The following two links will get you two outstanding organizations to provide direct help for Haiti.
Our main intention of being here is to preserve, introduce, and re-populate the land with all kinds of fruiting/beneficial trees, to promote breeding and exchanging seeds, to show that Haiti can produce valuable products in a sustainable way without clear cutting and deforestation and to create an educational and retreat center where people from all over the world can come visit and learn about the community here and what is happening first hand.
Trees are a precious resource. They provide us with cleaner air, oxygen, food, medicine, prevents water pollution, conserves energy, prevents soil erosion, and many more. Trees can also provide lumber and firewood if done sustainably but remember to replant multiples for every tree that is cut.
Trees are a precious resource. They provide us with cleaner air, oxygen, food, medicine, prevents water pollution, conserves energy, prevents soil erosion, and many more. Trees can also provide lumber and firewood if done sustainably but remember to replant multiples for every tree that is cut.
WHY SUPPORT REFORESTATION IN HAITI?
Like many islands in the Caribbean, the country of Haiti has experienced an alarming rate of deforestation in the past 20 years. Today, much of Haiti's natural rain forests are threatened by deforestation. Charcoal production remains the number one cause of deforestation in Haiti and has turned mountains once rich in lush forest and fertile soil into barren desert land. Deforestation not only dries the land, making it extremely hard to farm for locals, but also magnifies the effects of heavy rains causing landslides and damage to river banks. Reforestation efforts are important because trees help reduce heavy rain runoff, lower the risk of erosion, reduce our carbon footprint, control the effects of floods, regulate the temperature, and provide habitats for valuable species.
Could HEMP be a good choice to be grown in HAITI?
Hemp, or industrial hemp (from Old English hænep),[1] typically found in the northern hemisphere, is a variety of the Cannabis sativa plant species that is grown specifically for the industrial uses of its derived products.[2] It is one of the fastest growing plants[3] and was one of the first plants to be spun into usable fiber 10,000 years ago.[4] It can be refined into a variety of commercial items including paper, textiles, clothing, biodegradable plastics, paint, insulation, biofuel, food, and animal feed.[5]
Although cannabis as a drug and industrial hemp both derive from the species Cannabis sativa and contain the psychoactive component tetrahydrocannabinol (THC), they are distinct strains with unique phytochemical compositions and uses.[6] Hemp has lower concentrations of THC and higher concentrations of cannabidiol (CBD), which decreases or eliminates its psychoactive effects.[6] The legality of industrial hemp varies widely between countries. Some governments regulate the concentration of THC and permit only hemp that is bred with an especially low THC content.[7][8]
Contents
Etymology[edit]
The etymology is uncertain but there appears to be no common Proto-Indo-European source for the various forms of the word; the Greek term kánnabis is the oldest attested form, which may have been borrowed from an earlier Scythian or Thracian word.[9][10] Then it appears to have been borrowed into Latin, and separately into Slavic and from there into Baltic, Finnish, and Germanic languages.[11] Following Grimm's law, the "k" would have changed to "h" with the first Germanic sound shift,[9][12] after which it may have been adapted into the Old English form, hænep. However, this theory assumes that hemp was not widely spread among different societies until after it was already being used as a psychoactive drug, which Adams and Mallory (1997) believe to be unlikely based on archaeological evidence.[9] Barber (1991) however, argued that the spread of the name "kannabis" was due to its historically more recent drug use, starting from the south, around Iran, whereas non-THC varieties of hemp are older and prehistoric.[11] Another possible source of origin is Assyrian qunnabu, which was the name for a source of oil, fiber, and medicine in the 1st millennium BC.[11]
Cognates of hemp in other Germanic languages include Dutch hennep, Danish and Norwegian hamp, German Hanf, and Swedish hampa.[9]
Uses[edit]
Hemp is used to make a variety of commercial and industrial products including rope, textiles, clothing, shoes, food, paper, bioplastics, insulation, and biofuel.[5] The bast fibers can be used to make textiles that are 100% hemp, but they are commonly blended with other fibers, such as flax, cotton or silk, as well as virgin and recycled polyester, to make woven fabrics for apparel and furnishings. The inner two fibers of the plant are more woody and typically have industrial applications, such as mulch, animal bedding and litter. When oxidized (often erroneously referred to as "drying"), hemp oil from the seeds becomes solid and can be used in the manufacture of oil-based paints, in creams as a moisturizing agent, for cooking, and in plastics. Hemp seeds have been used in bird feed mix as well.[13] A survey in 2003 showed that more than 95% of hemp seed sold in the European Union was used in animal and bird feed.[14]
Food[edit]
| Nutritional value per 100 g (3.5 oz) | |
|---|---|
| Energy | 2,451 kJ (586 kcal) |
4.67 g
| |
| Sugars | 1.50 g
0.07 g
|
| Dietary fiber | 4.0 g |
48.75 g
| |
| Saturated | 4.600 g |
| Trans | 0 g |
| Monounsaturated | 5.400 g |
| Polyunsaturated | 38.100 g
9.301 g
28.698 g
|
31.56 g
| |
| Tryptophan | 0.369 g |
| Threonine | 1.269 g |
| Isoleucine | 1.286 g |
| Leucine | 2.163 g |
| Lysine | 1.276 g |
| Methionine | 0.933 g |
| Cystine | 0.672 g |
| Phenylalanine | 1.447 g |
| Tyrosine | 1.263 g |
| Valine | 1.777 g |
| Arginine | 4.550 g |
| Histidine | 0.969 g |
| Alanine | 1.528 g |
| Aspartic acid | 3.662 g |
| Glutamic acid | 6.269 g |
| Glycine | 1.611 g |
| Proline | 1.597 g |
| Serine | 1.713 g |
| Vitamins | Quantity%DV† |
| Vitamin A equiv. |
0%
1 μg
0%
7 μg |
| Vitamin A | 11 IU |
| Thiamine (B1) |
111%
1.275 mg |
| Riboflavin (B2) |
24%
0.285 mg |
| Niacin (B3) |
61%
9.200 mg |
| Vitamin B6 |
46%
0.600 mg |
| Folate (B9) |
28%
110 μg |
| Vitamin B12 |
0%
0 μg |
| Vitamin C |
1%
0.5 mg |
| Vitamin E |
5%
0.80 mg |
| Minerals | Quantity%DV† |
| Calcium |
7%
70 mg |
| Copper |
80%
1.600 mg |
| Iron |
61%
7.95 mg |
| Magnesium |
197%
700 mg |
| Manganese |
362%
7.600 mg |
| Phosphorus |
236%
1650 mg |
| Potassium |
26%
1200 mg |
| Sodium |
0%
5 mg |
| Zinc |
104%
9.90 mg |
| Other constituents | Quantity |
| Water | 4.96 g |
| Cholesterol | 0 mg |
| |
| †Percentages are roughly approximated using US recommendations for adults. | |
Hemp seeds can be eaten raw, ground into hemp meal, sprouted or made into dried sprout powder. Hemp seeds can also be made into a liquid and used for baking or for beverages such as hemp milk and tisanes.[15] Hemp oil is cold-pressed from the seed and is high in unsaturated fatty acids.[16] The leaves of the hemp plant, while not as nutritional as the seeds, are edible and can be consumed raw as leafy vegetables in salads, and pressed to make juice.[17]
In 2011, the U.S. imported $11.5 million worth of hemp products, mostly driven by growth in the demand for hemp seed and hemp oil for use as ingredients in foods such as granola.[18]
In the UK, the Department for Environment, Food and Rural Affairs treats hemp as a purely non-food crop, but with proper licensing and proof of less than 0.2% THC concentration, hemp seeds can be imported for sowing or for sale as a food or food ingredient.[19] In the U.S., imported hemp can be used legally in food products and, as of 2000, was typically sold in health food stores or through mail order.[16]
Nutrition[edit]
A 100-gram portion of hulled hemp seeds supplies 586 calories. They contain 5% water, 5% carbohydrates, 49% total fat, and 31% protein. Hemp seeds are notable in providing 64% of the Daily Value (DV) of protein per 100-gram serving.[20] Hemp seeds are a rich source of dietary fiber (20% DV), B vitamins, and the dietary minerals manganese (362% DV), phosphorus (236% DV), magnesium (197% DV), zinc (104% DV), and iron (61% DV). About 73% of the energy in hempseed is in the form of fats and essential fatty acids,[20] mainly polyunsaturated fatty acids, linoleic, oleic, and alpha-linolenic acids.[21]
Hempseed's amino acid profile is comparable to other sources of protein such as meat, milk, eggs and soy.[21] Protein digestibility-corrected amino acid scores (PDCAAS), which attempt to measure the degree to which a food for humans is a "complete protein", were 0.49–0.53 for whole hemp seed, 0.46–0.51 for hempseed meal, and 0.63–0.66 for hulled hempseed.[22]
Storage[edit]
Hemp oil oxidizes and turns rancid within a short period of time if not stored properly;[16] its shelf life is extended when it is stored in a dark airtight container and refrigerated. Both light and heat can degrade hemp oil. [23]
Fiber[edit]
Hemp fiber has been used extensively throughout history, with production climaxing soon after being introduced to the New World. For centuries, items ranging from rope, to fabrics, to industrial materials were made from hemp fiber. Hemp was also commonly used to make sail canvas. The word "canvas" is derived from the word cannabis.[24][25] Pure hemp has a texture similar to linen.[26] Because of its versatility for use in a variety of products, today hemp is used in a number of consumer goods, including clothing, shoes, accessories, dog collars, and home wares.
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Building material[edit]
Concrete-like blocks made with hemp and lime have been used as an insulating material for construction. Such blocks are not strong enough to be used for structural elements; they must be supported by a brick, wood, or steel frame.[27] However, hemp fibres are extremely strong and durable, and have been shown to be usable as a replacement for wood for many jobs, including creating very durable and breathable homes. The most common use of hemp lime in building is by casting the hemp and lime mix while wet around a timber frame with temporary shuttering, and tamping the mix to form a firm mass; after the removal of the temporary shuttering, the solidified hemp mix is then ready to be plastered with a lime plaster.[28]
The first example of the use of hempcrete was in 1986 in France with the renovation of the Maison de la Turquie in Nogent-sur-Seine by the innovator Charles Rasetti.[29] In the UK hemp lime was first used in 2000 for the construction of two test dwellings in Haverhill.[30]Designed by Modece Architects,[31] who pioneered hemp's use in UK construction, the hemp houses were monitored in comparison with other standard dwellings by BRE. Completed in 2009, the Renewable House is one of the most technologically advanced made from hemp-based materials.[32] The first US home made of hemp-based materials was completed in August 2010 in Asheville, North Carolina.[33]
A panellized system of hemp-lime panels for use in building construction is currently under test in a European Union-funded research collaboration led by the University of Bath. The panels are being designed to assure high-quality construction, rapid on-site erection, optimal hygrothermal performance from day one, and energy- and resource-efficient buildings. The 36-month-long work programme aims to refine product and manufacturing protocols, produce data for certification and marketing, warranty, insurance cover, and availability of finance. It also includes the development of markets in Britain, France, and Spain.[34]
Hemp is used as an internal plaster and is a mixture of hemp hurd (shive) mixed with larger proportions of a lime-based binder. Hemp plaster has insulative qualities.[35]
Plastic and composite materials[edit]
A mixture of fiberglass, hemp fiber, kenaf, and flax has been used since 2002 to make composite panels for automobiles.[36] The choice of which bast fiber to use is primarily based on cost and availability. Various car makers are beginning to use hemp in their cars, including Audi, BMW, Ford, GM, Chrysler, Honda, Iveco, Lotus, Mercedes, Mitsubishi, Porsche, Saturn, Volkswagen[37] and Volvo. For example, the Lotus Eco Elise[38] and the Mercedes C-Class both contain hemp (up to 20 kg in each car in the case of the latter).[39]
Paper[edit]
Hemp paper are paper varieties consisting exclusively or to a large extent from pulp obtained from fibers of industrial hemp. The products are mainly specialty papers such as cigarette paper[40], banknotes and technical filter papers[41] . Compared to wood pulp, hemp pulp offers a four to five times longer fibre, a significantly lower lignin fraction as well as a higher tear resistance and tensile strength. However, production costs are about four times higher than for paper from wood[42], so hemp paper could not be used for mass applications as printing, writing and packaging paper.
Jewelry[edit]
Hemp jewelry is the product of knotting hemp twine through the practice of macramé. Hemp jewellery includes bracelets, necklaces, anklets, rings, watches and other adornments. Some jewellery features beads made from crystals, glass, stone, wood and bones. The hemp twine varies in thickness and comes in a variety of colors. There are many different stitches used to create hemp jewellery, however, the half knot and full knot stitches are most common.
Shoes[edit]
In recent years, hemp has been growing in popularity as a material used in shoes. Today you can find boots, athletic shoes, sandals, and dress shoes that are made with 100% hemp fiber, or textiles that blend hemp fibers with materials such as cotton, jute, virgin polyester, and recycled polyester. The strength of hemp fibers makes it an ideal material for shoes because it's durable. In addition, it's breathable and naturally antimicrobial, so it doesn't hold on to odors.[43] Because hemp can be grown sustainably, shoes, clothing, and accessories made with hemp are representative of the sustainable fashion movement.
Cordage[edit]
Hemp rope was used in the age of sailing ships, though the rope had to be protected by tarring, since hemp rope has a propensity for breaking from rot, as the capillary effect of the rope-woven fibers tended to hold liquid at the interior, while seeming dry from the outside.[44] Tarring was a labor-intensive process, and earned sailors the nickname "Jack Tar". Hemp rope was phased out when Manila, which does not require tarring, became widely available. Manila is sometimes referred to as Manila hemp, but is not related to hemp; it is abacá, a species of banana.
Animal bedding[edit]
Hemp shives are the core of the stem, hemp hurds are broken parts of the core. In the EU, they are used for animal bedding (horses, for instance), or for horticultural mulch.[45] Industrial hemp is much more profitable if both fibers and shives (or even seeds) can be used.
Water and soil purification[edit]
Hemp can be used as a "mop crop" to clear impurities out of wastewater, such as sewage effluent, excessive phosphorus from chicken litter, or other unwanted substances or chemicals. Additionally, hemp is being used to clean contaminants at the Chernobyl nuclear disaster site, by way of a process which is known as phytoremediation—the process of clearing radioisotopes and a variety of other toxins from the soil, water, and air.[46]
Weed control[edit]
Hemp crops are tall, have thick foliage, and can be planted densely, and thus can be grown as a smother crop to kill tough weeds.[47] Using hemp this way can help farmers avoid the use of herbicides, gain organic certification, and gain the benefits of crop rotation. However, due to the plant's rapid and dense growth characteristics, some jurisdictions consider hemp a prohibited and noxious weed, much like Scotch Broom.[citation needed]
Biofuels[edit]
Biodiesel can be made from the oils in hemp seeds and stalks; this product is sometimes called "hempoline".[48] Alcohol fuel (ethanol or, less commonly, methanol) can be made by fermenting the whole plant.
Filtered hemp oil can be used directly to power diesel engines. In 1892, Rudolf Diesel invented the diesel engine, which he intended to power "by a variety of fuels, especially vegetable and seed oils, which earlier were used for oil lamps, i.e. the Argand lamp."[49][50][51]
Production of vehicle fuel from hemp is very small. Commercial biodiesel and biogas is typically produced from cereals, coconuts, palmseeds and cheaper raw materials like garbage, wastewater, dead plant and animal material, animal feces and kitchen waste.[52]
Processing[edit]
Traditionally, hemp stalks would be water-retted first before the fibers were beaten off the inner hurd by hand, a process known as scutching. As mechanical technology evolved, separating the fiber from the core was accomplished by crushing rollers and brush rollers that would produce a nearly clean fiber. After the Marijuana Tax Act was implemented in 1938, the technology for separating the fibers from the core remained "frozen in time".
Only in 1997, did Ireland, parts of the Commonwealth and other countries begin to legally grow industrial hemp again. Iterations of the 1930s decorticator have been met with limited success, along with steam explosion and chemical processing known as thermomechanical pulping.[citation needed]
Cultivation[edit]
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Hemp is usually planted between March and May in the northern hemisphere, between September and November in the southern hemisphere.[53] It matures in about three to four months.
Millennia of selective breeding have resulted in varieties that display a wide range of traits; e.g. suited for a particular environments/latitudes, producing different ratios and compositions of terpenoids and cannabinoids (CBD, THC, CBG, CBC, CBN...etc.), fibre quality, oil/seed yield etc. Hemp grown for fiber is planted closely, resulting in tall, slender plants with long fibers.
Use of industrial hemp plant and its cultivation was commonplace until the 1900s, when it was associated with its genetic sibling aka Drug-Type Cannabis species (which contain higher levels of psychoactive THC). Influential groups misconstrued hemp as a dangerous 'drug', even though it is not a 'drug' and it has the potential to be a sustainable & profitable alternative crop.
In the United States, the public's perception of hemp as marijuana has blocked hemp from becoming a useful crop and product,"[54] in spite of its vital importance prior to World War II.[55] Ideally, according to Britain's Department for Environment, Food and Rural Affairs, the herb should be desiccated and harvested towards the end of flowering. This early cropping reduces the seed yield but improves the fiber yield and quality.[56] In these strains of industrial hemp* the tetrahydrocannabinol (THC) content would have been very low.[54]
The seeds are sown from mid-April to mid-May with grain drills to 4–6 cm sowing depth. Hemp needs less fertilizer than corn does. A total of 60–150 kg of nitrogen, 40–140 kg phosphorus (P2O5) and 75–200 kg of potassium [5] per acre for hemp fiber made before sowing and again later, maybe three to four weeks. When practiced, especially in France double use of fiber and seed fertilization with nitrogen doses up to 100 kg / ha rather low. Organic fertilizers such as manure can utilize industrial hemp well. Neither weeds nor crop protection measures are necessary.[54]
Cultivars[edit]
In contrast to cannabis for medical use, varieties grown for fiber and seed have less than 0.3% THC and are unsuitable for producing hashish and marijuana.[57] Present in industrial hemp, cannabidiol is a major constituent among some 560 compounds found in hemp.[58]
Cannabis sativa L. subsp. sativa var. sativa is the variety grown for industrial use, while C. sativa subsp. indica generally has poor fiber quality and female buds from this variety are primarily used for recreational and medicinal purposes. The major differences between the two types of plants are the appearance, and the amount of Δ9-tetrahydrocannabinol (THC) secreted in a resinous mixture by epidermal hairs called glandular trichomes, although they can also be distinguished genetically.[57][59] Oilseed and fiber varieties of Cannabis approved for industrial hemp production produce only minute amounts of this psychoactive drug, not enough for any physical or psychological effects. Typically, hemp contains below 0.3% THC, while cultivars of Cannabis grown for medicinal or recreational use can contain anywhere from 2% to over 20%.[60]
Harvesting[edit]
Smallholder plots are usually harvested by hand. The plants are cut at 2 to 3 cm above the soil and left on the ground to dry. Mechanical harvesting is now common, using specially adapted cutter-binders or simpler cutters.
