• Foot-ruts

    From the seeds of not every apple, you can get a rootstock that meets the listed requirements. After long experiments, it was revealed that at present fairly uniform seedlings for rootstocks of apple-trees, for example, in the Non-chernozem zone, are obtained from apple seeds of Antonovka vulgaris, harvested in the queen-seed garden, where Anise is planted as a pollinator. Very good warp material is obtained from the seeds of apple-kitaek with a non-falling cup, Cherry varieties Shubinka, Lubskaja, Rastunya, plum - Red-breasted Red, Roklod kolkhoz.

    To force the seeds on time and grow drastically, they are subjected to stratification. Washed after extraction from apples and pears, dried seeds are stored until January. In January, they are soaked for 3 days in daily renewable water. Then mix with scalded sawdust or calcined river sand, pour into boxes( the thickness of the layer is not more than 25 centimeters) and keep in cold rooms with a temperature of 2 "C. Systematically, the substrate with the seeds is moistened and mixed

    The above substrates fulfill their function, but they are notThe developing chemical industry is already able to offer new substances for testing, for example, a crumb of polyurethane foam or something like that. These materials do not cake, they do not settle with fungi, they are light,they are simply separated from the seeds when they are prepared for sowing. It would be great if you could do without any substrate at all, placing the seeds in a container, where automatically a special solution would be injected, as necessary, and the seeds would be mixed with airflow

    Abroadand in our country methods of chemical, chemical-mechanical and physico-chemical effects on seeds of fruit crops are developed with a view to accelerating their germination.

    Foot - base, part of the leg below the ankle, root - root;foot-root - root root, rootstock( pun).

    It is undeniable that priority is given in this matter by Candidate of Biological Sciences SA Ostroiko. She found that some natural phenols, which were previously known as inhibitors, can also be used as stimulants depending on the concentration of the substance and the state of the object. To increase the germination of the bones of cherries on a production scale, it was recommended to soak them during the day in a 0,05-0,07% solution of gibberellin, dusting with TMTD and stored in polyethylene bags at a temperature of 2-4 ° C.Moisten with water once every two weeks.

    For a particularly valuable selection seed, Cherry Svetlana Adamovna proposed a set of actions that resulted in seedlings from almost all available pits. First, all the material is stratified and germinated. In unprotected hard cover is removed( split and neatly removed) and the selected seeds are placed in a moist chamber. The seeds, which in three days did not give germs, remove the next cover and even completely isolate the embryos. They are also sprouted for some time in a moist chamber. If, however, the "stubborn" embryos do not germinate, they are placed on a filter paper moistened with an aqueous solution of gibberellin( 0.01-0.04%).

    For apple seeds, a three-month period in the indicated substrate and regime is sufficient for them to begin the awakening of the embryo. This point needs to be grasped very accurately. If the seeds "sprout", they can not be sowed seeder. Therefore, after the specified period, the seeds of apple, pear, quince before planting are placed in a refrigerator with an air temperature of 0-1 ° C or snow.

    Wake up the bones of cherries, plums, apricots more difficult. Usually, immediately after separation from the edible part, the bones are laid in a substrate and stored at a high humidity and a temperature of 10 C for a month and a half. Then the humidity and temperature are lowered to 4-5 ° C, avoiding mass cracking of the bones. Systematically, the substrate is pitted with bones. They are grafted into conditions with a temperature of 0-2 ° C.

    Without pre-treatment, the achenes do not germinate to the strawberry and raspberry strawsOften to accelerate the preparation of seeds and pits for inoculation, in particular to soften their integumentary tissues, the inoculum is treated with acids, etc.

    Before loading in the seed drills, the seeds are slightly airborne, so that they acquire flowability. For different breeds, in different regions and for different cultivation methods, their seeding rates have been worked out. Very small seeds are sown with the sand in which they were stratified. Very hard to withstand the depth of sowing: on light soils, apple and pear seeds are sown to a depth of 2 cm, cherries - 3, plums - 5 centimeters. At autumn sowing the depth of seeding is increased by 1-2 centimeters.

    In order for the seedlings to appear in time and successfully developed, they monitor the moisture of the soil and water it in a timely manner. Do not allow the formation of a firm crust on the soil surface. If it is not destroyed in a timely manner, the seedlings will not be able to break through to the light. That plants do not menu each other, superfluous( weak, curves) delete.

