The 1995 BIORESOURCE HEMP
Symposium: An Overview
Michael Karus1 and Gero Leson2
1. nova. - Institute for Political and Ecological Innovation, Cologne, Germany
2. nova - Institute for Political and Ecological Innovation, Santa Monica, USA
The BIORESOURCE HEMP
technological and scientific symposium was held the by nova-Institute from March 2nd-5th
in Frankfurt, Germany. Our objectives were to provide researchers and businesses
from around the world with an opportunity to access recent developments in research,
technology, and markets for industrial hemp, to finally talk in person with their
counterparts from other countries and to inspect the range of hemp based products and
technologies now offered by various vendors. For the latter purpose, the symposium
was held in conjunction with BIORESOURCE HEMP, a trade show composed of 42 exhibitors from
9 different countries, including 35 developers, manufacturers, and distributors of hemp
products, as well as 7 research and other educational organizations. This was part
of the BIOF-ACH '95, the largest worldwide exhibition of ecological products, with 900
exhibitors and 16,500 visiting trade members.
In our opinion, the symposium was rather successful. The respected Hungarian hemp breeder Professor Ivan Bocsa referred to it as "the greatest conference in the history of hemp." 250 participants, predominantly researchers, from more than 20 countries attended, including scientists and engineers, developers of hemp based products, and journalists. The high level of interest was also apparent from the fact that only one of the 59 invited speakers from 15 countries canceled - a Chinese researcher who could not obtain a visa. 'Audience retention', usually in rapid decline during the afternoons of scientific conferences, remained high into the early evenings. In addition, several larger and smaller meetings were spontaneously organized during the conference. Our initial review of the results and contacts that were generated at the event suggests that BIORESOURCE HEMP, in addition to disseminating information on current and potential future industrial uses of hemp, helped establish the basis for several promising research and business cooperations.
First Day, March 2nd:
The six introductory talks discussed various facets of the recent rapid growth of the interest in, and cultivation and processing of, hemp. They included experiences made by industry, agricultural driving forces, and the objectives of two major associations involved in the science, politics and educational side of hemp.
Jurgen Schlegelmilch (Schneidersohn Papier, Germany) gave his account of the recent reintroduction of hemp into the German paper industry, the genesis of which was the Zweitausendeins Publishing Company's interest in printing the German translation of Jack Herer's book on hemp paper. Schlegelmilch accepted the challenge, faced and overcame all conceivable logistical and technical hurdles of the acquisition of hemp pulp and producing paper from it. Initially laughed at by their colleagues, Schneidersohne, the largest paper distributor in Germany, now offers a complete line of offset, writing and high quality art paper based on 100% hemp or hemp blended with recycled fiber. The pulp is produced in Spain. "Considering its generally slow and tradition oriented nature, you may imagine what it meant to me when the trade association of the German paper industry told me last week, that it would print its annual report on hemp paper, because they realized that this was truly innovative," Schlegelmilch said. Klaus Rehder (Member Agricultural Committee, European Parliament, Germany) pointed out the important role of renewable crops in the agricultural program of the European Union (EU). "EU guidelines from 1984 and 1986 permit the cultivation of hemp varieties containing less than 0.3 percent by weight of tetrahydrocannabinol (THC) in the upper third of the plant. The 12 French and Italian varieties certified in the EU are eligible for EU subsidies of approximately 1,500 DM/ha. Rehder demanded that the German federal government lift the current prohibition on hemp cultivation and establish regulations in concurrence with EU guidelines. According to Dieter Bockey (Deutscher Bauern-verband, German Farmers Association) his organization sees the establishment of a political framework which allows for a resurgence in renewable crops as a high priority. To reduce excess food production, in 1994 approximately 1.6 million ha of agricultural land were left fallow in Germany (7.1 million ha EU-wide, with long-term projections of 4.5 and 18 million ha, respectively). These areas are available for the production of non-food crops of which an estimated 450,000 ha will be grown in Germany in 1995. Despite its versatility, hemp is currently excluded from this development. Accordingly, the Farmers Association advocates modification of the German drug control law to permit cultivation of low-THC varieties. Bockey stated that "... this event is not least the result of a comprehensive campaign to make hemp publicly acceptable. Rarely has a renewable crop been supported so intensely by groups outside of the agricultural sector."
Robert Clarke (International Hemp Association, Amsterdam) introduced the IHA. It was set up to facilitate communication among those interested in factual information about Cannabis, and to advance the beneficial uses of hemp based products. Since its creation in 1992, the IHA has sponsored several programs in Russia, China, Hungary and the Netherlands. These programs center around the issues of germplasm collection and conservation, hemp fiber identification, hemp product quality control, the conservation of historical Cannabis-related artifacts, the creation of a Cannabis database, and the publishing of the IHA journal. He considers the IHA`s currently most important project to be the annual humanitarian aid grant to the Vavilov Research Institute in St. Petersburg, Russia, to support the maintenance of its Cannabis germplasm collection (see below).
Matthias Brockers, president of the German Hanfgesellschaft (Hemp Society, Berlin) introduced the group which was founded in February 1994. Founding members include farmers, agro-cooperatives and entrepreneurs who anticipate a considerable market potential for hemp based products as part of an ecologically sustainable economy. Its primary goal is the reintegration of hemp into farming and industrial processing. Consequently, the Hemp Society supports a currently pending lawsuit by farmers over permission to cultivate hemp on 110 ha in the Berlin area. The society also publishes information brochures and a bi-monthly "Hemp Bulletin" for its members, and focuses on media relations and public education.
The Rediscovery of
Hemp-Status Reports from
The rest of the first day was
devoted to status reports from 12 of hemp's main producer and user countries from all
continents, except for Africa. They included countries which do currently not
cultivate hemp but represent strong (potential) markets (North America, Australia,
Germany), those who have traditionally maintained domestic hemp industries (Eastern
Europe, China, France) and countries which have recently rediscovered the cultivation and
processing of hemp (The Netherlands, England, Switzerland).
Ken Friedman (Hemp Industries Association, USA) gave an overview of the current status of the hemp industry in the U.S. While demand for hemp based textiles, paper, and oil products has grown considerably since the late 1980s with estimated total retail sales of US $4 million and US $10 million in 1994 and 95, respectively, the U.S. hemp industry faces several problems. The lack of a domestic supply of hemp fibers combined with shortages on international markets results in competition over supplies and drives up the costs of raw materials. At the same time, the hemp industry is still struggling to overcome its image of being purely "drug driven" and to educate the public of the ecological and technical advantages of hemp based products. While the recent formation of a task force on hemp by the Governor of Kentucky is a hopeful sign that some governmental entities are beginning to take a more rational approach to the use of low-THC hemp, the defeat by the federal drug enforcement administration of a similar legislative attempt at legalizing hemp cultivation in Colorado, also points out the existing political obstacles. Accordingly, the Hemp Industries Association sees the education of the general public and public officials through cooperation with the media as one of its main responsibilities if the U.S. is not to fall behind in the areas of farming and development of innovative processing technologies and products.
