By the 16th century, hemp was being cultivated and widely used in Europe for the fiber and for the seeds, which were cooked with grains and eaten. During the 16th and 17th centuries, hemp production made its way to North America and South America. In the United States, hemp production provided weaving fiber for New England Puritans but could not displace the flax already in use. Cultivation spread to Kentucky and other states but did not take a strong hold, particularly as cotton production increased in the South. The Marijuana Tax Act of 1937 required all hemp producers to register with the U.S. Department of the Treasury Department; hemp production since then has been negligible in the United States.
Over 400 compounds are found in cannabis, 60 of which are peculiar to cannabis and are called cannabinoids (Turner et al. 1980; UNODC 2006). Cannabinoids exist in the form of carboxylic acids that readily decarboxylate when heated (De Zeeuw et al. 1972; Kimura and Okamoto 1970), in alkaline environments (Grlic and Andrec 1961; Masoud and Doorenboos 1973), and over time (Masoud and Doorenboos 1973; Turner et al. 1973). Ä-9-Tetrahydrocannabinol (THC) is the main cannabinoid that produces the psychoactive effects of cannabis-based products (UNODC 2006).
Cannabis produces a variety of secondary metabolic compounds, including flavonoids (Gellert et al. 1974; Paris et al. 1975), alkanes (Adams and Jones 1973; De Zeeuw et al. 1973; Mobarak et al. 1974a, 1974b), and nitrogenous compounds (Hanus 1975a, 1975b). Terpenes add to the characteristic odor of cannabis (Hood et al. 1973) and are abundant in the plant (Hanus 1975a; Hendricks et al. 1975) and in some of its preparations (such as hashish). Ecological factors and heredity are thought to contribute heavily to the production of these compounds (Fetterman et al. 1971; Small and Beckstead 1973).
There are two major products of illicit cannabis cultivation: resin and herb (marijuana). Resin is the pressed secretion of the cannabis plant, also commonly called hashish or charas in India, whereas the herb refers to the leaves and flowers of the plant (UNODC 2006).
Afghanistan is the largest producer of cannabis resin in the world (UNODC 2010a; see Table 1-1). Morocco has at least 3 times as much land in cultivation, but Afghanistan’s resin yields are 4 times as high per hectare (UNODC 2010a). Cannabis cultivation occurs in 17 of the 34 provinces of Afghanistan on an estimated 10,000-24,000 hectares. Mexico, Paraguay, Colombia, the Netherlands, Bolivia, Canada, and the United States are producers of cannabis herb; Mexico and Paraguay produce the majority (UNODC 2010a).
Cannabis can be cultivated nearly anywhere, including indoors. Seeds are readily obtained from marijuana samples or even by mail order in some countries. Cannabis plants can tolerate suboptimal soils (such as sand) but flourish in