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Hemp (Cannabis sativa L.) is a member of the Canabinaceae family a small group of herbaceous plants.

Hemp, most likely, originated in Central Asia and it is one of the oldest cultivated plants and has probably been cultivated in China for over 4500 years.

There are broadly three groups of Hemp varieties being cultivated today :

• Varieties primarily cultivated for their fibre characterized by long stems and little branching.
• Varieties grown for seed from which hemp oil is extracted
• Varieties grown for medicinal or narcotic purposes. The resin, known variously as hashish, ganja or bhang, is obtained from the dried inflorescences, leaves and stems.

Most hemp for fibre is mainly grown in the temperate regions while hemp for seed and the other purposes is more (sub) tropical in adaptation.

The use of hemp for fibre production has declined sharply over the past decades but still occupies an important place amongst natural fibres as it is strong, durable and unaffected by water. The main uses of hemp fibre are in ropes,, sacking, carpets, nets and webbing. In recent years hempis being used in increasing quantities in paper manufacturing. The cellulose content is about 70%.

Major hemp producing countries.

The former Commonwealth of Independent States (former Soviet Union) is the world largest producer (300.000 hectares). The main production areas are in the Ukraine, the Kursk and Orel regions and near the Polish border.

Other important producing countries are the former Yugoslavia, Roumania, Poland and Italy.

Harvesting the fibre

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 by using specially adapted cutter-binders or more simple cutters. The cut hemp is laid in swathes to dry for up to four days. This is followed by retting which can be water retting whereby the bundled hemp is floating in water or dew retting whereby the hemp remains on the ground and is affected by the action of dew moisture, moulds and bacterial action.

A new future for hemp ?

In the last decade hemp has been widely promoted as a crop for the future This is in particular stimulated by new technologies which make hemp suitable for industrial paper manufacturing, use as renewable energy source (biofuel) and the use of hemp derivatives as replacement for petrochemical products. The increased demand for health food has stimulated the trade in hempseed while hemp oil is increasingly being used in the manufacturing of bodycare products.

The THC debate

Hemp contains delta-9-tetrahydrocanabinol which is the actual narcotic stimulant found in hasish. THC is present in all hemp varieties to some extent. In varieties grown for medicinal or narcotic use, THC levels reach 20-30%. In hemp varieties for seed or fibre use, these levels are between 0.5% and 1.5% which is far too low to obtain any narcotic effect and low enough to make THC extraction extremely difficult or uneconomic. On October 9th, the US Drug Enforcement Agency (DEA) ruled that even traces of THC in products intended for food use would be illegal as from February 6th, 2002. This would ruleout the production or use of hempseed or hempseed oil in food use in the USA. The presence of THC in hemp varieties and the fear that THC could be extracted from industrial hemp for illegal purposes has hampered the development of hemp is many countries. Since the early 1990’s however countries like Canada, Australia, the UK and Germany have allowed experimental hemp plantings and some commercial scale production. Plant breeders ar working on the development of new varieties which are low in THC.

Hemp resources

• Hemp Industries Association http://www.thehia.org
• Global Hemp Resources http://www.globalhemp.com
• North American Industrial Hemp council http://www.naihc.org

see Cannabis : History