The cut hemp is laid in swathes to dry for up to four days. This was traditionally followed by retting, either water retting (the bundled hemp floats in water) or dew retting (the hemp remains on the ground and is affected by the moisture in dew, and by molds and bacterialaction).
_culture_du_Chanvre.JPG)
Location and crop rotation[edit]
For profitable hemp farming, particularly deep, humus-rich, nutrient-rich soil with controlled water flow is preferable. Waterlogged acidic, compressed or extremely light (sandy) soils primarily affect the early development of plants.[citation needed] Steep and high altitudes of more than 400 m above sea level are best avoided. Hemp is relatively insensitive to cold temperatures and can withstand frost down to −5 °C.[citation needed] Seeds can germinate down to 1–3 °C.[citation needed] Hemp needs a lot of heat, so earlier varieties come to maturation. The water requirement is 300–500 l/kg dry matter.[citation needed] This is around 1/14th that of cotton, which takes between 7,000 and 29,000 l/kg, according to WWF.[citation needed] Roots can grow up to 3 feet into the soil and use water from deeper soil layers.
Hemp benefits crops grown after it. So, it is generally grown before winter cereals. Advantageous changes are high weed suppression, soil loosening by the large hemp root system, and the positive effect on soil tilth. Since hemp is very self-compatible, it can also be grown several years in a row in the same fields (monoculture).
Diseases[edit]
Hemp plants can be vulnerable to various pathogens, including bacteria, fungi, nematodes, viruses and other miscellaneous pathogens. Such diseases often lead to reduced fiber quality, stunted growth, and death of the plant. These diseases rarely affect the yield of a hemp field, so hemp production is not traditionally dependent on the use of pesticides.
Environmental impact[edit]
Hemp is considered by a 1998 study in Environmental Economics to be environmentally friendly due to a decrease of land use and other environmental impacts, indicating a possible decrease of ecological footprint in a US context compared to typical benchmarks.[61] A 2010 study, however, that compared the production of paper specifically from hemp and eucalyptus concluded that "industrial hemp presents higher environmental impacts than eucalyptus paper"; however, the article also highlights that "there is scope for improving industrial hemp paper production".[62] Hemp is also claimed to require few pesticides and no herbicides, and it has been called a carbon negative raw material.[63][64] Results indicate that high yield of hemp may require high total nutrient levels (field plus fertilizer nutrients) similar to a high yielding wheat crop.[65]
Producers[edit]
The world-leading producer of hemp is China, which produces more than 70% of the world output. France ranks second with about a quarter of the world production. Smaller production occurs in the rest of Europe, Chile, and North Korea. Over 30 countries produce industrial hemp, including Australia, Austria, Canada, Chile, China, Denmark, Egypt, Finland, Great Britain, Germany, Greece,[66] Hungary, India, Italy, Japan, Korea, Netherlands, New Zealand, Poland, Portugal, Romania, Russia, Slovenia, Spain, Sweden, Switzerland, Thailand, Turkey and Ukraine.[67][68]
The United Kingdom and Germany resumed commercial production in the 1990s. British production is mostly used as bedding for horses; other uses are under development. Companies in Canada, the UK, the United States, and Germany, among many others, process hemp seed into a growing range of food products and cosmetics; many traditional growing countries still continue to produce textile-grade fibre.
Air-dried stem yields in Ontario have from 1998 and onward ranged from 2.6-14.0 tonnes of dry, retted stalks per hectare (1-5.5 t/ac) at 12% moisture. Yields in Kent County, have averaged 8.75 t/ha (3.5 t/ac). Northern Ontario crops averaged 6.1 t/ha (2.5 t/ac) in 1998. Statistic for the European Union for 2008 to 2010 say that the average yield of hemp straw has varied between 6.3 and 7.3 ton per ha.[69][70] Only a part of that is bast fiber. Around one tonne of bast fiber and 2-3 tonnes of core material can be decorticated from 3-4 tonnes of good-quality, dry-retted straw. For an annual yield of this level is it in Ontario recommended to add nitrogen (N):70–110 kg/ha, phosphate(P2O5): up to 80 kg/ha and potash (K2O): 40–90 kg/ha.[71] The average yield of dry hemp stalks in Europe was 6 ton/ha (2.4 ton/ac) in 2001 and 2002.[14]
FAO argue that an optimum yield of hemp fiber is more than 2 tonnes per ha, while average yields are around 650 kg/ha.[72]
Australia[edit]
In the Australian states of Tasmania, Victoria, Queensland, New South Wales, and most recently, South Australia, the state governments have issued licences to grow hemp for industrial use. The first to initiate modern research into the potential of cannabis was the state of Tasmania, which pioneered the licensing of hemp during the early 1990s. The state of Victoria was an early adopter in 1998, and has reissued the regulation in 2008.[73]
Queensland has allowed industrial production under licence since 2002,[74] where the issuance is controlled under the Drugs Misuse Act 1986.[75] New South Wales now issues licences[76] under a law, the Hemp Industry Regulations Act 2008 (No 58), that came into effect as of 6 November 2008.[77] Most recently, South Wales legalized industrial hemp under South Australia’s Industrial Hemp Act 2017, which commenced on 12 November 2017.[78]
Canada[edit]
Commercial production (including cultivation) of industrial hemp has been permitted in Canada since 1998 under licenses and authorization issued by Health Canada (9,725 ha in 2004, 5450 ha in 2009).[79]
In the early 1990s, industrial hemp agriculture in North America began with the Hemp Awareness Committee at the University of Manitoba. The Committee worked with the provincial government to get research and development assistance, and was able to obtain test plot permits from the Canadian government. Their efforts led to the legalization of industrial hemp (hemp with only minute amounts of tetrahydrocannabinol) in Canada and the first harvest in 1998.[80][81]
In 2017, the cultivated area for hemp in the Prairie provinces include Saskatchewan with more than 56,000 acres (23,000 ha), Alberta with 45,000 acres (18,000 ha), and Manitoba with 30,000 acres (12,000 ha).[82] Canadian hemp is cultivated mostly for its food value as hulled hemp seeds, hemp oils and hemp protein powders, with only a small fraction devoted to production of hemp fiber used for construction and insulation.[82]
France[edit]
France is Europe's biggest producer (and the world's second largest producer) with 8,000 hectares cultivated.[83] 70-80% of the hemp fibre produced in 2003 was used for specialty pulp for cigarette papers and technical applications. About 15% was used in the automotive sector, and 5-6% was used for insulation mats. About 95% of hurds were used as animal bedding, while almost 5% was used in the building sector.[14] In 2010/2011, a total of 11,000 hectares (27,000 acres) was cultivated with hemp in the EU, a decline compared with previous year.[70][84]
Russia and Ukraine[edit]
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From the 1950s to the 1980s, the Soviet Union was the world's largest producer of hemp (3,000 km2 in 1970). The main production areas were in Ukraine,[85] the Kursk and Orel regions of Russia, and near the Polish border. Since its inception in 1931, the Hemp Breeding Department at the Institute of Bast Crops in Hlukhiv (Glukhov), Ukraine, has been one of the world's largest centers for developing new hemp varieties, focusing on improving fiber quality, per-hectare yields, and low THC content.[86][87]
After the collapse of the Soviet Union, the commercial cultivation of hemp declined sharply. However, at least an estimated 2.5 million acres of hemp grow wild in the Russian Far East and Black Sea regions.[88]
United Kingdom[edit]
In the United Kingdom, cultivation licences are issued by the Home Office under the Misuse of Drugs Act 1971. When grown for nondrug purposes, hemp is referred to as industrial hemp, and a common product is fibre for use in a wide variety of products, as well as the seed for nutritional aspects and for the oil. Feral hemp or ditch weed is usually a naturalized fibre or oilseed strain of Cannabis that has escaped from cultivation and is self-seeding.[89]
United States[edit]
Hemp was made illegal to grow without a permit in the U.S. under the Controlled Substances Act passed in 1970 because of its relation to marijuana,[18] and any imported hemp products must meet a zero tolerance level.[90] Some states have made the cultivation of industrial hemp legal, but farmers in many states have not yet begun to grow it because of resistance from the federal Drug Enforcement Administration,[91] making "large-scale hemp growing" in the United States "not viable" as late as 2013.[92] In 2013, after the legalization of cannabis in the state, several farmers in Colorado planted and harvested several acres of hemp, bringing in the first hemp crop in the United States in over half a century.[93] Colorado,[94] Vermont, California, and North Dakota have passed laws enabling hemp licensure. All four states are waiting for permission to grow hemp from the DEA. Currently,[95] Oregon has licensed industrial hemp as of August 2009.[96] Congress included a provision in the Agricultural Act of 2014 that allowed colleges and state agencies to grow and conduct research on hemp in states where it is legal.[18] Hemp production in Kentucky, formerly the United States' leading producer, resumed in 2014.[97] Hemp production in North Carolina resumed in 2017,[98] and in Washington State the same year.[99] By the end of 2017, at least 34 U.S. states had industrial hemp programs.[100] In 2018, New York began taking strides in industrial hemp production, along with hemp research pilot programs at Cornell University, Binghamton University and SUNY Morrisville.[101]
As of 2015 the hemp industry estimated that annual sales of hemp products were around US$600 million annually; hemp seeds have been the major force driving this growth.[102]
Yet, even with this progress, hemp businesses seem to face difficulty expanding in the US as they face challenges in traditional marketing and sales approaches. According to a case study done by Forbes, hemp businesses and startups have had difficulty marketing and selling non-psychoactive hemp products, as some online advertising platforms and financial institutions do not distinguish between hemp and marijuana.[103]
The Hemp Farming Act of 2018, part of the 2018 Farm Bill[104] signed by President Donald Trump December 20, 2018,[105] changed hemp from a controlled substance to an agricultural commodity, which made it easier for farmers to get loans to grow hemp, and allowed them to get federal crop insurance.[104]
History[edit]
Hemp is possibly one of the earliest plants to be cultivated.[107][108] An archeological site in the Oki Islands near Japan contained cannabis achenes from about 8000 BC, probably signifying use of the plant.[109] Hemp use archaeologically dates back to the Neolithic Age in China, with hemp fiber imprints found on Yangshao culture pottery dating from the 5th millennium BC.[106][110] The Chinese later used hemp to make clothes, shoes, ropes, and an early form of paper.[106] The classical Greek historian Herodotus (ca. 480 BC) reported that the inhabitants of Scythia would often inhale the vapors of hemp-seed smoke, both as ritual and for their own pleasurable recreation.[111]
Textile expert Elizabeth Wayland Barber summarizes the historical evidence that Cannabis sativa, "grew and was known in the Neolithic period all across the northern latitudes, from Europe (Germany, Switzerland, Austria, Romania, Ukraine) to East Asia (Tibet and China)," but, "textile use of Cannabis sativa does not surface for certain in the West until relatively late, namely the Iron Age."[112] "I strongly suspect, however, that what catapulted hemp to sudden fame and fortune as a cultigen and caused it to spread rapidly westwards in the first millennium B.C. was the spread of the habit of pot-smoking from somewhere in south-central Asia, where the drug-bearing variety of the plant originally occurred. The linguistic evidence strongly supports this theory, both as to time and direction of spread and as to cause."[113]
Jews living in Palestine in the 2nd century were familiar with the cultivation of hemp, as witnessed by a reference to it in the Mishna (Kil'ayim 2:5) as a variety of plant, along with Arum, that sometimes takes as many as three years to grow from a seedling. In late medieval Germany and Italy, hemp was employed in cooked dishes, as filling in pies and tortes, or boiled in a soup.[114] Hemp in later Europe was mainly cultivated for its fibers, and was used for ropes on many ships, including those of Christopher Columbus. The use of hemp as a cloth was centered largely in the countryside, with higher quality textiles being available in the towns.
The Spaniards brought hemp to the Americas and cultivated it in Chile starting about 1545.[115] Similar attempts were made in Peru, Colombia, and Mexico, but only in Chile did the crop find success.[116] In July 1605, Samuel Champlain reported the use of grass and hemp clothing by the (Wampanoag) people of Cape Cod and the (Nauset) people of Plymouth Bay told him they harvested hemp in their region where it grew wild to a height of 4 to 5 ft. [117] In May 1607, "hempe" was among the crops Gabriel Archer observed being cultivated by the natives at the main Powhatan village, where Richmond, Virginia is now situated;[118] and in 1613, Samuell Argall reported wild hemp "better than that in England" growing along the shores of the upper Potomac. As early as 1619, the first Virginia House of Burgesses passed an Act requiring all planters in Virginia to sow "both English and Indian" hemp on their plantations.[119] The Puritans are first known to have cultivated hemp in New England in 1645.[115]
United States[edit]
George Washington pushed for the growth of hemp and even grew hemp himself, as it was a cash crop commonly used to make rope and fabric. In May 1765 he noted in his diary about the sowing of seeds each day until mid-April. Then he recounts the harvest in October which he grew 27 bushels that year.
There is some speculation that George Washington smoked the flower of the cannabis plant in order to achieve a recreational high ("Like all farmers, Washington probably sampled the quality and potency of what he grew, and he may have used this hemp to treat his chronic tooth aches"),[55] but there is no evidence in any of his writings that he grew hemp for anything other than industrial purposes. It is sometimes supposed that an excerpt from Washington's diary, which reads "Began to seperate [sic] the Male from the Female hemp at Do.&—rather too late" is evidence that he was trying to grow female plants for the THC found in the flowers. However, the editorial remark accompanying the diary states that "This may arise from their [the male] being coarser, and the stalks larger"[120] In subsequent days, he describes soaking the hemp[121] (to make the fibers usable) and harvesting the seeds,[122] suggesting that he was growing hemp for industrial purposes, not recreational.
George Washington also imported the Indian Hemp plant from Asia, which was used for fiber and, by some growers, for intoxicating resin production. In a letter to William Pearce who managed the plants for him Washington says, "What was done with the Indian Hemp plant from last summer? It ought, all of it, to be sown again; that not only a stock of seed sufficient for my own purposes might have been raised, but to have disseminated seed to others; as it is more valuable than common hemp."[citation needed]
Additional presidents known to have farmed hemp include Thomas Jefferson,[123] James Madison, James Monroe, Andrew Jackson, Zachary Taylor, and Franklin Pierce. [124]
Historically, hemp production had made up a significant portion of antebellum Kentucky's economy. Before the American Civil War, many slaves worked on plantations producing hemp.[125]
In 1937, the Marihuana Tax Act of 1937 was passed in the United States, levying a tax on anyone who dealt commercially in cannabis, hemp, or marijuana. The passing of the Act to destroy the US hemp industry has been disputed to involve businessmen Andrew Mellon, Randolph Hearst and the Du Pont family.[126][127][128]
One claim is that Hearst believed[dubious ] that his extensive timber holdings were threatened by the invention of the decorticator which he feared would allow hemp to become a cheap substitute for the paper pulp used for newspaper.[126][129] Historical research indicates this fear was unfounded because improvements of the decorticators in the 1930s – machines that separated the fibers from the hemp stem – could not make hemp fiber a cheaper substitute for fibers from other sources. Further, decorticators did not perform satisfactorily in commercial production.[130][126]
Another claim is that Mellon, Secretary of the Treasury and the wealthiest man in America at that time, had invested heavily in DuPont's new synthetic fiber, nylon, and believed[dubious ] that the replacement of the traditional resource, hemp, was integral to the new product's success.[126][131][132][133][134][135][136][137] The company DuPont and many industrial historians dispute a link between nylon and hemp, nylon became immediately a scarce commodity.[clarification needed] Nylon had characteristics that could be used for toothbrushes (sold from 1938) and very thin nylon fiber could compete with silk and rayon in various textiles normally not produced from hemp fiber, such as very thin stockings for women.[130][138][139][140][141]
Hemp was used extensively by the United States during World War II to make uniforms, canvas, and rope.[142] Much of the hemp used was cultivated in Kentucky and the Midwest. During World War II, the U.S. produced a short 1942 film, Hemp for Victory, promoting hemp as a necessary crop to win the war.
- History in the United States
Historical cultivation[edit]
Hemp has been grown for millennia in Asia and the Middle East for its fibre. Commercial production of hemp in the West took off in the eighteenth century, but was grown in the sixteenth century in eastern England.[145] Because of colonial and naval expansion of the era, economies needed large quantities of hemp for rope and oakum. In the early 1940s, world production of hemp fiber ranged from 250 000 to 350 000 metric tonnes, Russia was the biggest producer.[130]
In Western Europe, the cultivation of hemp was not legally banned by the 1930s, but the commercial cultivation stopped by then, due to decreased demand compared to increasingly popular artificial fibers.[146] Speculation about the potential for commercial cultivation of hemp in large quantities has been criticized due to successful competition from other fibers for many products. The world production of hemp fiber fell from over 300,000 metric tons 1961 to about 75,000 metric tons in the early 1990s and has after that been stable at that level.[147]
Japan[edit]
In Japan, hemp was historically used as paper and a fiber crop. There is archaeological evidence cannabis was used for clothing and the seeds were eaten in Japan back to the Jōmon period (10,000 to 300 BC). Many Kimonodesigns portray hemp, or asa (Japanese: 麻), as a beautiful plant. In 1948, marijuana was restricted as a narcotic drug. The ban on marijuana imposed by the United States authorities was alien to Japanese culture, as the drug had never been widely used in Japan before. Though these laws against marijuana are some of the world's strictest, allowing five years imprisonment for possession of the drug, they exempt hemp growers, whose crop is used to make robes for Buddhist monks and loincloths for Sumo wrestlers. Because marijuana use in Japan has doubled in the past decade, these exemptions have recently been called into question.[148]
Portugal[edit]
The cultivation of hemp in Portuguese lands began around the fourteenth century onwards, it was raw material for the preparation of rope and plugs for the Portuguese ships. Colonies for factories for the production of flax hemp, such as the Royal Flax Hemp Factory in Brazil.
After the Restoration of Independence in 1640, in order to recover the ailing Portuguese naval fleet, were encouraged its cultivation as the Royal Decree of D. John IV in 1656. At that time its cultivation was carried out in Trás-os-Montes, Zone Tower Moncorvo, more precisely in Vilariça Valley, fertile land for any crop irrigation, and a very large area, flat and very fertile culture still wide until the last century grew up tobacco, a plant that needs a large space to expand and grow, the area lies in the valley of Serra de Bornes.
