Dr. V. G. Virovets
Dr. V.G. Virovets is the head of the Hemp Breeding Department at the Institute of Bast Crops in Glukhov, the Ukraine. The Institute of Bast Crops is the largest hemp research center in the world. Plant breeders from Glukhov have created many hemp cultivars with very low THC contents and high fibre contents. This "fax-interview" was conducted by Hayo van der Werf and Rob Clarke in May 1998 with assistance from the Vavilov Institute.
What is your academic background and how did your career develop?
I was born on March 5, 1937 in the Ukraine. I graduated from agronomical college in 1952 and from the Kharkov Agricultural Institute, named after Dokuchaev, in the Ukraine in 1964 where I obtained my MSc degree in plant breeding and seed improvement. Since 1964 I have worked at the Institute of Bast Crops in Glukhov, Ukraine at first as a junior researcher, then as senior researcher. I have been Head of the Hemp Breeding Department since 1971. Scientific titles earned: N. I. Vavilov Institute of Plant Industry, 1981, Ph.D. in Agronomy; Institute of Sugar Beet, Kiev, 1992, Full Doctor of Science (Thesis: Creation of high-yielding, THC-free cultivars of hemp).
How did you get interested in hemp breeding?
I've been interested in scientific problems since I was a student. At the beginning of my work at the Institute of Bast Crops, I was recommended to Prof. G. I. Senchenko and Prof. A. I. Arinshtein. They became my teachers in practical breeding in improvement of hemp.
When, and from where, was hemp introduced in Ukraine?
It is impossible to indicate precisely the beginning of the use of hemp as a cultivated plant in the territory of modern Ukraine. Hemp as a crop was cultivated by mankind for a very long time side by side with cereals and vegetables since the birth of plant cultivation. Concerning introduction of hemp into cultivation, we share the opinions of Chinese and Indian scientists.
What is the current situation of hemp growing and processing in the Ukraine, and what are your perspectives for the future?
The modern situation with hemp cultivation in Ukraine is problematic, but during the last 1 to 2 years it is getting better, showing promise to restore because the material base of cultivation and processing and habits are still alive. During 1970-1980 hemp was a widely cultivated crop over the territory of Ukraine: approximately 60,000 hectares, producing up to 9,000 tonnes of high quality hemp seeds and a quarter of the world’s production of hemp fiber. The hemp crop currently attracts big attention both in the scientific field and with respect to practical cultivation. Increased interest takes place across the world: Western Europe, America and Australia. Regularly, various symposiums and conferences take place with the participation of famous scientists and agronomists, wide publicity is given to hemp in various journals, including the Journal of the International Hemp Association. This promises a bright future for hemp cultivation.
Do you require licenses to grow hemp in Ukraine?
According to the rules of the Ukraine, a variety may be accepted for cultivation only after State Trials. Cultivars are put on the List of Crops of Ukraine and may be cultivated within the country. In 1998, eight monoecious cultivars entered the List. Newly bred cultivars and foreign varieties now undergo State Trials within the system of State Committee for Trials of Cultivars.
What is the average yield level for fiber crops and seed crops?
Modern Ukraine includes different climatic zones. Early-maturing varieties of Middle Russian type (more early) are cultivated in the North-Eastern part of Ukraine, in the South cultivars of Southern type, possessing a longer vegetation period are grown. Southern-type varieties may be cultivated in the North for fiber. In contrast to Southern-type varieties, the Middle Russian varieties have better seed yields. The yield of Middle Russian type cultivars is 7-9 tonnes per hectares for fiber and 0.9-1.4 tonnes for seed; for Southern type: 9-11 tonnes per hectares for fiber and 0.8-1.0 tonnes for seed.
What is currently the maximum threshold for THC content of hemp cultivars in the Ukraine?
For the newly bred varieties ready for State Trials the level is 0.1% THC. For the currently cultivated varieties it is 0.2% THC.
How many researchers are currently carrying out hemp research at the Institute of Bast Crops at Glukhov?
Our staff includes eight researchers, including those at the Zolotonosha department and Dr. V. F. Solodushko at the Sinelnikovo station.
How is hemp research at Glukhov funded?
The Ukranian Academy of Agrarian Sciences support us from the State budget. But we have big financial problems because of the crisis in the Ukranian economy.
Do you collaborate with other hemp breeders outside Glukhov? If so, with whom?
We have scientific relations with the N. I. Vavilov Institute of Plant Industry (S. Kutuzova, L. Rumyant-seva, S. Grigoryev) without interruption after the breakdown of the USSR. We continue relations with the Krasnodar Agricultural Institute (P. Nimchenco, T. Sukhorada), we communicate with the Penza Institute (V. Tikhomirov). We have good relations with I. Bócsa from Hungary and with R. Kozlovsky, L. Grabovska and N. Timcov from Poland. We exchange inbred seeds with scientists from France, Italy (Bologna), from the Netherlands and with Michael Karus from Germany.
What are the main topics of research with respect to hemp at the Institute of Bast Crops?
The main direction in scientific research is the creation of monoecious cultivars of hemp which combine a high fiber yield and the absence of THC.
What are the major objectives of your current hemp breeding program? Can new cultivars be expected in the near future?
The major objectives of our current breeding program are: low THC level and high fiber productivity in combination with high seed yield and early maturation.
What is the bast fiber content of your best cultivars?
High fiber content prevailed over other traits in preceding breeding programs. We possess diverse inbred lines and cultivars with a fiber content of more than 30%.
Which of your cultivars has the lowest THC content and what is that content?
As a result of our previous hard work we reached THC levels of less than 0.03%. First of all cultivars: ‘USO-14’, ‘USO-31’, ‘Zolotonoshkaya USO-11’. These cultivars show high fiber yields and resistance to diseases. There is a new generation of newly bred varieties which is absolutely THC-free (‘Glukhovskaja 33’, ‘Zolotonoshkaya 15’, ‘Dneprovskaya monoecious 14’, etc.). We possess diverse breeding lines free of all components of cannabinoids.
Is there any pest or disease which occurs more in a cultivar which contains no THC?
We can't be sure about the direct correlation between the level of damage from any pest and disease and the THC-level in any of our cultivars. But we need to control this relation between the immunity and cannabinoid content.
Do you think bast fiber content can be increased further? If so, what content can be reached?
Cultivation of hemp is first of all for fiber. But we would't like to connect breeding fiber content and its quality. Our results in reducing secondary, short fiber weren't a success during our 15 years of breeding work. Secondary fiber has important role as a mechanical tissue in widely-spaced row and high-nutrition plant cultivation conditions.
How important is fiber quality relative to fiber content?
There is no need to discuss the question. Discussion of the question is according to various ways of fiber processing. Quality is a priority in using fiber for textile. In other cases it is not so important. The problem requires special attention and possibly may be solved by means of international cooperation on breeding work.
Do cultivars differ in fiber fineness?
As a rule, Ukranian-bred cultivars with low fiber content have good fiber fineness. The fineness trait is very sensitive to cultivation practices.
Current hemp cultivars have been developed for textile fiber production. Do you think it is feasible to develop special cultivars for seed production or for paper production?
Yes, we think it is feasible to develop special cultivars for seed and for paper production.
So far, you have bred monoecious cultivars only. Have you ever considered breeding dioecious cultivars?
The question is not simple. The nature of the hemp plant is dioecious, like animals: male and female and contains the elements of heterosis. We had to work with monoecious hemp because of lack of labour in fields to delete male plants before harvesting. After creating new technology of cultivation and developing the initial processing of fiber, the need in monoecious cultivars will dissappear in future.
Which of your cultivars can currently be bought in commercial quantities? Of these which are the most successful ones and in which countries are they sold?
‘USO-31’, ‘Zolotonoshskaya USO-11’, ‘Glukhovskaya 33’, ‘Zolotonoshskaya 15’, ‘Dneprovskaya monoecious 14’, ‘Glukhov-skaya 46’ for countries of European Community.
What do you consider to be your greatest contribution to the science of hemp breeding?
Results of breeding hemp to increase fiber content and to reduce THC level.
So far you have seen the presence of cannabinoids in hemp as a source of problems, an undesirable characteristic you want to eliminate. Have you ever considered breeding hemp cultivars for increased content of one of the cannabinoids?
No, I haven't. But in case of necessity, we are able to create bred-lines with high concentration of cannabinoids. But cultivation of hemp varieties with THC more 0.2% is prohibited in Ukraine.
If funded, what line of Cannabis research would you personally find the most interesting to pursue?
If funded, we'll start breeding hemp for seed and improving fatty acids content of hemp oil.
Is there anything else you might want to add to any of the previous questions?
Since 1931, we have been developing a unique school of hemp breeding. We are able to declare now: we have created new varieties of hemp which are out of list narcotic plants. Profs. N. Grishko, G. Senchenko, A. Arinshtein and E. Gurzhii performed the main part in creating and forming hemp breeding school. We would also like to mention the work of L. Gorshkova, I. Sherban, N. Orlov, R. Kaplunova, V. Sitnik and M. Sazhko and others.