Cultivation of Cannabis sativa L. in
H. Stambouli, A. El Bouri, M. A. Bellimam, T. Bouayoun and
N. El Karni
Researchers, Forensic Science Laboratory, Gendarmerie Royale, Rabat*
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 imme-
diately after preparation; that was done in order to prevent any alteration in the
-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 speci-
mens 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 spectro-
metry made it possible to determine the average -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 -9-THC content
than the Larache region.
In addition, the present study establishes that male plants, often considered
deficient in -9-THC, contain levels of the same order as those recorded for female
plants, both in the leaves and in the tops.
Keywords: Cannabis sativa L; -9-tetrahydrocannabinol; gas chromatography/
mass spectrometry; high performance liquid chromatography with
diode array detection
*The authors would like to thank the Agency for the Promotion and the Economic and Social
Development of the Northern Prefectures and Provinces of Morocco for having taken the Forensic Science
Laboratory of the Gendarmerie Royale into partnership for this study.
80 Bulletin on Narcotics, vol. LVII, Nos. 1 and 2, 2005
Projection: Universal Transverse
Cannabis cultivation (ha)
No cannabis cultivation
or area not surveyed
Figure I. Northern provinces of Morocco: cannabis cultivation, 2004
Source: United Nations Office on Drugs and Crime, Morocco: Cannabis Survey 2003 (December 2003).
Note: The boundaries shown do not imply official endorsement or acceptance by the United Nations.
Cultivation of Cannabis sativa L. in northern Morocco 81
The plant Cannabis sativa L. is grown widely throughout the world, in temper-
ate and tropical countries. According to the World Drug Report 2005  of the
United Nations Office on Drugs and Crime (UNODC), cannabis cultivation is
widespread in Africa, the Americas, Asia and Europe. Identifying a total of
86 countries where the cannabis plant is grown, the World Drug Report 2005
states that world cannabis production in 2004 was 47,000 tons, compared with
687 tons of cocaine and 565 tons of heroin. A total of 7,206 tons of cannabis
products were seized in 2003, which is 15 times the total of cocaine seized and
about 65 times the total of heroin seized.
Cannabis cultivation in Morocco, particularly in the central Rif, dates to
the seventh century. Originally confined to a largely mountainous area, cannabis
cultivation now takes place in the traditional growing areas of Chefchaouen and
Al Hoceima – in the central Rif – and in recently designated extension areas
north-west of Tetouan and Larache and south-east of Al Hoceima (figure I).
To evaluate the levels of THC of cannabis grown in Morocco, a study was
conducted in three northern areas that together accounted for more than 80 per
cent of the country’s cannabis production in 2004 (figure II). The first, the Al
Hoceima area of the central Rif, is characterized by small plots of land on hilly
Figure II. Distribution of cannabis production in the northern provinces
of Morocco, 2004
82 Bulletin on Narcotics, vol. LVII, Nos. 1 and 2, 2005
Figure III. Widespread use of traditional agricultural methods
terrain where rudimentary agricultural techniques are still used (figure III). The
second area is Chefchaouen, which was extended with the encouragement of the
Protectorate in 1912 to pacify the rebel tribes of Ketama. The third area,
situated in the Larache plain, was designated an extension area for cannabis
cultivation 20 years ago, and modern production methods are used there.
The aim of this study, which was conducted in the framework of a partner-
ship between the Agency for the Promotion and the Economic and Social
Development of the Northern Prefectures and Provinces of Morocco (APDN) and
the Forensic Science Laboratory of the Gendarmerie Royale, was to assess the
quality of the cannabis produced in northern Morocco and determine the levels
of the psychoactive constituent -9-tetrahydrocannabinol (THC) for the differ-
ent growing areas. The study was carried out pursuant to a cooperation agree-
ment concluded with UNODC in February 2004, complementing a study carried
out in the northern areas of Morocco in 2003 that focused on socio-economic
data related to cannabis cultivation in the country.
Synthesis of social-economic data
The territories where most cannabis cultivation is located  total about
20,000 square kilometres, or 2.7 per cent of the total surface area of Morocco
(figure I). It is estimated that in 2004, cannabis crops were grown on a total of
120,500 hectares (ha), with the largest cultivation area (figure IV) found in
Chefchaouen (75,195 ha, or 62 per cent of the total cultivation area), followed
Cultivation of Cannabis sativa L. in northern Morocco 83
by Taounate (14,718 ha, or 12 per cent), Larache (11,892 ha, or 10 per cent),
Al Hoceima (10,524 ha, or 9 per cent) and Tetouan (8,225 ha, or 7 per cent).
Most agricultural land in Morocco (88 per cent) is not irrigated but rain-
fed (bour), and the yield of cannabis herb is, on average, 750 kg/ha, depending
greatly on rainfall, soil quality, the number of successive years of cultivation, the
use of chemical fertilizers and climatic conditions. (Figures V and VI show
non-irrigated and irrigated cannabis cultivation.)
Figure IV. Distribution of total land area under cannabis cultivation in
Morocco, by province, 2004
Figure V. Non-irrigated (bour) cultivation
84 Bulletin on Narcotics, vol. LVII, Nos. 1 and 2, 2005
The crop, once it has been dried in the sun, is called kif. Kif is either sold
(66 per cent) or converted into cannabis resin at the production site (34 per
cent). About 100 kg of kif is required to obtain 1-3 kg of resin by pounding and
shaking, sifting it through fine nylon netting and pressing at either ambient or
an elevated temperature. The final product is a slab wrapped in cellophane.
Pounding the dried plant produces three qualities of powder:
Figure VI. Irrigated cultivation
Average share of cannabis Overall average share of
converted into powder cannabis converted into powder
Quality 1 Quality 2 Quality 3
1.04 0.94 0.84 2.82
The first-quality powder, which is called sigirma, is golden beige in colour,
is produced through the reduction of the flowering tops and the inflorescences
and is reputed to have a THC content of up to 20 per cent. The second quality,
which is called hamda, also contains plant waste, giving it a greenish colour;
more or less intensive sifting of this powder yields products of varying quality,
with a THC content of 2-10 per cent.
The population of the areas under cannabis cultivation in Morocco accounts
for 2.7 per cent of the country’s total population; the population density of
124 inhabitants per square kilometre is high compared with the national average
of only 34 inhabitants per square kilometre. The number of rural families engaged
in cannabis cultivation is estimated to be 96,600, which translates into a total
of about 800,000 people.
The average annual family income from the sale of cannabis products is
about $2,200, while the annual sale value of cannabis resin from Morocco on
Cultivation of Cannabis sativa L. in northern Morocco 85
the international market is estimated to be $13 billion. The income from
cannabis received by farmers of Chefchaouen and Al Hoceima provinces, where
cannabis has long been cultivated, accounts for 62 per cent of their total income.