In 1971, the cultivation of hemp became illegal, and the production was substantially reduced. Because of EU regulations 1308/70, 619/71 and 1164/89, this law was revoked (for some certified seed varieties).[149]
See also[edit]
SOURCE
WHY was hemp banned for about 70 years and now its legal again? -Corruption and Money
INDUSTRIAL HEMP SOLUTIONS
Hemp: A New Crop with New Uses for North America*
Ernest Small and David Marcus
*This paper was considerably improved by criticism provided by A. McElroy.
“Hemp” refers primarily to Cannabis sativa L. (Cannabaceae), although the term has been applied to dozens of species representing at least 22 genera, often prominent fiber crops. For examples, Manila hemp (abaca) is Musa textilis Née, sisal hemp is Agave sisalina Perrine, and sunn hemp is Crotolaria juncea L. Especially confusing is the phrase “Indian hemp,” which has been used both for narcotic Asian land races of C. sativa (so-called C. indica Lamarck of India) and Apocynum cannabinum L., which was used by North American Indians as a fiber plant. Cannabis sativa is a multi-purpose plant that has been domesticated for bast (phloem) fiber in the stem, a multi-purpose fixed oil in the “seeds” (achenes), and an intoxicating resin secreted by epidermal glands. The common names hemp and marijuana (much less frequently spelled marihuana) have been applied loosely to all three forms, although historically hemp has been used primarily for the fiber cultigen and its fiber preparations, and marijuana for the drug cultigen and its drug preparations. The current hemp industry is making great efforts to point out that “hemp is not marijuana.” Italicized,Cannabis refers to the biological name of the plant (only one species of this genus is commonly recognized, C. sativa L.). Non-italicized, “cannabis” is a generic abstraction, widely used as a noun and adjective, and commonly (often loosely) used both for cannabis plants and/or any or all of the intoxicant preparations made from them.
Probably indigenous to temperate Asia, C. sativa is the most widely cited example of a “camp follower.” It was pre-adapted to thrive in the manured soils around man’s early settlements, which quickly led to its domestication (Schultes 1970). Hemp was harvested by the Chinese 8500 years ago (Schultes and Hofmann 1980). For most of its history, C. sativa was most valued as a fiber source, considerably less so as an intoxicant, and only to a limited extent as an oilseed crop. Hemp is one of the oldest sources of textile fiber, with extant remains of hempen cloth trailing back 6 millennia. Hemp grown for fiber was introduced to western Asia and Egypt, and subsequently to Europe somewhere between 1000 and 2000 BCE. Cultivation in Europe became widespread after 500 ce. The crop was first brought to South America in 1545, in Chile, and to North America in Port Royal, Acadia in 1606. The hemp industry flourished in Kentucky, Missouri, and Illinois between 1840 and 1860 because of the strong demand for sailcloth and cordage (Ehrensing 1998). From the end of the Civil War until 1912, virtually all hemp in the US was produced in Kentucky. During World War I, some hemp cultivation occurred in several states, including Kentucky, Wisconsin, California, North Dakota, South Dakota, Minnesota, Indiana, Illinois, Ohio, Michigan, Kansas, and Iowa (Ehrensing 1998). The second world war led to a brief revival of hemp cultivation in the Midwest, as well as in Canada, because the war cut off supplies of fiber (substantial renewed cultivation also occurred in Germany for the same reason). Until the beginning of the 19th century, hemp was the leading cordage fiber. Until the middle of the 19th century, hemp rivaled flax as the chief textile fiber of vegetable origin, and indeed was described as “the king of fiber-bearing plants,—the standard by which all other fibers are measured” (Boyce 1900). Nevertheless, the Marihuana Tax Act applied in 1938 essentially ended hemp production in the United States, although a small hemp fiber industry continued in Wisconsin until 1958. Similarly in 1938 the cultivation of Cannabis became illegal in Canada under the Opium and Narcotics Act.
Hemp, grown under license mostly in Canada, is the most publicized “new” crop in North America. Until very recently the prohibition against drug forms of the plant prevented consideration of cultivation of fiber and oilseed cultivars in Canada. However, in the last 10 years three key developments occurred: (1) much-publicized recent advances in the legal cultivation of hemp in western Europe, especially for new value-added products; (2) enterprising farmers and farm groups became convinced of the agricultural potential of hemp in Canada, and obtained permits to conduct experimental cultivation; and (3) lobby groups convinced the government of Canada that narcotic forms of the hemp plant are distinct and distinguishable from fiber and oilseed forms. In March 1998, new regulations (under the Controlled Drugs and Substances Act) were provided to allow the commercial development of a hemp industry in Canada, and since then more than a thousand licenses have been issued. Hectares licensed for cultivation for 1998–2001 were respectively, 2,500, 14,200, 5,487, and 1,355, the decreasing trend due to a glut of seed produced in 1999 and pessimism over new potential regulations barring exports to the US. Information on the commercial potential of hemp in Canada is in Blade (1998), Marcus (1998), and Pinfold Consulting (1998). In the US, a substantial trade in hemp products has developed, based on imports of hemp fiber, grain, and oil. The American agricultural community has observed this, and has had success at the state level in persuading legislators of the advisability of experimental hemp cultivation as a means of evaluating the wisdom of re-establishing American hemp production. However, because of opposition by the federal government, to date there has only been a small experimental plot in Hawaii. Information on the commercial potential of hemp in the US is presented in the following.
Cannabis sativa is extremely unusual in the diversity of products for which it is or can be cultivated. Popular Mechanics magazine (1938) touted hemp as “the new billion dollar crop,” stating that it “can be used to produce more than 25,000 products, ranging from dynamite to Cellophane.” Table 1 presents the principal products for which the species is cultivated in Europe, all of which happen to be based on fiber. This presentation stresses the products that hold the most promise for North America, which also include a considerable range of oilseed applications (Table 2; Fig. 1).
Table 1. Hemp fiber usage in the European Union in 1999 (after Karus et al. 2000).
| Class of product | Quantity consumed (tonnes) | Relative percentage |
| Specialty pulp (cigarette paper, bank notes, technical filters, and hygiene products) | 24,882 | 87 |
| Composites for autos | 1,770 | 6 |
| Construction & thermal insulation materials | 1,095 | 4 |
| Geotextiles | 234 | 0.8 |
| Other | 650 | 2.2 |
| Total | 26,821 | 100 |
| Seeds (achenes) | Long ("bark) fiber | Woody stem core | Female floral (perigonal) bract | Whole plant |
| Confectionary, baked goods | Plastic-molded products | Animal bedding | Medicinal cannabinoids | Alcohol |
| Salad oil | Specialty papers | Thermal insulation | Essential oil (for flavor & perfume) | Fuel |
| ody care "cosmetics | Construction fiberboard | Construction (fiberboard, plaster board, etc.) | Insect repellant | Silage |
| Animal food (whole seeds for birds, presscake for mammalian livestock) | Biodegradable landscape matting & plant culture products | |||
| Gamma-linolenic acid dietary supplements | Coarse textiles (carpets, upholstery) | |||
| Specialty industrial oils | Fine textiles |
Fig. 1. Major uses of industrial hemp.
BASIC CATEGORIES OF CANNABIS AND THEIR FIELD ARCHITECTURE
Cannabis sativa is an annual wind-pollinated plant, normally dioecious and dimorphic, although sometimes monoecious (mostly in several modern European fiber cultivars). Figure 2 presents the basic morphology of the species. Some special hybrids, obtained by pollinating females of dioecious lines with pollen from monoecious plants, are predominantly female (so-called “all-female,” these generally also produce some hermaphrodites and occasional males). All-female lines are productive for some purposes (e.g. they are very uniform, and with very few males to take up space they can produce considerable grain), but the hybrid seed is expensive to produce. Staminate or “male” plants tend to be 10%–15% taller and are less robust than the pistillate or “female” (note the comparatively frail male in Fig. 3). So prolific is pollen production that an isolation distance of about 5 km is usually recommended for generating pure-bred foundation seed. A “perigonal bract” subtends each female flower, and grows to envelop the fruit. While small, secretory, resin-producing glands occur on the epidermis of most of the above-ground parts of the plant, the glands are very dense and productive on the perigonal bracts, which are accordingly of central interest in marijuana varieties. The root is a laterally branched taproot, generally 30–60 cm deep, up to 2.5 m in loose soils, very near the surface and more branched in wet soils. Extensive root systems are key to the ability of hemp crops to exploit deep supplies of nutrients and water. The stems are erect, furrowed, and usually branched, with a woody interior, and may be hollow in the internodes. Although the stem is often woody, the species is frequently referred to as a herb or forb. Plants vary enormously in height depending on genetic constitution and environment (Fig. 4), but are typically 1–5 m (heights of 12 m or more in cultivation have been claimed).
Fig. 2. Cannabis sativa. This superb composite plate by artist Elmer Smith, often reproduced at a very small scale and without explanation in marijuana books, is the best scientific illustration of the hemp plant ever prepared. 1. Flowering branch of male plant. 2. Flowering branch of female plant. 3. Seedling. 4. Leaflet. 5. Cluster of male flowers. 6. Female flower, enclosed by perigonal bract. 7. Mature fruit enclosed in perigonal bract. 8. Seed (achene), showing wide face. 9. Seed, showing narrow face. 10. Stalked secretory gland. 11. Top of sessile secretory gland. 12. Long section of cystolith hair (note calcium carbonate concretion at base). Reproduced with the permission of Harvard University, Cambridge, MA.
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| Fig. 3. Photograph of Cannabis sativa. Left, staminate (“male”) plant in flower; right, pistillate (“female”) plant in flower. | Fig. 4. United States National Institute of Health, University of Mississippi marijuana plantation site, showing variation in plant size. A tall fiber-type of hemp plant is shown at left, and a short narcotic variety (identified as “Panama Gold”) at right. |
Fig. 5. Typical architecture of categories of cultivated Cannabis sativa. Top left: narcotic plants are generally low, highly branched, and grown well-spaced. Top right: plants grown for oilseed were traditionally well-spaced, and the plants developed medium height and strong branching. Bottom left: fiber cultivars are grown at high density, and are unbranched and very tall. Bottom center: “dual purpose” plants are grown at moderate density, tend to be slightly branched and of medium to tall height. Bottom right: some recent oilseed cultivars are grown at moderate density and are short and relatively unbranched. Degree of branching and height are determined both by the density of the plants and their genetic background.
Highly selected forms of the fiber cultigen possess features maximizing fiber production. Since the nodes tend to disrupt the length of the fiber bundles, thereby limiting quality, tall, relatively unbranched plants with long internodes have been selected. Another strategy has been to select stems that are hollow at the internodes, with limited wood, since this maximizes production of fiber in relation to supporting woody tissues. Similarly, limited seed productivity concentrates the plant’s energy into production of fiber, and fiber cultivars often have low genetic propensity for seed output. Selecting monoecious strains overcomes the problem of differential maturation times and quality of male (staminate) and female (pistillate) plants (males mature 1–3 weeks earlier). Male plants in general are taller, albeit slimmer, less robust, and less productive. Except for the troublesome characteristic of dying after anthesis, male traits are favored for fiber production, in contrast to the situation for drug strains noted below. In former, labor-intensive times, the male plants were harvested earlier than the females, to produce superior fiber. The limited branching of fiber cultivars is often compensated for by possession of large leaves with wide leaflets, which obviously increase the photosynthetic ability of the plants. Since fiber plants have not generally been selected for narcotic purposes, the level of intoxicating constituents is usually limited.
An absence of such fiber-strain traits as tallness, limited branching, long internodes, and very hollow stems, is characteristic of narcotic strains. Drug forms have historically been grown in areas south of the north-temperate zone, often close to the equator, and are photoperiodically adapted to a long season. When grown in north-temperate climates maturation is much-delayed until late fall, or the plants succumb to cold weather before they are able to produce seeds. Unlike fiber strains that have been selected to grow well at extremely high densities, drug strains tend to be less persistent when grown in high concentration (de Meijer 1994). Drug strains can be very similar in appearance to fiber strains. However, a characteristic type of narcotic plant was selected in southern Asia, particularly in India and neighboring countries. This is dioecious, short (about a meter in height), highly branched, with large leaves (i.e. wide leaflets), and it is slow to mature. The appearance is rather like a short, conical Christmas tree.
Until recent times, the cultivation of hemp primarily as an oilseed was largely unknown, except in Russia. Today, it is difficult to reconstruct the type of plant that was grown there as an oilseed, because such cultivation has essentially been abandoned. Oilseed hemp cultivars in the modern sense were not available until very recently, but some land races certainly were grown specifically for seeds in Russia. Dewey (1914) gave the following information: “The short oil-seed hemp with slender stems, about 30 inches high, bearing compact clusters of seeds and maturing in 60 to 90 days, is of little value for fiber production, but the experimental plants, grown from seed imported from Russia, indicate that it may be valuable as an oil-seed crop to be harvested and threshed in the same manner as oil-seed flax.” Most hemp oilseed in Europe is currently obtained from so-called “dual usage” plants (employed for harvest of both stem fiber and seeds, from the same plants). Of the European dual-usage cultivars, ‘Uniko B’ and ‘Fasamo’ are particularly suited to being grown as oilseeds. Very recently, cultivars have been bred specifically for oilseed production. These include ‘Finola,’ formerly known as ‘Fin-314’ (Fig. 6) and ‘Anka’ (Fig. 7), which are relatively short, little-branched, mature early in north-temperate regions, and are ideal for high-density planting and harvest with conventional equipment. Dewey (1914) noted that a Turkish narcotic type of land race called “Smyrna” was commonly used in the early 20th century in the US to produce birdseed, because (like most narcotic types of Cannabis) it is densely branched, producing many flowers, hence seeds. While oilseed land races in northern Russia would have been short, early-maturing plants in view of the short growing season, in more southern areas oilseed landraces likely had moderate height, and were spaced more widely to allow abundant branching and seed production to develop. Until Canada replaced China in 1998 as a source of imported seeds for the US, most seeds used for various purposes in the US were sterilized and imported from China. Indeed, China remains the largest producer of hempseed. We have grown Chinese hemp land races, and these were short, branched, adapted to a very long growing season (i.e. they come into flower very slowly in response to photoperiodic induction of short days in the fall), and altogether they were rather reminiscent of Dewey’s description of Smyrna. Although similar in appearance to narcotic strains of C. sativa, the Chinese land races we grew were in fact low in intoxicating constituents, and it may well be that what Dewey thought was a narcotic strain was not. Although some forms of C. sativa have quite large seeds, until recently oilseed forms appear to have been mainly selected for a heavy yield of seeds, usually recognizable by abundant branching. Such forms are typically grown at lower densities than hemp grown only for fiber, as this promotes branching, although it should be understood that the genetic propensity for branching has been selected. Percentage or quality of oil in the seeds does not appear to have been important in the past, although selection for these traits is now being conducted. Most significantly, modern selection is occurring with regard to mechanized harvesting, particularly the ability to grow in high density as single-headed stalks with very short branches bearing considerable seed.
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| Fig. 6. ‘Finola,’ the first cultivar of Cannabis sativa bred exclusively for grain. (Courtesy of the breeder, J.C. Callaway, Univ. Kuopio, Finland.) | Fig. 7. ‘Anka,’ the first registered North American bred cultivar of Cannabis sativa. This variety is best suited for grain production. (Courtesy of the breeder, P. Dragla, and of the Industrial Hemp Seed Development Company, Chatham, Ontario.) |
CONTROLLING THE DRUG ABUSE POTENTIAL OF HEMP
As detailed below, the development of hemp as a new legal crop in North America must be considered in relation to illicit cultivation, so it is important to appreciate the scope of the drug situation. Up until the first half of the 20th century, drug preparations of Cannabis were used predominantly as a recreational inebriant in poor countries and the lower socio-economic classes of developed nations. After World War II, marijuana became associated with the rise of a hedonistic, psychedelic ethos, first in the United States and eventually over much of the world, with the consequent development of a huge international illicit market that exceeds the value of the hemp market during its heyday. Table 3 shows the “economic significance” (dollars generated in the black market plus dollar cost of control measures) of the illicit drug industry associated with C. sativa, and contrasts this with the estimated dollar value of major categories of legitimate uses. In the Netherlands, the annual value of narcotic hemp cultivation (ca. $10 billion) exceeds the value of tulips (Collins 1999). Marijuana has become the most widely disseminated illicit species in the world (Schultes and Hofmann 1980). With the exception of alcohol, it is the most widely used recreational euphoric drug. About 25% of North Americans are believed to have used Cannabis illegally. According to the US National Institute on Drug Abuse (www.nida.nih.gov/Infofax/marijuana.html), more than 72 million Americans (33%) 12 years of age and older have tried marijuana. Cultivation, commerce, and consumption of drug preparations of Cannabis have been proscribed in most countries during the present century. The cost of enforcing the laws against Cannabis in North America is in the billions of dollars annually. In addition, there are substantial social costs, such as adverse effects on users, particularly those who are convicted. Tragically this includes some legitimate farmers who, faced with financial ruin because of the unprofitability of crops being grown, converted to growing marijuana.Table 3. Comparative annual world economic significance of categories of Cannabis activity.
| Category | World ($) | North America ($) | Type of investment |
| Recreational drugs | > 1 trillion | 100s of billions | Law enforcement, eradication, education |
| Industrial hemp | 100s of millionsz | 10s of millions | Production, development, marketing, research |
| Therapeutic drugs | 100s of millions | 10s of millions | Production, development, marketing, research |
| Phytoremediation | 10s of thousands | nil | Research |
| Ornamental hemp | thousands | nil | Development |
A rather thorough analysis of the scope of the illicit marijuana industry in Canada for 1998 is reported at www.rcmp-grc.gc.ca/html/drugsituation.htm#Marihuana and summarized in MacLeod (1999). At least 800 tonnes (t) of marijuana were grown in Canada in 1998, representing a harvest of 4.7 million flowering plants. More than 50% of the marijuana available in Canada is grown domestically. An average mature plant was estimated to produce 170 g of “marketable substance.” The value of the Canadian crop is uncertain, but has been estimated to be in the billions of dollars annually (Heading 1998; MacLeod 1999).