Gordon Reichert (Department of Agriculture and Agri-Food, Canada) pointed out some of the factors motivating the renewed Canadian interest in hemp. They include shortages and price increases for traditional raw materials, such as wood chips for pulp production; increasing interest within Canadian agriculture towards industrial crops; an increase in environmental awareness among consumers, and the government's interest in developing new crops and processing technologies for the creation of jobs in agriculture and industry. The cultivation of low-THC hemp for research purposes only is currently legal in Canada but involves a cumbersome licensing process with the Ministry of Health. However, recognizing its potential benefits for the domestic economy, federal and provincial governments have begun in earnest to embrace the re-establishment of industrial hemp. A license to cultivate the first legal hemp crop in nearly 40 years was granted in 1994 to a private firm, Hempline, Inc. Private and cooperative research focuses on the agronomic and economic benefits of industrial hemp. Reichert stated that long-term political and financial commitments from federal and provincial governments which have not yet been made will be crucial to the re-establishment of a domestic hemp industry. Recent issuance by the Health Ministry of some 6 licenses to grow hemp in 1995 is a hopeful sign that Canada may be moving cautiously towards the reintegration of hemp into its economy.
Shaun Lisson (University of Tasmania, Australia) presented a somewhat similar picture for Australia, where hemp related activities have recently gained considerable momentum despite the lack of a domestic hemp industry. Field and laboratory trials are underway in Tasmania and Southern Australia to assess hemp's use for reinforcement of wood and straw based pulp. This may allow the replacement of imported softwood-based Kraft pulp, of which 20,000 tons per annum are used to reinforce pulp for newsprint. Two major pulp and paper firms have highlighted the potential for mechanical pulping of hemp and expressed the need for further pulping trials. Their main goal is to assess the potential of hemp, and possibly flax, for pulping in existing equipment to produce economically pulp able to replace the imported Kraft supplement. Also, in response to growing demand, hemp-based merchandise manufactured entirely, or in part, overseas (China, Hungary, USA, England) is now available in all major cities. Retailers have expressed a strong interest in raw material grown and processed domestically.
Ryszard Kozlowski (Institute of Natural Fibres, Poland) presented results from the cultivation of two domestic varieties, Bialobrzeskie and Beniko. In the Polish climate, typical yields of 10 tons/ha of hemp straw with a 27-29% (Beniko) fiber content and 500 kg/ha of seeds can be achieved. Fiber yields per hectare have almost doubled since the 1950s. The THC content of the Bialobrzeskie variety is below 0.01%. For optimum growth, hemp requires a fertile, deep soil, rich in minerals and humus. In crop rotation, hemp is best grown after perennial leguminous plants or small grains fertilized in Autumn with 20-30 tons of manure/ha, or following root or tuber crops fertilized with manure. Hemp uses both mineral and organically bound fertilizers efficiently. As optimum rates of fertilization, Kozlowski suggested 90-120 kg/ha nitrogen (N), 150-180 kg/ha of K20, and 70-100 kg/ha of phosphate (P205). Optimum seed usage for fiber hemp is 60-70 kg of seeds/ha with a row spacing of 15-20 cm. Russian equipment is used for harvesting, followed by dew-retting in the field. Subsequent processing involves a drier, braking machine, scutchers and shakers, all manufactured domestically by the Notec Company. Coarse hemp yarns (Nm 2-Nm 5) from pure hemp are predominantly spun in Poland.
Approximately 3,000 ha of hemp are under commercial cultivation with plans for an additional 2,500 ha for the production of cellulose by the CELLINEN company. Kozlowski estimated that, in the Polish climate, hemp's annual biomass yield could be 2-3 times that from trees.
Pavel Goloborodko (Institute of Bast Crops, Ukraine) reported on the current status of hemp industry and research in Ukraine. Until the 1950s, hemp was grown for fiber and oil on more than 150,000 ha for industrial products, but also by peasants for cloth and household goods. Due to competition from cotton and synthetic fibers, this area fell to 4,000 in 1994, but is expected to rebound in 1995. Hemp is currently used exclusively for technical products, such as cordage for ships, ropes, cores for steel ropes, twines, and technical clothes.
The Institute of Bast Crops has researched anatomy, biology, physiology, selection, genetics, harvesting and processing of hemp for 60 years. Intensive breeding has increased fiber content from an initial 12-15% to over 30% in some varieties. Since Ukraine's independence in 1992, the Institute has established a genetic fund of bast crops. It currently contains 211 dioecious and 72 monoecious varieties, each of which is cataloged by fiber and cannabinoid content, stem and seed yield, plant height, length of vegetative cycle, and resistance to diseases and pests.
Hemp is usually grown on large areas in rotation with cereal and root-crops. If grown for fiber and seed, hemp is harvested with a combine which cuts, thrashes and cleans seeds, and binds or spreads stems. Hemp grown for fiber only is harvested with a cutter which spreads stems out for dew retting. Goloborodko expects that domestic use of hemp in the pulp and textile industries will soon rise considerably, given the current shortages in the supply of wood resources and the lack of domestically grown cotton and its high price on the world market. This will involve the establishment of a domestic textile industry based on flax and hemp, potentially blended with other natural or synthetic fibers. JIHA, 2(1)
John Masura (Krasnohirska, Ukraine) discussed the considerable structural, organizational and communication problems involved in establishing a private enterprise in Ukraine for the cultivation, processing and export of hemp. However, eight private Ukrainian farmers in 1994 formed such a venture, called Krasnohirska, a new phenomenon for the former Soviet Union. Aware of the range of nontraditional applications for hemp and the growing demand in the West, they grew hemp on 1,000 ha without a single confirmed buyer. Masura perceived that the biggest threat to the developing private hemp industry is that government may try to step in and control it once it seems to be profitable.
Stanislav Shulga (Russian Institute of Land Use and Erosion Protection) gave an overview of the traditional hemp cultivation in the Kursk Region. In the 18th century, hemp was grown on most farms for the production of textiles and seed oil. The cultivation of hemp (~30,000 ha in the 1950s) began to decline in the 1960s, and fell to 9,200 ha in 1970, and 1,500 in 1994. Fertilization tests conducted by the institute using 30 t/ha of manure yielded 7 t/ha of dry stalks and 590 kg/ha of seeds producing 190 kg/ha of oil. Using 80 t/ha of manure yielded 1.2 t/ha of high quality fiber. A typical five-year crop rotation in Kursk involves oat and clover in the first, clover in the second, hemp in the third, potatoes in the fourth, and hemp in the fifth year. Since technical know-how and the equipment for harvesting and processing are still available, Shulga expressed confidence that the cultivation of hemp in the Kursk Region could be expanded considerably if demand increases.
Robert Clarke (IHA, Amsterdam) reviewed the history of hemp cultivation in the Tai'an District of Shandong Province in the People's Republic of China and demonstrated, supported by impressive slides, the cultivation and processing techniques currently used. Hemp cultivation in China dates back more than 5,000 years. Until recently, hemp was processed almost entirely by traditional methods. However, a modern degumming, spinning, and weaving mill was constructed in 1987. In 1993, a Chinese-American joint venture, established for production and export of textiles, invested in the mill and initiated changes to cultivation, market structure and processing of hemp.
While Shandong Province produced more than 100,000 tons per annum of hemp fiber in the early 1980s, production fell to less than 8,000 tons per annum in 1993, grown on 4,200 ha. Because of the high plant densities for fiber hemp, weeding is only required for the more widely spaced plants grown for seed production. Because of the low susceptibility of hemp to serious pests, herbicides or insecticides are also not used in Tai'an District. Water retting of hemp stalks involves the bundling of 200 stalks and their immersion in a pond for 2-3 days. Hemp has a typical fiber content of 12%, and a good crop yields ~2.25 t/ha of first and second quality hemp ribbon. Traditionally, peasants have produced twine, rope, sacking, burial clothes and other domestic items from hemp. Hurds and fibers are used by local pulping plants for the strengthening of wheat straw paper. Western investment in local hemp production will soon result in rapid changes in hemp farming and processing.
