PROCEDURE FOR THE PRODUCTION OF VEGETABILISCH GRAFTING SETZLINGEN

The present invention relates to the field of agriculture and more particularly that of the vine growing. It has as an aim a process of production of grafted seedlings of woody plants or semi-ligneous family starting from an understock and of a graft, and more particularly a process of production of young vines, vinis variety will vitifera as well as the seedlings obtained by the implementation of the known as process.

It is known that the Clerc's Office is an important operation for agriculture and more particularly for the vine growing because it allows a protection against the diseases, a diversification of the varieties and an adaptation of certain species to climates which are not favorable for them a priori.

In France, the Clerc's Office is essential to ensure the resistance of the vine will phylloxéra. All the seedlings sold and planted in this country are thus grafted seedlings.

This technique is very largely deployed in the world, even if certain countries still have unscathed grounds of phylloxéra authorizing them to use frank seedlings of foot i.e. not grafted.

The techniques of Clerc's Office on wood are well controlled and almost industrialized today with a productivity raised about 100.000 Clerc's Offices/personne/an.

The grafted seedlings are initially cultivated in seedbeds before being planted with the vineyard the following year.

The complete cycle of the operations active of the harvest of wood to the plantation of the final seedling grafted in the vineyard lasts approximately 18 months.

The development of the culture out of pots after the grafting made it possible to bring back the duration of this cycle to approximately 8 months. The vineyard can thus be planted the year even of the Clerc's Office of the seedlings.

However, this technique of the traditional Clerc's Office presents three major disadvantages. It first of all requires a large surface of vineyard upstream for the production of the grafts and the understocks. The production of this reproductive material proceeds, so in the production zones, where the health hazards are highest.

Then, the work of grafting is unequally distributed over the year, with an intense peak of activity during April and March.

Lastly, the Clerc's Office on wood (also called “clerk's office wood”) does not allow the reproduction in very great number of only one individual. It does not allow thus or with difficulty the development and the development of an interesting nature carried by a foot.

It is for stage these various problems that the technique of the Clerc's Office known as “herbaceous cutting” was developed.

The purpose of the Clerc's Office herbaceous cutting is to produce in conditions out-ground, all the year, of the seedlings grafted starting from feet mothers of reduced number, with an almost infinite rate of multiplication.

This is allowed by the use of vegetable material in growth (stem green and pushing) the place of material in dormancy (woody wood stem).

With the passing, one notes however that it is difficult to maintain a production throughout the year.

Indeed, on the one hand the costs of maintenance in culture of the seedlings the winter are increased and on the other hand, one notes significant drops of the output of the Clerc's Offices carried out apart from the natural period of growth of the vegetation.

Nevertheless, subject to a simplification of the conditions of production and of a better reliability of its output, the Clerc's Office herbaceous cutting preserves two advantages, namely, on the one hand the lengthening of a few months of the period of grafting and, on the other hand, obtaining a multiplication factor starting from one only individual of about a 2000 per annum.

The goal of this invention is to bring a series of simplifications to the Clerc's Office herbaceous cutting in order to significantly improve its effectiveness and its cost price. The advantages described above can then be completely operational and exploited.

For this purpose, the present invention has as an aim a process of production of grafted seedlings of woody plants or semi-ligneous family starting from an understock and of a graft, characterized in which it includes/understands primarily the stages in which:

1. a) one supports the development of the roots of the known as understock by feeding it with a first nutritive solution including at least a growth factor,
2. b) one inserts and fixes a herbaceous graft including/understanding at least a node prolonged on both sides by a first and a second segment of herbaceous stem on an understock including/understanding at least two nodes of which one is laid out at the lower end, near to the roots, a stem forming the principal body of the known as understock, the aforementioned stem carrying or being prolonged, in his upper part, opposed at the aforementioned lower end, by at least another node prolonged by at least a third segment of herbaceous stem on the loose lead which one grafts the loose lead of known as the first segment of herbaceous stem which is located in lower part of at least node of the known as herbaceous graft,
3. c) one modifies the composition of the food of the grafted understock and/or one directly feeds the graft with one second nutritive solution including at least a growth factor to support the catch of the Clerc's Office, in particular cal, for the case where the understock presents at least a root right after the operation of grafting referred to above,
4. d) one directly feeds the graft with one second nutritive solution including at least a growth factor to support the catch of the Clerc's Office, in particular cal, for the case where the understock does not present a root right after the operation of grafting referred to above,
5. e) one places the unit obtained at the stage c) or d) in an enclosure of culture at controlled atmosphere in which reign a temperature ranging between 15 °C and 40 °C and a water content ranging between 70% and 100% until obtaining one cal clerk's office filling all the interstices substantially existing between the understock and the graft.

The present invention also has as an aim the seedlings obtained by the implementation of the process according to the invention.