The US Drug Enforcement Administration’s online criminal justice statistics for 2000 (cscmosaic.albany.edu/sourcebook/1995/pdf/t440.pdf) shows the following seizures and eradication of plants of C. sativa: 40,929 outdoor plots (2,597,796 plants), 139,580,728 ditchweed (ruderal plants), 2,361 indoor operations (217,105 plants), for a grand total of 2,814, 903 plants destroyed. Impressively, the species was grown in all 50 states (including outdoor seizures in every state except Wyoming)! It is of course impossible to know exactly how much marijuana is cultivated in the United States, and perhaps only 10% to 20% of the amount grown is seized. The profitability of the illegal crop is indicated by a comparison of the cost of a bushel of corn (roughly $2.50) and a bushel of manicured marijuana (about $70,000; it has been suggested that prices range from $500 a pound, for low-quality marijuana, to more than $5,000 a pound for “boutique” strains like “Northern Lights” and “Afghan Kush”). According to a National Organization for the Reform of Marijuana Laws (NORML) (mir.drugtext.org/marijuananews/marijuana_ranks_fourth_largest_c.htm) marijuana is at least the fourth most valuable crop in America, outranked only by corn, soybeans, and hay. It was estimated that 8.7 million marijuana plants were harvested in 1997, worth $15.1 billion to growers and $25.2 billion on the retail market (the wholesale value was used to compare marijuana to other cash crops). Marijuana was judged to be the largest revenue producing crop in Alabama, California, Colorado, Hawaii, Kentucky, Maine, Rhode Island, Tennessee, Virginia, and West Virginia, and one of the top five cash crops in 29 other states.
Cannabis contains a seemingly unique class of chemicals, the cannabinoids, of which more than 60 have been described, but only a few are psychoactive. Cannabinoids are produced in specialized epidermal glands, which differ notably in distribution on different organs of the plant (high concentrations occur on the upper surface of the young leaves and young twigs, on the tepals, stamens, and especially on the perigonal bract). Given this distribution, the glands would seem to be protective of young and reproductive above-ground tissues (the roots lack glands). Two classes of epidermal glands occur—stalked and sessile (Fig. 8), but in either case the glandular cells are covered by a sheath under which resin is accumulated, until the sheath ruptures, releasing resin on the surface. The resin is a sticky mixture of cannabinoids and a variety of terpenes. The characteristic odor of the plant is due to the abundant terpenes, which are not psychoactive. The more important cannabinoids are shown in Fig. 9. In the plant the cannabinoids exist predominantly in the form of carboxylic acids, which decarboxylate with time or when heated. Delta-9-tetrahydrocannabinol (D9-THC, or simply THC) is the predominant psychoactive component. Other THC isomers also occur, particularly D8-THC, which is also psychoactive. Technically, the euphoric psychological effects of THC are best described by the word psychotomimetic. Cannabidiol (CBD) is the chief non-psychotomimetic cannabinoid. A THC concentration in marijuana of approximately 0.9% has been suggested as a practical minimum level to achieve the (illegal) intoxicant effect, but CBD (the predominant cannabinoid of fiber and oilseed varieties) antagonizes (i.e. reduces) the effects of THC (Grotenhermen and Karus 1998). Concentrations of 0.3% to 0.9% are considered to have “only a small drug potential” (Grotenhermen and Karus 1998). Some cannabinoid races have been described, notably containing cannabichromene (particularly in high-THC forms) and cannabigerol monomethyl ether (in some Asian strains). The biosynthetic pathways of the cannabinoids are not yet satisfactorily elucidated, although the scheme shown in Fig. 10 is commonly accepted. At least in some strains, THC is derived from cannabigerol, while in others it may be derived from CBD. CBN and D8-THC are considered to be degradation products or analytical artifacts (Pate 1998a).
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| Fig. 8. Scanning electron micrographs of the abaxial surface of a perigonal bract (which envelops the fruit). These bracts are the most intoxicating part of the plant, and may contain 20% THC, dry weight. The resin is synthesized both in stalked and sessile glands. Multicellular secretory glands (of phallic appearance), some broken stalks of these (note cellular appearance), and unicellular cystolith hairs (claw-like structures) are pictured. | Fig. 9. Some important cannabinoids of cannabis resin. D9-THC (delta-9 tetrahydrocannabinol) is the chief intoxicant chemical and predominates in intoxicant strains, while the isomer D8-THC is usually present in no more than trace amounts. CBD (cannabidiol) is the chief non-intoxicant chemical, and predominates in non-intoxicant strains; it has sedative effects. The non-intoxicant CBN (cannabinol) is a frequent degradation or oxidation product. The non-intoxicant cannabichromene (CBC) is typically found in trace amounts in intoxicant strains. The non-intoxicant cannabigerol (CBG) is considered to be a precursor of the other cannbinoids (see Fig. 10). |
Fig. 10. Proposed biosynthetic pathways of the principal cannabinoids (after Pate 1998b).
Both in Canada and the US, the most critical problem to be addressed for commercial exploitation of C. sativa is the possible unauthorized drug use of the plant. Indeed, the reason hemp cultivation was made illegal in North America was concern that the hemp crop was a drug menace. The drug potential is, for practical purposes, measured by the presence of THC. THC is the world’s most popular illicit chemical, and indeed the fourth most popular recreational drug, after caffeine, alcohol, and nicotine. “Industrial hemp” is a phrase that has become common to designate hemp used for commercial non-intoxicant purposes. Small and Cronquist (1976) split C. sativa into two subspecies: C. sativa subsp. sativa, with less than 0.3% (dry weight) of THC in the upper (reproductive) part of the plant, and C. sativa subsp. indica (Lam.) E. Small & Cronq. with more than 0.3% THC. This classification has since been adopted in the European Community, Canada, and parts of Australia as a dividing line between cultivars that can be legally cultivated under license and forms that are considered to have too high a drug potential. For a period, 0.3% was also the allowable THC content limit for cultivation of hemp in the Soviet Union. In the US, Drug Enforcement Agency guidelines issued Dec. 7, 1999 expressly allowed products with a THC content of less than 0.3% to enter the US without a license; but subsequently permissible levels have been a source of continuing contention. Marijuana in the illicit market typically has a THC content of 5% to 10% (levels as high as 25% have been reported), and as a point of interest, a current Canadian government experimental medicinal marijuana production contract calls for the production of 6% marijuana. As noted above, a level of about 1% THC is considered the threshold for marijuana to have intoxicating potential, so the 0.3% level is conservative, and some countries (e.g. parts of Australia, Switzerland) have permitted the cultivation of cultivars with higher levels. It should be appreciated that there is considerable variation in THC content in different parts of the plant. THC content increases in the following order: achenes (excluding bracts), roots, large stems, smaller stems, older and larger leaves, younger and smaller leaves, flowers, perigonal bracts covering both the female flowers and fruits. It is well known in the illicit trade how to screen off the more potent fractions of the plant in order to increase THC levels in resultant drug products. Nevertheless, a level of 0.3% THC in the flowering parts of the plant is reflective of material that is too low in intoxicant potential to actually be used practically for illicit production of marijuana or other types of cannabis drugs. Below, the problem of permissible levels of THC in food products made from hempseed is discussed.
There is a general inverse relationship in the resin of Cannabis between the amounts of THC present and the amount of the other principal cannabinoid, CBD. Whereas most drug strains contain primarily THC and little or no CBD, fiber and oilseed strains primarily contain CBD and very little THC. CBD can be converted to THC by acid catalyzed cyclization, and so could serve as a starting material for manufacturing THC. In theory, therefore, low-THC cultivars do not completely solve the problem of drug abuse potential. In practice, however, the illicit drug trade has access to easier methods of synthesizing THC or its analogues than by first extracting CBD from non-drug hemp strains.
Breeding for low THC cultivars in Europe has been reviewed by Bócsa (1998), Bócsa and Karus (1998), and Virovets (1996). Some researchers have claimed to have produced essentially THC-free strains, although at present no commercial cultivar seems to be 100% free of THC. THC content has proven to be more easily reduced in monoecious than in dioecious varieties. It should be possible to select THC-free strains, and there has been speculation that genetic engineering could be helpful in this regard. As a strategic economic and political tactic, France has been attempting for several years to have the European Union (EU) adopt legislation forbidding the cultivation of industrial hemp cultivars with more than 0.1% THC, which would mean that primarily French varieties would have to be cultivated in Europe. However, the Canadian government has found that some French material has proven to be excessively high in THC.
There is certainly a need to utilize available germplasm sources in order to breed suitable cultivars for North America. A list of the 24 approved cultivars for the 2001 season in Canada is at www.hc-sc.gc.ca/hpb-dgps/therapeut/htmleng/hemp.html. Most of these are regulated by the European Organization of Economic Cooperation and Development (OECD). These cultivars are “approved” for use in Canada not on agricultural criteria, but merely on the basis that they meet the THC criterion. Indeed, most of these are unsuitable or only marginally suitable for Canada (Small and Marcus 2000), and only a very few Canadian cultivars to date have been created. In Canada, every acquisition of hemp grown at a particular place and time must be tested for THC content by an independent laboratory and, under the industrial hemp regulations, fields of hemp with more than 0.3% THC may require destruction (a slight degree of flexibility is generally exercised). Importation of experimental hemp lines (i.e. other than the approved cultivars) requires importation licenses (as well as phytosanitary clearance of the shipment by the Canadian Food Inspection Agency), and the importation licenses require an indication that the THC contents are low.
In Canada, the methodology used for analyses and sample collection for THC analysis of hemp plantings is standardized (at the Health Canada/Therapeutics Program/Hemp web site at www.hc-sc.gc.ca/hpb-dgps/therapeut/htmleng/hemp.html, see “Industrial Hemp Technical Manual” for procedures on sampling plant materials and chemical procedures for determining THC levels). The regulations require that one of the dozen independent laboratories licensed for the purpose conduct the analyses and report the results to Health Canada. Sample collection is also normally carried out by an independent authorized firm. The Canadian system of monitoring THC content has rigidly limited hemp cultivation to cultivars that consistently develop THC levels below 0.3%.
Because C. sativa has been a neglected crop for so long in North America, there are only negligible genetic resources available on this continent. Most germplasm stocks of hemp are in Europe, and the largest and most important collection is the Vavilov Institute gene bank in Leningrad. Figure 11 shows THC concentrations in the Vavilov collection, as well as in our own collection, largely of European germplasm. A disturbingly high percentage of the collections have THC levels higher than 0.3%, making it difficult to incorporate these into breeding programs.
Fig. 11. Frequency histograms of THC concentration in germplasm collections. Left, collection of E. Small and D. Marcus; of the 167 accessions, 43% had THC levels >0.3%. Right, the collection of the Vavilov Institute, St. Petersburg; of the 278 accessions for which chemical analyses were reported in Anonymous (1975), about 55% had THC levels >0.3%.
Soil characteristics, latitude and climatic stresses have been found to have significant effects on THC concentrations, and there are seasonal and even diurnal variations (Small 1979; Pate 1998b). However, the range of THC concentrations developed by low-THC cultivars (those typically with £0.3% THC) under different circumstances on the whole is limited, for the most part generally not varying more than 0.2 percentage points when grown in a range of circumstances, and usually less (note information in Scheifle et al. 1999; Scheifle 2000, Scheifle and Dragla 2000). Practically, this has meant in Canadian experience that a few cultivars have been eliminated from further commercial cultivation because they sometimes exceed the 0.3% level (‘Fedora 19’ and ‘Futura,’ authorized in 2000, have now been removed because some test results in several years exceeded 0.3%; ‘Finola’ and ‘Uniko B’ are under probation because of elevated levels), but on the whole most of the permitted cultivars have maintained highly consistent development of quite low levels of THC.
Hemp seeds contain virtually no THC, but THC contamination results from contact of the seeds with the resin secreted by the epidermal glands on the leaves and floral parts, and also by the failure to sift away all of the bracts (which have the highest concentration of THC of any parts of the plant) that cover the seeds. This results in small levels of THC appearing in hempseed oil and foods made with the seeds. Although most of the western hemp-growing world uses 0.3% THC as a maximum concentration for authorized cultivation of hemp plants, regulations in various countries allow only a much lower level of THC in human food products manufactured from the seeds. Currently, up to 10 ppm THC is permitted in seeds and oil products used for food purposes in Canada. In Germany, more stringent limits were set for food in 2000: 5 ppm in food oil, 0.005 ppm in beverages, and 0.15 ppm in all other foods. The US Drug Enforcement Administration published new regulations on hemp in the Federal Register on October 9th 2001 that in effect 4 months later would ban the food use of hemp in the US because any amount of THC would be unacceptable in foods (follow links at www.hempreport.com/). These proposals are currently being challenged by the hemp industry. Limits have been set because of concerns about possible toxicity and interference with drug tests (Grotenhermen et al. 1998). An extensive analysis of literature dealing with the toxicity of hemp is in Orr and Starodub (1999; see Geiwitz 2001 for an analysis). Because hemp food products are considered to have great economic potential, there is considerable pressure on the hemp industry in North America to reduce THC levels.
The Drug Enforcement Agency and the Office of National Drug Control Policy of the US raised concerns over tests conducted from 1995 to 1997 that showed that consumption of hempseed products available during that period led to interference with drug-testing programs for marijuana use. Federal US programs utilize a THC metabolite level of 50 parts per billion in urine. Leson (2000) found that this level was not exceeded by consuming hemp products, provided that THC levels are maintained below 5 ppm in hemp oil, and below 2 ppm in hulled seeds. Nevertheless the presence of even minute trace amounts of THC in foods remains a tool that can be used by those wishing to prevent the hemp oilseed industry from developing.
FIBER USES
Based on world production of fibers in 1999, about 54.5% was synthetic (of which 60.3% was polyester), 42.9% was plant fiber (of which 78.5% was cotton), and 2.6% was wool (Karus 2000). In addition to cotton, flax is the only other significant plant fiber crop grown in temperate regions of the world (kenaf has received some enthusiastic backing in the southern US in recent years, but is most cheaply produced in India, Bangladesh, and China). Flax held 2.7% of the world plant fiber market in 1999, while hemp had only 0.3% (Karus 2000). Hemp fiber can potentially replace other biological fibers in many applications, but also, as noted below, can sometimes compete with minerals such as glass fiber and steel. As forests diminish, cultivation of annual plants as fiber sources is likely to increase. While crop residues like cereal straw will probably supply much of the need, specialty fiber plants such as hemp also have potential. The four conditions that will need to be met are (after Bolton 1995): (1) the material should be produced at a large enough scale; (2) the price should be low enough; (3) the fiber characteristics should be adequate for the end use; and (4) proven technology should be available for the processing of the new raw material. Of these criteria only point 3 is adequately met at this time for hemp in North America, but this is to be expected in a crop that has only begun to be cultivated after an absence of many years.One of the reasons hemp fiber has been valued is because of its length. The primary bast fibers in the bark are 5–40 mm long, and are amalgamated in fiber bundles which can be 1–5 m long (secondary bast fibers are about 2 mm long). The woody core fibers are short—about 0.55 mm—and like hardwood fibers are cemented together with considerable lignin. The core fibers are generally considered too short for high grade paper applications (a length of 3 mm is considered ideal), and too much lignin is present. While the long bast fibers have been used to make paper almost for 2 millennia, the woody core fibers have rarely been so used. Nevertheless it has been suggested that the core fibers could be used for paper making, providing appropriate technology was developed (de Groot et al. 1998). In any event, the core fibers, have found a variety of uses, as detailed below. The long, lignin-poor bast fibers also have considerable potential to be used in many non-paper, non-textile applications, as noted below.
Selection for fiber has resulted in strains that have much more bark fiber tissues and much less woody core than encountered in narcotic strains, oilseed strains, and wild plants (Fig. 12). In non-fiber strains of Cannabis, bark can be less than one quarter of the stem tissues (i.e. more than three quarters can be woody core). By contrast, in fiber strains half of the stem tissues can be bark, and more than half of this can be the desirable long primary fibers (de Meijer 1995). Non-fiber strains rarely have as much as 15% fiber in the bark.
Fig. 12. Cross sections of stems at internodes of a fiber plant (left) and of a narcotic plant (right). Fiber cultivars have stems that are more hollow at the internodes, i.e. less wood, since this allows more energy to be directed into the production of bark fiber.
Other desirable features of hemp fibers are strength and durability (particularly resistance to decay), which made hemp useful in the past for rope, nets, sail-cloth, and oakum for caulking. During the age of sailing ships, Cannabis was considered to provide the very best of canvas, and indeed this word is derived from Cannabis. Several factors combined to decrease the popularity of hemp in the late 19th and early 20th centuries. Increasing limitation of cheap labor for traditional production in Europe and the New World led to the creation of some mechanical inventions, but too late to counter growing interest in competitive crops. Development of other natural fibers as well as synthetic fibers increased competition for hemp’s uses as a textile fiber and for cordage. Hemp rag had been much used for paper, but the 19th century introduction of the chemical woodpulping process considerably lowered demand for hemp. The demise of the sail diminished the market for canvas. Increasing use of the plant for drugs gave hemp a bad image. All this led to the discontinuation of hemp cultivation in the early and middle parts of the 20th century in much of the world where cheap labor was limited. In the 19th century softer fabrics took over the clothing market, and today, hemp constitutes only about 1% of the natural fiber market. At least some production of hemp for fiber still occurs in Russia, China, the Ukraine, Poland, Hungary, the countries of the former Yugoslavia, Romania, Korea, Chile, and Peru. There has been renewed interest in England, Australia, and South Africa in cultivating fiber hemp. Italy has an outstanding reputation for high-quality hemp, but productivity has waned for the last several decades. In France, a market for high-quality paper, ironically largely cigarette paper, has developed (such paper is completely free of the intoxicating resin). Modern plant breeding in Europe has produced several dozen hemp strains, although by comparison with other fiber crops there are relatively few described varieties of hemp. Since World War II, breeding has been concerned most particularly with the development of monoecious varieties. Gehl (1995) reviewed fiber hemp development in Canada in the early 20th century, and concluded that the prospects for a traditional fiber industry were poor. However, as outlined below, there are now many non-traditional usages for hemp fiber which require consideration. Hemp long fiber is one of the strongest and most durable of natural fibers, with high tensile strength, wet strength, and other characteristics that make it technically suited for various industrial products (Karus and Leson 1996).
From 1982 to 2002 the EU provided the equivalent of about 50 million dollars to develop new flax and hemp harvesting and fiber processing technologies (Karus et al. 2000). Because of the similarities of flax and hemp, the technologies developed for one usually are adaptable to the other. In addition, various European nations and private firms contributed to the development of hemp technologies. Accordingly, Europe is far more advanced in hemp development with respect to all fiber-based applications than other parts of the world. The EU currently dedicates about 30,000 ha to hemp production. France is the leading country in hemp cultivation in the EU, and 95% of the non-seed production is used for “specialty pulp” as described below. Harvesting and processing machinery for fiber hemp is highly advanced in Europe, and some has been imported into Canada. However, there is insufficient fiber processing capacity to handle hemp produced in Canada.