In the province of Larache, by contrast, where cannabis cultivation is a recent
phenomenon, only 15 per cent of the income of farmers is estimated to be from
Literature on cannabis
Cannabis is a member of the Cannabinaceae family. It is a dicotyledon, herba-
ceous (a non-woody plant whose aerial part dies after fruiting), annual, apetalous
(the flower has no corolla) and most often dioecious (the male plants are dis-
tinct from the female plants). The height of the plant varies between 60 cm for
the smallest varieties and 7 m for the largest. Under optimum conditions, the
average height is about 3 m. The leaves on the lower part and the middle of the
stalk are palmate, that is to say, consisting of 5-7 unequal, elliptical segments
with dentate margins. The plants are a fairly dark shade of green.
Cannabis is anemophilous, being pollinated only by the wind, but the male
plants are often lifted young to prevent pollination of the female plants, in order
to produce the sinsemilla variety, which is the only one used for the
commercial production of cannabis herb, powder and resin.
The morphological, biological and pharmaco-chemical characteristics of
cannabis depend on the growing conditions — altitude, temperature, humidity
and light conditions — and the type of fertilizer used. As a general rule, crops
grown in countries with a temperate climate contain only a small quantity of
resin and thus have a low THC level. Indoor cultivation of cannabis plants can
produce specimens with a high -9-THC content.
Several hundred different compounds have been isolated from cannabis ,
including terpene-based essential oils, flavonoids, sugars, fatty acids, phenolic
spiro-indanes, dihydrostilbenes and nitrogenous compounds. The most interest-
ing constituents, however, are the cannabinoids, found in the leaves and con-
centrated in the bracts and the resin. These are terpenophenols, classified in
several groups according to their structure, the main ones being -9-THC and
its acid, cannabidiol (CBD) and cannabinol (CBN). These compounds are accom-
panied by homologues with shorter side chains (propyl and methyl cannabi-
noids), precursors (cannabigerol (CBG)) and chromane derivatives (cannabicyclol
and cannabichromene), among others. In addition, R. Smith  has noted the
existence of homologues with the butyl side chain C4H9 (figure VII), but at a
concentration barely 1 per cent higher of that of pentyl homologues. The
structures of those homologues (butyl-THC, butyl-CBD and butyl-CBN) were
86 Bulletin on Narcotics, vol. LVII, Nos. 1 and 2, 2005
determined by means of gas chromatography/mass spectrometry, using cannabis
fractions concentrated by preparative thin-layer chromatography.
In addition to the usual constituents of a great number of plants, such as flavo-
noids and terpenes, more than 60 cannabinoids have been found to be present
in cannabis. The main cannabinoids (figure VIII) having pharmacological effects
on humans  include:
•-9-THC, the product with the strongest psychoactive effect on humans;
•-8-THC, which is less psychoactive than -9-THC;
• CBN, which is not psychoactive but may have an anti-inflammatory effect;
•-8-THC acid and -9-THC acid (the latter is not active, but it is
converted into -9-THC when heated);
• CBG, which is not psychoactive but may have a bacteriological effect;
• Cannabichromene, cannabicyclol and their acids;
Cannabis varieties or chemotypes
The varieties, or chemotypes, of cannabis depend on the biosynthesis of the
cannabinoid constituents. The first stage in that process , shown in figure IX,
is the condensation of geranyl pyrophosphate (I) with olivetol (II) to form CBG
(III), the precursor of cannabichromene (IV), CBD (V) and -9-THC (VI). Each
stage is controlled by a specific enzymatic action [7-9] linked to the biogenetic
factor that has an influence on the biosynthesis of the cannabinoids and on their
abundance in the plant. Thus, there are different cannabis chemotypes: the drug
type, the fibre type and the intermediate type. In practice, it is possible to dis-
tinguish between those chemotypes simply by determining the -9-THC level .
Drug type, with a high -9-THC content (>2 per cent). This type of compo-
sition may be observed in all cannabis plants that grow in hot climatic zones and
produce a great deal of resin. There are many types of these plants, whose names
differ from country to country.
Figure VII. Inferior homologues of -9-tetrahydrocannabinol
Cultivation of Cannabis sativa L. in northern Morocco 87
Synonym : CBV
Synonym : Cannabivarol
Synonym : CBNA
Synonym : CBDA
Synonym : CBN
Synonym : CBD
Synonym : CBG
Figure VIII. Chemical structures of the principal cannabinoids
characteristic of cannabis
Fibre type, with a very low -9-THC content (<0.3 per cent) and a high CBD
content. The plant is grown for the manufacture of special kinds of paper, non-
woven textiles and animal litter. The -9-THC content of most varieties grown
in northern temperate zones for the manufacture of textiles does not exceed
0.03 per cent.
Intermediate type, high in -9-THC (>0.5 per cent) and CBD (>0.5 per cent).
In the three chemotypes described above, the biosynthesis of the cannabi-
noids reaches completion. Recently, however, Fournier , has described a
cannabis chemotype, the Santhica 23 and 27 varieties, in which biosynthesis stops
88 Bulletin on Narcotics, vol. LVII, Nos. 1 and 2, 2005
Ion Carbonium Cannabigerol (III)
Geranyl pyrophosphate (I)
Figure IX. Biosynthesis of the principal cannabinoids
at the CBG stage. The chemical composition of these varieties includes barely more
than 0.1 per cent CBD, and they lack THC (both the acid and neutral forms of
-9-THC and -8-THC). For that reason, they do not have any psychotropic prop-
erties. It is proposed that they be considered “second-generation fibre varieties”.
The chemical content of the three chemotypes  is summarized in table 1.
R = H, cannabinoid form
R = COOH, acid form of cannabinoid
Cultivation of Cannabis sativa L. in northern Morocco 89
Compound content by chemotype (percentage)
Cannabinoids Drug Intermediate Fibre
-9-Tetrahydrocannabinol >2 >0.5 <0.3 <0.1
Cannabidiol — >0.5 >0.5 <0.1
Cannabigerol — — <0.1 >0.5
Table 1. Cannabinoid content of cannabis chemotypes 
Different forms of cannabis
Stockley  describes several kinds of preparations based on the drug-type
cannabis plant, whose shape, colour, consistency and other characteristics differ
according to the country of origin. In particular, he describes a cannabis prepara-
tion derived from the compressed herb (marijuana) and one derived from the resin
(hashish). The first takes the form of blocks of pulverized vegetable matter, includ-
ing the various parts of the plant: the inflorescences, the leaves, the stalk and the
seeds. When the males plants are lifted and the female plants are not pollinated,
the resulting product, known as sinsemilla, has a high -9-THC content. The
second preparation, known as cannabis resin (or hashish), is, according to Stockley,
made up of sticky, oily layers derived from the flowering tops of the plant, which
are collected and compressed into blocks that can be malleable or hard, dry and
The slabs of cannabis produced in Morocco, known locally as chira or hashish
and in Europe as cannabis resin, are produced by compressing the powder obtained
by drying, pounding or sifting the dry female plant. They are stamped with a
variety of marks (see figure X).