Due to visa problems, Hui-Min Wang (North-West Institute of Textile Science & Technology, China) was not able to give his presentation on hemp research, developments and concepts in China. However, his paper suggests that China is the current center of hemp production in Asia. Cultivation area ranks third for any bast fiber worldwide, just behind the areas for ramie and flax grown in China. Output of hemp fibers is estimated at 50,000 tons per annum. Textiles from hemp have been in decline in China for decades due to competition from more easily processed fibers (wool, cotton, synthetic fibers). The production of ropes, pulp, and hand knitting products, and the use of seeds for oil and of leaves and flowers in traditional Chinese medicine remained as its main uses. The recent resurgence of hemp was caused by a growing demand for natural fibers, a drop in world market prices for flax and ramie products and the emergence of advanced technical applications.
For textile applications, the longer hemp fibers (60-80 mm) are spun into pure yarns using processing equipment for waste silk (Nm 8-Nm 54) or into hemp/wool (15/85%), or hemp/wool/polyester blends using wool or ramic processing equipment. Shorter fibers (40-60 mm in length) are spun into hemp/cotton (45/55%) yarns. Hemp shives are processed into high density fiber boards used for high grade furniture and building materials. The short fiber is processed into pulp for high grade paper, such as cigarette paper. In China, hemp is again considered as an important resource. New products for various applications have been developed and hemp textiles have become fashionable worldwide, despite their generally higher price.
Michka, author and journalist from Paris, France, provided an over-view of the hemp industry in France. Hemp has a unique status in France in that it has been grown legally with no interruption for several centuries. While its use for textiles ceased in the 1960s, today hemp fiber is processed almost entirely into pulp for long-fiber specialty papers. For examples, the German company EFKA, one of the sponsors of the symposium, manufactures its "Canuma" papers from 100% French hemp. Innovative uses for hurds (shives) have been explored for over a decade, particularly in construction. Various firms, such as Chenevotte Habitate (Isochanvre) and La Chanvriere de l'Aube (Canobiote) now use hemp shives as raw material for insulation or construction products. For production of these materials, shives are usually mixed with natural or hydrated lime, or with cement. They can be used without further additives in foundations, walls, floors, ceilings and plaster. If used for insulation in floors, walls and roof tops, the mineralized shives are blown or poured into the respective cavities. Other well established uses for shives include livestock bedding and cat litter (see also: JIHA, 1(2), p.50).
Ian Low (Hemcore, England) presented their three-year old program to develop the cultivation, processing and marketing of hemp in the UK. In addition to three years of trials, Hemcore has grown two commercial crops (600 ha in 1993 and 800 ha in 1994). In England, even low-THC hemp requires permits and must be grown in remote locations. While some crop theft occurred in 1993 it was absent in 1994 as marihuana users realized that the plants did not cause any psychoactive effects.
Low provided the following summary of their cultivation experiences. For plant development, hemp prefers a fine seedbed without compaction. It requires sufficient supplies of N, P & K. Required rates of application vary with soil type and expected yield with typical values of 120 kg/ha N, 160 kg/ha of K20, and 100 kg/ha of P205, which are best applied by predrilling.
Pesticides were not used on any of the crops and Low does not foresee any future need for their use. The hemp crop is deep rooting and demonstrated its benefits as a break crop, cleaning the ground, providing a good disease break, and improving the soil structure. Harvesting involved cutting and swathing of the crop, followed by field retting and baling. Dry matter yields varied between 5 and 11 t/ha. The use of improved varieties and growing techniques will make higher yields more common. Fiber processing is considered one of the bottlenecks and will be a main focus of any future expansion plans. Low perceives specialty papers and textiles as the main markets for the fiber. The shives are very suitable for their current predominant use for animal bedding because of their excellent absorbency (50% higher than the competing wood shavings) and of their rapid degradation by composting (see also: JIHA, 1(1), p.15).
Floris de Vries (HEMP-FLAX, The Netherlands) discussed history and status of hemp cultivation and use in the Netherlands. Until several decades ago hemp had been the most important fiber crop in the country. Rembrandt's paintings and Dutch world exploration would not have been possible without hemp for canvas and ropes. Since the late 1980s, government has provided considerable support to hemp research in order to fill the technology gap and establish cooperation between farmers and industry.
In 1994, Ben Dronkers founded HEMP-FLAX as a-private company. He purchased a modern flax processing plant and contracted with Dutch farmers in 1994 for the cultivation of 140 ha of hemp. For 1995, 500 ha are under contract. HEMP-FLAX used seeds from the French monoecious Fedora, Felina, Fibrimon, and Fedrina varieties. Liquid manure provided effective fertilization. Farmers were enthusiastic about hemp's effect on soil structure, ease of cultivation and performance. Although no fungicides or pesticides were used, losses caused by Botrytis cinerea and other pathogens were insignificant. Dry matter yield was 6-9 t/ha. Of the harvesting methods tested, swath mowing, followed by dew retting and turning, proved to be the most practical. The air-dried crop was pressed into large bales and stored. HEMP-FLAX has realized several new applications for fiber and shives, including planting substrate, building materials, non-wovens, biofilter material, and adsorbents (see also: JIHA, 1(2), p.57).
Olivier Pittet (Eidgenossische Forschungsanstalt fur Agrarwissenschaftund Landtechnik, Federal Institute for Agroscience & Technology, Switzerland) reported that Switzerland permits hemp cultivation with certain restrictions. In a four-year experimental program, the federal agriculture administration is subsidizing the cultivation of renewable fiber crops with sFr 3,000/ha. The program focuses on rape, Miscanthus, kenaf, sunflowers, cereal for starch production and hemp. Two manufacturers of pulp and compression molded parts, respectively, have committed to the purchase of the hemp from a 10 ha area. In other projects, hemp has been used for the production of building materials, and of oil. Harvesting involved conventional equipment, such as a bar-cutter which produced good results and can be further improved with minor modifications. Crops included the French Fedora-19, Felina 34-R2P, and Futura 77 varieties with fiber contents between 19 and 25%, and fiber yields between 0.9 and 2.6 t/ha. Futura 77 achieved the highest yields.
Michael Karns (nova-Institute, Germany) gave an overview of the past, present, and potential future of German hemp cultivation. The use of hemp textiles can be dated back as far as 800 BC. Hemp retting was used as early as 800 AD and hemp eventually became an important resource for ropes, canvas, textiles, and rags for pulp production. Following its prime in the 1600s, with a cultivated area of 150,000 ha, hemp cultivation gradually declined in the 1700s and 1800s due to the demise of commercial sailing, improvements in mechanized cotton processing, inexpensive fibers from the colonies (sisal, jute, ramie) and hemp imports from Eastern Europe, and the discovery of wood as a source for pulp. During the wars, hemp cultivation was revived to replace lost fiber supplies from overseas, and modern processing technologies, such as the "cottonization", were developed. After WW II, hemp rapidly lost ground to the competition from synthetic fibers and cotton. In West Germany, breeding for high fiber and low THC content was conducted through the 1950s by Bredemann, Hoffmann, and van Sengbusch. In 1982 all hemp cultivation was banned, regardless of THC content, and the plant was consequently overlooked in the recent rediscovery of non-food crops which involved e.g., a DM 60 million flax program which achieved no major breakthroughs.