Textiles
Hemp is a bast fiber crop, i.e. the most desirable (“long”) fibers are found in the phloem-associated tissues external to the phloem, just under the “bark.” The traditional and still major first step in fiber extraction is to ret (“rot”) away the softer parts of the plant, by exposing the cut stems to microbial decay in the field (“dew retting,” shown in Figs. 46 and 47) or submerged in water (“water retting, ” shown in Fig. 13). The result is to slough off the outer parts of the stem and to loosen the inner woody core (the “hurds”) from the phloem fibers (Fig. 14). Water retting has been largely abandoned in countries where labor is expensive or environmental regulations exist. Water retting, typically by soaking the stalks in ditches, can lead to a high level of pollution. Most hemp fiber used in textiles today is water retted in China and Hungary. Retting in tanks rather than in open bodies of water is a way of controlling the effluents while taking advantage of the high-quality fiber that is produced. Unlike flax, hemp long fiber requires water retting for preparation of high-quality spinnable fibers for production of fine textiles. Improved microorganisms or enzymes could augment or replace traditional water retting. Steam explosion is another potential technology that has been experimentally applied to hemp (Garcia-Jaldon et al. 1998). Decorticated material (i.e. separated at least into crude fiber) is the raw material, and this is subjected to steam under pressure and increased temperature which “explodes” (separates) the fibers so that one has a more refined (thinner) hemp fiber that currently is only available from water retting. Even when one has suitably separated long fiber, specialized harvesting, processing, spinning and weaving equipment are required for preparing fine hemp textiles. The refinement of equipment and new technologies are viewed as offering the possibility of making fine textile production practical in western Europe and North America, but at present China controls this market, and probably will remain dominant for the foreseeable future. |  |
| Fig. 13. Water retting of hemp in Yugoslavia. (Courtesy of Dr. J. Berenji, Institute of Field and Vegetable Crops, Novi Sad.) | Fig. 14. Fiber in retted hemp stem. This stem was bent sharply after retting, breaking the woody central portion (hurds), leaving the bark fibers unbroken. The two portions of stem are separated in this photograph, and are joined by the tough bark fibers. |
Although always sold at a premium price, hemp clothing has a natural appeal to a sector of the population. Hemp clothes are resistant to abrasion, but are typically abrasive. However, appropriate processing and blending with other natural fibers has significantly improved the “feel” of the product, and in China hemp textiles indistinguishable from fine linens in texture are available. Weaving of hemp fibers into textiles and apparel is primarily done in China, Hungary, Romania, Russia, and the Ukraine. Processing costs are higher for industrial hemp because the fibers vary from the standard specifications for fiber length and diameter established for the equipment used in most textile and apparel factories, necessitating the use of specialty machines. The North American hemp apparel industry today is based on fiber, yarn, and fabrics imported from Eastern Europe and China. The extraction technology and spinning facilities, to say nothing of much lower labor costs, make it very difficult for the potential development of a hemp textile industry in North America. The fact that spinning facilities for natural fibers are so concentrated in China is making it increasingly difficult to competitively produce hemp fabrics elsewhere. This of course lessens the value-added future of growing hemp for a potential textile industry in North America. It is possible, however, that new technologies could change this situation, and especially in the EU development is underway to establish a fledgling domestic hemp textile industry. In addition to textiles used in clothing, coarser woven cloth (canvas) is used for upholstery, bags, sacks, and tarpaulins. There is very little effort in North America to produce such woven products, and non-woven material (Fig. 15) can be more easily produced. Hempline in Ontario, the first firm to grow hemp for commercial purposes in North America since the second word war (starting with experimental cultivation in 1994), is the exception, and is concerned with production of fiber for upholstery and carpeting.
Fig. 15. Multi-purpose matting, fabricated from hemp. (Courtesy of Kenex Ltd., Pain Court, Ontario.)
Pulp and Paper
Van Roekel (1994) has pointed out that Egyptian papyrus sheets are not “paper,” because the fiber strands are woven, not “wet-laid;” the oldest surviving paper is over 2,000 years of age, from China, and was made from hemp fiber (Fleming and Clarke 1998). Until the early 19th century, hemp, and flax were the chief paper-making materials. In historical times, hemp rag was processed into paper. Using hemp directly for paper was considered too expensive, and in any event the demand for paper was far more limited than today. Wood-based paper came into use when mechanical and chemical pulping was developed in the mid 1800s in Germany and England. Today, at least 95% of paper is made from wood pulp.The pulp and paper industry based on wood has considered the use of hemp for pulp, but only on an experimental basis. Hemp’s long fibers could make paper more recyclable. Since virgin pulp is required for added strength in the recycling of paper, hemp pulp would allow for at least twice as many cycles as wood pulp. However, various analyses have concluded that the use of hemp for conventional paper pulp is not profitable (Fertig 1996).
“Specialty pulp” is the most important component of the hemp industry of the EU, and is expected to remain its core market for the foreseeable future. The most important specialty pulp products made from hemp are cigarette paper (Fig. 16), bank notes, technical filters, and hygiene products. Other uses include art papers and tea bags. Several of these applications take advantage of hemp’s high tear and wet strength. This is considered to be a highly stable, high-priced niche market in Europe, where hemp has an 87% market share of the “specialty pulp” sector (Karus et al. 2000). In Europe, decortication/refining machines are available that can produce 10 t/hour of hemp fiber suitable for such pulp use. North American capacity for hemp pulp production and value-added processing is much more limited than that of Europe, and this industry is negligible in North America.
Fig. 16. Hemp cigarette paper, the most profitable paper product currently manufactured from hemp.
Hemp paper is useful for specialty applications such as currency and cigarette papers where strength is needed. The bast fiber is of greatest interest to the pulp and paper industry because of its superior strength properties compared to wood. However, the short, bulky fibers found in the inner part of the plant (hurds) can also be used to make cheaper grades of paper, apparently without greatly affecting quality of the printing surface. Hemp is not competitive for newsprint, books, writing papers, and general paper (grocery bags, coffee cups, napkins), although there is a specialty or novelty market for those specifically wishing to support the hemp industry by purchasing hemp writing or printing paper despite the premium price (Fig. 17).
Fig. 17. Hemp paper products (writing paper, notebook, envelopes).
A chief argument that has been advanced in favor of developing hemp as a paper and pulp source has been that as a non-wood or tree-free fiber source, it can reduce harvesting of primary forests and the threat to associated biodiversity. It has been claimed that hemp produces three to four times as much useable fiber per hectare per annum as forests. However, Wong (1998) notes evidence that in the southern US hemp would produce only twice as much pulp as does a pine plantation (but see discussion below on suitability of hemp as a potential lumber substitute in areas lacking trees).
Hemp paper is high-priced for several reasons. Economies of scale are such that the supply of hemp is minute compared to the supply of wood fiber. Hemp processing requires non-wood-based processing facilities. Hemp paper is typically made only from bast fibers, which require separation from the hurds, thereby increasing costs. This represents less than 50% of the possible fiber yield of the plant, and future technologies that pulp the whole stalks could decrease costs substantially. Hemp is harvested once a year, so that it needs to be stored to feed mills throughout the year. Hemp stalks are very bulky, requiring much handling and storage. Transportation costs are also very much higher for hemp stalks than for wood chips. Waste straw is widely available from cereals and other crops, and although generally not nearly as desirable as hemp, can produce bulk pulp far more cheaply than can be made from hemp. In addition to agricultural wastes, there are vast quantities of scrub trees, especially poplar, in northern areas, that can supply large amounts of low-quality wood fiber extremely cheaply. Moreover, in northern areas fast-growing poplars and willows can be grown, and such agro-forestry can be very productive and environmentally benign. And, directly or indirectly, the lumber/paper industry receives subsidies and/or supports, which is most unlikely for hemp.
Plastic Composites for the Automobile and Other Manufacturing Sectors
With respect to fiber, a “composite” is often defined as a material consisting of 30%–70% fiber and 70%–30% matrix (Bolton 1995). However, in North America particleboards and fiberboards, which generally contain less than 10% adhesive or matrix, are sometimes referred to as composites. This section addresses plastic-type composites. In plastics, fibers are introduced to improve physical properties such as stiffness, impact resistance, bending and tensile strength. Man-made fibers of glass, kevlar and carbon are most commonly used today, but plant fibers offer considerable cost savings along with comparable strength properties.Plastic composites for automobiles are the second most important component of the hemp industry of the EU. Natural fibers in automobile composites are used primarily in press-molded parts (Fig. 18). There are two widespread technologies. In thermoplastic production, natural fibers are blended with polypropylene fibers and formed into a mat, which is pressed under heat into the desired form. In thermoset production the natural fibers are soaked with binders such as epoxy resin or polyurethane, placed in the desired form, and allowed to harden through polymerization. Hemp has also been used in other types of thermoplastic applications, including injection molding. The characteristics of hemp fibers have proven to be superior for production of molded composites. In European manufacturing of cars, natural fibers are used to reinforce door panels, passenger rear decks, trunk linings, and pillars. In 1999 over 20,000 t of natural fiber were used for these purposes in Europe, including about, 2,000 t of hemp. It has been estimated that 5–10 kg of natural fibers can be used in the molded portions of an average automobile (excluding upholstery). The demand for automobile applications of hemp is expected to increase considerably, depending on the development of new technologies (Karus et al. 2000).
Fig. 18. C-class Mercedes-Benz automobiles have more than 30 parts made of natural fibers, including hemp. (Courtesy of T. Schloesser, Daimler-Chrysler.)
Henry Ford recognized the utility of hemp in early times. In advance of today’s automobile manufacturers, he constructed a car with certain components made of resin stiffened with hemp fiber (Fig. 19). Rather ironically in view of today’s parallel situation, Henry Ford’s hemp innovations in the 1920s occurred at a time of crisis for American farms, later to intensify with the depression. The need to produce new industrial markets for farm products led to a broad movement for scientific research in agriculture that came to be labeled “Farm Chemurgy,” that today is embodied in chemical applications of crop constituents.
Fig. 19. Henry Ford swinging an axe at his 1941 car to demonstrate the toughness of the plastic trunk door made of soybean and hemp. (From the collections of Henry Ford Museum & Greenfield Village.)
There is also considerable potential for other industries using hemp in the manner that the automobile industry has demonstrated is feasible. Of course, all other types of transportation vehicles from bicycles to airplanes might make use of such technology. Natural fibers have considerable advantages for use in conveyance (Karus et al. 2000): low density and weight reduction, favorable mechanical, acoustical, and processing properties (including low wear on tools), no splintering in accidents, occupational health benefits (compared to glass fibers), no off-gassing of toxic compounds, and price advantages. Additional types of composite using hemp in combination with other natural fibers, post-industrial plastics or other types of resins, are being used to produce non-woven matting for padding, sound insulation, and other applications.
Building Construction Products
Thermal Insulation. Thermal insulation products (Fig. 20, 21) are the third most important sector of the hemp industry of the EU. These are in very high demand because of the alarmingly high costs of heating fuels, ecological concerns about conservation of non-renewable resources, and political-strategic concerns about dependence on current sources of oil. This is a market that is growing very fast, and hemp insulation products are increasing in popularity. In Europe, it has been predicted that tens of thousands of tonnes will be sold by 2005, shared between hemp and flax (Karus et al. 2000). |  |
| Fig. 20. Spun, loosely compacted hemp insulation. (Manufactured by La Chanvrière de l’Aube, France.) | Fig. 21. Loose Isochanvre® thermal insulation being placed between joists. (Courtesy of M. Périer, Chènovotte Habitat, France.) |
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| Fig. 22. Experimental fiberboard made with hemp. (Courtesy Dr. K. Domier, Univ. Alberta, Edmonton.) | Fig. 23. Molded fiberboard products. (Courtesy of HempFlax, Oude Pekela, The Netherlands). |
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| Fig. 24. New building in France being constructed entirely of hemp. Wall castings are a conglomerate of Isochanvre® lime-hemp, for production of a 200 mm thick monolithic wall without an interior wall lining. (Courtesy of M. Périer, Chènovotte Habitat, France.) | Fig. 25. The “hemp house” under construction on the Oglala Lakota Nation (Pine Ridge Reservation), South Dakota. Foundation blocks for the house are made with hemp fiber as a binder in cement. Stucco is also of hemp. Shingles are 60% hemp in a synthetic polymer. Hemp insulation is used throughout. (Courtesy of Oglala Sioux Tribe, Slim Butte Land Use Association, and S. Sauser.) |
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| Fig. 26. Renovation of plaster walls of a traditional timber frame 16th century house (Mansion Raoul de la Faye, Paris) with Isochanvre® lime-hemp conglomerate. (Courtesy of M. Périer, Chènovotte Habitat, France.) | Fig. 27. Hemp “ceramic tile.” (Courtesy of Kenex Ltd., Pain Court, Ontario.) |
Animal Bedding
The woody core (hurds, sometimes called shives) of hemp makes remarkably good animal bedding (Fig. 28, 29). The hurds are sometimes molded into small pellets for bedding applications (Fig. 30). Such appears to be unsurpassed for horse bedding, and also make an excellent litter for cats and other pets (Fig. 31). The hurds can absorb up to five times their weight in moisture (typically 50% higher than wood shavings), do not produce dust (following initial dust removal), and are easily composted. Hemp bedding is especially suited to horses allergic to straw. In Europe, the animal bedding market is not considered important (Karus et al. 2000), but in North America there are insufficient hemp hurds available to meet market demand. |  |
| Fig. 28. Commercial warehouse of baled hemp animal bedding. (Courtesy of Kenex Ltd., Pain Court, Ontario.) | Fig. 29. Animal bedding made from hemp hurds. |
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| Fig. 30. Pelleted hemp hurds. (Courtesy of La Chanvrière de l’Aube, Bar sur Aube, France.) | Fig. 31. Songbirds on hemp litter. (Courtesy of La Chanvrière de l’Aube, Bar sur Aube, France.) |
Geotextiles
“Geotextiles” or “agricultural textiles” include (1) ground-retaining, biodegradable matting designed to prevent soil erosion, especially to stabilize new plantings while they develop root systems along steep highway banks to prevent soil slippage (Fig. 32); and (2) ground-covers designed to reduce weeds in planting beds (in the manner of plastic mulch). At present the main materials used are polymeric (polythene, spun-blown polypropylene) and some glass fiber and natural fibers. Both woven and non-woven fibers can be applied to geotextiles; woven and knitted materials are stronger and the open structure may be advantageous (e.g. in allowing plants to grow through), but non-wovens are cheaper and better at suppressing weeds. Flax and hemp fibers exposed to water and soil have been claimed to disintegrate rapidly over the course of a few months, which would make them unacceptable for products that need to have long-term stability when exposed to water and oil. Coco (coir) fiber has been said to be much more suitable, due to higher lignin content (40%–50%, compared to 2%–5% in bast fibers); these are much cheaper than flax and hemp fibers (Karus et al. 2000). However, this analysis does not do justice to the developing hemp geotextile market. Production of hemp erosion control mats is continuing in both Europe and Canada. Given the reputation for rot resistance of hemp canvas and rope, it seems probable that ground matting is a legitimate use. Moreover, the ability to last outdoors for many years is frequently undesirable in geotextiles. For example, the widespread current use of plastic netting to reinforce grass sod is quite objectionable, the plastic persisting for many years and interfering with lawn care. Related to geotextile applications is the possibility of using hemp fiber as a planting substrate (biodegradable pots and blocks for plants), and as biodegradable twine to replace plastic ties used to attach plants to supporting poles. Still another consideration is the “green ideal” of producing locally for local needs; by this credo, hemp is preferable in temperate regions to the use of tropical fibers, which need to be imported.
Fig. 32. Hemp-based erosion control blanket. Top left: Close-up of 100% hemp fiber blanket. Top right: Grass growing through blanket. Bottom: Demonstration of installation of blanket, near La Rivière, Manitoba. (Courtesy of Mark Myrowich, ErosionControlBlanket.com)
OILSEED USES
The cultivation of hemp in the EU is heavily weighted toward fiber production over oilseed production. In 1999, the EU produced about 27,000 t of hemp fiber, but only about 6,200 t of hemp seeds, mostly in France, and 90% of this was used as animal feed (Karus et al. 2000). The seeds (Fig. 33) have traditionally been employed as bird and poultry feed, but feeding the entire seeds to livestock has been considered to be a poor investment because of the high cost involved (although subsidization in Europe allows such usage, especially in France where hemp seeds are not legally permitted in human food). As pointed out later, higher yield and better harvesting practices may make whole hempseed an economical livestock feed. Moreover, seed cake left after expressing the oil is an excellent feed. Efforts are underway in Europe to add value in the form of processed products for hemp, especially cosmetics and food but, as noted below, the North American market is already quite advanced in oilseed applications.
Fig. 33. “Seeds” (achenes) of hemp, with a match for scale.
In the EU and Canada, hemp has often been grown as a dual-purpose crop, i.e. for both fiber and oilseed. In France, dual purpose hemp is typically harvested twice—initially the upper seed-bearing part of the stems is cut and threshed with a combine, and subsequently the remaining stems are harvested. Growing hemp to the stage that mature seeds are present compromises the quality of the fiber, because of lignification. As well, the hurds become more difficult to separate. The lower quality fiber, however, is quite utilizable for pulp and non-woven usages.
In North America, oilseed hemp has several advantages over fiber hemp. Hemp seed and oil can fetch higher prices than hemp fiber. Hemp seed can be processed using existing equipment, while processing of hemp fiber usually requires new facilities and equipment.
Canada is specialized on oilseed production and processing, so that hemp oil and grain are much more suitable than fiber. Because of the extensive development of oilseeds in Canada, there is extensive capacity to produce high-quality cold-pressed hemp oil. Canada in the last 5 years has made great advances in the growing, harvesting, and processing of hempseed, and indeed has moved ahead of the EU in the development of raw materials and products for the natural foods, nutraceuticals, and cosmetics industries. In the EU, a yield of 1 t/ha is considered good. In Canada, extraordinary yields of 1.5 t/ha have been realized, at least locally, although in the initial years of hempseed development in Canada yields were often less than 500 kg/ha. In 1999, the year of largest Canadian hemp acreage, yields averaged 900 kg/ha. (Ideally, hemp seed yield should be based on air dry weight—with about 12% moisture. Hemp yields are sometime uncertain, and could be exaggerated by as much as 50% when moist weights are reported.)
