Book Review
Re-discovery of the Crop Plant Cannabis Marihuana Hemp
(Die Wiederentdeckung der Nutzplanze Cannabis Marihuana Hanf).

By Jack Herer, Mathias Bröckers and Katalyse. Zweitausend-eins, Frankfurt am main, Germany. Nineteenth printing, 463 pp.

Judging by its length and the broad spectrum covered, this book could be regarded as a monograph if the style, contents and presentation were not of such a popular nature. It will still fill a definite need, however, since over the past 40-50 years not only has the production and processing of this crop been discontinued in Western Europe, but the plant itself has almost faded into oblivion. One reason for this was the craze for synthetic fiber materials in the late fifties and early sixties (e.g., nylon) which supplanted not only hemp, but flax as well, though they were also unable to compete with cotton. The other reason was the hysterical attitude towards drugs, which started in the USA and had such an influence on other governments. They were poorly informed on this subject, but committed to this campaign for other reasons and even fibre hemp, which is not classified as a drug, was banned from cultivation (as in Germany, for instance). The only exceptions to this were France, where 4,000-5,000 hectares of hemp have always been grown for paper manufacturing purposes, and Holland, with its liberal drug policy, where the sale and consumption of hashish was tolerated in the justified hope that this would distract the attention of the population from harder drugs (e.g. heroin, cocaine etc.). This concept has been a success.

Returning to a criticism of the book itself, it is a pity that the title includes the word marihuana, which is compromised throughout the world. This is hardly the way to popularise hemp. To date, only specialists are aware of the medical effects of THC, while marihuana still has a disreputable sound for society in general.

The book is characterised throughout by an enthusiasm and bias in favour of a good cause that sometimes goes to extremes, leading to material errors and illusory lines of argument. Nevertheless, the book does good service towards the enlightenment of the relevant authorities, organisations and governments in the hope that this propaganda on behalf of hemp will be a success.

The book is a "hybrid": chapters II and III were written by Germans on the European and specifically German aspects of the plant. While the first chapter, written by the American author Herer, deals mainly with the many-sided practical utilisation of hemp, the German sections attempt to give a certain amount of scientific background: botany, ecological requirements, production technology, etc. Of particular interest are the detailed discussion of the process which finally led, in 1937, to the prohibition of hemp production in the USA and to the banning of research into THC, again in the USA, in 1978, and the description of the road which led to synthetic THC. The struggle being wrought in the USA by marihuana lobbyists at all levels right up to the president also makes fascinating reading, while the arguments and factual information presented on the medicinal action of THC are convincing, as are references to the collusion between the pharmaceutics industry and the government, aimed at maintaining the ban on THC.

Finally, there is a unique summary of the history of hemp cultivation, the like of which, as regards both the extent and richness of data, has never previously been published.

The Americans have every right to complain about the prohibition of hemp production and to lobby for its reauthorisation since the ban was actually lifted for a few years during the war ("Hemp for Victory"), but Western Europeans have no cause to complain about the disappearance of hemp, because they have undeservedly forgotten about it over the last 40 years.

In Western Europe, nobody banned the cultivation of hemp. It was simply ousted by artificial fibres. The largest hemp producing state was Italy, where cultivation also ceased in the sixties, so the statement that hemp is still grown commercially in Italy (p. 269) is incorrect. On the other hand, French hemp production is mentioned as if it had begun again in 1990, although it was never abandoned there, an area of 4,000 - 5,000 hectares having been constantly sown to hemp for paper manufacturing purposes. It was also the French who produced the first low THC monoecious varieties. In Eastern Europe, the production of hemp was never discontinued, though the situation differed considerably from one country to the other. Large-scale production was only carried out in the Soviet Union, Romania, and Hungary, which is not mentioned at all in the book, but where the highest yield averages were produced (9 t stems/ha on 6,000 ha in 1989). Hungary was also the biggest exporter of hemp cloth to the Soviet Union (5 million m2/year), since it provided the best quality. I do not know where the author found his data on the highly developed hemp production of Romania, because the average yields in this country were actually extremely low. Regarding the Bulgarian hemp production, it was never of great importance and there has been no breeding for the last 30 years.

It is true that no books on hemp have been published in Germany over the last 40 years, but there was no call for such books, as nobody was interested in the subject. It is only now that the time is ripe for this venture. It is also true, however, that in 1961 Prof. Hoffmann devoted a full chapter to hemp breeding in the monumental work by Roemer and Rudorf Handbuch der Pflanzen-züchtung in which he made frequent references to the author of this review. A decade later, the book by Hoffmann, Mudra and Plarre, Lehrbuch der Züchtung landw. Kulturpflanzen, also discussed hemp breeding at far greater length than was justified by its importance in Germany, and this was repeated in the 2nd edition published in 1980. Finally, in 1988, Prof. Geisler included a brief but correct chapter on hemp production in his book entitled Pflanzenbau. So there was no shortage of literature, just a lack of interest.