According to Mura and Piriou , kif (as it is called in Morocco), marijuana
(in Canada and the United States of America) or takrouri (in Tunisia) is a mix-
ture of flowering tops and leaves, dried and powdered, whereas, cannabis resin,
also called hashish, is a compact brownish or yellowish powder that is obtained
by pounding and sifting the dry leaves and flowering tops (see figure XI) and
compressed into blocks (see figure XII).
Cannabis oil is a viscous liquid, greenish-brown to black in colour, with a
characteristic smell. It is derived by extraction using 90-per-cent alcohol, followed
by exposure to the sun to evaporate the alcohol. The liquid thus obtained is
heated to solidify it, making it a marketable product. The oil has a -9-THC
content of 30-60 per cent.
Variations in the level of -9-tetrahydrocannabinol in cannabis products
The differences in the level of -9-THC found in various cannabis products can
undoubtedly be attributed in large part to climatic and growing conditions. Factors
such as hours of sunshine, temperature, humidity, altitude, maturity of the plant
and the genetics of the sown seeds are particularly significant [14-20].
90 Bulletin on Narcotics, vol. LVII, Nos. 1 and 2, 2005
The dried leaves of fibre hemp contain less than 0.5 per cent -9-THC,
whereas drug-type cannabis has a -9-THC content of about 5 per cent, even
7-8 per cent. In the United States, a variety containing 15 per cent -9-THC
is produced in California, while cannabis grown indoors in the Netherlands
Figure X. Sample marks stamped on slabs of chira
Cultivation of Cannabis sativa L. in northern Morocco 91
produces cannabis resin containing up to 30 per cent -9-THC . However,
lack of standardization of analytical laboratory procedures also results in data
that may not be directly comparable. An overview of recent scientific studies
on the subject is presented below.
A retrospective study of the -9-THC content of cannabis confiscated in
the United States between 1980 and 1997 , covering 35,213 samples of
cannabis and its derivatives, taken from a total of 7,717 tons of confiscated
products, showed that the average level of -9-THC in samples of cannabis
rose from 1.5 per cent in 1980 to 3.3 per cent in the period 1983-1984, stay-
ing at about the 3 per cent mark until 1992. After that, there was an upward
trend, with the average level of -9-THC rising from 3.1 per cent in 1992 to
4.2 per cent in 1997. The average -9-THC in all cannabis products followed
the same trend, rising from 3 per cent in 1991 to 4.47 per cent in 1997. In
contrast, the average level of -9-THC in cannabis oil did not follow any
Figure XI. Pounding and sifting the dried cannabis plant
Figure XII. Cannabis resin packaged in various-sized slabs, stamped with a
mark and wrapped in cellophane
92 Bulletin on Narcotics, vol. LVII, Nos. 1 and 2, 2005
A study by the European Monitoring Centre for Drugs and Drug
Addiction (EMCDDA)  provides statistics on the levels of -9-THC in
cannabis herb and resin declared by European countries. According to the
study, the most recent data, collected in 2001 and 2002, indicate a -9-THC
concentration of 1.6-15.2 per cent in cannabis herb and 2-20.6 per cent in
A study in France  of 5,152 results of analyses conducted between
1993 and 2000 on cannabis-based products confiscated by customs officials,
the police and the gendarmerie revealed wide variations in the concentration
of -9-THC in both cannabis herb and cannabis resin. In particular, 18 per
cent of the samples analysed had a -9-THC level below 2 per cent; until 1995,
75 per cent of the samples of cannabis herb had a -9-THC level below 5.5 per
cent; and 47 per cent of the samples of cannabis resin had a -9-THC
content of 5-10 per cent. Although that general trend continued after 1996,
there was an exponential increase in products with an extremely high
-9-THC concentration. For example, it was noted that 3 per cent of the
samples of cannabis herb and 18 per cent of the samples of cannabis resin in
2000 had a -9-THC concentration greater than 15 per cent.
A study carried out in Greece  on 36 samples of cannabis herb seized
during 1996 in the northern and southern parts of the country revealed a
-9-THC level ranging from 0.24 to 4.41 per cent in the north and 0.08 per
cent and 3.41 per cent in the south. The study also drew attention to the dif-
ficulty of differentiating between the drug and fibre chemotypes of 20 per cent
of the 36 samples analysed on the basis of the following ratios:
% -9-THC + % CBN or % -9-THC and % CBN
% CBD % CBD % CBD
A study of the -9-THC level in 220 cannabis products seized on entry into
the United Kingdom of Great Britain and Northern Ireland between 1979 and 1981
 found that samples of cannabis herb had an average -9-THC concentration
of 1.0-8.5 per cent. The level for the cannabis resin seized was between 3.8 per
cent and 21 per cent, the average value being in the range 5.8-12.5 per cent. The
-9-THC concentrations in three samples of cannabis resin probably of Moroccan
origin were estimated in the study to be 6.8 per cent, 7.1 per cent and 8.2 per
cent. Fairly similar concentrations were found in samples of cannabis resin that
came from Lebanon, Pakistan and Turkey.
Lastly, the Forensic Science Laboratory of the Gendarmerie Royale determined
that 30 samples of cannabis resin seized in Morocco in 2004 had an average
-9-THC content of approximately 6 per cent. The -9-THC concentration of those
samples varied within a range of 0.4-16.0 per cent, with a confidence interval of
4.5-7.5 per cent. Thus, there was wide variation in the content of -9-THC on the
Cultivation of Cannabis sativa L. in northern Morocco 93
Study of cannabis in Morocco
Presentation of the study
The purpose of the present study was to determine the chemical composition of
various cannabis crops grown in northern Morocco and assess the levels of the
psychoactive constituent -9-THC found in them. The approach adopted was to
subject Moroccan cannabis to qualitative analyses using high performance liquid
chromatography with diode array detection (HPLC-DAD) and gas chromatography/
mass spectrometry (GC/MS) and to determine, by means of GC/MS, the levels of
the psychoactive constituent -9-THC. The analyses were conducted on the
growing (fresh) plant, the dry, mature plant and the powdered form obtained by
drying, pounding and sifting, taking into account the contribution of the flower-
ing tops and the leaves. In total, 245 samples of leaves and inflorescences were
analysed: 180 samples of fresh male and female plants (inflorescences and leaves),
52 samples of dry female plants (inflorescences and leaves) and 13 samples of
powdered plants. The THC concentrations in the male plants, which are usually
removed early to prevent pollination, were determined and compared with those
in female plants at the same stage of growth.