The process according to the invention allows several significant improvements. The first major improvement allows an adaptation of the conditions of culture after the grafting. It supports in particular, the survival of the graft what increases the rate of success of the Clerc's Offices considerably.

For this purpose, an additional nutritive contribution is placed at the disposal of the grafted plant, for example thanks to the addition of a plug absorbing piqué to the one of the ends higher of the graft.

In this plug are then brought various nutritive and hormonal solutions complementary to those already provided by the means of the various solutions of steeping employed to the level of the roots and the grafting preconditions.

In the very first days after the grafting, this plug thus brings the nutrients necessary to the survival of the graft before the roots of the understock do not become functional and ensure their role which is to nourish the whole of the plant.

The presence of the hormones in the plug, supports the development of cal on the level of the point of grafting and thus accelerates the cicatrization of this last.

In addition, when the aforementioned plug is placed at the loose lead of the stem of the known as graft, this last also strongly slows down the desiccation of the higher stem of the graft which is not then any more one simple section of cut stem.

The second major improvement allows a shortening of the cycle of production.

It consists in working on growths of understocks obtained starting from cuttings wood in the place to work on the stems or branches completely green, i.e. entirely herbaceous, of understocks.

Indeed, the phase of growing under glass of the understocks, very expensive, is limited to the only culture of the cuttings collected in the traditional seedbeds of understocks.

The advantages of the use of a marbled cutting are in particular:

• a reduction of the time of incubation after the Clerc's Office, of the time of acclimatization and more generally of all the cycle of production,
• big raise of the rate of success of the grafting which can reach the 90%,
• production of seedlings equipped with a good capacity of resistance thanks to the nutritive reserves of wood, and
• an establishment in the easier vineyard and more rapid.

The invention will be included/understood better, thanks to the description, which refers to two preferred modes of realization, given hereafter as nonrestrictive examples.

The process of production of seedlings grafted of woody plants or semi-ligneous family starting from an understock and of a graft according to the invention is characterized in it includes/understands primarily the stages in which:

1. a) one supports 1e development of the roots of the known as understock by feeding it with a first nutritive solution including at least a growth factor,
2. b) one inserts and fixes a herbaceous graft including/understanding at least a node prolonged on both sides by a first and a second segment of herbaceous stem on an understock including/understanding at least two nodes of which one is laid out at the lower end, near to the roots, a stem forming the principal body of the known as understock, the aforementioned stem carrying or being prolonged, in his upper part, opposed at the aforementioned lower end, by at least another node prolonged by at least a third segment of herbaceous stem on the loose lead which one grafts the loose lead of known as the first segment of herbaceous stem which is located in lower part of at least node of the known as herbaceous graft,
3. c) one modifies 1a composition of the food of the grafted understock and/or one directly feeds the graft with one second nutritive solution including at least a growth factor to support the catch of the Clerc's Office, in particular cal, for the case where the understock presents at least a root right after the operation of grafting referred to above,
4. d) one directly feeds the graft with one second nutritive solution including at least a growth factor to support the catch of the Clerc's Office, in particular cal, for the case where the understock does not present a root right after the operation of grafting referred to above,
5. e) one places the unit obtained at the stage c) or d) in an enclosure of culture at controlled atmosphere in which reign a temperature ranging between 15 °C and 40 °C and a water content ranging between 70% and 100% until obtaining one cal clerk's office filling all the interstices substantially existing between the understock and the graft.

Preferably, the process according to the invention is characterized in that one places the unit obtained at the stage c) or d) in an enclosure of culture at atmosphere controlled in which reign a temperature ranging between 20 °C and 32 °C and a water content ranging between 75% and 85% until obtaining one cal Clerc's Office formed perfectly.

According to a first aspect, the process according to the invention is primarily characterized in that the operation of grafting of the stage b) is carried out with an understock consisted a primarily woody branch already cutting before the realization of the aforesaid the Clerc's Office.

According to a second aspect, the process according to the invention is characterized in that the understock is a primarily herbaceous branch. As one will further see it, this branch can itself be marbled or not at the time to carry out the aforementioned Clerc's Office, i.e. it can present one or more roots at this time there.

Advantageously, the process according to the invention is characterized in that one feeds, with the stage c) or d), directly the graft with one second nutritive solution per pulverization of the latter directly on whole or part of the known as graft. For this purpose, any means of pulverization usually used in gardening can be appropriate.

According to a first alternative, one feeds, with the stage c) or d), directly the graft with one second nutritive solution per direct perfusion in the aforementioned graft since at least a drain and at least an external storage tank. The means used with this intention are also well-known of the expert and do not require more explanations. The aforementioned second solution can run out of itself by gravity or be pulled by an adapted means, such as a pump, for example.