In 1993, release of a significantly expanded German translation of Herer's book caused considerable public interest, triggered a host of research and development activities, and marked the revival of hemp in Germany. Hemp was elected 'EcoChampion 1994'. Innovative products, such as high grade paper, textile collections and various hemp oil products, were developed in short order. The HanfHaus established a nationwide retail outlet chain for hemp products, and several mail order companies for natural textiles include lines of hemp products. Concurrently, increasing pressure is mounting to end the prohibition on hemp cultivation, to incorporate hemp into national research programs and to implement innovative fiber processing technologies on the pilot and full-scale level (see also: JIHA, 1(2), p.52).
Second Day, March
3rd- The Hemp Plant: Breeding, Cultivation and Harvesting
Presentations on day 2 revolved around past and present experiences with the physiological and agricultural characteristics of hemp, approaches to improve its performance by breeding and/or optimization of growing conditions, and methods for harvesting and initial storage and processing.
Etienne de Meijer (formerly CPRO-DLO, The Netherlands) presented results from Dutch hemp breeding research. Stem production and quality, psychoactive potency, and resistance to soil pathogens were considered relevant criteria to assess the suitability of hemp for crop rotation and as raw material for pulp. Total fiber content in the subject varieties varied from 9-34%, with fiber cultivars showing a higher content of bark tissues, primary, and secondary fiber as compared to wild populations, drug strains and fiber landraces. Continued selection for high bast fiber content appears to be successful in genetic improvement of pulping quality, resulting in a lower percentage of shives. Accessions were classified into the phenotypes 'drug', 'intermediate', and 'non-drug', based on their average cannabinoid profiles. There was no strict correlation between these profiles and the nonchemical traits, such as fiber content or quality. Since hemp would be grown in the Netherlands mainly in sandy soils and in narrow crop rotation dominated by potatoes and sugar beets, it should preferably be a poor host for root knot nematodes. Results indicated that the tested varieties were generally poor to moderate hosts for several nematodes, but susceptibility varied between varieties. Some highly resistant individual plants retained from accessions with poor agronomic properties were expected to be useful for cross-breeding.
Robert Clarke (IHA, Amsterdam) reported on the maintenance of the hemp germplasm collection at the St. Petersburg Vavilov Research Institute (VIR). The collection consists of 397 accessions from three different eco-geographical groups: Northern, Central and Southern. Ninety-four accessions were planted in 1994 at locations in Russia, Ukraine and Italy. Reproduction was achieved for 72 accessions, two yielded no seeds, four were cut prematurely, four perished from drought, and 12 were insufficiently isolated to ensure genetic purity.
The project's primary goal is to grow a minimum of 1,000 plants for each accession, in order to conserve its entire gene pool. A secondary goal is to produce more than the 200 grams of seeds alloted for storage and later reproduction and to distribute excess seeds to researchers worldwide. The project was made possible by a humanitarian aid grant from the IHA. Pointing out the lack of funding at the VIR and the importance of the project, Clarke appealed to the audience to support the IHA's fundraising efforts (see also: JIHA, 1(1), p.1).
Jan van der Veen (University of Wageningen, The Netherlands) studied the effect of age and developmental stage of hemp on bast fiber strength relevant to its use for paper production. His findings suggest that age has no significant impact on the strength of bast fibers, and of handsheets made from thermo-mechanical pulp, once the plant has matured. Thus, fiber hemp may be harvested from mid-August to mid-October without concern over loss of fiber quality. Primary bast fibers are 5-40 mm long and heterogeneous, while secondary fibers are smaller with a more uniform length of ~2 mm. Core fibers are thin, typically 2 um in diameter, and short (0.55 mm) and have a chemical composition similar to hardwood. The long and lignin-poor bast fibers will find various specialty applications following chemical processing. Because of the low lignin content, less chemicals and energy than for wood processing is required.
David Pate (IHA, Amsterdam) has researched the function of cannabinoids and their associated terpenes for Cannabis. While admitting that no comprehensive explanation exists yet for their 'raison d'etre', he suggested several possibilities. Formation of the sticky cannabinoids may represent a line of mechanical defense strategy against travel by small insects and chewing by larger ones. Terpenes' aromatic properties may repel insects. Since antibiotic properties have been demonstrated for several major carmabinoids, they may also provide protection from pathogenic microorganisms e.g., fungi. They may also provide protection from heat and dessication in a manner analogous to the waxy coating of cacti and other succulents. Finally, there is an apparent correlation between a variety's THC content and local levels of UV-B radiation. Pate concluded that UV-B selection pressure may not only be responsible for the evolution of the THC-rich Cannabis varieties found in high altitude and equatorial regions, but also for an alternate biogenetic THC production pathway in some of these strains. Although the chemistry of Cannabis has come under extensive investigation, he urged that more work be done to probe the relationship of its resin to biolic and abiotic factors in the environment (see also: JIHA, 1(2), p.29).
Lothar Loch (Plant Breeder, Germany) provided an overview of his 40 years of experience with hemp which focused on the breeding of monoecious varieties containing both male and female flowers in one plant. In this context Loch discussed several fundamental questions related to the genetics of hemp. His monoecious variety for fiber and seed production, best grown on neutral to alkaline soils, was registered with the German authorities in 1993.
Siegfried Handke (formerly MaxPlanck-Institute, Hamburg, Germany), a former co-worker of the well-known hemp breeder R. von Sengbusch, presented a revised version of a 1956 talk by von Sengbusch, including a number of historic slides. Starting from native hemp varieties with typical dry matter yields of 6-7 t/ha and fiber contents of 10%, they were able to breed, between the 1930s and the 1950s, various monoecious and dioecious varieties with yields of 10-12 t/ha and a 20-24% fiber content. Individual plants achieved fiber contents of as high as 30%. This success depended crucially on the prior development of methods for accurate determination of fiber content and quality, and for the selection of varieties for a high primary fiber content.
Ivan Bocsa (GATE, Hungary) summarized the methods and successes of his decades-long involvement in hemp breeding and gave an overview of the currently available fiber hemp varieties. For example, the fiber content of the "Kompolti" variety was increased by more than 200% to ~38%, with a technically usable fiber content of 28%. Kompolti is a dioecious, southern variety with a coarse fiber, not as suitable for textiles but, because of its high fiber yield, excellent for pulping. It has a dry matter yield of 11-12 t/ha, a vegetative period of 110-115 days, and a THC content of 0.15-0.2%. Bocsa then compared advantages and disadvantages of monoecious and dioecious varieties. Because of their higher yields, the dioecious ones are preferable for fiber production while monoecious varieties allow for concurrent production of fiber and seeds. He also presented six of the varieties registered in Hungary, crossbred from Hungarian, German, French, Chinese and Russian stock. Worth mentioning is the Kompolti TC hybrid which produces very high seed yields (up to 1,600 kg/ha), but cannot be grown in the EU because of its relatively high THC content of 0.5-0.7%.
In the 1970s, Bocsa also improved a southern dioecious yellow stemmed hemp which can be used for both the paper and textile industries. The plants lose their chlorophyll content before flowering, thus the fiber does not turn brown. The fiber also does not require bleaching and thus lends itself to the production of environmentally friendly paper products. Bocsa suggested that Hungary is prepared for a worldwide upturn in hemp cultivation. In 1989, a total area of 6,000 ha was under cultivation with average yields of 9 t/ha. Following a rapid decline, caused by the collapse of the Russian demand, hemp cultivation is now on the rise again. Bocsa states that Hungary exports among the best seeds worldwide and has large spinning and weaving capacities which require some modernization (see also: JIHA, 1(2), p.61).