    If there are signs of starvation or disease, carry out fertilizing and spraying against pathogens. Watch that the weed vegetation does not develop - a competitor for light, moisture, food. By the autumn it is necessary to grow plants with a stem of at least 7 millimeters in diameter. And this can be achieved only with very careful care of plants in accordance with the emerging weather conditions.

    In autumn the seedlings are excavated, sorted according to quality, stored and later used as a stock for winter grafting, or planted in spring in the field in order to spend the summer in budding.

    You probably noticed how diverse the requirements, the fulfillment of which only presupposes the success of the case. Take, for example, watering. How can one keep track of the formation of a soil crust so dangerous for tender seedlings? Thought, thought and came up with: the soil in the crops covered with mulching tape. Under it, moisture is better preserved, weeds do not grow, no crusts are formed, the sprouting seedlings in the first few days are protected from direct sunlight and possible frost. To solve the issue of water supply, under the film lay hoses with small holes or special "sweating" tubes, through which the supply of moisture in the root layer of the soil is constantly replenished. Good. But how to know, maybe one of you will offer something even more perfect?

    When sowing, they tend to uniform distribution of seeds. Still, the seedlings in the garden are densely populated, then empty. There, where it is thick, it is necessary to thin out. Hence, seeds and soil and materials are irrationally used. To avoid this, it is necessary to be sure of the high viability of each seed being sown and to ensure that each of them is placed in a precisely designated place on the bed. Here's another thing for you, the young creators of robots!

    As a rootstock of apple, cherry, pear, plum, plants of appropriate breeds can be used, which multiply intensively by vegetative means. As we have already said, such stock must also meet a whole set of requirements: it is good to combine with most of the varieties planted on them, to promote their early entry into fruiting, to ensure the development of a compact crown of these varieties( most often use dwarf or semicariferous rootstocks, but alsovigorous vegetatively propagated stock is of undoubted interest).These plants must multiply rapidly, have a good root system, so that the resulting trees possess high stability, that is, they do not fall from the wind or under the weight of the crop. They must be winter-hardy, drought-resistant, not affected by pests and diseases.

    And now in the gardens there are apple trees on dwarf vegetatively propagated M8 rootstocks( paradise VIII), M9( paradise

    ka IX), semi-dwarf MZ( Dusen III).Plants are either a bush height of 1.1-1.6 meters( paradise), or a tree with a height of 3 to 8 meters( dusene) with reduced winter hardiness.

    In the Soviet Union, VIA Budagovsky, SN Stepanov, VA Potapov, Candidates of Sciences BA Popov and NF Seregin were engaged in vegetatively propagated stock for the difficult natural conditions of the Non-chernozem zone.

    For many years, Valentin Ivanovich Budagovsky, the doctor of agricultural sciences, headed the Fruit Growing Chair and the Scientific Problem Laboratory on Biology and Selection of Dwarf and Fruit Plants at the IV Michurin Fruit and Vegetable Institute in the city of Michurinsk. A scientist with a world name, all his scientific activity associated with the creation of intensive gardens on dwarfish stocks, in his final book, however, wrote that it is not necessary to contrast the orchards with sylvestris rootstocks and weakly grown ones."In our" fruit growing should find a reasonable combination of different forms of fruit trees, taking into account specific conditions. "Having chosen his own way, he proved with the works of his life that "the culture of sparse fruit trees is the most pronounced form of intensive fruit growing."However, he also owns the words: "What is recommended now, in a few years can be revised."These words turned out to be prophetic: as we already know, in recent years gardens of so-called column-shaped trees have been created.

    It is well known not only in our country, the rootstock Paradise red-leaved. Look at the diagram of its origin, and you will see that it was not a simple matter to get this stem:

    Pepin English


    Renate Orleans

    Hybrid( IV Michurin)

    Apple tree of Nedzwiecki

    Antonovka, ordinary

    Pepin saffron( I.V. Michurin)

    Ruby( IV Michurin)

    Red standard( IV Michurin)

    -Reddish redwood vase( VI Budagovskiy)

    Having continued crosses already Paradises of red-leaved with a stock of 13-14, V.I.Budagovskii received more promising stock 54-118, 57-490, 62-396.Thus, semi-dwarfish rootstock 54-118 is distinguished by a sufficiently developed frost-resistant root system, trees grown on it do not bend. This stock is quickly multiplied by layers, it is well compatible with many varieties. In the semi-dwarf rootstock 57-490, the root system is powerful, frost-resistant. Excellent reproduction of layers, well compatible with various

    varieties. No worse indicators for dwarf rootstocks 62-396 are considered to be the most promising at the moment, and 57-366.As a dwarf insert recommend 57-491, as well as hybrids obtained by SN Stepanov.

