REMOVING ONE MORE BAR TO LARGE-SCALE PRODUCTION OF HERBS AND SPICES

March 12, 2003

One of the factors limiting growth of Saskatchewan's herb and spice industry has been the harvesting of flowering medicinal plants: hand-picking the blossoms and specialty plant parts, a method that is expensive, inconsistent and time-consuming.

According to a senior partner in the Saskatoon company Ben-Don Innovations Inc. (BDI), however, that limitation has been mitigated by his company's design for a harvesting unit that is adaptable to a variety of herbal crops, and "provides an excellent starting point for the mass production of a commercially available unit."

Ben Voss says the successful production of medicinal plants is highly dependent on the ability to harvest and prepare the product according to the desires of the end market. He says volume, throughput, moisture content and size of product are some of the important considerations, so new harvesting equipment technology is only one key to enabling large-scale medicinal herb production.

"In order for field scale production to be cost-effective and viable, post-harvest cleaning and processing are also necessary. Contamination by leaves, stems, weeds or other material must be removed, cut or separated from the desired product, in order to secure higher prices and increase the likelihood of production success in the future," says Voss.

The three-year project undertaken by BDI, therefore, researched, developed, designed, built, tested and reported on the machines needed to harvest and process flowering medicinal plants in Saskatchewan, specifically chamomile, St. John's wort, calendula and red clover. Based on producer interest and market demand, however, chamomile and red clover became the primary focus. The project was supported by the Agriculture Development Fund (ADF.)

Two harvester prototypes were initially fabricated: one self-propelled and one a pull type. Two years of testing resulted in a modified pull-type harvester that was adaptable to a variety of herbal crops and production processes. It harvests only mature blossoms, allowing the immature blossoms to grow and mature until they too can be harvested.

BDI also designed and built a sorting unit, which removed contaminants such as leaves, stems and weeds in the crop. Voss says it is best operated on freshly harvested product because the handling of green product is less damaging to the blossoms than handling a dry product, and removing contaminants prior to drying significantly reduces the demand on the dryer.

A third piece of equipment, a trimmer, was developed specifically for chamomile, but Voss says the design principle could be modified for other crops as well. It trimmed 80 per cent of the stems exceeding the allowable length.

The production of medicinal plants was also addressed because of its effect on harvesting. Voss says production of flowering medicinal plants in a field-scale setting provides only two major options - row cropping or full-field planting - both of which have merits. But he says it was determined that row-cropping has several advantages in terms of quality, consistency, content of foreign material and harvestability. Test sites were established at various locations throughout the province but drought conditions killed many of them. Still, says Voss, BDI collected enough data to provide beneficial information to Saskatchewan producers.

The prototype built by BDI was successfully used by producers during the 2003 season, and Voss says other producers could make use of the technology as well. He suggests growers interested in building a unit based on the BDI design should contact him at 306-931-2610 in Saskatoon.

A copy of the ADF project Development of Production, Harvesting and Value-Added Processes and Equipment for Flowering Medicinal Herbs in Saskatchewan, # 19990313, may be obtained by phoning 306-787-5929 in Regina. The final report is also available on Saskatchewan Agriculture, Food and Rural Revitalization's Web site.