Ion Fruja (Banat University for Agricultural Science, Romania) reported on quality standards for hemp fiber, such as color, length, tensile strength, and fineness. In Romania, the Fibridia, Fibramulta 151 and Lovrin 110 varieties are predominantly grown. Their fiber content is typically 22-26% and the fibers show a high degree of fineness and tensile strength. The most suitable cultivation areas are found in western Romania with fertile soils, containing 4-6% humus. Precipitation during the vegetative period is 300-500 mm. Typical dry matter yields in the area are 8-10 t/ha and 2-2.5 t/ha of fiber. Fertilizing with nitrogen in excess of 120 kg/ha results in fiber with inferior tensile strength. Fiber quality also depends on the proper N/ /K ratios. For optimum fiber quality, Fruja recommends avoiding premature sowing (soil temperature should exceed 8-9 C), limiting seed density to 450/m2, and sowing no deeper than 6 cm. Typically 49% of the plants are male with a 6-8% higher fiber content compared to females. Plants are best harvested at the end of the male flowering period since later harvest may cause fungal infestation which diminishes fiber quality. The stalks are cut mechanically and left in the field for 4-8 days for drying. Leaves and flowers are removed manually and the stalks are then assembled in 20-30 cm diameter bundles and erected in a pyramid-shaped pattern before transportation for further processing. No pesticides are used for hemp cultivation in Romania.
Vito Mediavilla (Eidgenossissche Forschungsanstalt fur landwirtschaftlichen Pflanzenbau FAP, Federal Institute for Agriculture, Switzerland) presented initial results from cultivation tests in Switzerland. Industrial hemp was grown in 1994 on a trial basis to assess its suitability as a source of fiber and oil. Grown in locations throughout Switzerland were the French varieties Fedora, Felina and Futura. At 0.13-0.26% the measured THC contents were below the EU-limit of 0.3%. They were not affected significantly by the level of fertilization, sowing date and plant density. Fedora yielded 3.2-8.8 t/ha of dry stalks and 1.5 t/ha of seeds with manual harvest, while Futura and Felina yielded 5.9-10.7 t/ha and 5-10.7 t/ha of dry stalks, respectively. The tests demonstrated that hemp is demanding with respect to nitrogen supply and soil structure. Soil compaction and crust formation diminished yields. Only minor problems with pests were observed. Weeds were generally suppressed. Extensive rains during plant development caused some losses due to snails. A very limited infestation with Botrytis cinerea was also observed.
Frank Höppner (FAL Braunschweig, Germany) presented initial results from an extensive, two-year cultivation program for hemp, involving the Felina 34 and Kompolti Hibrid TC varieties. Overall, the results confirmed that hemp can be grown in an environmentally friendly manner. Hoppner's group found that rates of nitrogen fertilization between 60 and 100 kg/ha - which is low compared to other crops - were sufficient. Higher doses did not improve yields and excessive fertilization reduced fiber content. Optimum plant density was found to depend on the selected variety and varied from 200-250/m2 for Kompolti to 300-350/m2 for Felina. The use of pesticides and herbicides was not required. Fungal diseases which have been observed in Holland (based on Hoppner's observations and data in the literature) will not cause any significant problems in countries with more continental climates. Felina and Kompolti achieved dry matter yields of 10-13.8 t/ha and 13.8 and 17 t/ha, respectively, and fiber yields of 2-5 t/ha. Fiber content ranged from 17-23% for Felina and 19-26% for Kompolti. Seed yields were determined upon maturity. While Felina achieved oil yields of 290 kg/ha, the yield for Kompolti was only 110 kg/ha because this late variety did not achieve full seed maturity. Fatty acid spectra were dominated by linoleic acid (60%), linolenic acid (20%), and palmitic acid (5%) (see also: JIHA, 2(1)).
David Watson, Lester Grinspoon and Michka meet at Frankfurt.
Hayo van der Werf
(AB-DLO, The Netherlands) presented several of the main results of the Dutch research
program on crop physiology and agronomy of hemp (1987-93). Hemp's maximum stem yield
under favorable conditions for a late-flowering variety in the Netherlands was estimated
at 17-18 t/ha. Actual yields were lower; a maximum of 15 t/ha for Kompolti Hibrid TC
(maximum bark content: 35.7%) was achieved. For late varieties an optimum plant
density of 90/m2 was found.
At a high density of 270 plants/m2 self-thinning resulted in lower stem yield. The tests also demonstrated
that hemp crops may suffer severe damage from fungal diseases (Botrytis cinerea) in rainy
years, unless fungicides are frequently applied. Preventive application of
fungicides is not useful since they improve yields only modestly in wet years.
Breeding of fiber cultivars less susceptible to Botrytis cinerea is preferable.
Van der Werf went on to address several of the frequently made claims on the potential of hemp. His research indicates that the annual dry matter yield of hemp (less than 20 t/ha) is by no means exceptional compared to corn, beets or potato. He suggested that making unrealistic claims on the potential of hemp would not well serve the growing hemp industry. However, he stated that hemp has the profile of an attactive new crop for farmers in the Netherlands under a sustainable agricultural system, since it has moderate fertilizer requirements, needs little or no pesticides and suppresses weeds and some major soil-borne pathogens (see also: JIHA, 1(2), p.58).
David Stickland (Organic Farmers & Growers, England) discussed his position that hemp is an ideal crop for the ecological farmer in that it fits nicely into a properly designed rotation without damaging the soil's fertility or structure. Since weeds can be a serious problem in eco-farming, a crop which suppresses all weeds, such as hemp does, is almost "too good to be true". Grown in proper rotation, hemp also seems to be almost disease free. Ecological farmers also prefer deep rooting crops, such as hemp, that can utilize deeper lying food sources. He concluded that modernization of harvesting and fiber processing equipment will be the major challenge in tapping the huge market potential for hemp.
Przemyslaw Baraniecki (Institute of Natural Fibers, Poland) concluded from four years of cultivation on soils contaminated with heavy metals that hemp is suitable for such soils and may aid in their recultivation. The tests suggested that elevated soil levels of heavy metals do not impair plant growth and development, and that yield and fiber quality are not different from those achieved with non-contaminated soils. They also suggested that hemp removes heavy metals from soils and accumulates them, preferentially in roots, seeds, and leaves. Stems, including bast fibers, generally showed the lowest degree of accumulation. This suggests the potential for gradual and inexpensive remediation of heavy metal contaminated soils by hemp. Baraniecki concluded that hemp may be a suitable replacement for food crops in highly contaminated soils. However, he did not discuss whether accumulation of heavy metals in the plant may make hemp unsuitable for use in textiles, seed-basd foods or other products.
Finally, Wim Huisman (Agricultural University Wageningen, The Netherlands) discussed issues related to the harvesting and storage of hemp. In wet climates, such as the Netherlands, the conventional dry harvesting techniques may prove risky and cause concern over loss in fiber quality. Consequently, an innovative approach involving the production of silage from harvested stems has been developed. It is particularly attractive for subsequent pulping since it reduces energy requirements and facilitates the separation of bast and shives. Fiber hemp can be harvested by field choppers with a row-independent header, but the sharpness of knives and the throughput of the chopped fibers require special attention to prevent wrapping or blocking. Chopping provides for an initial high degree of separation of bark and core. Prior to pulping, further separation of the lighter shives can be achieved by floating. This approach is very compatible with the proposed combination of chopping and ensiling. Of the tested ensiling strategies, acidic or alkaline methods did provide for good preservation, but also caused some loss in fiber strength. Huisman suggested further research into more effective ways of controlling fiber quality during ensilage, (see also: JIHA, 1(2), p.38).
