Cultivation of Cannabis sativa L. in northern Morocco.
Field studies on cannabis cultivation have provided socio-economic data relating to, inter alia, production, yield and income. But only laboratory analyses of cannabis plants can provide information on their chemical composition and their levels of psychoactive constituents, thus enabling them to be classed as a drug type or a fibre type. The present study, which covers cannabis in its fresh, dried and powdered forms, drew on fresh samples, obtained on the day they were harvested or immediately after preparation; that was done in order to prevent any alteration in the A-9-tetrahydrocannabinol (THC) caused by the oxidation that takes place as the product ages. The purpose of this study is to determine the THC level in 245 specimens obtained from 30 cannabis plots in three provinces of northern Morocco: Al Hoceima and Chefchaouen, where cannabis cultivation has a long tradition, and Larache, where cannabis cultivation has started only recently. Qualitative analysis using high performance liquid chromatography with diode array detection revealed the presence of both the acid and the decarboxylated form of the main cannabinoids, cannabidiol, THC and cannabinol, and gas chromatography/mass spectrometry was used for the characterization of minor cannibinoids. Quantitative analysis using gas chromatography coupled with mass spectrometry made it possible to determine the average delta-9-THC content of cannabis in its fresh form (0.5 per cent), its dry form (2.21 per cent) and its powdered form (8.3 per cent). The results show that the traditional areas of cannabis cultivation--Al Hoceima and Chefchaouen--produce cannabis with a higher delta-9-THC content than the Larache region. In addition, the present study establishes that male plants, often considered deficient in delta-9-THC, contain levels of the same order as those recorded for female plants, both in the leaves and in the tops.