32
Cultivation of Cannabis oil seed varieties in Finland
J.C. Callaway1 and T.T. Laakkonen2
1Department of Pharmaceutical Chemistry,
University of Kuopio POB 1627, FIN-70211 Kuopio, Finland
2Palkkila Farm, Hatsinantie 219, FIN-16710 Hollola, Finland
Introduction
From a nutritional perspective, Cannabis seed
is quite extraordinary (Deferne and Pate 1996). But aside from this, the Finnish
farmer is currently in desperate need of valuable cash crops to maintain what is left of
the traditional family farm. Increasing industrialization since the 1940s, in
combination with more recent European Union (EU) restrictions on agriculture, have all but
eliminated this rural mode of existence. It was hoped that the introduction of an
early-blooming and frost-tolerant variety of Cannabis might add a significant
financial contribution to Nordic farm life. From the available information on the
nutritional value of hemp seed, it should be only a matter of time before the potential of
this resource is fully appreciated.
Trial Preparations
Two early-blooming varieties of Cannabis (VIR-313
and 315) were originally sourced from the Vavilov Research Institute (VIR) in St.
Petersburg, Russia via the International Hemp Association. We received a
mixture (800 grams) of both varieties in April of 1995. These were planted in
several plots throughout central Finland in early June at a density of 20-30 seeds/m2
and harvested between late September and early October (Table 1, typical data). The
resulting hybrid is tentatively designated FIN-314.
Table 1. Events, days and corresponding dates for the development of VIR-313 and VIR-315 in central Finland during 1995. | ||||||||
Event | Day | Date | Height (cm) |
|||||
Local sheriff informed Planting Police collect samples Male flowering begins Female flowering begins First pollen appears Police collect samples Frost -2 °C Frost -6 °C Initial harvest Police collect samples Final harvest |
- 0 24 27 37 39 57 97 99 103 114 118 |
April 24 June 10 July 4 July 7 July 17 July 19 August 6 September 15 September 17 September 18 September 28 October 9 |
- 0 30 35 70 85 135 145 145 145 150 155 |
Observations
Considerable competition with common weeds resulted
from the sparse planting of seed. Males began to flower on July 7 (day 27), and
females began on July 17 (day 37). Interestingly, both males and females continued
to grow and develop after inflorescence (Figure 1 and Table 1). The typical maximum
growth rate was recorded to be 4.2 cm/day during July 4-29 (days 24-49) from a smaller
garden plot in central Finland, having good soil (Figure 1). Day lengths during this
time of rapid growth averaged 19 hours. In the sunniest portions of the plots, some
plants reached a height of 210 cm. Surprisingly, these varieties were not
significantly effected by a series of night frosts between September 15-28 (days
97-110). The larger leaves typically regained their original unwilted form during
the following day as temperatures increased. Another outstanding feature of these
varieties was their reluctance to branch after flowering, even when allowed adequate
space. Instead, they continued to grow in height. Only late in September did
some of the plants begin to show significant branching.
Figure 1. Oil seed hemp growth rate (1995) in central Finland at 62.2° N. latitude.
The total yield from the largest plot (0.1 hectare) was 22 kg of seed (after mechanical threshing) from a very sparse planting of 500 grams of seed. Analysis of the seed (Table 2) resulted in data that indicated a clear superiority over most other varieties, in terms of both oil yield and fatty acid (particularly GLA) content.
Table 2. FIN-314 Seed Analysis Results (means of 2 analyses each of 2 random samples, standard deviation in brackets), chlorophyl in mg/kg, other parameters in %. | |||||||||
Parameter | Sample 1 | Sample 2 | |||||||
oil content chlorophyll Palmitic acid (C16:0) Palmitoleic acid (C16:1) Stearic acid (C18:0) Oleic acid (C18:1) Linoleic acid (C18:2) GLA (C18:3) Linolenic acid (C18:3) Arachidic acid (C20:0) Eicosenoic acid (C20:1) Eicosadienoic acid (C20:2) Behenic acid (C22:0) Lignoceric acid (C24:0) |
36.94 181.50 5.65 0.12 2.18 8.76 56.53 3.96 21.03 0.79 0.39 0.00 0.29 0.27 |
(0.226) (2.121) (0.007) (0) (0) (0.028) (0.205) (0.077) (0.120) (0.007) (0) (0) (0.063) (0.014) |
36.79 197.00 5.76 0.15 2.25 8.87 56.13 4.07 20.89 0.81 0.41 0.09 0.29 0.24 |
(0.431) (4.242) (0.070) (0.007) (0.021) (0.077) (0.141) (0.021) (0.007) (0.021) (0.014) (0.007) (0.028) (0.014) |
Approximately 1-5% of the total plant population
succumbed to mold (Sclerotinia) or black aphids. An additional 1% of the
developing females began to develop mold on and around the bracts during maturation, and
these individuals were culled from the plots by hand.
Although the cultivation of Cannabis in Finland for 'non-drug'
purposes has never been prohibited in Finland, and despite favorable forensic laboratory
analyses, a few officials attempted to enforce a non-extant 'zero-line' policy they
claimed applicable to Cannabis containing any detectable amounts of THC.
Fortunately, after much discussion and support from the agricultural community, our plots
of these VIR varieties were allowed to mature and be harvested.
Conclusions
These two early-blooming strains are truly unique
varieties of Cannabis. Considering their growth habit, it seems possible that
these strains are descended from Cannabis ruderalis, which is thought native to the
Altai region of Siberia. Although the seed was delivered as a mixture of the two
varieties, it was possible after flowering to distinguish between them. For both
male and female plants, one variety had flowers distinctly darker in color (light purple)
while the other was lighter (light-yellow). No other differences were readily
apparent.
The season was unusually warm and dry during 1995, which may have
enhanced growth rates in this typically cool and wet environment. However, many
plots were not in areas of maximum solar exposure. Also, the soil was somewhat
depleted in the 0.1 hectare plot after growing barley the previous year and rape seed the
year before that, with no additional fertilization prior to the cultivation of hemp.
In addition, planting depth in this plot was uneven and mild compaction of the soil
surface may have hindered germination. With this in mind, and considering the
results from smaller plots on better soil, it seems likely that yield can be increased
under optimal conditions.
Recent reports (Theimer and Mölleken 1995, Deferne and Pate 1996)
suggest that degree of molecular unsaturation in hemp seed oil may be higher in temperate vs.
tropical varieties of Cannabis. It is not clear, however, whether this effect would
be due to genetic or environmental influences. Should an actual correlation exist
between latitude and polyunsaturation (and our preliminary results support this), Nordic
hemp farmers may realize a distinct advantage over Cannabis grown further south for
the production of food oil.
We received a considerable amount of attention from the media and law
enforcement agencies throughout the course of this project. Through frank and open
dialog, we were able to continue this experiment to fruition. Fortunately, these
Russian varieties possessed THC levels well below the EU-mandated 0.3% level, which was
verified by laboratory tests (0.08% maximum). This was certainly of great advantage
during our interactions with the Finnish authorities. It seems that the 'non-drug'
cultivation of Cannabis will be allowed to continue in Finland.
Acknowledgments
We gratefully acknowledge David Watson and the
International Hemp Association for providing the seeds for this adventure in botany and
politics, and we especially thank David Pate for his technical support. Additional
thanks are due to Hannele Sankari and Leila Salo for the seed oil analyses.
References