    For the conditions of the Baltic, winter-resistant, well-breeding E-20, E-28, E-56 stocks are bred. The N. Ya. Seregin bream, which was bred in Leningrad, is very early-ripening, with an exceptionally high coefficient of reproduction. Unique properties of the stock allow one to obtain high quality seedlings already planted with the cultivar during the season. In its creation, another part of NF Seregina, Bystretsovskii, participated. The YAC-1 rootstock and the technology of its reproduction have a high patent ability.

    In the creation of vegetatively propagated apple rootstocks significant successes have been achieved in the UK.For example, the MM-106 semi-dwarf fillet, bred by the East Mollings experimental station and the Research Institute in Merton, is widely distributed in Ukraine, Belarus, Moldova, Lithuania, Transcaucasia, some Central Asian republics, and the Northern Caucasus. For the Ukraine and Moldova, the M-26 East Mollings dwarf stock has come very close. Extensive testing in our country of the English dwarfish M-27.In Sweden, a sturdy A-2 stock was obtained, which is now zoned in the Crimea, Belorussia, Moldova, Azerbaijan, Armenia, the Baltic, successfully hibernates in the Moscow suburbs quite successfully. In the Republic of Poland, the stock of the P-series( P-2, R-22, etc.) is multiplied, with the extraction of which used the old Russian variety Antonovka vulgaris. Its own series of TE-F rootstocks is available in the CSFR, and in the USA - MAS-9.

    As vegetatively propagated cherry rootstocks, shoots or plants grown from green cuttings of Shubinka, Vladimirskaya and Polevka varieties are used. In addition, special P-3 and P-7 stockpiles were withdrawn from the Scientific Research Zonal Institute of Horticulture of the Non-chernozem zone, VP-1 at the Oryol Experimental Station.



    possibility Zone


    Compatibility Features,



    dwarf rootstock


    Foot Use

    successive ACT


    early appearance of fruit,




    or insert


    lities, UCO-








    South European


    well developed with good wood



    ( good for

    parts center




    unbreakable; no need of

    ( red




    varieties and the fruit




    fragile zone,





    on 2-3rd year

    ( -14 C)










    zone, center

    early maturity

    black earth







    Powerful, dos


    wood very high

    tattochno holo




    hotter( -16 ° C)



    Zone possibility


    Compatibility Features,



    dwarf rootstock


    Foot Use

    vateyanaya spo






    or insert


    lities, UCO-






    Semi-dwarf( Good for


    Shoots strong

    Developed, ho




    but developed,

    is well mastered



    in moderate

    is not 40-centime 4-5 year

    is affected by


    three layer




    mildew resistant

    ( -16 ° to




    Central Cher

    Too Powerful,





    hardy fruiting


    region and

    ( -16 ° C)

    for the 5th-6th year

    boundary with

    H? 1M




    Regions with DOS- Moderate





    harshly severe

    fast breeder




    winter hardy

    3-3-72 and

















    winter resistant;little

    is hit by the


    These plants - the realized idea of ​​IV Michurin: to obtain 1 outlandish plants - hybrids between cherry( cerazus) and bird cherry( padus).The author of the P-3 and P-7 rootstocks is Anatoly Mikhailovich Mikheyev, candidate of agricultural sciences. In the libraries you can find the books he wrote about the cherry. And once he himself, a teenage boy, was pushed into the way of designing new plants and a sensible book and a good botany teacher. His first experience was the planting of Tradescantia on a palm tree. By ignorance, of course. The knowledge, diligence, original thinking, intangible fantasy, improvisation acquired in the TAShA and the graduate school of the NIZISNP made it possible to achieve what was desired. In addition to the rootstock for the cherry tree, it was adopted into the regionalization of the rootstock VC-13 for cherries and cherries.

