Ginkgo biloba is the oldest living plant originated 250-300 million years ago.

Since natural range of spreading is China, it is not suppressing that first knowledge about its use for medicinal purposes comes from that region. Ginkgo trees grow very well under our environmental conditions. Since it is dioecious, it is not easy to secure normal numerical relationship between female and male individuals, so in order to provide regularity, the best genotypes should be vegetatively propagated. Vegetative propagation is even more emphasized by the fact that for urban needs, more male trees should be produced, do to unpleasant smell of fruits. In this paper we presented our attempt to use winter cuttings for rooting.

Using this technique of vegetative reproduction is possible to produce genotypes distinguished by large leaves production. Rooted cuttings can be used for establishment of specialized plantations for production of raw material-leaves for pharmaceutical industry. This is significant since a kilo of dry leaves has rather high international market price, in some instances over 100 dollars.

Key words: Ginkgo, rooting, winter cuttings, hormone rooting powder.

For centuries the Taoist monks of Japan and China have revered gingko's tea an elixir of longevity and an aid to clearing their minds and deepening their meditations. Now we know, there is scientific truth behind their sacred tradition. There have been many hundred scientific studies conducted on extracts of the leaf of Ginkgo during the last three decades. Since the first research conducted by the W. Schwabe Co. of Karlsruhe, Germany, Ginkgo biloba leaf extract becomes the most important herbal medicine in the world. Ginkgo biloba, large tree from remote forests of eastern China at the beginning of the eighteenth century find its way to Europe. With its hardiness against pollution and pests this tree was recognized as an ideal ornamental tree for streets of industrial cities. Now, Ginkgo grows just about anywhere in a temperate climate.

Although many Europeans, traveled to China, were aware of ginkgo s role in traditional Chinese medicine, but it was not until the 1960 that Ginkgo began to be investigated as medicinal plant.

In our country could be found this species planted in the past as individual or in groups on streets and gardens. Since its medicinal use has been confirmed, we have attempted to propagate it, in this case, from winter cuttings so we can be certain of the sex. Namely, due to slippery and bad-smelling fruits the best way to know the sex of seedlings is via vegetative propagation.

Ginkgo plants can be readily propagated from seed. In this seedling population you get both female and male trees. But in order to produce only male trees we used vegetative reproduction by rooting of cuttings. Starting from February 2, 2000 we have inserted 1 and 2 year old cuttings. Each cutting was wounded at the base. According to the last year crop, tree used for taking cuttings appears to be male. All cuttings were treated with rooting hormone *STIM-ROOT* (0,8% IBA in powder form) and placed in greenhouse under mist line in sand. We provided good drainage since bench was elevated. Mist was manually operated and used only to keep alive rooted cuttings. On February 2, 2000 the following cuttings were used:

60 - 1 year old and 50 - 2 year old cuttings were inserted.

On February 3, 2000 another batch of cuttings was inserted: 106 - 1 year old.

On February 15, 2000 we inserted another 36 -1 year old cuttings. Since insertion up to May 25, 2000 cuttings were misted regularly in order to prevent drying of developed leaves. At that time all cuttings were lifted and counted as alive - rooted; then cuttings without roots but alive with callus and leaves and dead as it is shown on the following table. Some cuttings were returned to bench for another year.

Using the above-described technique we obtained the following results. As we only had a very limited access to propagating material, our trial was only on a very small scale this year.

From this table is evident that 1-year old cuttings rooted better than 2-year old. Large percentage of cuttings developed leaves and callused figure No.1. At the inspection of cuttings on May 25, we noted roots as it is shown on figure No. 2.

However, roots were small. All cuttings which were not rooted were put back in the bench to see if they are going to root the following summer. According to our previous year experience we believe that cuttings with leaves and callus will eventually root, since cuttings were pulled out before root initiation in order to be presented at the Conference.
 

Figure 1. Cuttings with leaves and callus		Figure 2. Rooted cutting of Ginkgo biloba

As a medicinal plant Ginkgo biloba is becoming more and more important. If the present there are about 5.000 ha of plantation on the world, so this is a very prospective species.

Since alternate and irregular bearing of Ginkgo biloba is quite common, vegetative reproduction can alleviate this problem.

Although we obtained rather fair results with winter cuttings it is not going to stop us from continuing work on including other factors which have large impact on rooting of cuttings. We choose vegetative reproduction using cuttings, although there are other methods. The main reason is that by rooting of cuttings using standard methods of individual selection for choosing matter trees we could provide initial basis for mass production of rooted cuttings with a final objective to establish plantations.

1. Hartmann T. Hudson and Kester E.D. (1983): Plant Propagation: Principles and Practices, Prentice Hall International, Inc. London.

2. Lamb J.G.D., Kelly J. and Bowbrick C. (1975): Nursery Stock Manual Grower Books. London. Vermeulen John (1960): Propagation of Ginkgo biloba by cuttings Combined Proceeding of IPPS. Vol. 10.127-130 pp.