Small Mechanical Harvester for Edamame and Green Bean Production

Final Report for FNC13-927

Project Type: Farmer/Rancher
Funds awarded in 2013: $7,481.90
Projected End Date: 12/31/2015
Grant Recipient: Mary Ellen Raymond farm
Region: North Central
State: Missouri
Project Coordinator:
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Project Information


This SARE Farmer Rancher grant supported the design and construction of a small edamame or green bean picker. Bean or edamame picking by hand is very slow and limits market growth for small growers. Equipment is available for large growers, but there are no small-scale pickers available for the thousands of small producers that are struggling to make a living by selling for the fresh market. A lack of commercial interest spurs the need for farmer innovation and research into this problem, which affects the viability and sustainability of small growers throughout the north central region. Harvest equipment needs to be designed and manufactured with small growers in mind since most fresh, local produce comes from small farms. Having mechanical harvest options will help raise on-farm income for small growers and ease their workloads, making it more likely that they will be able to continue to produce fresh, local food. This project spurred interest in the small bean picker by two commercial companies. One is Gnismer Farm Equipment ( in Riesel, Texas and the other is Marshall Prototyping and Machining ( in Columbia, Missouri, who were also responsible for the design of this prototype.


Most edamame in the United States is imported for the frozen food market. Local US production for the fresh food market is growing, but is limited by harvest methods. Edamame can be harvested with a mechanical green bean picker, but commercially available bean pickers are not economically viable for use on small farms.  A used Oxbo pull-type bean picker can cost $20,000 and is approximately 16 feet long, making it too large and cumbersome to use on a small farm, as well as too expensive. Picking edamame and bush type green beans by hand is very laborious, not cost effective and not sustainable. Although demand is high and prices can be fairly good for edamame ($8/lb at farmer’s markets), the selling price does not support the cost of harvest labor. This is unfortunate because edamame is very popular amongst children and an excellent healthy substitute for snack foods, such as chips. Making edamame and bean production more feasible and productive for small growers will help raise farm incomes, keep small farmers in business, produce locally available vegetables and provide healthy foods to consumers.

To provide the ability to mechanically harvest edamame and bush beans, Ethan Marshall designed and constructed a new bean picker for small farmers. The design is semi-compact, relatively easy to build for someone with fabrication experience and easy to operate (diagram attached). The cost of materials for the bean picker was $7000. Many of the parts were machined by hand by Ethan, but if the design is picked up by a commercial fabricator or replicated by other farmers, design modifications could allow use of commercially available parts, eliminating the need for custom machining.

Project Objectives:

The primary objective of this research was to make edamame and bean production more feasible and productive for small growers thereby leading to increased farm incomes, keeping small farmers in business, producing locally available vegetables and providing healthy foods to consumers. This was accomplished by designing and constructing a prototype bean picker for use by small growers.


Materials and methods:

The harvester was designed using a software program called Solid Works and the plans can only be opened using that software program. Pdfs can be made available upon request.

The harvester was finished in the summer of 2014 and tested in the field that year.

To compare harvest speed, rows of edamame soybean were hand harvested and compared to the amount of time it took the bean picker to harvest a similar length row. Mechanical damage was also compared between the two harvest methods.

Research results and discussion:

The picker is approximately 10 feet long (not including tongue) and hydraulically operated. The reel is designed to finger through the plants, pulling both the beans and the leaves onto the conveyor belt. The conveyor assembly uses two 12-inch ribbed belts and carries the beans from the reel to sacks or a small wagon pulled behind the harvester. Because of cost overruns and time constraints, the winnowing fan was not put on the prototype. The wheels are adjustable so the user can move the conveyor closer or farther away from the ground. The harvester turned out a little large for growers with small edamame plots. Recommended size for this harvester is one acre or more of edamame or beans. Smaller growers may want to consider a table-top picker where whole plants are fed into the machine and pods are separated from the stem. Photos of the finished harvester are attached.

Parameters for measuring the success of the project include changes in yield due to increased harvest capacity and decreases in amount of time spent on harvest. Hand harvested edamame requires about one hour to obtain 8 pounds. The edamame harvester picked 8 pounds of edamame pods in 2 minutes. Mechanical damage to the pods was less than 5%. The harvester is capable of picking an acre of edamame in approximately 5 hours compared to 871 man hours for hand harvesting one acre of edamame beans. It pulled approximately 95% of the pods off the plants.

Impact of Results/Outcomes

The harvester was designed and constructed in 2014 and tested in the field that summer. Modifications were made to the picking fingers after it was determined that harvest was not being accomplished. Testing was accomplished to compare harvest times and pod damage to hand harvest. Videos of the harvester were made and posted to YouTube and outreach was accomplished in 2014-2015. The harvester will be used for full production by Mary Ellen Raymond in 2015.

Participation Summary

Educational & Outreach Activities

Participation Summary:

Education/outreach description:

We made a presentation on the bean picker at the Bradford Research Center Organic Field Day in 2014. This event had about 75 attendees, including Extension personnel and producers. We presented a poster on the picker at the 2015 Great Plains Vegetable Growers Conference (audience approximately 300 vegetable growers from Kansas, Missouri, Iowa and Nebraska) and the Missouri Organic Association Conference (audience approximately 300 organic producers from Missouri and neighboring states). A video of the harvester was posted on YouTube ( After it goes into full use in 2015, we will serve as a case study for one article in the Lincoln University Innovative Small Farm Outreach Program newsletter, which goes out statewide to small and urban farmers.

Project Outcomes


Potential Contributions

This project spurred interest in the small bean picker by two commercial companies. One is Gnismer Farm Equipment ( in Riesel, Texas and the other is Marshall Prototyping and Machining ( in Columbia, Missouri, who were also responsible for the design of this prototype. If developed commercially, the harvester could become a very useful tool for the many small produce growers in the North Central region.

Future Recommendations

We recommend that SARE continue to fund equipment innovations for small farmers and work to connect farmers with commercial equipment manufacturers who are interested in producing technologies for smallholder agricultural production.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.