The study covered the areas of Chefchaouen, Al Hoceima and Larache (see
figure XIII). The choice of plots took account of the traditional agricultural
methods used in the Chefchaouen and Al Hoceima areas, where cannabis culti-
vation is a long-established practice, in contrast to the modern methods used in
the Larache area, which was established two decades ago. The cannabis plants
sampled came from both irrigated land, accounting for 12 per cent of the total
area of cultivation, and unirrigated (bour) fields, which make up the remaining
88 per cent. In 2004, average raw cannabis production for those two forms of
cultivation was 1,270 kg/ha and 750 kg/ha, respectively.
From an analytical point of view, it has been established that, while the
qualitative analysis of cannabis poses no real difficulty, quantitative analyses
aimed at determining the -9-THC level in cannabis often entail the problem of
the reproducibility of the results. That factor, which is liable to affect the accu-
racy of the values obtained, is due principally to the plant’s heterogeneity: the
flowering tops normally have a higher -9-THC concentration than the leaves,
while the stalks and the seeds do not contain -9-THC. The lifting and sam-
pling stages are therefore of great importance, and care was taken in the study
not to neglect those stages but to try to assess their impact on the reliability of
the concentration determinations. The study also took into account another influ-
ential factor: the drying process. Although several authors [11, 24 and 27] rec-
ommend the systematic drying of samples before analysis, at a temperature below
70° C for 6-8 hours, until a constant weight is achieved, the risk of losing
-9-THC due to the transformation process remains. One source  reports
a loss of -9-THC when cannabis is stored at temperatures above room
temperature (37°-50° C).
Another difficulty lies in choosing the analytical technique that is most appro-
priate for determining the -9-THC concentration: liquid or gas chromatography.
94 Bulletin on Narcotics, vol. LVII, Nos. 1 and 2, 2005
Figure XIII. Geographic distribution of plots studied
This study was conducted using GC/MS with autoinjector. That technique has
the advantage of permitting the determination of the total -9-THC, because the
two forms, the psychoactive (-9-THC) and the acid (THCA), are measured
Cultivation of Cannabis sativa L. in northern Morocco 95
simultaneously after decarboxylation of the acid  as a result of the high
temperatures in the injection part of the gas chromatograph. Decarboxylation may
continue even during elution of the analytical column, which is also heated to high
temperatures (Tf = 280° C).
Materials and methods
Samples were taken from plots located in areas of Morocco where cannabis is
traditionally grown (Chefchaouen and Al Hoceima) and the recently established
cultivation area (Larache). The sowing of those plots took place over a period
extending from February to May 2004, after which the -9-THC levels in the crops
of the three regions were monitored. Sampling was optimized by lifting a large
number of plants from each plot and by taking material from the upper and lower
thirds of each plant.
The study covered growing plants, mature plants dried in the sun and plants
converted to powder form. A total of 245 samples of leaves and inflorescences
from male and female plants were collected in the three regions:
Samples of green, growing plants (a male and two female plants about
10 metres apart) were collected from the middle of 30 plots (13 in
Chefchaouen, 8 in Al Hoceima and 9 in Larache).
Bunches of dry plants were collected from 26 plots (10 in Chefchaouen,
8 in Al Hoceima and 8 in Larache).
Several grams of powdered cannabis derived by drying, pounding and sift-
ing the leaves and flowering tops were obtained from 13 plots (5 in
Chefchaouen and 8 in Al Hoceima). No samples of powdered cannabis
were available in the Larache area, where the conversion of dry plants
into powder is believed to be still uncommon.
For the extraction of the samples, use was made of organic solvents and stan-
dards of analytical quality. Extractions were carried out in a 9:1 methanol/
chloroform solution with a 0.05 g/l nonadecane internal standard.
In the case of the fresh plant, two distinct types of samples were taken and
analysed separately. The first type consisted entirely of flowering tops, and the
Green plant Dry plant Powdered plant
(sampling date: 21 July 2004) (sampling date: 10 Sept. 2004) (sampling date: 10 Sept. 2004)
Chefchaouen 13 10 5
Al Hoceima 8 8 8
Larache 9 8 —
Total 30 26 13
Table 2. Summary of cannabis samples, 2004 growing season
96 Bulletin on Narcotics, vol. LVII, Nos. 1 and 2, 2005
second of a one-to-one mixture of leaves taken from the lower and upper extremi-
ties of the plant. The samples, wrapped in aluminium paper, were immersed in
liquid nitrogen. They were then crushed, and a test specimen of 100 mg was
soaked in 3 ml of extraction solution. In the case of the dry plant, leaves from
the lower and upper extremities and flowering tops were removed separately. They
were ground, and a test specimen of 15 mg of each powder thus obtained was
soaked in 3 ml of extraction solution. For powdered cannabis, a test specimen of
10 mg was taken directly after homogenization and soaked in 6 ml of extraction
solution. The extractions were made by sonication for 30 minutes. The resulting
solutions were dried over magnesium sulfate and filtered, and 1 l of each solu-
tion was injected into the GC/MS system, or 20 l was injected into the HPLC
The -9-THC level in the cannabis plant and powder was estimated using the
internal standard method. The calibration curve was obtained by injecting into the
GC/MS system 1 l of seven standard solutions of -9-THC in concentrations of
0.65-0.91 g/l, again with a 0.05 g/l nonadecane internal standard. The correlation
coefficient of the curve (see figure XIV) is 0.996.
The analyses by means of liquid chromatography (HPLC-DAD) were carried out
using a Merck L-5025 injection system, a Hypersil column ODS (100 mm ×4 mm
×3 m), a Merck Hitachi L-3000 diode array detector and a Merck L-6200 A
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Concentration of THC (
Y = 14,695X + 0,0056
R2 = 0,996
Figure XIV. Calibration curve of -9-tetrahydrocannabinol
Cultivation of Cannabis sativa L. in northern Morocco 97
pump. The mobile phase used was a 0.02 M acetonitrile/water/0.02 M sulphuric
acid mixture, in the proportions 70:20:10, with a flow rate of 1 ml/min.
The GC/MS analyses were carried out using a Varian CP-3800 gas chromato-
graph coupled with a Saturn 2200 ion trap mass spectrometer, equipped with a
CTC Analytics CombiPAL automatic sampler and a PTV 1079 injector.