    When introducing vegetatively propagated rootstocks into production practice, it turned out that it is not so easy to propagate them. I had to look for ways and means to increase the intensity of reproduction of rootstocks. Relatively simple and often used

    60-165 Semi-dwarf "" Moderate;Good enough;

    high well-developed twisted;winter 4-5 year resistant( -14 ° C)

    60-165 Semi-dwarf "" Moderate;Good enough;

    high well-developed twisted;winter 4-5 year resistant( -14 ° C)


    Continuation of

    has become a method of vertical layers. The plant planted for reproduction in the first year is rooted and forms several shoots. In autumn, after the fall of the fall, they are cut off almost at the soil itself, leaving 2-3 buds. In spring the plant is covered with a black opaque film. Under it grow etiolated( deprived chlorophyll) shoots. When they reach a height of 6-10 centimeters, the film is removed, the shoots are covered with loose wet soil. Soaking with soil is repeated when shoots grow to 20-25 centimeters. Plants are watered, weeds are removed. In autumn the soil is raked, shoots with roots are cut off from the mother plant and used as seedlings, stock.

    The multiplication factor increases if horizontal layers are used. Seedling stock, planted in the mother liquor, within a year roots. Growing over the summer shoots are cut off, leaving 2-3 buds. The next year, of them grows more shoots. In autumn, the best of them are laid in the grooves excavated around the bush and sprinkled with soil. The remaining shoots are cut into 1-2 buds, in order to create new shoots in the bush that are suitable for subsequent laying in grooves and rooting.

    Along the entire length of the layers laid in the grooves, roots are formed over the summer, and new shoots grow from the kidneys. In the autumn, the layers are separated from the mother plant, excavated and cut into separate sauzkevtsi-podvisi. Then they are planted in the nursery, where they are subsequently planted with the right sort.

    Fig. Alignment of clonal rootstocks with horizontal layers

    Fig. The alternation of clonal rootstocks with horizontal layers

    It would seem that here you can come up with a new one? The candidate of agricultural sciences Vasily Ivanovich Demekko had his own point of view this time. By the way, many of his proposals are officially recognized as inventions, as evidenced by numerous author's certificates. He proposed horizontal layers with roots grown on them and shoots in the first year not to dig, but immediately on site to conduct the incubation with the selected varieties. The next year, out of the buds that have survived, sprouts grow. In the autumn, as a result of the division of the layers, one-year saplings of an oculized variety are obtained, ready for planting in the garden. Saves a whole year. Developing this idea to use its own JC-1, NF Seregin did not cover all the shoots: the one-dea left again laid as horizontal layers. In the same year they sprouted, suitable for budding.

    For those of you who are inclined to creativity, nitonikovodstvo opens the widest field of activity. And this is easy to see if you get acquainted with other ways of reproduction of rootstocks.

    The original method was developed by VI Budagovskii for the reproduction of bedbug rootstocks. He suggested using seed stocks, prepared for the cultivation of cultivars. Simultaneously with the eye of the selected variety, a second eye of the vegetatively propagated rootstock is also eyed on a single seminal stock. The next year, two shoots develop. One of them - from the eye of the clonal stock - after reaching 15-20 centimeters, it is bent, and the soil of the lower bend is sprinkled with soil. Escape continues to grow and take root. In autumn, it is cut off from the main plant, which continues to develop as a future seedling of a cultivar. The seedlings of the clonal stock are in this case obtained as an additional product.

    And here is an example of how evil was turned into good. We have already mentioned the word "incompatibility" - this is when the graft is at first seemingly fused with the stock, but after a while their connection is broken, the priow is dying, and the place in the garden is occupied by the undesirable beast. Scientists of different countries, including the candidate of agricultural sciences BA Popov, once observed that if a seminal stem is planted with a poorly compatible clonal rootstock, the sprouting shoots of the latter become much more rooted. Here is another task for you: among the appropriate breeds, find such a stock that in the first two to three years shows compatibility with the multiplied clone stock, and when the latter takes root it loses it. In this case, the clone stock goes to its roots and spontaneously separates from the plant to which it was grafted. There is no need for "surgical intervention".This idea has partly been implemented: the stock A-2, MM-106 successfully propagated in this way on seedlings pears and mountain ash.

    Boris Alexandrovich Popov is a native Muscovite. In science came, as they say, from the machine tool - during the war he worked as a teenager at a factory that produced shells and mines. Another student "sick" idea of ​​gardens on dwarfish stocks. I learned and tested a lot of folk recipes, how to make clonal rootstocks better to take root. I've developed my own. He brought out his own bug-base for the apple-tree T-273.Together with the director of the Tulsky state farm, the candidate of agricultural sciences

    Boris A. Arkhangelsky, the author of another clone stock, No. 67, created a garden on maple stocks that not only survived the severe winter of 1978/79, but also fructified the nextyear, whereas a lot of gardens of the usual type had to be rusted. For many years, Boris Alexandrovich is known to the country's viewers as the host of the program "Our Garden".

    Using technical innovations, it is possible to improve the technology of reproduction of clonal rootstocks. In practice, there were so-called fogging plants, which made it possible to propagate the stock with green cuttings.

    The theory and practice of "green cuttings" fruit in our country is associated with the names of doctors of agricultural sciences Mikhail Trofimovich Tarassiko, Faina Yakovlevna Polikarpova and a large number of their students. There are so many of them that there was even a joke that the dear doctors of the method of propagating cuttings of plants extended to graduate students - many of the experienced stations were rooted in the candidates of science that they had prepared.

    But at the present time in the theory and practice of green propagation there are many problems. For example, it is necessary to create such conditions that a film of water is constantly present on the surface of the rooting cuttings. At the same time, it is impossible to wet the substrate, in which the cuttings are planted, because oxygen is needed to develop the roots. Yes, and fungal diseases cuttings are easier to "pick up" in a wetland substrate.

    Abroad there are already installations that allow creating different types of artificial fog. In our country this very important problem is waiting for its solution. It remains a mystery to determine the timing of harvesting cuttings. Until recently, it was believed that cutting off shoots for cuttings is necessary in the period of maximum growth, when they are sufficiently lignified. Yes, and the stalk was advised to take a small one, consisting of 2-3 internodes: it seems as though the decay is prevented, and the multiplication factor will be increased.

    But what happens in the fall? If the light-rooting currant is propagated in this way, then a good planting material grows. But the rooting cuttings of the bedbugs have a deplorable appearance. They practically do not give a gain, they need additional irrigation.

    What happens to the maple stocks? It has been established that the earlier we start the cuttings, the more cuttings will become rooted. Yes, and their quality will be better. So, if the rootstock is 54118 on June 1, by the autumn, an average of 40 rootlets on each cut will be obtained. A week of delay with cuttings will reduce the formation of roots, they will be slightly over 20, struck after June 20, had 7 roots, and in July this laborious operation is meaningless. The costs invested in the installation, the flow of water and electricity will be in vain. Cuttings form only callus and a few weak primary roots.

    How to extend the time for cuttings propagation? How to get to the end of May -

    beginning of June, shoots suitable for. Who among you is ready to offer your original and reasonably cheap method? Maybe plant the uterine plants in the greenhouse? We will achieve goals, but we will increase costs.

    And yet, let's try. In the greenhouse in the early period we will get a strong, more than 30 centimeters increase, cut from the uterine plant and divide into cuttings consisting of two or three internodes. Now, at the lower end of each cut, cut at an angle of 45 ° to 0.5 cm below the kidney. Scientists found that in this place the tissues are less damaged by fungal diseases. Lower the two leaves are removed so that they do not rot and cause the death of the cuttings. Next, the green cuttings must be tied into bundles, leveling the bases, and placed in a special solution that will promote root formation. For better penetration of the solution into the tissue cuttings are sometimes placed in special vacuum plants. After a certain period of time, the cuttings are washed with plain water and planted directly in the greenhouse soil or in individual containers filled with a substrate and installed in the greenhouse - plastic bags, peat pots. The operation of the fogging unit is controlled by a time relay or humidity sensors.

    In the period of root formation, it is important to monitor not only the moisture regime, but also the temperature of the substrate and air. With the appearance of roots, the mode of further growing of seedlings is substantially changed-without the need to include an irrigation system, film shelter is removed. At the final stage, the plants are transferred to a regime close to the natural one, so that they finish the growth in time and prepare for the winter time. Later they are used for planting in the nursery field and for budding or for winter grafting.

    The need for rapid multiplication of clonal rootstocks, the release of more seedlings of cultivars, the technical capabilities of the fogging plant, the physiological state of the green cuttings, led scientists to search for reserves and develop new methods. The search was aimed at combining the processes of rooting of green cuttings of rootstocks and inoculation of cuttings of cultivars on them.