Canadian experience with growing hemp commercially for the last 4 years has convinced many growers that it is better to use a single-purpose cultivar, seed or fiber, than a dual-purpose cultivar. The recent focus of Canadian hemp breeders has been to develop cultivars with high seed yields, low stature (to avoid channeling the plants’ energy into stalk, as is the case in fiber cultivars), early maturation (for the short growing seasons of Canada), and desirable fatty acid spectrum (especially gamma-linolenic acid).
Food
Dehulled (i.e. hulled) hemp seed is a very recent phenomenon, first produced in quantity in Europe. Hemp seeds have been used as food since ancient times, but generally the whole seed, including the hull, was eaten. Hemp seed was a grain used in ancient China, although there has been only minor direct use of hemp seed as food by humans. In the past, hemp seed has generally been a food of the lower classes, or a famine food. Peanut-butter type preparations have been produced from hemp seed in Europe for centuries, but were rather gritty since technology for removing the hulls was rudimentary. Modern seed dehulling using mechanical separation produces a smooth, white, gritless hemp seed meal that needs no additional treatment before it is consumed. It is important to understand, therefore, that the quality of modern hemp seed for human consumption far exceeds anything produced historically. This seed meal should be distinguished from the protein-rich, oil-poor seed cake remaining after oil has been expressed, that is used for livestock feed. The seed cake is also referred to as “seed meal,” and has proven to be excellent for animals (Mustafa et al. 1999).Hemp seeds have an attractive nutty taste, and are now incorporated into many food preparations (Fig. 34), often mimicking familiar foods. Those sold in North America include nutritional (granola-type) or snack bars, “nut butters” and other spreads, bread, pretzels, cookies, yogurts, pancakes, porridge, fruit crumble, frozen dessert (“ice cream”), pasta, burgers, pizza, salt substitute, salad dressings, mayonnaise, “cheese,” and beverages (“milk,” “lemonade,” “beer,” “wine,” “coffee nog”). Hemp seed is often found canned or vacuum-packed (Fig. 35). Alcoholic beverages made with hemp utilize hempseed as a flavorant. Hemp food products currently have a niche market, based particularly on natural food and specialty food outlets.
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| Fig. 34. Some North American food products made with hemp seed and/or hemp seed oil. | Fig. 35. Canned hulled hemp seed. (Courtesy of Kenex Ltd., Pain Court, Ontario.) |
Edible Oil
The use of Cannabis for seed oil (Fig. 36) began at least 3 millennia ago. Hempseed oil is a drying oil, formerly used in paints and varnishes and in the manufacture of soap. Present cultivation of oilseed hemp is not competitive with linseed for production of oil for manufacturing, or to sunflower and canola for edible vegetable oil. However, as noted below, there are remarkable dietary advantages to hempseed oil, which accordingly has good potential for penetrating the salad oil market, and for use in a very wide variety of food products. There is also good potential for hemp oil in cosmetics and skin-care products.
Fig. 36. Hemp oil. (Courtesy of La Chanvrière de l’Aube, Bar sur Aube, France.)
Foreign sources, China in particular, can produce hemp seed cheaply, but imported seed must be sterilized, and the delays this usually requires are detrimental. Seed that has been sterilized tends to go rancid quickly, and so it is imperative that fresh seed be available, a great advantage for domestic production. An additional extremely significant advantage that domestic producers have over foreign sources is organic production, which is important for the image desired by the hemp food market. Organic certification is much more reliable in North America than in the foreign countries that offer cheap seeds. Whereas China used to supply most of the hempseed used for food in North America, Canadian-grown seeds have taken over this market.
About half of the world market for hemp oil is currently used for food and food supplements (de Guzman 2001). For edible purposes, hempseed oil is extracted by cold pressing. Quality is improved by using only the first pressing, and minimizing the number of green seeds present. The oil varies in color from off-yellow to dark green. The taste is pleasantly nutty, sometimes with a touch of bitterness. Hemp oil is high in unsaturated fatty acids (of the order of 75%), which can easily oxidize, so it is unsuitable for frying or baking. The high degree of unsaturation is responsible for the extreme sensitivity to oxidative rancidity. The oil has a relatively short shelf life. It should be extracted under nitrogen (to prevent oxidation), protected from light by being kept in dark bottles, and from heat by refrigeration. Addition of anti-oxidants prolongs the longevity of the oil. Steam sterilization of the seeds, often required by law, allows air to penetrate and so stimulates rancidity. Accordingly, sterilized or roasted hemp seeds, and products made from hemp seed that have been subjected to cooking, should be fresh. The value of hemp oil from the point of view of the primary components is discussed below. In addition, it has been suggested that other components, including trace amounts of terpenes and cannabinoids, could have health benefits (Leizer et al. 2000). According to an ancient legend (Abel 1980), Buddha, the founder of Buddhism, survived a 6-year interval of asceticism by eating nothing but one hemp seed daily. This apocryphal story holds a germ of truth—hemp seed is astonishingly nutritional.
Fatty Acids. The quality of an oil or fat is most importantly determined by its fatty acid composition. Hemp is of high nutritional quality because it contains high amounts of unsaturated fatty acids, mostly oleic acid (C18:1, 10%–16%), linoleic acid (C18:2, 50%–60%), alpha-linolenic acid (C18:3, 20%–25%), and gamma-linolenic acid (C18:3, 2%–5%) (Fig. 37). Linoleic acid and alpha-linolenic acid are the only two fatty acids that must be ingested and are considered essential to human health (Callaway 1998). In contrast to shorter-chain and more saturated fatty acids, these essential fatty acids do not serve as energy sources, but as raw materials for cell structure and as precursors for biosynthesis for many of the body’s regulatory biochemicals. The essential fatty acids are available in other oils, particularly fish and flaxseed, but these tend to have unpleasant flavors compared to the mellow, slightly nutty flavor of hempseed oil. While the value of unsaturated fats is generally appreciated, it is much less well known that the North American diet is serious nutritionally unbalanced by an excess of linoleic over alpha-linonenic acid. In hempseed, linoleic and alpha-linolenic occur in a ratio of about 3:1, considered optimal in healthy human adipose tissue, and apparently unique among common plant oils (Deferne and Pate 1996). Gamma-linolenic acid or GLA is another significant component of hemp oil (1%–6%, depending on cultivar). GLA is a widely consumed supplement known to affect vital metabolic roles in humans, ranging from control of inflammation and vascular tone to initiation of contractions during childbirth. GLA has been found to alleviate psoriasis, atopic eczema, and mastalgia, and may also benefit cardiovascular, psychiatric, and immunological disorders. Ageing and pathology (diabetes, hypertension, etc.) may impair GLA metabolism, making supplementation desirable. As much as 15% of the human population may benefit from addition of GLA to their diet. At present, GLA is available in health food shops and pharmacies primarily as soft gelatin capsules of borage or evening primrose oil, but hemp is almost certainly a much more economic source. Although the content of GLA in the seeds is lower, hemp is far easier to cultivate and higher-yielding. It is important to note that hemp is the only current natural food source of GLA, i.e. not requiring the consumption of extracted dietary supplements. There are other fatty acids in small concentrations in hemp seed that have some dietary significance, including stearidonic acid (Callaway et al. 1996) and eicosenoic acid (Mölleken and Theimer 1997). Because of the extremely desirable fatty acid constitution of hemp oil, it is now being marketed as a dietary supplement in capsule form (Fig. 38).
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| Fig. 37. Content of principal fatty acids in hempseed oil, based on means of 62 accessions grown in southern Ontario (reported in Small and Marcus 2000). | Fig. 38. Hemp oil in capsule form sold as a dietary supplement. |
Protein. Hemp seeds contain 25%–30% protein, with a reasonably complete amino acid spectrum. About two thirds of hempseed protein is edestin. All eight amino acids essential in the human diet are present, as well as others. Although the protein content is smaller than that of soybean, it is much higher than in grains like wheat, rye, maize, oat, and barley. As noted above, the oilcake remaining after oil is expressed from the seeds is a very nutritious feed supplement for livestock, but it can also be used for production of a high-protein flour.
Personal Care Products
In the 1990s, European firms introduced lines of hemp oil-based personal care products, including soaps, shampoos, bubble baths, and perfumes. Hemp oil is now marketed throughout the world in a range of body care products, including creams, lotions, moisturizers, and lip balms. In Germany, a laundry detergent manufactured entirely from hemp oil has been marketed. Hemp-based cosmetics and personal care products account for about half of the world market for hemp oil (de Guzman 2001).One of the most significant developments for the North American hemp industry was investment in hemp products by Anita and Gordon Roddick, founders of The Body Shop, a well known international chain of hair and body care retailers. This was a rather courageous and principled move that required overcoming American legal obstacles related to THC content. The Body Shop now markets an impressive array of hemp nutraceutical cosmetics (Fig. 39), and this has given the industry considerable credibility. The Body Shop has reported gross sales of about a billion dollars annually, and that about 4% of sales in 2000 were hemp products.
Fig. 39. Body care products offered by the Body Shop. (“Chanvre” is French for hemp.)
Industrial Fluids
The vegetable oils have been classified by “iodine value” as drying (120–200), semi-drying (100–120), and non-drying (80–100), which is determined by the degree of saturation of the fatty acids present (Raie et al. 1995). Good coating materials prepared from vegetable oil depend on the nature and number of double bonds present in the fatty acids. Linseed oil, a drying oil, has a very high percentage of linolenic acid. Hempseed oil has been classified as a semi-drying oil, like soybean oil, and is therefore more suited to edible than industrial oil purposes. Nevertheless hemp oil has found applications in the past in paints, varnishes, sealants, lubricants for machinery, and printing inks. However, such industrial end uses are not presently feasible as the oil is considered too expensive (de Guzman 2001). Larger production volumes and lower prices may be possible, in which case hemp oil may find industrial uses similar to those of linseed (flax), soybean, and sunflower oils, which are presently used in paints, inks, solvents, binders, and in polymer plastics. Hemp shows a remarkable range of variation in oil constituents, and selection for oilseed cultivars with high content of valued industrial constituents is in progress.MEDICINAL MARIJUANA
Marijuana has in fact been grown for medicinal research in North America by both the Canadian (Fig. 40) and American governments, and this will likely continue. The possibility of marijuana becoming a legal commercial crop in North America is, to say the least, unlikely in the foreseeable future. Nevertheless the private sector is currently producing medicinal marijuana in Europe and Canada, so the following orientation to marijuana as a potential authorized crop is not merely academic.
Fig. 40. A truckload of Canadian medicinal marijuana from a plantation in Ottawa in 1971. More than a ton of marijuana was prepared for experimental research (described in Small et al. 1975).
The objectivity of scientific evaluation of the medicinal value of marijuana to date has been questioned. In the words of Hirst et al. (1998): “The ...status of cannabis has made modern clinical research almost impossible. This is primarily because of the legal, ethical and bureaucratic difficulties in conducting trials with patients. Additionally, the general attitude towards cannabis, in which it is seen only as a drug of abuse and addiction, has not helped.” In a recent editorial, the respected journal Nature (2001) stated: “Governments, including the US federal government, have until recently refused to sanction the medical use of marijuana, and have also done what they can to prevent its clinical testing. They have defended their inaction by claiming that either step would signal to the public a softening of the so-called ‘war on drugs.’... The pharmacology of cannabinoids is a valid field of scientific investigation. Pharmacologists have the tools and the methodologies to realize its considerable potential, provided the political climate permits them to do so.” Given these current demands for research on medicinal marijuana, it will be necessary to produce crops of drug types of C. sativa.
Earliest reference to euphoric use of C. sativa appears to date to China of 5 millennia ago, but it was in India over the last millennium that drug consumption became more firmly entrenched than anywhere else in the world. Not surprisingly, the most highly domesticated drug strains were selected in India. While C. sativa has been used as a euphoriant in India, the Near East, parts of Africa, and other Old World areas for thousands of years, such use simply did not develop in temperate countries where hemp was raised. The use of C. sativa as a recreational inebriant in sophisticated, largely urban settings is substantially a 20th century phenomenon.
Cannabis drug preparations have been employed medicinally in folk medicine since antiquity, and were extensively used in western medicine between the middle of the 19th century and World War II, particularly as a substitute for opiates (Mikuriya 1969). A bottle of commercial medicinal extract is shown in Fig. 41. Medical use declined with the introduction of synthetic analgesics and sedatives, and there is very limited authorized medical use today, but considerable unauthorized use, including so-called “compassion clubs” dispensing marijuana to gravely ill people, which has led to a momentous societal and scientific debate regarding the wisdom of employing cannabis drugs medically, given the illicit status. There is anecdotal evidence that cannabis drugs are useful for: alleviating nausea, vomiting, and anorexia following radiation therapy and chemotherapy; as an appetite stimulant for AIDS patients; for relieving the tremors of multiple sclerosis and epilepsy; and for pain relief, glaucoma, asthma, and other ailments [see Mechoulam and Hanus (1997) for an authoritative medical review, and Pate (1995) for a guide to the medical literature]. To date, governmental authorities in the US, on the advice of medical experts, have consistently rejected the authorization of medical use of marijuana except in a handful of cases. However, in the UK medicinal marijuana is presently being produced sufficient to supply thousands of patients, and Canada recently authorized the cultivation of medicinal marijuana for compassionate dispensation, as well as for a renewed effort at medical evaluation.
Fig. 41. Medicinal tincture of Cannabis sativa. (Not legal in North America.)
Several of the cannabinoids are reputed to have medicinal potential: THC for glaucoma, spasticity from spinal injury or multiple sclerosis, pain, inflammation, insomnia, and asthma; CBD for some psychological problems. The Netherlands firm HortaPharm developed strains of Cannabis rich in particular cannabinoids. The British firm G.W. Pharmaceuticals acquired proprietary access to these for medicinal purposes, and is developing medicinal marijuana. In the US, NIH (National Institute of Health) has a program of research into medicinal marijuana, and has supplied a handful of individuals for years with maintenance samples for medical usage. The American Drug Enforcement Administration is hostile to the medicinal use of Cannabis, and for decades research on medicinal properties of Cannabis in the US has been in an extremely inhospitable climate, except for projects and researchers concerned with curbing drug abuse. Synthetic preparations of THC—dronabinol (Marinol®) and nabilone (Cesamet®)—are permitted in some cases, but are expensive and widely considered to be less effective than simply smoking preparations of marijuana. Relatively little material needs to be cultivated for medicinal purposes (Small 1971), although security considerations considerably inflate costs. The potential as a “new crop” for medicinal cannabinoid uses is therefore limited. However, the added-value potential in the form of proprietary drug derivatives and drug-delivery systems is huge. The medicinal efficacy of Cannabis is extremely controversial, and regrettably is often confounded with the issue of balancing harm and liberty concerning the proscriptions against recreational use of marijuana. This paper is principally concerned with the industrial uses of Cannabis. In this context, the chief significance of medicinal Cannabis is that, like the issue of recreational use, it has made it very difficult to rationally consider the development of industrial hemp in North America for purposes that everyone should agree are not harmful.
Key analyses of the medicinal use of marijuana are: Le Dain (1972), Health Council of the Netherlands (1996), American Medical Association (1997), British Medical Association (1997), National Institutes of Health (1997), World Health Organization (1997), House of Lords (1998), and Joy et al. (1999).
MINOR USES
Biomass
It has been contended that hemp is notably superior to most crops in terms of biomass production, but van der Werf (1994b) noted that the annual dry matter yield of hemp (rarely approaching 20 t/ha) is not exceptional compared to maize, beet, or potato. Nevertheless, hemp has been rated on a variety of criteria as one of the best crops available to produce energy in Europe (Biewinga and van der Bijl 1996). Hemp, especially the hurds, can be burned as is or processed into charcoal, methanol, methane, or gasoline through pyrolysis (destructive distillation). As with maize, hemp can also be used to create ethanol. However, hemp for such biomass purposes is a doubtful venture in North America. Conversion of hemp biomass into fuel or alcohol is impractical on this continent, where there are abundant supplies of wood, and energy can be produced relatively cheaply from a variety of sources. Mallik et al. (1990) studied the possibility of using hemp for “biogas” (i.e. methane) production, and concluded that it was unsuitable for this purpose. Pinfold Consulting (1998) concluded that while there may be some potential for hemp biomass fuel near areas where hemp is cultivated, “a fuel ethanol industry is not expected to develop based on hemp.”Essential Oil
Essential (volatile) oil in hemp is quite different from hempseed oil. Examples of commercial essential oil product products are shown in Fig. 42. The essential oil is a mixture of volatile compounds, including monoterpenes, sesquiterpenes, and other terpenoid-like compounds that are manufactured in the same epidermal glands in which the resin of Cannabis is synthesized (Meier and Mediavilla 1998). Yields are very small—about 10 L/ha (Mediavilla and Steinemann 1997), so essential oil of C. sativa is expensive, and today is simply a novelty. Essential oil of different strains varies considerably in odor, and this may have economic importance in imparting a scent to cosmetics, shampoos, soaps, creams, oils, perfumes, and foodstuffs. Switzerland has been a center for the production of essential oil for the commercial market. Narcotic strains tend to be more attractive in odor than fiber strains, and because they produce much higher numbers of flowers than fiber strains, and the (female) floral parts provide most of the essential oil, narcotic strains are naturally adapted to essential oil production. Switzerland has permitted strains with higher THC content to be grown than is allowed in other parts of the world, giving the country an advantage with respect to the essential oil market. However, essential oil in the marketplace has often been produced from low-THC Cannabis, and the THC content of essential oil obtained by steam distillation can be quite low, producing a product satisfying the needs for very low THC levels in food and other commercial goods. The composition of extracted essential oil is quite different from the volatiles released around the fresh plant (particularly limonene and alpha-pinene), so that a pleasant odor of the living plant is not necessarily indicative of a pleasant-smelling essential oil. Essential oil has been produced in Canada by Gen-X Research Inc., Regina. The world market for hemp essential oil is very limited at present, and probably also has limited growth potential.
Fig. 42. Bottles of hemp fragrance (left) and essential oil (center), and pastilles flavored with hemp essential oil (right).
