” trellis using a modified Florida weave. 2) “V” trellis system using T posts and ½” rebar with 4’ Tenax Hortonova stretched between. And 3) Angled or incline trellis using T posts and ½” rebar at a 30 degree angle with 5’ Tenax Hortonova stretched between. We also developed a shaker mechanism using a simple hook welded onto a blade that fit into a battery powered reciprocating saw.

Several lessons immediately came out of this years’ trellis methods: 1) The Tenax Hortonova not only stretches too much under the weight of the tomato vines and fruit, but prevents good vine management (translation: the vines got far too tangled). 2) The Florida weave upright trellis not only shook the best, but also provided the best vine management. Still, getting all of the grape tomatoes from under this system was challenging as many fruit fell between the collection tarps. 3) Our shaker mechanism was nearly perfect and very simple.
We demonstrated these plantings and the harvester at growers meetings at both farms and found growers very interested in the system and in offering their advice on how to solve the problems with the trellis. All of the growers appreciated the simplicity and usefulness of the reciprocating saw / shaker.

For the 2010 season, we are going to install a modified “V” trellis using most of the materials from last years’ trial, but narrowing the spread on the trellis to 7 degrees off center in both directions and using a modified Florida weave. This system will keep the weight over the center and the vines well-organized.

Impacts and Contributions/Outcomes

The greatest impact of the work has been the development of the shaker mechanism and the interest in exploring mechanical harvesting versus hand harvesting for grape tomatoes. Since we have only solved part of the puzzle, the full outcome of this project has yet to be determined.

• Battery powered reciprocating saw modified with a hook arc welded to a used blade.
• View of the 3 trellis systems at the Dickinson College Farm

Collaborators: