Pavlo Holoborod'ko

Institute of Bast Crops, Hlukhiv, Ukraine

Introduction
        Hemp has been grown in Ukraine for centuries. Before the 1950s the area under hemp cultivation in Ukraine exceeded 150,000 ha.

Table 1.  Area of hemp production in Ukraine from 1950-1993.

        Hemp fibre was widely used in the manufacture of technical products, and was used by peasants to make cloth, clothes and household goods.  Hemp seeds, after different kinds of processing, and hemp seed oil, were used as food and for technical purposes.
        The large-scale cultivation of cheaper cotton, and development of the synthetic fibres industry caused the hemp area in Ukraine, as well as all over the world, to decrease.  This decline was also due to the spread of its use as a drug, especially in the southern regions of Ukraine.
        In 1994, about 4,000 ha were sown for fibre hemp in Ukraine.  Hemp was grown in three zones: the northern zone (Sumy region ~1,000 ha), the forest and steppe zone (Poltava and Cherkassy region ~2,000 ha), and the steppe zone (Dnipropetrovs'k region ~1,000 ha).  Hemp fibre is used exclusively to manufacture technical products such as marine and river cordage, ropes, cores for steel cables, twines, technical clothes, etc.  Since industrial demand for hemp fiber is not satisfied, and there is a large demand for hemp products, the area under hemp production in Ukraine will increase.

Contemporary history
        During 1929-1930 in the Soviet Union large collective farms (kolkhoz) and state farms (sovkhoz) replaced individual peasant farms.  Hemp growing was concentrated on collective farms or state farms with 100-500 ha sown.  In 1931, the All-Union Scientific and Research Institute of Bast Crops was organized in the town of Hlukhiv to study problems of the cultivation, harvesting, and processing of hemp.  The Institute exists now as the Institute of Bast Crops of the Ukrainian Academy of Agrarian Sciences and carries out research on hemp and fiber flax.  For more than 60 years the Institute thoroughly investigated the problems of the anatomy, biology, and physiology of hemp plants, researched selection and genetics; developed methods of hemp growing for different soil and climatic zones, developed technologies of harvesting stalks and seeds and primary fiber processing, and designed harvesting equipment.
        Ukrainian hemp breeding progressed through two stages.  During the first stage, local varieties with stem fiber content of 12-15% long fiber yield were replaced by the dioecious hemp varieties with high fiber content.   The varieties US-1, US-6, US-9, Hlukhivska 1, and Hlukhivska 10 were grown in the northern zone, Yuzhna Cherkasska was grown in the forest and steppe zone, and Dniprovs'ka 4, Yuzhna Krasnodars'ka, and Krasnodars'ka 35 were grown in the south of Ukraine and the Northern Caucasus.  Due to acclimatization in different zones of southern hemp varieties, and to use of different methods of hybridization and breeding, stem fiber content in these varieties was increased to 22-27%, and in some varieties stem fiber content exceeded 30%.
        The second stage of hemp breeding consisted in development of monoecious hemp varieties which could help solve the problems of harvest mechanization.  In the early 1960s the hemp variety Bernburgska Odnodomna from Germany was grown.  Hybridization of that variety with the dioecious hemp variety US-6 of high fiber content, and subsequent breeding, resulted in 1968 in the high yield monoecious hemp variety USO-1.  Later the varieties USO-4, Poltavska Odnodomna 3, and USO-16 were developed.  Since the 1980s only monoecious hemp has been grown in Ukraine.
        Due to the spread of the use of illicit drugs, many countries imposed limitations, and even made hemp growing illegal.  According to the laws of the Soviet Union it was illegal to grow new hemp varieties with tetrahydrocannabinol (THC) content higher than 0.3%. Later the allowable THC content was reduced to 0.25%, and since 1988 it has been reduced to 0.1%.  Hemp breeding for low cannabinoid content was preceded by study of cannabinoid combinations, through determining different methods of analysis and diagnostics including express diagnostics, which underlay the methods of breeding hemp varieties with low drug potency.  Several generations of varieties with different THC content were developed.  At present 5 hemp varieties with low THC content and differing economic indices are being grown in Ukraine.

Present techniques
        The system of seed growing of monoecious hemp varieties preserves a high level of varietal typicalness.   To produce super-elite seeds and elite seeds staminate plants are removed.   Plants in the first reproduction are grown under the conditions of spatial isolation and free cross-pollination and the number of starninate plants does not exceed 5%.  Seeds of the second reproduction are used to grow hemp only for fiber and the number of staminate plants does not exceed 25%.

