Agriculture Reference
In-Depth Information
1. Drug varieties characterized firstly by a high
Δ-9-THC content and secondly by a virtual
absence of CBD. These varieties are found
growing primarily in warm climates (Mexico,
Afghanistan, India, Africa and Jamaica). In
temperate climates, however, these varieties
can be grown in greenhouses, often using
hydroponic
number of plants to be sampled, plant parts to
be collected) and the treatment of the samples
collected (drying and storage). This selection
programme has been described elsewhere in
this topic.
During the selection programme, a new
variety containing no
-9-THC (<0.005%, and
therefore barely detectable by chromatographic
analysis) was discovered. CBD is present in this
new variety, but at a low concentration. By
contrast, the major cannabinoid is CBG. This
last cannabinoid, as mentioned above, is the
biogenetic precursor to
Δ
techniques
(nederwiet,
for
example).
2. Intermediary drug varieties that possess
high levels of both
-9-THC, conferring phar-
macological properties on them, and CBD.
These varieties come principally from the
Mediterranean basin (Morocco and Lebanon).
3. Fibre varieties, with a particularly low
Δ
-9-THC and CBD;
this therefore suggests that the biogenesis of
THC and CBD is halted early, favouring the
build-up of CBG. Three new varieties present-
ing this cannabinoid profile have been created:
Santhica 23, Santhica 27 and Santhica 70.
These are second-generation fibre varieties
(Fournier
et al
., 2004).
Finally, we have discovered very recently a
new chemical type characterized by the absence
of cannabinoids. Biosynthesis is halted even
earlier in the metabolic pathway and must
occur before the assembly of cannabinoid pre-
cursors. This certainly represents an interest-
ing and very promising discovery.
Δ
-9-
THC content. The main cannabinoid is CBD.
These are the varieties found in France and
other countries with a temperate climate.
Δ
Figure 19.2 shows that the fibre varieties culti-
vated in France a few years ago register a Δ-9-
THC concentration below 0.3%. Despite this
being at the upper limit permitted by the
European Community until 2000 (0.2% as
from the 2001 season) (
Journal Officiel de la
République Française
, 2004), a selection pro-
gramme was undertaken to reduce the
-9-
THC concentrations of French varieties. It
should be noted here, however, that these lev-
els of
Δ
-9-THC do not demonstrate any psy-
chotropic effects.
Hemp selection was undertaken by the
Fédération Nationale des Producteurs de
Chanvre
(FNPC), in partnership with the
Laboratoire de Pharmacognosie de la Faculté
de Pharmacie de Châtenay-Malabry
.
The selection programme started by look-
ing for a very strict operating protocol, both
with regard to cultivation, the sampling method
and the chemical analysis itself, which involved
the testing of more than 5000 samples/year. It
should be pointed out that the official texts
concerning the 'EU method for the quantita-
tive determination of Δ-9-THC in hemp varie-
tals' (
Journal Officiel de la République
Française
, 2004) has been developed from,
most notably, the French experience in this
field (Fournier
et al
., 2001, 2003; Fournier,
2003a,b, 2004). This document not only
describes the dosing methodology (by gas chro-
matography) but also specifies the procedure
for sample selection (season of collection,
Δ
19.5 Principal Morphological and
Chemical Characteristics of Hemp
Cultivated in France
At this point, the following question can be
asked: are there any morphological differences
among these varieties and can they be distin-
guished from each other in the field? An
unequivocal answer cannot be given.
The main differences observed concern
cultivation practices and, in particular, popu-
lation density. Seeds of the same variety
planted at a low (1-2 kg/ha) or high (50 kg/
ha) density will produce plants with very dif-
ferent morphologies. In the first case, they
will branch considerably, whereas in the sec-
ond they will be reduced to a primary stem.
By contrast, in identical cultural conditions,
plants with different chemotypes, as outlined
above, will have similar morphological char-
acteristics and only chromatographic analysis
will distinguish them.