Third Day, March 4th:
The Hemp Fiber - Processing and Products. This session, with the overall,
strongest attendance, was devoted to the discussion of experiences with existing methods
of hemp fiber processing, and the presentation of innovative technologies and products.
Major topics included fiber separation technologies, the production from hemp fiber
of industrial and insulation materials, textiles, pulp and paper, and the assessment of
market potentials for hemp.
Pat Terentie (Fibratex, Romania) followed-up on the previous day's presentation on hemp farming in Romania. With support from Heidrun Neascu and illustrated by a video, he discussed the main steps involved in the traditional processing of hemp in Romania from water retting to spinning. The two-step process involves the microbiological retting of stalks followed by mechanical processing. For economic reasons, a cold water retting process is used. It is performed in large tanks, 100-150 m3 in volume. A crane drops the stalks into the tanks where they are entirely covered with water. Once tests indicate that the optimum degree of retting is reached (over-retting diminishes fiber quality) the water is drained and the stalks are field dried for 5-10 days. The equipment for the subsequent separation of long fiber, tow, and shives has a capacity of 200 kg of fiber per 8 hours. The shives are burned for fuel, used in combination with gypsum for the production of insulation boards, and used for bedding in chicken farms.
Johann Gschosmann (Bahmer Maschinenbau, Germany) presented the design of their two-step hemp processing technology, originally developed for flax. It involves the use of a field unit for initial breaking and decorticating of the slightly retted hemp to ease handling and transportation. The baled fiber is further processed in a stationary fiber separator which involves removal of residual hurds and dust, followed by several wet separation steps which yield increasingly fine fiber. Using mainly traditional mechanical methods, the system promises to be a versatile combination of decentralized preprocessing and centralized production of long fiber of various qualities. According to Bahmer, the sale of a flax processor based on this concept to East Germany is pending.
Kai Nebel (IAF, Institute for Applied Research, FH Reutlingen, Germany) summarized the characteristics and limitations of the now predominantly used technologies for the processing of long fiber and tow. The fact that hemp fibers cannot easily be separated by conventional means to produce fibers of consistent quality usually requires specialized machinery, e.g. for spinning, and often results in undesirable product characteristics.
Nebel suggested that these major obstacles to the development of a wider range of applications for hemp fibers could be overcome by the use of innovative separation technologies, such as the steam explosion based "cottonization" process redeveloped by IAF. It produces a cottonlike material which can be spun, using existing technology for cotton, into fine yarn, yet has retained some of the hemp fiber's characteristics, such as high tenacity and low elongation. Finer cotton yarns currently constitute a large share of the natural fiber market for textiles. Thus, steam explosion may, by closely controlling product characteristics through control of the process parameters (temperature, pressure, duration), open a considerable market for hemp fibers. The process' versatility with respect to end product specifications also make it particularly suitable for a variety of industrial hemp applications, such as substitution of the fiberglass material used for reinforcement in composites, or for insulation. Nebel suggested processing cost of 0.5-2 Deutschmark (DM) per kg of product, once the technology is established on the full-scale level (see also: JIHA, 2(1)).
Hugo Zimmer (Ecco Gleittechnik, Germany) also pointed out the need for close control of characteristics and quality of hemp fiber if it is to find new industrial applications and presented Ecco's alternative to the chemo-mechanical fiber separation: ultrasound. Ecco has demonstrated the efficient removal of lignin, pectin and dirt from hemp or flax straw. The resulting product is of high consistency and purity and its characteristics can be modified by varying the process parameters. The process also handles straw of various degrees of retting, thus reducing the farmer's dependence on weather conditions for harvesting and preprocessing. Finally, the process allows for the recovery of the extracted lignin and pectin from the process water and their use, e.g. as binders in particleboard. Ecco is currently in the planning phase for a fullscale demonstration project with an annual throughput of 10,000 tons/year of raw material.
The following 3 presentations, addressed the use of hemp fiber in innovative, non-textile applications.
Karl-Heinz Hensel (Ecco Gleittechnik, Germany) predicted that plant fibers, such as hemp, will compete successfully with synthetic or mineral fibers in numerous industrial applications if improved separation and refining processes are established to customize fiber characteristics to the respective product requirements. Examples of hemp fiber based products currently developed by Ecco focus on automotive applications (insulation fleece, bumpers, seat covers, brake and clutch linings) and construction (insulation, concrete reinforcement). Hensel estimated the potential German market for plant fibers in these industries at ~650,000 tons p.a. but expects a maximum market penetration of 20% (130,000 tons p.a.) over the next 10 years.
Axel Herrmann of the DLR (German Aerospace Research Institute) provided a specific example of such applications. His presentation of a composite material made from a starch based resin reinforced with hemp fiber generated significant interest. The material is fully biodegradable, i.e. it provides for composting or other raw material recovery options. More importantly, it matches the stiffness of epoxy resin reinforced with fiberglass and may replace it in a variety of applications, including automotive construction, piping, furniture, and recreational products. DLR is currently investigating various biodegradable matrix materials, based on starch or cellulose, in combination with renewable fibers such as hemp, flax, and ramie. Herrmann predicted that the price of these composites, once sufficient demand provides for better economy of scale, will eventually be comparable to that of conventional composites.
Benno Steiner (Flintsbach, Germany) presented the concept of his company's ISO-FLACHS insulation fleece which focuses on optimizing both product quality and the ecological acceptability of each process step, and is now in commercial production. According to Steiner, his firm has technically mastered the production of a hemp based ISO-HANF product and expects to market it, once domestically grown high quality hemp fiber becomes available. The fleece is impregnated with borate and sodium silicate for flame resistance. Initial tests with ISO-HANF indicate that its insulation capacity is inferior to that of competing products, e.g. based on mineral wool. The hemp fiber is also tougher than competing fibers, which causes production equipment to experience higher loads and requires operation at lower production rates. Other hemp based products currently manufactured by Steiner include covers for mattresses, geotextiles and hemp felt.
Two presentations evaluated potential future markets for hemp fibers in the EU.
Jan van Dam (ATO-DLO, The Netherlands) presented the results of a EU-wide market assessment for hemp and other agricultural fibers. The study conservatively estimates markets of 100,000-400,000 tons p.a., mostly for composites and other construction materials. He also discussed existing obstacles to the realization of this potential. They include inertia and low willingness in industry to shift to alternative raw materials, limited advanced processing capacities, fluctuations in supply and product quality, the generally higher price of the raw material, and the problems involved in applying lab-scale technologies in the field.
Sue Riddlestone (The Ecology Centre, England) described the potential ecological and economic benefits from small-scale processing industries for hemp and other fibers from regional crops. She suggested that the growing "green consumerism" would be the primary driver for such a development. It would also require the formation of cooperative investment structures by ecologically minded investors and farmers. The Center currently investigates the feasibility of developing such structures in England.
The use of hemp fiber for textiles, i.e: the main driver for hemp's recent resurgence in the U.S. and Europe, was discussed by Sue Riddlestone and Robert Franck of the Ecology Centre. They concluded that hemp, even if processed by the traditional long fiber technology, has the technical potential to substitute significant amounts of cotton and flax in the textile sector, particularly for applications requiring less fine yarn qualities, such as the furnishing fabric sector. The unsuitability of dew retting in the rainy English climate, and the need to adapt available flax processing technology were identified as problems to be resolved prior to the establishment of a regional textile industry.