Separation was carried out using a 5 per cent phenyl methyl siloxane capil-
lary column (HP-5) (25 m ×0.2 mm ×0.11 m), with helium as the carrier gas.
A 22-minute oven temperature programme was adopted: Ti 60° C (2 min), tempera-
ture ramp 15° C/min, Tf 280° C (5 min). The injector, operating in the splitless
mode, was set at an isothermal temperature of 270° C.
Mass spectrometry was carried out using 70 eV electron impact over a mass
range of 35-500 amu. The trap temperature was 180° C and the transfer line
temperature was 280° C.
Results and discussion
A qualitative analysis was carried out on each of the three forms of the plant,
fresh, dry and powdered, using GC/MS and HPLC-DAD. GC/MS is suitable for
dealing with the plant’s thermally stable compounds, while HPLC-DAD, being
more sensitive, registers even the thermally labile acid forms and thereby gives
a better idea of the real cannabinoid composition of the plant (acid forms and
The GC/MS-type chromatographic profiles did not indicate any dissimilari-
ties between the products of the regions studied in any of the three plant forms.
GC/MS revealed (see figure XV) a terpenic fraction eluting before the nonade-
cane internal standard and a fraction of cannabinoids, the most characteristic
of which were -9-THC, CBD and CBN in trace amounts. Their retention times
were 14.920 min, 14.380 min and 15.293 min, respectively.
A series of other cannabinoids was revealed by reconstitution of the speci-
fic ions from the total ion current. The presence of inferior homologues of the
plant’s active constituent (methyl-, ethyl-, propyl- and butyl-THC), along with its
natural precursors (cannabigerol, cannabichromene, cannabivarin and others),
was noted (figure XVII). In addition, as reported in the literature [18, 28-31],
three natural THC isomers were present: trans--8-THC, cis--9-THC and trans-
-9-THC (figures XVI and XVII). Although the trans--8-THC form was the most
thermodynamically stable, the trans--9-THC form was the most common. Those
three isomers, having similar mass spectra, were identified by their respective
retention times (14.17 min, 14.61 min and 14.920 min). That sequence in the
order of elution has been partially described by R. Smith .
Lastly, GC/MS analysis makes it possible to trace the natural development
of -9-THC from cannabidiol from the time that the green plant is growing to
the dry plant stage (see figure XVIII, which shows a variation in opposite direc-
tions of the intensity of peaks 2 and 3 on chromatograms A and B) and also
98 Bulletin on Narcotics, vol. LVII, Nos. 1 and 2, 2005
50 100 150 200 250 300
41 67 91 121 147174 193
50 100 150 200 250 300
41 67 91 121 147174 193
50 100 150 200 250 300
50 100 150 200 250 300
43 116 165 223
43 116 165 223
Figure XV. GC/MS-profile of the organic extract from the dried cannabis
plant and mass spectra of the principal cannabinoids
Figure XVI. Chemical structures of the natural isomers of tetrahydrocannabinol
present in Moroccan cannabis
Cultivation of Cannabis sativa L. in northern Morocco 99
the increase in -9-THC in cannabis powder as a result of the preparation process
(see figure XVIII, which shows the increase in the relative intensity of peak 3
as between chromatograms B and C).
HPLC-DAD analysis was carried out to determine the levels of the major
cannabinoids contained in the cannabis and to trace their development from
the growing plant stage to the stage of maturity and following the plant’s
conversion into powder. The presence of the two principal cannabinoids, THC
and CBD, with traces of CBN, was observed, as expected; most notable, how-
ever, was the clear dominance, at various stages of the plant’s growth, of
the acid forms cannabidiolic acid (CBDA), cannabinolic acid (CBNA) and
14 15 16 13
510 15 20
1 : Methyl-tetrahydrocannabinol m/z = 358
2 : Cannabivarol m/z = 386
3 : isomer CBD m/z = 314
4 : Tetrahydrocannabivarin m/z = 386
5 : Butyl-tetrahydrocannabinol m/z = 300
6 : Cannabichromene m/z = 314
7 : Trans
–THC m/z = 314
8 : Cannabidiol m/z = 314
9 : Cannabicoumaronone m/z = 328
10 : Cis
–THC m/z = 314
11 : Hydroxy-tetrahydrocannabinol m/z = 330
12 : Trans
–THC m/z = 314
13 : Cannabigerol m/z = 316
14 : Cannabinol m/z = 310
Figure XVII. Determination by gas chromatography/mass spectrometry of the
cannabinoids present in Cannabis sativa L. in powdered form
Figure XVII. Determination by gas chromatography/mass spectrometry of the
cannabinoids present in Cannabis sativa L. in powdered form
100 Bulletin on Narcotics, vol. LVII, Nos. 1 and 2, 2005
2: Cannabidiol CBD
3: Tetrahydrocannabinol THC
4: Cannabinol CBN
RIC : Fresh plant
RIC : Dry plant
RIC : Powdered plant
6 10 16 20
Figure XVIII. Evolution of the GC/MS profile of the organic extract from
cannabis in fresh, dry and powdered form
-9-tetrahydrocannabinolic acid (THCA), which were not detectable by GC/MS
(see figure XIX). The same results were obtained for all samples from three areas.
The GC/MS analysis of organic extracts from the cannabis plant was used in
determining the thermally stable components THC, CBD and CBN and their
respective acid forms THCA, CBDA and CBNA, which are decarboxylated under
the effect of heat (injector and oven), giving the forms THC, CBD and CBN. The
-9-THC levels in the three sample types – the green plant, the dry plant and
the powdered plant – were determined by applying the peak area ratio -9-THC
chromatographic peak area/internal standard area to the previously established
Cultivation of Cannabis sativa L. in northern Morocco 101
Determination of -9-tetrahydrocannabinol levels in fresh cannabis plants
The -9-THC levels of the leaves of the fresh female plants varied from region
to region (figure XX). The average levels were of the same order (0.4 per cent)
in the three regions.
Figure XIX. Chromatographic profile of powdered cannabis obtained using
high performance liquid chromatography-diode array detection
and UV spectra of key cannabinoids and their acid forms
(CBD = cannabidiol; CBDA = cannabidiolic acid; CBN = cannabinol; CBNA = cannabinolic acid;
THC = tetrahydrocannabinol; THCA = tetrahydrocannabinolic acid)
102 Bulletin on Narcotics, vol. LVII, Nos. 1 and 2, 2005
In the case of the flowering tops of the fresh plants, which had average
levels of the order of 0.6 per cent (see figure XXI), the highest average concentra-
tions were found in the samples from Al Hoceima (0.7 per cent) and Chefchaouen
(0.6 per cent), compared with the samples from Larache (0.4 per cent).
