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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.

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.

    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

• Deferne, J.-L., and D.W. Pate 1996.  Hemp seed oil: A source of valuable essential fatty acids. JIHA 3(1): 1, 4-7.
• Erasmus U. 1995a.  Hemp: LA, LNA, and GLA - Nature's most perfectly balanced oil? in Fats that Heal, Fats that Kill, Alive Books, Burnaby, B.C., Canada.
• Erasmus U. 1995b.  ibid., Table D7, page 237.
• Horrobin D.F. (ed.)1982.  Essential Fatty Acids: A Review in Clinical Uses of Essential Fatty Acids, Eden Press, London, England.
• Theimer R.R. and H. Mölleken, 1995.  Analysis of the oils from different hemp (Cannabis sativa L.) cultivars-perspective for economic utilization in Bioresource Hemp, Proceedings of the Symposium, Frankfurt, Germany 2-5.3.1995, 2nd edition, nova-Institute, Büro Hürth, Cologne. pp. 536-545a.
• Wirtshafter, D., 1995.  Nutrition of hemp seeds and hemp seed oil? ibid. pp. 546-555.