Pesticide and Repellent Potential
McPartland (1997) reviewed research on the pesticide and repellent applications of Cannabis. Dried plant parts and extracts of Cannabis have received rather extensive usage for these purposes in the past, raising the possibility that research could produce formulations of commercial value. This possibility is currently hypothetical.Non-Seed Use of Hemp as Livestock Feed
As noted above, hemp seed cake makes an excellent feed for animals. However, feeding entire plants is another matter, because the leaves are covered with the resin-producing glands. While deer, groundhogs, rabbits, and other mammals will nibble on hemp plants, mammals generally do not choose to eat hemp. Jain and Arora (1988) fed narcotic Cannabis refuse to cattle, and found that the animals “suffered variable degrees of depression and revealed incoordination in movement.” By contrast, Letniak et al. (2000) conducted an experimental trial of hemp as silage. No significant differences were found between yield of the hemp and of barley/oat silage fed to heifers, suggesting that fermenting hemp plants reduces possible harmful constituents.Hemp as an Agricultural Barrier
One of the most curious uses of hemp is as a fence to prevent pollen transfer in commercial production of seeds. Isolation distances for ensuring that seeds produced are pure are considerable for many plants, and often impractical. At one point in the 1980s, the only permitted use of hemp in Germany was as a fence or hedge to prevent plots of beets being used for seed production from being contaminated by pollen from ruderal beets. The high and rather inpenetrable hedge that hemp can produce was considered unsurpassed by any other species for the purpose. As well, the sticky leaves of hemp were thought to trap pollen. However, Saeglitz et al. (2000) demonstrated that the spread of beet pollen is not effectively prevented by hemp hedges. Fiber (i.e. tall) cultivars of hemp were also once used in Europe as wind-breaks, protecting vulnerable crops against wind damage. Although hemp plants can lodge, on the whole very tall hemp is remarkably resistant against wind.Bioremediation
Preliminary work in Germany (noted in Karus and Leson 1994) suggested that hemp could be grown on soils contaminated with heavy metals, while the fiber remained virtually free of the metals. Kozlowski et al. (1995) observed that hemp grew very well on copper-contaminated soil in Poland (although seeds absorbed high levels of copper). Baraniecki (1997) found similar results. Mölleken et al. (1997) studied effects of high concentration of salts of copper, chromium, and zinc on hemp, and demonstrated that some hemp cultivars have potential application to growth in contaminated soils. It would seem unwise to grow hemp as an oilseed on contaminated soils, but such a habitat might be suitable for a fiber or biomass crop. The possibility of using hemp for bioremediation deserves additional study.Wildlife Uses
Hemp is plagued by bird predation, which take a heavy toll on seed production. The seeds are well known to provide extremely nutritious food for both wild birds and domestic fowl. Hunters and birdwatchers who discover wild patches of hemp often keep this information secret, knowing that the area will be a magnet for birds in the fall when seed maturation occurs. Increasingly in North America, plants are being established to provide habitat and food for wildlife. Hemp is not an aggressive weed, and certainly has great potential for being used as a wildlife plant. Of course, current conditions forbid such usage in North America.Ornamental Forms
Hemp has at times in the past been grown simply for its ornamental value. The short, strongly-branched cultivar ‘Panorama’ (Fig. 43) bred by Iván Bósca, the dean of the world’s living hemp breeders, was commercialized in Hungary in the 1980s, and has been said to be the only ornamental hemp cultivar available. It has had limited success, of course, because there are very few circumstances that permit private gardeners can grow Cannabis as an ornamental today. By contrast, beautiful ornamental cultivars of opium poppy are widely cultivated in home gardens across North America, despite their absolute illegality and the potentially draconian penalties that could be imposed. Doubtless in the unlikely event that it became possible, many would grow hemp as an ornamental.
Fig. 43. ‘Panorama,’ the world’s only ornamental cultivar, with the breeder, Ivan Bócsa. (Courtesy of Professor Bócsa.)
AGRONOMY
The following sketch of hemp cultivation is insufficient to address all of the practical problems that are encountered by hemp growers. Bócsa and Karus (1998) is the best overall presentation of hemp growing available in English. The reader is warned that this book, as well as almost all of the literature on hemp, is very much more concerned with fiber production than oilseed production. McPartland et al. (2000) is the best presentation available on diseases and pests, which fortunately under most circumstances do limited damage. The resource list presented below should be consulted by those wishing to learn about hemp production. Provincial agronomists in Canada now have experience with hemp, and can make local recommendations. Particularly good web documents are: for Ontario (OMAFRA Hemp Series, several documents): www.gov.on.ca/OMAFRA/english/crops/hort/hemp.html); for Manitoba (several documents): www.gov.mb.ca/agriculture/crops/hemp/bko01s00.html; for British Columbia: (BC Ministry of Agriculture and Foods Fact Sheet on Industrial Hemp, prepared by A. Oliver and H. Joynt): www.agf.gov.bc.ca/croplive/plant/horticult/specialty/specialty.htmIn the US, extension publications produced up to the end of World War II are still useful, albeit outdated (Robinson 1935; Wilsie et al. 1942; Hackleman and Domingo 1943; Wilsie et al. 1944).
Hemp does best on a loose, well-aerated loam soil with high fertility and abundant organic matter. Well-drained clay soils can be used, but poorly-drained clay soils are very inappropriate because of their susceptibility to compaction, which is not tolerated. Young plants are sensitive to wet or flooded soils, so that hemp must have porous, friable, well-drained soils. Sandy soils will grow good hemp, provided that adequate irrigation and fertilization are provided, but doing so generally makes production uneconomical. Seedbed preparation requires considerable effort. Fall plowing is recommended, followed by careful preparation of a seedbed in the spring. The seedbed should be fine, level, and firm. Seed is best planted at 2–3 cm (twice as deep will be tolerated). Although the seedlings will germinate and survive at temperatures just above freezing, soil temperatures of 8°–10°C are preferable. Generally hemp should be planted after danger of hard freezes, and slightly before the planting date of maize. Good soil moisture is necessary for seed germination, and plenty of rainfall is needed for good growth, especially during the first 6 weeks. Seeding rate is specific to each variety, and this information should be sought from the supplier. Fiber strains are typically sown at a minimum rate of 250 seeds per m2 (approximately 45 kg/ha), and up to three times this density is sometimes recommended. In western Europe, seeding rates range from 60–70 kg/ha for fiber cultivars. Recommendations for seeding rates for grain production vary widely, from 10–45 kg/ha. Densities for seed production for tall, European, dual-purpose cultivars are less than for short oilseed cultivars. Low plant densities, as commonly found in growing tall European cultivars for seed, may not suppress weed growth adequately, and under these circumstances resort to herbicides may pose a problem for those wishing to grow hempseed organically. Hemp requires about the same fertility as a high-yielding crop of wheat. Industrial hemp grows well in areas that corn produces high yields. Growing hemp may require addition of up to 110 kg/ha of nitrogen, and 40–90 kg/ha of potash. Hemp particularly requires good nitrogen fertilization, more so for seed production than fiber. Adding nitrogen when it is not necessary is deleterious to fiber production, so that knowledge of the fertility of soils being used is very important. Organic matter is preferably over 3.5%, phosphorus should be medium to high (>40 ppm), potassium should be medium to high (>250 ppm), sulfur good (>5,000 ppm), and calcium not in excess (<6,000 ppm).
Finding cultivars suited to local conditions is a key to success. Hemp prefers warm growing conditions, and the best European fiber strains are photoperiodically adapted to flowering in southern Europe, which provides seasons of at least 4 months for fiber, and 5.5 months for seed production. Asian land races are similarly adapted to long seasons. In Canada, many of the available cultivars flower too late in the season for fiber production, and the same may be predicted for the northern US. Fiber production should also be governed by availability of moisture throughout the season, and the need for high humidity in the late summer and fall for retting, so that large areas of the interior and west of North America are not adapted to growing fiber hemp. The US Corn Belt has traditionally been considered to be best for fiber hemp. There are very few cultivars dedicated to oilseed production (such as ‘Finola’ and ‘Anka’) or that at least are known to produce good oilseed crops (such as ‘Fasamo’ and ‘Uniko-B’). Oilseed production was a specialty of the USSR, and there is some likelihood that northern regions of North America may find short-season, short-stature oilseed cultivars ideal.
Although hemp can be successfully grown continuously for several years on the same land, rotation with other crops is desirable. A 3- or preferably 4-year rotation may involve cereals, clover or alfalfa for green manure, maize, and hemp. In Ontario it has been recommended that hemp not follow canola, edible beans, soybeans or sunflowers. However, according to Bócsa and Karus (1998), “it matters little what crops are grown prior to hemp.”
For a fiber crop, hemp is cut in the early flowering stage or while pollen is being shed, well before seeds are set. Tall European cultivars (greater than 2 m) have mostly been grown in Canada to date, and most of these are photoperiodically adapted to mature late in the season (often too late). Small crops have been harvested with sickle-bar mowers and hay swathers, but plugging of equipment is a constant problem. Hemp fibers tend to wrap around combine belts, bearings, indeed any moving part, and have resulted in large costs of combine repairs (estimated at $10.00/ha). Slower operation of conventional combines has been recommended (0.6–2 ha/hour). Large crops may require European specialized equipment, but experience in North America with crops grown mainly for fiber is limited. The Dutch company HempFlax has developed or adapted several kinds of specialized harvesting equipment (Fig. 44, 45).
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| Fig. 44. A John Deere Kemper harvester, with circular drums that cut and chop hemp stalks, shown in operation in southern Ontario. (Courtesy of Kenex Ltd., Pain Court, Ontario.) | Fig. 45. A hemp harvester operated by HempFlax (Netherlands), with a wide mowing head capable of cutting 3 m long stems into 0.6 m pieces, at a capacity of 3 ha/hour. (Courtesy of HempFlax, Oude Pekela, The Netherlands.) |
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| Fig. 46. Windrowed fiber hemp in process of dew retting. Photograph taken in 1930 on the Central Experimental Farm, Ottawa, Canada. | Fig. 47. Shocked fiber hemp in process of dew retting. Photograph taken in 1931, near Ottawa, Canada. The shocks shed water like pup-tents, providing more even retting than windrows. |
Fig. 48. Baled, retted hemp straw. (Courtesy of Kenex Ltd., Pain Court, Ontario.)
Harvesting tall varieties for grain is difficult. In France, the principal grower of dual-purpose varieties, the grain is taken off the field first, leaving most of the stalks for later harvest (Fig. 49). Putting tall whole plants through a conventional combine results in the straw winding around moving parts, and the fibers working into bearings, causing breakdown, fires, high maintenance, and frustration. Following the French example of raising the cutting blade to harvest the grain is advisable. Growing short varieties dedicated to grain production eliminates many of the above problems, and since the profitability of hemp straw is limited at present, seems preferable. Grain growers should be aware that flocks of voracious birds are a considerable source of damage to hempseed, particularly in small plantations.
Fig. 49. Harvesting hemp in France. (Courtesy of La Chanvrière de l’Aube, Bar sur Aube, France.)
ECOLOGICAL FRIENDLINESS OF HEMP
Although the environmental and biodiversity benefits of growing hemp have been greatly exaggerated in the popular press, C. sativa is nevertheless exceptionally suitable for organic agriculture, and is remarkably less “ecotoxic” in comparison to most other crops (Montford and Small 1999b). Figure 50 presents a comparison of the ecological friendliness of Cannabis crops (fiber, oilseed, and narcotics) and 21 of the world’s major crops, based on 26 criteria used by Montford and Small (1999a) to compare the ecological friendliness of crops.
Fig. 50. A crude comparison of the biodiversity friendliness of selected major crops and three Cannabis sativa crops (fiber, oilseed, drug) based on 26 criteria (after Montford and Small 1999a).
The most widespread claim for environmental friendliness of hemp is that it has the potential to save trees that otherwise would be harvested for production of lumber and pulp. Earlier, the limitations of hemp as a pulp substitute were examined. With respect to wood products, several factors appear to favor increased use of wood substitutes, especially agricultural fibers such as hemp. Deforestation, particularly the destruction of old growth forests, and the world’s decreasing supply of wild timber resources are today major ecological concerns. Agroforestry using tree species is one useful response, but nevertheless sacrifices wild lands and biodiversity, and is less preferable than sustainable wildland forestry. The use of agricultural residues (e.g. straw bales in house construction) is an especially environmentally friendly solution to sparing trees, but material limitations restrict use. Another chief advantage of several annual fiber crops over forestry crops is relative productivity, annual fiber crops sometimes producing of the order of four times as much per unit of land. Still another important advantage is the precise control over production quantities and schedule that is possible with annual crops. In many parts of the world, tree crops are simply not a viable alternative. “By the turn of the century 3 billion people may live in areas where wood is cut faster than it grows or where fuelwood is extremely scarce” (World Commission on Environment and Development 1987). “Since mid-century, lumber use has tripled, paper use has increased six-fold, and firewood use has soared as Third World populations have multiplied” (Brown et al. 1998). Insofar as hemp reduces the need to harvest trees for building materials or other products, its use as a wood substitute will tend to contribute to preserving biodiversity. Hemp may also enhance forestry management by responding to short-term fiber demand while trees reach their ideal maturation. In developing countries where fuelwood is becoming increasingly scarce and food security is a concern, the introduction of a dual-purpose crop such as hemp to meet food, shelter, and fuel needs may contribute significantly to preserving biodiversity.
The most valid claims to environmental friendliness of hemp are with respect to agricultural biocides (pesticides, fungicides, herbicides). Cannabis sativa is known to be exceptionally resistant to pests (Fig. 51), although, the degree of immunity to attacking organisms has been greatly exaggerated, with several insects and fungi specializing on hemp. Despite this, use of pesticides and fungicides on hemp is usually unnecessary, although introduction of hemp to regions should be expected to generate local problems. Cannabis sativa is also relatively resistant to weeds, and so usually requires relatively little herbicide. Fields intended for hemp use are still frequently normally cleared of weeds using herbicides, but so long as hemp is thickly seeded (as is always done when hemp is grown for fiber), the rapidly developing young plants normally shade out competing weeds.
Fig. 51. Grasshopper on hemp. Most insects cause only limited damage to hemp, and substantial insect damage is uncommon, so the use of insecticides is very rarely required.
BREEDING HEMP FOR NORTH AMERICA
The basic commercial options for growing hemp in North America is as a fiber plant, an oilseed crop, or for dual harvest for both seeds and fiber. Judged on experience in Canada to date, the industry is inclined to specialize on either fiber or grain, but not both. Hemp in our opinion is particularly suited to be developed as an oilseed crop in North America. The first and foremost breeding goal is to decrease the price of hempseed by creating more productive cultivars. While the breeding of hemp fiber cultivars has proceeded to the point that only slight improvements can be expected in productivity in the future, the genetic potential of hemp as an oilseed has scarcely been addressed. From the point of view of world markets, concentrating on oilseed hemp makes sense, because Europe has shown only limited interest to date in developing oilseed hemp, whereas a tradition of concentrating on profitable oilseed products is already well established in the US and Canada. Further, China’s supremacy in the production of high-quality hemp textiles at low prices will be very difficult to match, while domestic production of oilseeds can be carried out using technology that is already available. The present productivity of oilseed hemp—about 1 t/ha under good conditions, and occasional reports of 1.5 to 2 t/ha, is not yet sufficient for the crop to become competitive with North America’s major oilseeds. We suggest that an average productivity of 2 t/ha will be necessary to transform hempseed into a major oilseed, and that this breeding goal is achievable. At present, losses of 30% of the seed yields are not uncommon, so that improvements in harvesting technology should also contribute to higher yields. Hemp food products cannot escape their niche market status until the price of hempseed rivals that of other oilseeds, particularly rapeseed, flax, and sunflower. Most hemp breeding that has been conducted to date has been for fiber characteristics, so that there should be considerable improvement possible. The second breeding goal is for larger seeds, as these are more easily shelled. Third is breeding for specific seed components. Notable are the health-promoting gamma-linolenic acid; improving the amino acid spectrum of the protein; and increasing the antioxidant level, which would not only have health benefits but could increase the shelf life of hemp oil and foods.Germplasm Resources
Germplasm for the improvement of hemp is vital for the future of the industry in North America. However, there are no publicly available germplasm banks housing C. sativa in North America. The hundreds of seed collections acquired for Small’s studies (reviewed in Small 1979) were destroyed in 1980 because Canadian government policy at that time envisioned no possibility that hemp would ever be developed as a legitimate crop. An inquiry regarding the 56 United States Department of Agriculture hemp germplasm collections supplied to and grown by Small and Beckstead (1973) resulted in the reply that there are no remaining hemp collections in USDA germplasm holdings, and indeed that were such to be found they would have to be destroyed. While hemp has been and still is cultivated in Asia and South America, it is basically in Europe that germplasm banks have made efforts to preserve hemp seeds. The Vavilov Institute of Plant Research in St. Petersburg, Russia has by far the largest germplasm collection of hemp of any public gene bank, with about 500 collections. Detailed information on the majority of hemp accessions of the Vavilov Institute can be found in Anon. (1975). Budgetary problems in Russia have endangered the survival of this invaluable collection, and every effort needs to be made to find new funding to preserve it. Maintenance and seed generation issues for the Vavilov hemp germplasm collection are discussed in a number of articles in the Journal of the International Hemp Association (Clarke 1998b; Lemeshev et al. 1993, 1994). The Gatersleben gene bank of Germany, the 2nd largest public gene bank in Europe, has a much smaller Cannabis collection, with less than 40 accessions (detailed information on the hemp accessions of the Gatersleben gene bank are available at fox-serv.ipk-gatersleben.de/). Because hemp is regaining its ancient status as an important crop, a number of private germplasm collections have been assembled for the breeding of cultivars as commercial ventures (de Meijer and van Soest 1992; de Meijer 1998), and of course these are available only on a restricted basis, if at all.The most pressing need of the hemp industry in North America is for the breeding of more productive oilseed cultivars. At present, mainly European cultivars are available, of which very few are suitable for specialized oilseed production. More importantly, hempseed oil is not competitive, except in the novelty niche market, with the popular food oils. As argued above, to be competitive, hemp should produce approximately 2 t/ha; at present 1 t/ha is considered average to good production. Doubling the productive capacity of a conventional crop would normally be considered impossible, but it needs to be understood just how little hemp has been developed as an oilseed. There may not even be extant land races of the kind of hemp oilseed strains that were once grown in Russia, so that except for a very few very recent oilseed cultivars, there has been virtually no breeding of oilseed hemp. Contrarily, hemp has been selected for fiber to the point that some breeders consider its productivity in this respect has already been maximized. Fiber strains have been selected for low seed production, so that most hemp germplasm has certainly not been selected for oilseed characteristics. By contrast, drug varieties have been selected for very high yield of flowers, and accordingly produce very high yield of seeds. Drug varieties have been observed to produce more than a kilogram of seed per plant, so that a target yield of several tonnes per hectare is conceivable (Watson and Clarke 1997). Of course, the high THC in drug cultivars makes these a difficult source of germplasm. However, wild plants of C. sativa have naturally undergone selection for high seed productivity, and are a particularly important potential source of breeding germplasm.