More generally, a comparison between the average -9-THC concentrations
in the inflorescences and the leaves revealed, as expected, high concentrations
in the inflorescences (figure XXII).
(n = 13) (n = 8) (n = 9)
(13 Specimens) (8 Specimens) (9 Specimens)
Figure XX. Average -9-tetrahydrocannabinol content in the leaves of fresh
female cannabis plants from three areas in Morocco
(n = 13) (n = 9)
(13 Specimens) (8 Specimens) (9 Specimens)
Figure XXI. Average -9-tetrahydrocannabinol levels in the flowering tops of
fresh female cannabis plants from three areas in Morocco
Cultivation of Cannabis sativa L. in northern Morocco 103
Lastly, a comparison of the average -9-THC levels, including both flower-
ing tops and leaves, and the respective confidence intervals for the three areas
(see figure XXIII) show that, at this stage of growth, the cannabis from
Chefchaouen and Al Hoceima had slightly higher levels of -9-THC than that
Fresh leaves Fresh flower heads
Figure XXII. Average -9-tetrahydrocannabinol content in the leaves and
tops of fresh female cannabis plants
Chefchaouen AlHoceima Larache Maroc
(n=13) (n=8) (n=9) (n=30)
(13 Specimens) (8 Specimens) (9 Specimens) (30 Specimens)
Figure XXIII. Differences in the -9-tetrahydrocannabinol content of fresh
female cannabis plants from Chefchaouen, Al Hoceima and
Larache, with their respective average
104 Bulletin on Narcotics, vol. LVII, Nos. 1 and 2, 2005
It should be emphasized that the comparison of cannabis plants that are
still growing is of a merely indicative nature, owing to the fact that sowing dates
differed from one plot to the next. In the 2004 season in Larache, Al Hoceima
and Chefchaouen, there were differences with respect to the time of ploughing,
sowing, weeding, the removal of male cannabis plants and harvesting (see
The present study has demonstrated that, contrary to the widespread belief
that male cannabis plants do not secrete the active constituent -9-THC, the
compound was, in fact, present in the leaves and tops of male plants.
The leaves of the male plants contained appreciable -9-THC levels, the
regional variations of which are shown in figure XXV. The average levels were
similar, at about 0.4 per cent.
The values recorded for flowering tops of fresh male plants (figure XXVI)
indicated average concentrations of 0.2 per cent for Chefchaouen, 0.3 per cent
for Al Hoceima and 0.5 per cent for Larache.
Date of harvest
Date of sowing
Date of ploughing
January February March April May June July August
Figure XXIV. Management and harvest periods in cannabis cultivation, 2004
Cultivation of Cannabis sativa L. in northern Morocco 105
Those results confirm studies [32, 33] that have reported that -9-THC
levels are similar in male and female cannabis plants grown under the same
conditions. The average general -9-THC level in male cannabis plants has been
estimated at 0.4 per cent, and the average levels for tops and leaves were very
similar in Chefchaouen, Al Hoceima and Larache (see figure XXVII).
(n = 12) (n = 8) (n = 8)
Limit values Confidence interval
(13 Specimens) (8 Specimens) (9 Specimens)
Figure XXV. Average -9-tetrahydrocannabinol content in the leaves of fresh
male cannabis plants from three areas in Morocco
(n = 12) (n = 8) (n = 8)
(12 Specimens) (8 Specimens) (8 Specimens)
Figure XXVI. Average -9-tetrahydrocannabinol content in the flowering
heads of fresh male cannabis plants from Chefchaouen,
Al Hoceima and Larache in Morocco
106 Bulletin on Narcotics, vol. LVII, Nos. 1 and 2, 2005
0.40% 0.40% 0.40%
Chefchaouen Al Hoceima Larache Morocco
0.1 % 0.1 %
0.7 % 0.7 %
Figure XXVII. Average -9-tetrahydrocannabinol content of fresh male
cannabis plants from Chefchaouen, Al Hoceima and Larache
1 6 11 16 21 26 31
Percentage of THC
% average THC female
% average THC male
Chefchaouen Al Hoceima Larache
- female : 0.4 % ;
- male : 0.3 %
- female : 0.6 % ;
- male : 0.4 %
- female : 0.4 % ;
- male : 0.4 %
Average THC levels
Figure XXVIII. Average -9-tetrahydrocannabinol content of male and female
cannabis plants from Chefchaouen, Al Hoceima and Larache
Those values, while substantial, were slightly lower than those found in
female plants. This is due to the fact that the vegetative cycle of the male plant
is longer than that of the female. Moreover, the farmers’ practice of removing
male plants to prevent pollination of the female plants  tends to promote
the formation of a variety that is similar to sinsemilla and richer in -9-THC.
The two curves in figure XXVIII represent the variations in the average -9-THC
level in green male and female cannabis plants from the 30 plots studied.
Cultivation of Cannabis sativa L. in northern Morocco 107
On the other hand, given the random variations recorded in the -9-THC
levels in plants from different plots, it was not possible to establish any corre-
lation with bioclimatic factors or cultivation conditions. Analysis showed that
neither the leaves nor the inflorescences of two female plants growing 10 metres
apart on the same plot consistently presented the same -9-THC level. For that
reason, this study gives the average -9-THC concentration in the leaves and
flowering tops obtained from two female plants that were analysed separately.
Determination of -9-tetrahydrocannabinol levels in dry cannabis plants
In presenting the analysis results for the dry cannabis plants, it is worth con-
sidering the problems resulting from the methods of lifting and sampling such
plants. As mentioned already, the dry plants from the 30 plots studied were
lifted and randomly combined into bunches, each containing about 30 plants.
Whereas the average -9-THC level of the flowering tops were not significantly
affected by the height on the plant at which samples were taken, in the case of
the leaves, there were non-negligible variations according to sampling height.
With respect to the -9-THC content of leaves from the lower third of the dry
plants and leaves from the upper third, there was a general tendency towards
higher concentrations of -9-THC in the leaves from the upper part (see
table 4). Thus, in this study, -9-THC levels in dry cannabis plants were
determined based on samples from both the top and the base of the plant.
-9-Tetrahydrocannabinol levels in dry cannabis plants
The leaves of dry, mature plants contain -9-THC levels that differ noticeably
from one region to another (see figure XXIX). The Al Hoceima area stands out
as having the highest concentration, 1.7 per cent on average; it is followed by
the Chefchaouen area at 1.2 per cent and the Larache area at 0.6 per cent.