        Since 1992, following the proclamation of the independent state of Ukraine, the Institute has been working on the formation of the national gene bank of bast crops.  In 1994, 283 hemp accessions (211 dioecious and 72 monoecious) were studied.  The collection was thoroughly investigated for fiber and cannabinoid content, stalk and seed yield, plant height, length of vegetative cycle, and resistance to diseases and pests.  The most valuable accessions were introduced as initial material for breeding.

        The Institute developed agrotechnical hemp-growing methods for the soil and climatic, organizational, and economic conditions of Ukraine.  Hemp is cultivated in special short rotations.  In kolkhozes and sovkhozes with large hemp areas, hemp is grown in cereal root crop rotations.   Recently an energy-saving system of soil preparation in hemp rotations was developed based on the combination of mold-board plowing and post-plowing tillage.   Fertilizers consisting of nitrogen (N), phosphorous (P), and potassium (K) macro nutrients and boron (B), bromine (Br), copper (Cu), and Zinc (Zn) micro nutrients are applied according to the results of soil diagnostics.
        Two hemp-growing technologies are used in Ukraine.  The first technology is for the production of fiber and seed.  Hemp is sown in wide rows at row width of 45 or 60 cm.  Seeding rate for elite seeds is 60-90 seeds per m², for seeds of the first reproduction is 120-180 seeds per m², and for seeds of the second reproduction is 180-240 seeds per m².  Hemp is harvested when the seeds ripen.   This technology is used to grow 30% of hemp in the northern zone, 50% of hemp in the forest and steppe zone and 100% of hemp in the steppe zone.  The second technology is used to produce only fiber.  Hemp is sown at row width of 7.5 or 15 cm.   Seeding rate is 450-500 seeds per m².  Hemp is harvested after the end of the flowering of the staminate plants.   According to which technology of hemp growing is used, different harvesting technologies are employed.
        To grow hemp for fiber and seeds direct combining and swath harvesting are used.  For direct combining we use the combine KKY-1.9.  The combine cuts plants, threshes and cleans seeds, and binds stems with twine or spreads them out in the field.  Hemp is harvested when 75-80% of seeds in inflorescences are ripe as seed shedding losses are minimal.  Since not all the seeds are ripe the humidity level of threshed seeds may be as high as 20%.  To avoid damage it is necessary to dry the seeds to decrease the humidity level to 12-13%.  The Institute worked out a method of chemical drying of hemp stands by treating them with desiccants during the 7-10 days before the start of harvest.  MgClO₃·6 H₂O (10 kg/ha) and Reglon (Diquat) (1 l/ha) are used as desiccants.
        Unfortunately, due to the insignificant area devoted to hemp, mass production of hemp combine harvesters is not organized.  We consider it possible, through the common efforts of interested firms, to organize joint production of hemp combines.  For swath hemp harvesting we use the cutter GK-1.9 which cuts hemp plants, binds them, and throws them down.  Binds are threshed by the hemp thresher pK-4.5A.  This technology results in greater seed losses and higher-manual labor costs.  Hemp grown for fiber only is harvested by the cutter GK-1.9 which cuts plants and spreads them out in the field for dew retting.  During dry weather stalks are turned over to obtain even retting.
        After dew retting the picking-up machine KB-1 picks up the stalks and binds them.  Further operations with loading and unloading binds are connected with high manual labor costs.  We also have the technology and machines for rolling retted hemp with parallel arrangement of the stalks.
        Hemp-growing and hemp-harvesting technologies in Ukraine differ in many ways from the technologies used in other countries.  In Ukraine processing technology is based on treatment of parallelizing hemp stems as in the case of fiber flax.  Using this technology we obtain both long and short fiber.   About 30% is long fiber and it is used to manufacture the most important products, primarily cordage for marine and river boats.

Conclusions
        This process technology is more expensive and requires the expenditure of more labor than technologies in other countries.  In the years to come, hemp-growing will be revived in Ukraine and the sphere of hemp usage will change.  Side by side with a traditional use of fiber to manufacture spun products, use of hemp for the pulp, paper, and textile industries will increase considerably.
        Forests occupy about 13% of the territory in Ukraine and they are mostly preserved to protect the natural environment.  Hemp can play a considerable role in solving the problem of acute shortages of both pulp and paper production.  At the Institute we conduct breeding programs aimed at increasing the biological potential of hemp and raising stalk yield to 12-15 t/ha.  Hemp harvest and hemp processing technologies will be made considerably simpler and cheaper.
        Due to the lack of our own cotton production, and sharp increases in cotton's price on the world market, the development of the textile and knitting industries of Ukraine will be aimed at utilizing pure hemp and flax fiber, and blends with other natural and synthetic fibers in the manufacture of clothes and other products.