Jan Marek of the Czech Textile Finishing Research Institute VUTZ presented his research on the development of eco-friendly textile dying and finishing methods, such as anti-shrink treatment. While the hemp fiber's comparatively high content in calcium, magnesium and lignin taxes conventional finishing processes, Marek was confident that his institute will develop sophisticated combinations of fiber pretreatment and finishing methods which would meet product quality and eco-labeling requirements.
The production of paper from hemp as a truly renewable fiber resource has fueled much of the recent interest in hemp. However, extremely limited pulping capacities and inefficient pulping technologies keep current supplies low and prices high, and hamper a more rapid growth in market penetration. Consequently, the last five presentations discussed past experiences with pulping and paper making from hemp and presented innovative pulping technologies.
Gertjan van Roekel (ATO-DLO, The Netherlands) presented their chemo-mechanical pulping technology for hemp fibers, which provides flexibility in the fiber length of the produced pulp, eliminates the need for a Hollander beater and produces a high quality writing paper. In comparison, the production of pulp for high quality paper from wood involves, because of its higher lignin content, extensive cooking and usage of chemicals. The technology also provides for the pulping of hurds, or shives, which are mostly used in low-profit applications, such as horse bedding, if at all. Van Roekel's prediction that projected small pulping units with throughputs of typically several 1,000 tons of dry pulp per year will produce hemp pulp (US$530/dry ton) at a price lower than that for softwood Kraft pulp (US$820/dry ton), stimulated particular interest. However, this comparison benefits from the currently high market price for softwood wood pulp and the EU subsidy for hemp cultivation. Van Roekel was subsequently contacted by several investors interested in implementing the technology, possibly in England, Hungary and Holland (see also: JIHA, 1(1), p.12).
Birgit de Groot, also ATO-DLO, presented her research on the chemical pulping of hemp hurds. Her modeling of pulping process kinetics is targeted at controlling process parameters such that pulp from hurds could replace hardwood pulp in less demanding applications.
Karl-Heinz Hofmann (Chemische Bleicherei Eugen Jetter, Germany) discussed his plans for the conversion of his existing cotton bleaching operation into a hemp pulping facility with a capacity of 7,000 tons p.a. He also discussed the results from his pilot tests aimed at reducing chemical usage and process waste through optimization of process parameters. If his appeal to potential investors (which stimulated some interest at the symposium) is successful, his plant would add considerably to the current European hemp pulping capacity. At least in Europe, it would also be the first one to produce unbleached or hydrogen peroxide bleached pulp. Hofmann has already found potential buyers for 4,000 tons of his production, mostly manufacturers of filter paper.
Another innovative pulping technology for hemp was presented by John Masura for Vladimir Krotov of the Ukrainian Pulp and Paper Research Institute (UPPRI) in Kiev. It is based on the extraction of lignin and pectin in an ammonia-sulfite-alcohol process. Its proclaimed advantages include the use of the entire hemp stalks, avoiding the need for pretreatment and allowing for the beneficial use of the shives in a pulp "which is not inferior in strength and superior in yield to softwood Kraft pulp." The UPPRI is currently developing plans for a pilot demonstration unit (see also: JIHA, l(1), p.28).
Robert Zulauf (Diosgyori Papirgyar, Hungary) discussed problems encountered with paper making from various hemp pulps and the process changes subsequently implemented at his paper mill. Problems included wide variability in the specification of the purchased pulp, repeated clogging of pumps and disk and cone type grinders by fibers longer than 4 mm, and the need for time consuming grinding in a Hollander beater. The subsequent paper production did not experience particular problems, but mandated lower production rates compared to wood pulp. With respect to brightness and smoothness, the quality was only slightly lower than for paper from softwood Kraft pulp, except for a pulp based on a mixture of bast fiber and hurds. The talk exemplified the need for close control of the raw fiber characteristics already discussed in previous presentations.
Fourth Day, March
5th: Shives, Hemp Oil and Other Uses of Hemp.
The last day provided an overview of several of the non-fiber uses of hemp, both traditional and innovative ones. It also addressed other topics relevant to the establishment of a viable hemp industry, such as marketing and certification.
Michael Klug introduced his firm (Okomarkt, Germany), as the German representative of Chenevotte Habitate, the French manufacturer of ISOCHANVRE products, and discussed potential applications of these materials. Based on petrified shives, they are now increasingly used for the insulation of walls or, mixed with lime, as a substitute for plaster or concrete (see also: JIHA 1(2), p.50).
One particular example of the potential uses of hemp as an energy source, i.e. as a boiler fuel, was discussed by Hans-Bernhard von Buttlar (Gesamthochschule Kassel, Germany). Their cultivation tests indicated that crop combinations of hemp and winter rye can, depending on plant density and rate of fertilization, achieve combined annual dry matter yields of up to 24 tons p.a., equivalent to approximately 10,000 liters of fuel oil. Combustion properties of hemp were considered favorable because of its high ash melting point. The plant's mineral content could be lowered further by wet pressing, reducing emissions of nitrogen oxides and improving ash melting. As for other renewables, large-scale use of hemp as a boiler fuel cannot currently compete economically with fossil fuels, but offers the advantage of a CO2-neutral fuel supply.
The next four talks were devoted to the properties of, and applications for, the other major resource from hemp: seeds and oil.
The editors of "TextileForum" visit with Dave Pate at the IHA booth at Frankfurt
(Bergische Universitat, Germany) reported test results for the fatty acid (FA) spectra
found in various hemp oils. They confirm that hemp oils contain high proportions of
essential poly-unsaturated fatty acids. Theimer found that the major
poly-unsaturated FA present in hemp oil, i.e. linoleic, linolenic, and oleic acids,
typically account for 55%, 15%, and 10% of the total fatty acid content, respectively.
Particularly significant is the high content of linolenic acid which is essential
for human nutrition, but under-represented in most vegetable oils and animal fats.
In addition, hemp oil also contains smaller percentages of shorter (C14:0) fatty
acids which may account for some of its useful properties, e.g. as detergent (see below).
Since FA composition was found to vary widely between hemp varieties, hemp breeders
should also strive to optimize FA composition depending on specific product requirements.
Don Wirtshafter (Ohio Hempery, USA), further elaborated on the nutritional value of hemp seeds which, in addition to essential FA, also contain all the essential amino acids, and several vitamins and minerals. He also discussed his experiences with importing hemp seeds into the US and developing products and markets. He identified the current legal situation in the U.S., which prohibits hemp cultivation and allows only for trade in sterile seeds, as the main obstacle to the establishment of a supply of less expensive, fresh seeds and oils for the growing domestic markets.
Peter Rausch (Nektar Naturkosmetik, Austria) gave an overview of applications for hemp oil in cosmetics and personal hygiene products. Results from his tests suggest that the replacement of vegetable oils in creams and lotions by hemp oil improves skin penetration and reduces stickiness. Rausch also proposed the use of hemp oil as altemative raw material in conventional production processes for soaps, emulsifiers, shampoos and cosmetics. In 1994, his firm released a line of hemp oil based personal care items (soap, shampoo, gel). Owing to their high content of conventionally produced, non-hemp based ingredients, these products should be labeled 'conventional', rather than 'ecological'.