Wild North American hemp is derived mostly from escaped European cultivated hemp imported in past centuries, perhaps especially from a revival of cultivation during World War II. Wild Canadian hemp is concentrated along the St. Lawrence and lower Great Lakes, where considerable cultivation occurred in the 1800s. In the US, wild hemp is best established in the American Midwest and Northeast, where hemp was grown historically in large amounts. Decades of eradication have exterminated many of the naturalized populations in North America. In the US, wild plants are rather contemptuously called “ditch weed” by law enforcement personnel. However, the attempts to destroy the wild populations are short-sighted, because they are a natural genetic reservoir, mostly low in THC. Wild North American plants have undergone many generations of natural adaptation to local conditions of climate, soil and pests, and accordingly it is safe to conclude that they harbor genes that are invaluable for the improvement of hemp cultivars. We have encountered exceptionally vigorous wild Canadian plants (Fig. 52), and grown wild plants from Europe (Fig. 53) which could prove valuable. Indeed, studies are in progress in Ontario to evaluate the agronomic usefulness of wild North American hemp. Nevertheless, present policies in North America require the eradication of wild hemp wherever encountered. In Europe and Asia, there is little concern about wild hemp, which remains a valuable resource.
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| Fig. 52. Wild female hemp plant collected Oct. 17, 2000 near Ottawa, Canada. This vigorous plant had a fresh weight of 1.5 kg. | Fig. 53. A wild female hemp plant grown in southern Ontario [accession #16 from Georgia (formerly USSR), reported in Small and Marcus (2000)]. Such highly-branched plants can produce very large quantities of seeds, and may be useful for breeding. |
HARD LESSONS FOR FARMERS
It is clear that there is a culture of idealistic believers in hemp in North America, and that there is great determination to establish the industry. As history has demonstrated, unbridled enthusiasm for largely untested new crops touted as gold mines sometimes leads to disaster. The attempt to raise silk in the US is probably the most egregious example. In 1826 a Congressional report that recommended the preparation of a practical manual on the industry resulted in a contagious desire to plant mulberries for silk production, with the eventual collapse of the industry, the loss of fortunes, and a legacy of “Mulberry Streets” in the US (Chapter 2, Bailey 1898). In the early 1980s in Minnesota, Jerusalem artichoke was touted as a fuel, a feed, a food, and a sugar crop. Unfortunately there was no market for the new “wonder crop” and hundreds of farmers lost about $20 million (Paarlberg 1990). The level of “hype” associated with industrial hemp is far more than has been observed before for other new crops (Pinfold Consulting 1998). Probably more so than any plant in living memory, hemp attracts people to attempt its cultivation without first acquiring a realistic appreciation of the possible pitfalls. American presidents George Washington and Thomas Jefferson encouraged the cultivation of hemp, but both lost money trying to grow it. Sadly in Canada in 1999 numerous farmers contracted to grow half of Canada’s crop area for hemp for the American-based Consolidated Growers and Processors, and with the collapse of the firm were left holding very large amounts of unmarketable grain and baled hemp straw. This has represented a most untimely setback for a fledgling industry, but at least has had a sobering effect on investing in hemp. In this section we emphasize why producers should exercise caution before getting into hemp.In Europe and Asia, hemp farming has been conducted for millennia. Although most countries ceased growing hemp after the second word war, some didn’t, including France, China, Russia, and Hungary, so that essential knowledge of how to grow and process hemp was maintained. When commercial hemp cultivation resumed in Canada in 1997, many farmers undertook to grow the crop without appreciating its suitability for their situation, or for the hazards of an undeveloped market. Hemp was often grown on farms with marginal incomes in the hopes that it was a savior from a downward financial spiral. The myth that hemp is a wonder crop that can be grown on any soil led some to cultivate on soils with a history of producing poor crops; of course, a poor crop was the result.
Market considerations also heavily determine the wisdom of investing in hemp. Growing hemp unfortunately has a magnetic attraction to many, so there is danger of overproduction. A marketing board could be useful to prevent unrestrained competition and price fluctuations, but is difficult to establish when the industry is still very small. As noted above, unwise investment in Canada produced a glut of seeds that resulted in price dumping and unprofitable levels for the majority. Cultural and production costs of hemp have been said to be comparable to those for corn, and while the truth of this remains to be confirmed, the legislative burden that accompanies hemp puts the crop at a unique disadvantage. Among the problems that Canadian farmers have faced are the challenge of government licensing (some delays, and a large learning curve), very expensive and sometime poor seed (farmers are not allowed to generate their own seed), teenagers raiding fields in the mistaken belief that marijuana is being grown, and great difficulties in exportation because of the necessity of convincing authorities that hemp is not a narcotic. Unless the producer participates in sharing of value-added income, large profits are unlikely. The industry widely recognizes that value added to the crop is the chief potential source of profit, as indeed for most other crops.
THE POLITICS OF CANNABIS WITH PARTICULAR REFERENCE TO THE US
Cannabis has long had an image problem, because of the extremely widespread use of “narcotic” cultivars as illegal intoxicants. The US Drug Enforcement Administration has the mandate of eliminating illicit and wild marijuana, which it does very well (Fig. 54–56). Those interested in establishing and developing legitimate industries based on fiber and oilseed applications have had to struggle against considerable opposition from many in the political and law enforcement arenas. The United States National Institute on Drug Abuse (NIDA) information web site on marijuana, which reflects a negative view of cannabis, is at www.nida.nih.gov/DrugPages/Marijuana.html, and reflects several basic fears: (1) growing Cannabis plants makes law enforcement more difficult, because of the need to ensure that all plants cultivated are legitimate; (2) utilization of legitimate Cannabis products makes it much more difficult to maintain the image of the illegitimate products as dangerous; (3) many in the movements backing development of hemp are doing so as a subterfuge to promote legalization of recreational use of marijuana; and (4) THC (and perhaps other constituents) in Cannabis are so harmful that their presence in any amount in any material (food, medicine or even fiber product) represents a health hazard that is best dealt with by a total proscription. |  |
| Fig. 54. The war on drugs: helicopter spraying of Paraquat herbicide on field of marijuana. (Courtesy US Drug Enforcement Administration.) | Fig. 55. The war on drugs: clandestine indoor marijuana cultivation. (Courtesy US Drug Enforcement Administration.) |
Fig. 56. The war on drugs: burning seized marijuana. (Courtesy US Drug Enforcement Administration.)
Ten years ago hemp cultivation was illegal in Germany, England, Canada, Australia, and other countries. Essential to overcoming governmental reluctance in each country was the presentation of an image that was business-oriented, and conservative. The merits of environmentalism have acquired some political support, but unless there is a reasonable possibility that hemp cultivation is perceived as potentially economically viable, there is limited prospect of having anti-hemp laws changed. Strong support from business and farm groups is indispensable; support from pro-marijuana interests and what are perceived of as fringe groups is generally counterproductive. It is a combination of prospective economic benefit coupled with assurance that hemp cultivation will not detrimentally affect the enforcement of marijuana legislation that has led most industrially advanced countries to reverse prohibitions against growing hemp. Should the US permit commercial hemp cultivation to resume, it will likely be for the same reasons.
The US Office of National Drug control Policy issued a statement on industrial hemp in 1997 (www.whitehousedrugpolicy.gov/policy/hemp%5Fold.html) which included the following: “Our primary concern about the legalization of the cultivation of industrial hemp (Cannabis sativa) is the message it would send to the public at large, especially to our youth at a time when adolescent drug use is rising rapidly... The second major concern is that legalizing hemp production may mean the de facto legalization of marijuana cultivation. Industrial hemp and marijuana are the product of the same plant, Cannabis sativa... Supporters of the hemp legalization effort claim hemp cultivation could be profitable for US farmers. However, according to the USDA and the US Department of Commerce, the profitability of industrial hemp is highly uncertain and probably unlikely. Hemp is a novelty product with limited sustainable development value even in a novelty market... For every proposed use of industrial hemp, there already exists an available product, or raw material, which is cheaper to manufacture and provides better market results.... Countries with low labor costs such as the Philippines and China have a competitive advantage over any US hemp producer.”
Recent European Commission proposals to change its subsidy regime for hemp contained the following negative evaluation of hemp seed: “The use of hemp seed ... would, however, even in the absence of THC, contribute towards making the narcotic use of cannabis acceptable... In this light, subsidy will be denied producers who are growing grain for use in human nutrition and cosmetics.”
A USDA analysis of hemp, “Industrial hemp in the United States: Status and market potential,” was issued in 2000, and is available at www.ers.usda.gov/publications/ages001e/index.htm. This is anonymously-authored, therefore presumably represents a corporate or “official” evaluation. The conclusion was that “US markets for hemp fiber (specialty textiles, paper, and composites) and seed (in food or crushed for oil) are, and will likely remain, small, thin markets. Uncertainty about longrun demand for hemp products and the potential for oversupply discounts the prospects for hemp as an economically viable alternative crop for American farmers.” Noting the oversupply of hempseeds associated with Canada’s 12,000 ha in 1999, the report concluded that the long term demand for hemp products is uncertain, and predicts that the hemp market in the US will likely remain small and limited. With respect to textiles, the report noted the lack of a thriving textile flax (linen) US industry (despite lack of legal barriers), so that it would seem unlikely that hemp could achieve a better market status. With respect to hemp oil, the report noted that hemp oil in food markets is limited by its short shelf life, the fact that it can not be used for frying, and the lack of US Food and Drug Administration approval as GRAS (“generally recognized as safe”). Moreover, summarizing four state analyses of hemp production (McNulty 1995, Ehrensing 1998, Kraenzel et al. 1998, Thompson et al. 1998), profitability seemed doubtful.
Without arguing the merits of the above contentions, we point out that the legitimate use of hemp for non-intoxicant purposes has been inhibited by the continuing ferocious war against drug abuse. In this atmosphere, objective analysis has often been lacking. Unfortunately both proponents and opponents have tended to engage in exaggeration. Increasingly, however, the world is testing the potential of hemp in the field and marketplace, which surely must be the ultimate arbiters. De Guzman (2001), noting the pessimistic USDA report, observed that “Nevertheless, others point to the potential of [the] market. Hemp products have a growing niche market of their own, and the market will remain healthy and be well supported with many competing brands.”
A wide variety of hemp clothing, footwear, and food products are now available in North America. Some American manufacturers and distributors have chosen to exploit the association of hemp products with marijuana in their advertising. Such marketing is unfortunate, sending the message that some in the industry are indifferent to the negative image that this generates in the minds of much of the potential consuming public. Admittedly, such advertising works. But marketing based on the healthful and tasteful properties of hemp food products, the durable nature of hemp textiles, and the environmental advantages of the crop has proven to be widely acceptable, and is likely to promote the long term development of hemp industries.
Will hemp commercial cultivation resume in the US in the foreseeable future? This is difficult to judge, but the following considerations suggest this might occur: (1) increasing awareness of the differences between industrial hemp and marijuana; (2) growing appreciation of the environmental benefits of hemp cultivation; (3) continuing demonstration of successful hemp cultivation and development in most of the remaining western world; all the G8 countries, except the US, produce and export industrial hemp; and (4) increasing pressure on state and federal governments to permit hemp cultivation by farmers, particularly wheat, corn, and tobacco farmers in desperate need of substitute crops, but also for rotation crops to break pest and disease cycles.
More than a century ago, an expert on hemp concluded his manual on hemp-growing in the US by stating “There is no question that when the inventive genius, comprehension and energies of the American people become interested, another grand source of profitable employment and prosperity will be established” (Boyce 1900).
MARKET DEVELOPMENT
Individual entrepreneurs, and indeed whole industries, as a matter of economic survival need to adopt a clear investment policy with respect to whether their market is to be output-driven or demand-led. From the individual producer’s perspective, the old adage “find your market before you plant your seed” remains sound advice.In the mid 1990s, the EU provided subsidization for hemp cultivation of ca. $1,050/ha. This support was instrumental in developing a hemp industry in western Europe. However, no comparable support is available in North America, and indeed those contemplating entering into hemp cultivation are faced with extraordinary costs and/or requirements in connection with licensing, security, THC analysis, and record keeping. Those involved in value-added processing and distribution are also faced with legal uncertainties and the regular threat of idiosyncratic, indeed irrational actions of various governments. Simply displaying a C. sativa leaf on advertising has led to the threat of criminal charges in the last decade in several G8 countries. Attempting to export or import hemp products among countries is presently a most uncertain activity.
It often takes 10 to 15 years for the industry associated with a new agricultural crop to mature. While it is true that foreign imports have been the basis for hemp products in North America for at least a decade, North American production is only 4 years of age in Canada, and farming of hemp in the US has not even begun. Viewed from this perspective, the hemp industry in North America is still very much in its infancy. Varieties of hemp specifically suited to given products and regions have only started to be developed in North America. There is considerable uncertainty regarding yields, costs of production, harvesting and processing equipment, product characteristics, foreign competition, governmental support, and the vagaries of the regulatory environment. Hemp is not presently a standard crop, and is likely to continue experiencing the risks inherent in a small niche market for some time. Hemp is currently a most uncertain crop, but has such a diversity of possible uses, is being promoted by extremely enthusiastic market developers, and attracts so much attention that it is likely to carve out a much larger share of the North American marketplace than its detractors are willing to concede.
Given the uncertainties and handicaps associated with hemp, it is fortunate that there are compensating factors. As noted, as a crop hemp offers some real environmental advantages, particularly with regard to the limited needs for herbicides and pesticides. Hemp is therefore pre-adapted to organic agriculture, and accordingly to the growing market for products associated with environmentally-friendly, sustainable production. Hemp products are an advertiser’s dream, lending themselves to hyperbole (“healthiest salad oil in the world,” “toughest jeans on the market”). While the narcotics image of C. sativa is often disadvantageous, advertisers who choose to play up this association do so knowing that it will attract a segment of the consuming population. In general, the novelty of hemp means that many consumers are willing to pay a premium price. It might also be said that those who have entered the hemp industry have tended to be very highly motivated, resourceful, and industrious, qualities that have been needed in the face of rather formidable obstacles to progress.
INFORMATION RESOURCES
Organizations
- North American Industrial Hemp Council Inc.: www.naihc.org
- Hemp Industries Association: www.thehia.org
- International Hemp Association: mojo.calyx.net/~olsen/HEMP/IHA/
- Hemp Food Association: hempfood.com/
- Ontario Hemp Alliance: www.ontariohempalliance.org
- International Association for Cannabis as Medicine: www.acmed.org/english/main.htm
Web
- The Hemp Commerce & Farming Report: www.hempreport.com
- Industrial hemp information network: www.hemptech.com
Journals
- Journal of the International Hemp Association. Vol. 1 (1994)–Vol. 6 (1999). (Vols. 1–5 and part of Vol. 6 available online at mojo.calyx.net/~olsen/HEMP/IHA/). Superseded by Journal of Industrial Hemp.
- Journal of Cannabis Therapeutics. Hawarth Press. Vol. 1 published 2001.
- Journal of Industrial Hemp. Haworth Press. Vol. 1 to be published 2002.
Books
- Blade (1998), Bócsa and Karus (1998), Ceapoiu (1958), Clarke (1977, 1998a), Joyce and Curry (1970), McPartland et al. (2000), de Meijer (1994), Nova Institute (1995, 1997a, 1997b, 2000), Ranalli (1998), Riddlestone et al. 1994, Small (1979), Van der Werf (1994a).
REFERENCES
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- American Medical Association. 1997. Report 10 of the Council on Scientific Affairs (I-97) to the American Medical Association House of Delegates. Subject: Medical Marijuana. American Medical Association, Chicago. www.ama-assn.org/ama/pub/article/2036-4299.html
- Anon. 1975. Catalogue of the global collection of VIR. Issue 162, Fiber crops. Vavilov Institute, Leningrad, USSR.
- Bailey, L.H. 1898. The evolution of our native fruits. MacMillan, Harrisburg, PA.
- Baraniecki, P. 1997. Industrial plants in clean-up of heavy metal polluted soils. p. 277–283. In: Nova Institute, Bioresource hemp. Proc. Symp. (Frankfurt am Main, Germany, Feb. 27–March 2, 1997). Nova Institute, Hürth, Germany.
- Biewinga, E.E. and G. van der Bijl. 1996. Sustainability of energy crops in Europe. A methodology developed and applied. Centre for Agriculture and Environment, Utrecht, The Netherlands.
- Blade, S. (ed.). 1998. Alberta Hemp Symposia proceedings, Red Deer, Alberta, March 10, 1998, and Edmonton Alberta, April 8, 1998. Alberta Agriculture, Food and Rural Development, Edmonton, AB.
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- Boyce, S.S. 1900. Hemp (Cannabis sativa). A practical treatise on the culture of hemp for seed and fiber with a sketch of the history and nature of the hemp plant. Orange Judd Company, New York.
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- Callaway, J.C. 1998. Formation of trans-fatty acids in heated hempseed oil: a rebuttal. J. Int. Hemp Assoc. 5:106–108.
- Callaway, J.C., T. Tennilä, and D.W. Pate. 1996. Occurrence of “omega-3” stearidonic acid (cis-6,9,12,15-octadecatetraenoic acid) in hemp (Cannabis sativa L.) seed. J. Int. Hemp Assoc. 3:61–63.
- Ceapoiu, N. 1958. Hemp, monographic study. (in Romanian) Bucharest. Editura Academiei Republicii Populare Rominae, Bucharest, Romania.
- Clarke, R.C. 1977. The botany and ecology of Cannabis. Pods Press, Ben Lomond, CA.
- Clarke, R.C. 1998a. Hashish! Red Eye Press, Los Angeles.
- Clarke, R.C. 1998b. Maintenance of Cannabis germplasm in the Vavilov Research Institute gene bank - five year report. J. Int. Hemp Assoc. 5:75-79.
- Collins, L. 1999. Holland’s half-baked drug experiment. Foreign Affairs 78:82–98.
- Deferne, J.-L. and D.W. Pate. 1996. Hemp seed oil: A source of valuable essential fatty acids. J. Int. Hemp Assoc. 3:4–7.
- Dewey, L.H. 1914. Hemp. p. 283–146. In: Yearbook of the US Department of Agriculture - 1913.
- Ehrensing, D.T. 1998. Feasibility of industrial hemp production in the United States Pacific Northwest. Department of Crop and Soil Science, Oregon State Univ. Expt. Sta. Bul. 681. Oregon State University, Corvallis. www.css.orst.edu/Hemp/body.html
- Fertig, M. 1996. Analysis of the profitability of hemp cultivation for paper. J. Int. Hemp Assoc. 3:42–43. (Review of a German M.Sc. thesis.)
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