    This work was carried out by a large group of women scientists. It worked, apparently, a natural habit for women to nurse, swaddle, nurse weak living beings. And what are green cuttings? These are completely helpless creatures, completely unadapted for independent life, since they do not have roots, and the leaves and stem quickly evaporate small moisture reserves. Cuttings not only need to survive and root themselves, but it is necessary to take care of a more helpless cuttings-privo. You can not apply unjustified injuries to cuttings, so you need the sensitive and firm hands of the master.

    With this method, cut green cuttings of rootstocks and green cuttings of scions. At the interstices of the grafting with a sharp knife, a wedge-shaped cut is made, and in the interstice of the stock, a vertical incision is made.

    Fig. Inoculation with green handle

    The components are combined so that there is a complete coincidence of the cambial layers on at least one side, and bind them with a film. The lower part of the stem of the rootstock is treated in a solution of growth substance, washed with water and planted in a substrate in a greenhouse or a greenhouse with a fogging plant. The moisture and temperature regime is differentiated as the rootstock and the fusion of the graft components grow.

    In the first days after planting cuttings on their leaves should be a wet film. When it is lost cuttings quickly overheat, lose moisture, wilt, slow down or stop completely the processes of root formation and cell division in the place of combining the components of the graft. Approximately in 30-45 days from the moment of planting they begin to temper the plants, prepare them for life in the usual field conditions.

    However, it is easiest to propagate clonal rootstocks with root cuttings. They can be harvested by digging up the uterine plant. Ordinary cutting is a segment of a root 8-10 centimeters in length and 5-8 millimeters in diameter. They are stored in containers connected in bundles, sprinkled with damp sand, sphagnum moss. Storage temperature 0-9 C. Planted in the spring on a site with an irrigation system, fertilized soil and carefully looked after. Plant cuttings vertically( the end of a larger diameter up) to a depth of 1.5-2 centimeters from the soil surface. Use the means already known to you to prevent the formation of soil crust and irrational consumption of moisture, as well as to control weed vegetation. From buds on the cuttings sprouts grow. Leave the best of them, the rest is deleted. By autumn, a ready seedling of the clonal stock is obtained.

    The use of lignified cuttings was very technologically effective in multiplying clonal rootstocks. It would seem that it could be easier? In the autumn I cut the shoots( I can even mow them with an ordinary mower), planted it like a blackcurrant in early spring into the soil - and now the leaf has blossomed, the roots have appeared.

    If lignified cuttings of clonal rootstocks were barked with the same ease as black currant. ..

    Unfortunately, lignified cuttings of clonal rootstocks of apple trees in

    normal open ground conditions do not take root well. Even if buds are budding, a leaf turns green, roots can not be waited, and the stalk from desiccation will still perish.

    Therefore, for successful rooting cuttings must be prepared. For regions with a humid climate, it is sufficient to hold the lower bases of the cuttings in a humidified substrate at a positive temperature throughout the winter. Callus and root rudiments are formed on the lower bases of the cuts. Early in the spring cuttings are planted in the open ground, and in the absence of an atmospheric drought, they become well-rooted. But such conditions exist not everywhere, but the guaranteed high yield of rootstocks with other methods of reproduction does not work.

    The Department of Fruit Growing of the Michurin Horticultural Institute developed and introduced an original method of reproduction. Cuttings are planted in a plant where an artificial mist is created. The absence of an atmospheric drought prevents drying of the cuttings before the appearance of roots. First, the leaves are formed on the cuttings, and then the roots.

    It is very interesting that one and the same idea can appear in different scientists in different places at the same time.

    Scientists have decided that if you plant a lignified stalk of a cultivar on the lignified stem of the stock, then simultaneously with the rooting of the stock, the grafting will take place and you can get a small grafted seedling on a cloned rootstock. The same work was performed at the Department of Fruit Growing at the Michurin Horticultural Institute. Instead of the stock, which must be excavated, preserved and then planted, one-year-old seedlings are immediately obtained on a cloned rootstock.

    However, the creation of fogging plants is not always feasible. Is it possible to create conditions for rooting in another way? This promising method of reproduction requires serious scientific development.

    There are some other ways of breeding clonal rootstocks. But it can hardly be asserted that their diversity has been exhausted and there are no ways of further improvement.