Another one of the symposium's highlights was Max Olschewski's (SATIVA, Germany) presentation of an innovative, 100% hemp oil based laundry detergent, which will go into production in Germany this summer. It is produced from hemp oil and yeast in an innovative biochemical process. Its advantages include not only environmentally friendly production and very high biodegradability, but tests also confirmed that the detergent removes persistent stains (grease, ink, blood) more efficiently than synthetic detergents or those based on other vegetable oils. This can be attributed to the fact that its surface tension is considerably lower than that of conventional detergents. The audience was able to see proof of these claims in form of heavily soiled rags, 'before and after' laundering. Other potential applications include the detergent's use as an industrial cleaner, e.g. for engines and, because of its bioaegradability, in the remediation of soil contaminated with petroleum products.
High concentrations of THC and other cannabinoids in some hemp varieties offer the potential for their use in medical therapy, but are also the cause of political obstacles to the cultivation of fiber hemp in Germany and North America. Several aspects revolving around this subject were addressed in the following talks.
In the U.S. and most of Europe the prohibition on the use of marihuana even for medical applications has hindered a rational approach to, and scientific study of, its potential benefits. Lester Grinspoon a currently much engaged researcher from the Harvard Medical School, Boston (USA), is among the few who have studied hemp's medical applications for over twenty years. He summarized the results of his research with patients, predominantly based on anecdotal evidence but no less convincing. They strongly suggest that Cannabis effectively treats a variety of illnesses without the often severe side-effects of pharmaceutical drugs used for the same purpose. The beneficial effects of Cannabis seem particularly evident in the treatment of glaucoma and of the strong nausea and anorexia which is routinely encountered by cancer chemotherapy and AIDS patients, which results in general weakness of the patients and often causes them to abandon therapy. While synthetic THC (Marinol) can be legally prescribed for these applications, most patients prefer the smoking of marihuana because of better dosage control and avoidance of side effects. Consequently, Grinspoon strongly advocates a more rational approach to and legalization of the use of marihuana as a low cost, versatile, safe medicine.
The beneficial effects of marihuana and synthetic cannabinoids on anorexia and cachexia among AIDS patients were further discussed by Robert Gorter. The presentation of the results from his own clinical studies at the University of California Medical Center in San Francisco demonstrated that their appetite stimulating and mood improving effects resulted routinely in generally improved physical and mental condition without significant side effects.
Gunther Michael (Humboldt Universitat Berlin) has investigated the reliability of the EU standard method for THC analysis. He found that its mandated use of a packed GC column for the separation of various cannabinoids can cause considerable errors in the measured concentrations. Figures for the THC content of hemp plants, hemp products or drugs, obtained with that method and used for regulatory purposes, must therefore be considered highly unreliable. As an alternative to the standard method, which is, for the above reasons, rarely used by serious researchers, he strongly advocates its modification as to require the use of capillary GC columns.
Michael Karus (nova-Institute, Germany) presented results from a recent study of the potential for "drug abuse" of low-THC hemp. The study finds that smoking of even large amounts of fiber hemp does not cause the desired psychotropic effects. This can be attributed to (a) the insufficient accumulation of the effects of THC and (b) the elevated CBD content in fiber hemp which suppresses the psychotropic effects of THC. These findings are supported by tests during which experienced marihuana smokers could not distinguish cigarettes containing hemp with less than 0.9% THC from placebos. This demonstrates that the EU-limit of 0.3% for THC in fiber hemp is sufficient to exclude the use of low fiber hemp as a drug. Karus suggested that the creativity demonstrated by German authorities in developing speculative concepts for the use of fiber hemp as a drug resource could be used more beneficially for the development of a framework under which fiber hemp could be grown legally.
The last four talks addressed the need to improve communication within and outside of the hemp industry, and to set product quality standards.
Till Grether (TERBATEC AG, Switzerland), identified the lack of communication between the agriculture and processing industries as one of the current obstacles to the growth of the hemp industry.
Don Wirtshafter warned that the cheap imitations of hemp products increasingly found in the U.S. may create a bad reputation for the industry. He encouraged participants to develop and implement certification standards for hemp products in cooperation with the recently founded Hemp Industries Association.
Mathias Brockers, founder of the German HanfHaus, gave a first-hand account of the rapid growth of the German hemp industry since late 1993, discussed the problems related to product supply and quality, and suggested the HanfHaus franchise concept as an efficient way to accelerate the reintroduction of hemp into the economy.
Finally, Wilfried Korfmacher (Zeichenverkehr, Germany) presented a series of provocative and entertaining fictitious advertisements for hemp products designed by his students at the Dusseldorf arts college. They underlined the need to identify and address, through smart advertising, the potential interest of various societal groups in the reestablishment of hemp. Slogans included "Hemp is all right!" (as the progressive pleading of a smart, young lawyer), "Legalize Socks" (made from hemp), and "Hemp helps - help hemp". Korfmacher's students have already completed several projects for German customers, such as Schneidersohne and The Hanf Company, and several complete ad campaigns await their customers.
The final panel discussion, which ended the symposium, focused primarily on the relationship between the use of industrial hemp and the legalization of marihuana, an issue that had intentionally been excluded by the organizers of the symposium. Unfortunately, the discussion did not produce any major breakthroughs in this heavily debated area, as both panelists and audience were exhausted after four intense days and were very ready to go home.
The feedback we obtained showed participants were highly appreciative of the opportunity for exchange with scientists and developers. The envisioned goals of achieving a more differentiated, realistic assessment of hemp and generating synergistic effects between the participants, particularly between scientists, developers and potential investors, were apparently met. This was supported by feedback, such as that from Robert Clarke, IHA.
"You really worked hard to make this wonderful event such a great success. The BIORESOURCE HEMP symposium and hemp trade fair were the best things yet to happen for the hemp movement. From this time on we will see the distant horizon for world wide acceptance of hemp moving closer at a much accelerated rate. Mainstream attention and investment are what are really needed to move hemp forward. BIORESOURCE HEMP offered a serious setting for that message to get across."
When will there be another BIORESOURCE HEMP symposium? Nova currently has no plans for an event of comparable size in 1996. Organization of the first symposium was very labor intensive and presented us with major organizational and financial challenges. Despite the considerable admission fees, the event would not have been possible without funding from the German Bundesstiftung Umwelt, EFKA, Sunder & Rottner and the willingness of the speakers to forego payment. Since we have not secured any funding for 1996 we expect that a smaller, one day national symposium will be held in conjunction with BIO-FACH 1996 and with the BIORESOURCE HEMP trade fair which by itself will be worth the trip to Frankfurt. The 1995 hemp fair, organized by the Bochum marketing firm TriTec, represented the largest product and technology show on hemp to date. Several participating firms expressed their satisfaction with large volume contracts. For 1996, an even larger number of exhibitors is expected.
Finally, the symposium has, through media coverage and public education, contributed to the gradual change in the political climate for hemp in Germany. The Social Democrats, the second largest faction in the federal parliament, have demanded an end to the prohibition on fiber hemp. Their request was referred to the appropriate committee. In June, an expert hearing on modifications to the current Drug Control laws will also take up the issue of legalizing fiber hemp cultivation. Finally, the federal Department of Agriculture plans to conduct a comprehensive study aimed at compiling available information on hemp.
Proceedings which contained most of the papers and presentations summarized above were available at the symposium, but sold out rapidly. A second, revised and expanded edition will be published in June 1995. It will be 600 pages in length and include contributions in English and/or German. The proceedings can be ordered from nova (Thielstr. 35, 50345 Hürth, Germany) or the International Hemp Association. A prepayment (check, international money order, traveller check) of 100 DM (Germany), 110 DM (surface post outside of Germany) and 140 DM (international air mail), including shipping and handling, is required.