It is disappointing to note that both the American and the German authors betray a great deficiency in knowledge on hemp production and research in Eastern Europe, though a book of this calibre deserves to have been supported by more accurate data. Instead, the authors plead the difficulty of not understanding the language (though the publications always have a German or English summary). I myself, for example, have written four articles in German, published in various German journals, reporting on the results of Hungarian hemp breeding. If the authors had read these articles they would not have written the erroneous statement that monoecious hemp varieties have a 50% higher fibre content than dioecious varieties. The variety with the highest fibre content in the world is, in fact, the Hungarian dioecious variety KOMPOLTI, which was used to improve the fibre content of French varieties and which has a considerably greater stem yield than any monoecious variety. It was also in Hungary that the first hybrid varieties were produced and the first unisexual forms consisting solely of females. Dutch researchers from Wageningen set up the experiments needed for their paper project (p. 344) using the Hungarian variety Kompolti hybrid TC, which proved to have the greatest stem yield.

Romania is often mentioned in the book, though it has only two varieties with moderate yield potential (Fibramulta and Secueni 1). A number of dioecious varieties are available in Italy, but these are not cultivated now. Many monoecious varieties are available at Gluchov in the Ukraine, and many types of harvesters have been developed in Gluchov, but yield averages are very low. It is strange that the book makes no mention of French monoecious hemp varieties (Futura, Fédrina, Félina, etc.), although these are grown on the greatest area in EU countries at present.

As already indicated above, over- enthusiasm, sometimes without good groundings, often leads the authors into the dead-end of objective errors and illusory lines of argument. For instance, it is a great exaggeration to calculate that hemp could be grown on 6 million hectares in the EU countries. This would require an enormous infrastructure, for which the funds are simply not available. Several dozen hemp factories, oil plants, spinning and weaving mills and panel-making factories would be needed within the production area, since it is not worth transporting hemp more than 40-50 km even in bales. It is a great error to expect an oil yield of 24 million tons: this is obviously based on the data in Table 12 (p. 452), which have been incorrectly understood from Romanian literature, suggesting that hemp gives a seed yield of 4000 kg/ha (pp. 314, 347, 349). This is a biological absurdity. Present knowledge puts the yield potential of the best seed-producing varieties (mid-Russian) as 1000 kg/ha, which is far lower than that of sunflower, and on average only 600-800 kg can be expected. It follows from this that in Germany rapeseed far surpasses hemp in seed-yielding ability and thus in oil yield. It can thus be seen that hemp is not, and never will be, a mass oil-producing plant, as it produces few seeds. For this reason, its excellent but expensive oil will remain the foodstuff of the rich. Herer's speculation on the conversion of hemp into methanol is equally illusory (p. 105). If even 10% of the many hundreds of millions of tonnes of oil used in the USA each year were to be replaced by hemp methanol, hemp would have to be sown on 5-10 million hectares: the cost of infrastructure and technology would exceed even the capital potential of the USA. In addition, due to transportation problems, thousands of decentralised methanol plants would be required. This belongs to the world of fantasy.

I think it is also unrealistic to expect a dry stem yield of 10-12 t/ha in Germany. This can only be achieved in more southern-lying countries and only with southern (late) varieties.

It is an exaggeration to suggest that hemp fibre could be used without mixing with other fibres to weave the finest cloths (shirts), since it is common knowledge that with the present technology, threads of at most Nm 10-12 can be spun from hemp, compared to Nm 40-50 for flax. The difference in fineness between the two plants requires no explanation. We do know that very fine hemp yarn is made in China using various half-manual technologies. However these processes can not be directly applied in Europe.

In summary, the publication of this book was very timely and provides interesting, convincing and useful reading for all those who wish to work with or perhaps invest in this crop, or who have to teach or study it. Although it is a popular account rather than a scientific work, it will nevertheless prove informative for researchers, since it contains many data which are only otherwise available after long searching in libraries.

The errors and exaggerations listed above do not detract from the usefulness of the book or from the burning desire of the authors to see hemp reinstated to its rightful place among the valuable crops, for the good of humanity. The criticism is not intended to deter the authors, but to encourage them to eliminate the exaggerations and errors from later editions of the book.

Dr. Iván Bócsa, GATE Agricultural Research Institute, Kompolt - Hungary