Also in the case of the inflorescences of dry, mature plants (see figure XXX),
the highest -9-THC levels were recorded in samples from Al Hoceima (4.1 per
cent on average). This confirms the tendency noted in the case of leaves from
Plant 1 Plant 2
Sample Lower third Upper third Lower third Upper third
1 0.01 0.09 0.21 0.33
2 0.30 0.39 0.16 0.15
3 0.10 0.11 0.07 0.87
4 0.07 0.21 0.77 1.76
Table 4. Comparison of the -9-tetrahydrocannabinol content of leaves
taken from the lower and upper thirds of the cannabis plant
108 Bulletin on Narcotics, vol. LVII, Nos. 1 and 2, 2005
(n = 10) (n = 8) (n = 8)
(10 Specimens) (8 Specimens) (8 Specimens)
Figure XXIX. Average -9-tetrahydrocannabinol content of dried cannabis
leaves from three areas in Morocco
Limit values Confidence interval
(10 Specimens) (8 Specimens) (8 Specimens)
Figure XXX. Average -9-tetrahydrocannabinol content of dry cannabis plant
tops from three areas in Morocco
that area. The Chefchaouen area, with an average level of 2.1 per cent, is in
second position; it is followed by Larache, with an average level of 1.8 per cent.
As in the case of fresh plants, a comparison between the -9-THC levels
of the inflorescences and leaves of dry plants (see figure XXXI) revealed that the
inflorescences contained levels that were higher by a factor of 2-3. That pre-
dictable result was corroborated by a study  showing that the -9-THC
Cultivation of Cannabis sativa L. in northern Morocco 109
levels of a plant’s parts decrease in the following order: bracts, flowers, leaves,
stalks, roots and seeds.
More generally, the average -9-THC level in the inflorescences and leaves
of the dry plants analysed varied within a range of 0.7-4.8 per cent, and most
of the plants had a -9-THC level higher than 1 per cent. Larache was notable
for the fact that three of the plots produced cannabis low in -9-THC (<1 per
cent), while in Al Hoceima, a relatively high concentration (>3 per cent) was
recorded at four plots. Cannabis plants grown in Chefchaouen were characterized
by intermediate levels of -9-THC (1-3 per cent). Only one plot in Chefchaouen
had cannabis with a fairly high -9-THC level (4.8 per cent).
It is clear from figure XXXII, which shows the -9-THC levels for the three
areas studied, that there is a marked difference between the different crops.
Calculating the average -9-THC level in each area, and taking into account the
respective confidence interval, a ranking can be established headed by Al
Hoceima and Chefchaouen, the two areas where the practice of cannabis culti-
vation is long-standing with average -9-THC levels of 2.9 per cent and 2.1 per
cent, respectively, followed by Larache, where the average -9-THC level is below
1.2 per cent. The overall average -9-THC level was 2.1 per cent.
The trend in the -9-THC levels noted in dry female plants confirms the
above-mentioned results for fresh female plants.
Influence of irrigation on
It proved difficult to establish a relationship between the results obtained
and the state of irrigation of the land under cannabis cultivation. The average
-9-THC levels for dry cannabis leaves and tops in the three regions under
Dry leaves Dry heads
Figure XXXI. Average -9-tetrahydrocannabinol content of leaves and heads
of dry cannabis plants (total specimens: 26)
110 Bulletin on Narcotics, vol. LVII, Nos. 1 and 2, 2005
Chefchaouen Al Hoceima Larache
Irrigated Non irrigated
(n = 4) (n = 6) (n = 4) (n = 4) (n = 4) (n = 4)
Figure XXXIII. Influence of irrigation on -9-tetrahydrocannabinol levels
Chefchaouen Al hoceima Larache Morocco
(10 Specimens) (8 Specimens) (8 Specimens) (26 Specimens)
Figure XXXII. Differences in -9-tetrahydrocannabinol in dry cannabis plants
from three regions in Morocco
consideration varied according to whether irrigation was used, but in an incon-
sistent manner (see figure XXXIII). In Al Hoceima and Larache, the -9-THC
levels were higher in the unirrigated areas than in the irrigated ones. The
average -9-THC levels ranged from 2.7 per cent to 3.3 per cent in Al Hoceima
and from 1.1 per cent to 1.4 per cent in Larache. In Chefchaouen, however, the
average levels did not conform to that pattern; they were higher in the irrigated
areas (2.5 per cent) than in the unirrigated ones (1.9 per cent).
Cultivation of Cannabis sativa L. in northern Morocco 111
The effects of this reduction in weight on the calculations of the -9-THC
level were then assessed. The tests carried out for that purpose consisted of
determining the -9-THC concentrations in the powder before and after drying
for seven hours at 70° C. The results of some of those tests (see figure XXXV)
In order to better establish a correlation between irrigation and average
-9-THC content, it would be necessary to study a much larger number of
samples covering the three areas in their entirety and to take into account factors
such as rainfall, sowing periods, bioclimatic stages, the use of phytosanitary
products and fertilizers and the genotype of the sown seeds.
Determination of -9-tetrahydrocannabinol levels in powdered cannabis
(a) Effect of drying on the assessment of
The drying of cannabis samples before determination of their -9-THC
content has been described by several authors [11, 24 and 27]. The purpose of
the process, which consists of heating at a temperature below 70° C until a
constant sample weight is achieved, is complete dehydration in order to
achieve greater accuracy. However, heating always entails the risk of denaturing
the product through the conversion of -9-THC into CBN. The effect of drying
cannabis at 70° C on the behaviour of -9-THC and thus on the accuracy of the
concentration calculations was examined in this study. Two samples of
powder with an initial weight of 2.5 g were heated at a temperature of 70° C
for seven hours, and the loss of weight over time was checked every 90 minutes
(see figure XXXIV). The loss of weight was 4 per cent after three hours of
drying, and the mass stabilized around that level during the next four hours.
Heating time (h)
Figure XXXIV. Variations in the mass of two samples of powdered cannabis
when heated at 70° C
112 Bulletin on Narcotics, vol. LVII, Nos. 1 and 2, 2005
Chefchaouen Al Hoceima Morocco
(5 Specimens) (13 Specimens)(8 Specimens)
Figure XXXVI. -9-Tetrahydrocannabinol levels in powdered cannabis: range
THC content (%)
Before heating After heating
THC content (%)
Before heating After heating
Figure XXXV. Influence of drying on the -9-tetrahydrocannabinol content
of powdered cannabis
show that drying had little effect on the -9-THC concentrations in the powder.
That was probably due to the fact that the powder had just been prepared and
its humidity level was very low: slightly more than 4 per cent.
