Submitted to: American Society of Agricultural Engineers Meetings Papers
Publication Type: Proceedings
Publication Acceptance Date: 7/9/2000
Publication Date: 7/12/2000
Citation: Willoughby, R.A., Solie, J.B., Whitney, R.W., Maness, N.O., Buser, M.D. 2000. A mechanical harvester for marigold flowers. American Society of Agricultural Engineers Meetings Papers. Paper #001062. 13pp.
Interpretive Summary: Marigolds for xanthophyll production are primarily grown in Mexico, India, Peru, and Third World Countries and imported into the United States for chemical processing. Xanthophyll is a yellow-gold pigment found in marigold petals in high concentrations. These pigments are used as an additive in poultry rations, dog food, and multi-vitamins, and as a natural lfood colorant in dairy products. Other countries are able to produce marigolds cheaper than the United States, since the crop is primarily harvested by hand. In order for U. S. farmers to economically produce marigolds, a relatively efficient harvester than can harvest the flowers with limited plant damage is required so that multiple crops can be harvested during a single season. Two different mechanical header systems were developed and tested for harvesting marigolds. One design uses extendable fingers mounted in a drum and the other uses solid-mounted fingers to pluck the flowers from the plant. Both headers were designed with rigid fingers to remove marigold flowers from the plants without permanently damaging the plant. By limiting the plant damage during harvesting, multiple crops were harvested from the same plants during the same season. The extendable finger design produced a slightly higher picking efficiency but the current design limited the potential ground speed for the overall machine, as compared to the solid mounted finger design. Additional work will focus on increasing the overall efficiency of the solid mounted finger design. The overall efficiency of this design is approximately 50 to 60 percent and can be increased by modifications to the conveyance system. Mechanically harvesting marigolds is essential in justifying the economics of bringing this alternative crop to the U. S.
Technical Abstract: Marigold flowers are harvested for xanthophyll pigments, which are found in the petals. These yellow-gold pigments are present in the petals at concentrations of 10 to 100 times that found in other sources. Xanthophyll pigments are used as an additive in poultry rations, dog food, and multi-vitamins and as a natural food colorant in dairy products. Currently, most marigolds for production purposes are grown in Mexico and Third World Countries, since the crop is generally harvested by hand. Development of a mechanical harvester is essential in bringing this alternative crop into production in the United States. Two different header systems were developed. One design used extendable fingers mounted in a drum and the other used solid-mounted fingers to pluck the flowers from the plants. The extendable finger design produced a slightly higher picking efficiency but the current design limited the potential ground speed for the overall machine, as compared to the solid mounted finger design. The overall efficiencies of the headers were substantially lower than the picking efficiencies and additional design work will need to be completed to decrease the losses associated with collecting the flowers after they are picked.