-9-Tetrahydrocannabinol levels in powdered cannabis
The cannabis powder samples studied came exclusively from Al Hoceima
and Chefchaouen, where the conversion of dry cannabis into powder form is a
long-established practice. The -9-THC levels in the cannabis powder analysed
Cultivation of Cannabis sativa L. in northern Morocco 113
were found to be between 5.5 per cent and 11.3 per cent, with an overall aver-
age estimated at 8.3 per cent. The powders from plots in Al Hoceima had an
average -9-THC level of 8.5 per cent, slightly higher than those from
Chefchaouen, the average -9-THC level of which was 8 per cent. Figure XXXVI
shows the variations in the -9-THC levels in powdered cannabis from
Chefchaouen and Al Hoceima, together with the overall average -9-THC level.
It should be noted that this average level of -9-THC in freshly prepared
powdered cannabis, at 8.3 per cent, was higher than the estimated -9-THC levels
(of 6 per cent) in samples from 30 consignments of cannabis resin seized
during 2004 by the Gendarmerie Royale (see figure XXXVII). This difference may
be due to the effects of the methods used in preparing the powder, adulteration
prior to seizure and/or the conditions under which the plants and the resin
blocks had been stored for various periods of time.
Evolution of -9-tetrahydrocannabinol levels through the various stages
Figure XXXVIII illustrates the development of -9-THC in the crops grown on
the 13 plots which supplied the three specimen types: fresh cannabis plants,
dry cannabis plants and powdered cannabis. It shows that, in each region, the
-9-THC levels increased markedly as the plant grew and was then converted
The estimated average -9-THC level in cannabis was 0.5 per cent in its
fresh plant state and 2.1 per cent in its dry plant state. Conversion of the plant
to powdered form was accompanied by a marked increase in its -9-THC level,
to 8.3 per cent, probably because of the substantial contribution made by the
inflorescences and the resin of the plant (see figure XXXIX).
Seizures 2004 Morocco
Figure XXXVII. Average -9-tetrahydrocannabinol level of the powdered
cannabis analysed in the present study and that of
samples of cannabis resin seized in 2004
114 Bulletin on Narcotics, vol. LVII, Nos. 1 and 2, 2005
1 2 5 8 9 1415161718192021
Chefchaouen Al Hoceima
Fresh plant - Average content = 0,5 %
Dry plant - Average content = 2,1 %
Powder - Average content = 8,3 %
Figure XXXVIII. Evolution of -9-tetrahydrocannabinol levels in cannabis
crops from two areas in northern Morocco
Fresh plant Dry plant Powder
(30 Specimens) (26 Specimens) (13 Specimens)
Figure XXXIX. Evolution of -9-tetrahydrocannabinol levels at the fresh
plant, dry plant and powdered cannabis stages
The first survey conducted in northern Morocco, in 2003, yielded socio-economic
data about the territories where cannabis cultivation has been prevalent for many
years and about the recently established cultivation areas. The second survey,
Cultivation of Cannabis sativa L. in northern Morocco 115
conducted in the Moroccan Rif during 2004, had a different purpose: to assess the
quality of local cannabis crops. Three areas, accounting for more than 75 per cent
of Morocco’s cannabis production in 2004, were selected for the study: Chefchaouen
and Al Hoceima, where cannabis cultivation had been a long-standing practice,
and Larache, where cannabis had only been cultivated for two decades.
Field studies of cannabis cultivation provide socio-economic data on pro-
duction, yields and income, among other things, but only the laboratory analy-
sis of cannabis crops can provide the information on chemical composition and
levels of psychoactive constituents making it possible to classify them as drug
type or fibre type. The analytical work carried out on fresh plants, dry plants
and powdered plants benefited from the use of fresh specimens, obtained on the
day of harvesting or immediately after preparation, in order to minimize any
-9-THC transformations as a result of oxidation due to ageing.
Qualitative analyses of cannabis grown in Morocco using HPLC-DAD pro-
vided chromatographic profiles giving a clearer picture of the cannabinoid com-
position of the plant, dominated by the acid forms (CBDA, THCA and CBNA)
along with the corresponding decarboxylated forms (CBD, THC and CBN).
Qualitative analyses using GC/MS revealed the principal cannabinoids present in
trace amounts in Moroccan cannabis. Tetrahydrocannabinol is present as three
natural isomers: cis--9-THC, trans--9-THC and trans--8-THC. Its inferior homo-
logues butyl--9-THC, methyl--9-THC and propyl--9-THC were also found. The
qualitative study did not, however, reveal any difference in chemical composition
between the cannabis crops grown in the three areas in northern Morocco.
The quantitative analysis of the cannabis crops grown in the three areas in
northern Morocco was carried out using GC/MS. It focused exclusively on deter-
mining the levels of the psychoactive constituent -9-THC in the growing plant,
at the stage of maturation and after its reduction to powder, which is the last
stage before it is turned into blocks of chira.
The -9-THC levels found were 0.1-1.5 per cent for the growing plant,
0.7-4.8 per cent for the dry plant and 5.5-11.3 per cent for powdered cannabis.
Thus, it is clear that the plants progressively gain in -9-THC. Average levels
were calculated for each stage: 0.5 per cent for the growing plant, 2.1 per cent
for the dry plant and 8.3 per cent for the powder.
It is worth placing those values in a wider context, comparing them with
the -9-THC levels found in cannabis seized in various parts of the world. A retro-
spective study of -9-THC levels in cannabis seized in the United States between
1980 and 1997  pointed to average -9-THC concentrations in samples
of cannabis herb within the range 3-4.47 per cent. A study by the European
Monitoring Centre for Drugs and Drug Addiction , which presents data
reported by European countries on -9-THC levels in cannabis herb and resin,
should also be noted. According to that study, the most recent information, com-
piled in 2001 and 2002, points to -9-THC concentrations of 1.6-15.2 per cent
in the plant and 2.0-20.6 per cent in the resin.
Analysis of the flowering tops and leaves of male plants confirmed the secre-
tion of -9-THC at different stages of plant growth. Although the values are
116 Bulletin on Narcotics, vol. LVII, Nos. 1 and 2, 2005
slightly lower than those obtained for female plants, they are very significant;
they are due to the fact that the vegetative cycle of the male plant is longer
than that of the female plant. In addition, a comparison of -9-THC levels
in the inflorescences and leaves of dry plants shows that the inflorescences
contain higher concentrations of -9-THC by a factor of 2-3.
Lastly, the study shows that in Larache, where cannabis cultivation is rela-
tively recent, the cannabis crop has -9-THC levels lower than those recorded
in Al Hoceima and Chefchaouen, where such cultivation is a longer-established
practice. In addition to the know-how accumulated by the farmers in the latter
two areas over the years, other factors should be taken into consideration when
attempting to explain this fact, for example, growing conditions, rainfall, alti-
tude, hours of sunshine, nature of the soil, irrigation, phytosanitary treatment
and even the genotype of the seeds sown.
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