According to one second alternative, one feeds, with the stage c) or d), directly the graft with one second nutritive solution by steeping of all or part of the known as graft in at least a reserve of second nutritive solution. It is enough to place the graft near the known as tank so that a part or integrality of this one soaks in the aforementioned second solution.

According to a third particularly interesting and preferred alternative, one feeds, with the stage c) or d), directly the graft with one second nutritive solution per aspiration by capillarity from with less the one tank built in a soaked absorbing or porous matter and directly in contact with the aforementioned graft.

In an advantageous way, the tank made out of an absorbing or porous matter is consisted a block of floral foam soaked of the aforesaid the second nutritive solution and piqué directly on the loose lead with the second segment with herbaceous stem with the known as graft. Of course, other synthetic or natural absorbing matters (cotton, textile matter, light porous rocks…) can also be appropriate.

According to a mode of realization particularly preferred, the tank made out of an absorbing or porous matter is consisted a block of soaked floral foam and piqué, before the Clerc's Office, directly on the second segment of herbaceous stem of the known as graft on its end close to the place of assembly with the understock, the aforementioned soaked plug being brought back, after the Clerc's Office on the aforementioned place of assembly in order to cover all or appreciably all the zone where the graft and the understock are contacted.

With this intention, it is enough with the operator to rather deeply insert the aforementioned plug on the stem of the graft so that the loose lead of the graft can be correctly connected to the understock at the time of the operation of grafting. In the second time, the operator will be able to then cover the junction obtained by the Clerc's Office while making move or slide with the hand the aforementioned plug impregnated of the second nutritive substance of the stem on which it was spit towards and on the aforementioned junction.

The volume of graft significantly increasing the volume of the stem at the point of Clerc's Office, it follows a pressure created by the aforementioned plug on the point of the clerk's office maintaining advantageously the assembly obtained.

This provision of the plug makes it possible to avoid the use of small ustensils of fixing (clothes pin, etc) which can wound the plant or contaminate the wound if they are not correctly installed or are not cleaned.

By a sterilizing treatment adapted to material of the plug (heat, radiation or chemical treatment) one can moreover provide that this last is perfectly sterile even can contain a solution sterilizing in its part external (film deposited at the time of the manufacture of the plug or solution of steeping on the surface) thus blocking any contamination of the wound of size by pathogenic outsides.

Thus, the second nutritive solution contained in the tank can be brought and act directly on the place even where the Clerc's Office is and support the cicatrization (formation of the cal) while preventing a drying of certain portions of plants on the level of this junction and by protecting the latter from the physical aggressions, chemical, bacteriological, etc coming from outside.

In order to guarantee a sufficient and/or regular food one can moreover provide that the aforementioned tank is restocked with second nutritive solution by watering or steeping as soon as necessary.

According to another characteristic, the first nutritive solution includes/understands at least a growth hormone supporting the development of the roots, preferably a mixture of ANNA hormone and hormone AIB.

Advantageously, the second nutritive solution contains at least a substance supporting the formation of the cal of the Clerc's Office.

In particular, the second nutritive solution contains moreover at least a hormone supporting the growth of the air parts of the grafted seedling, in particular of the sheets and the stems, in particular of the cytokinine.

In a particularly advantageous way, one can still provide that the second nutritive solution contains moreover at least a substance élicitrice, i.e. who stimulates immunizing defenses of the latter.

Preferably, one modifies, with the stage c) or d), the food of the understock grafted in order to at least compensate for consumption by the understock in substances brought by the first nutritive solution, if necessary while supporting in more the catch of the Clerc's Office, in particular the formation of the cal.

According to another aspect of the invention, the process is still characterized in that, for the stage c), the modification takes account of the contributions by the second nutritive substance of kind to support as well as possible the development of the roots.

Although the process according to the invention can be implemented for a great number of different plant varieties, the aforementioned process moreover is characterized in that the graft belongs to the plant variety vitis will vinifera.

Lastly, the present invention still has as an aim a grafted seedling obtained by the implementation of the process in conformity with the present invention.

In this part of description will be now successively described an example of Clerc's Office known as “herbaceous cutting”, i.e. the Clerc's Office of an entirely green or herbaceous branch on another entirely green or herbaceous branch, then an example of Clerc's Office of an entirely green or herbaceous branch on a woody branch (wood).

In this technique, the seedling mother is cutting starting from wood taken in the vineyard, preferentially after the first cold ones.

This wood is put at bouturer in a hot room having a high moisture of the air (typically higher 80%) in order to facilitate the catch of the roots. A water treatment of wood, in the form of at least a washing or at least a steeping can possibly be practised as a preliminary, to improve the medical condition of it.

After a deadline from 14 to 30 days, the marbled cuttings are put in culture under greenhouse in pots containing an adapted culture medium, for example formed mixture of 50% of compost and peat 50%.

A vertical training is installed to make it possible the air parts to push in good order (what facilitates harvest) and vertically (what supports the lengthening of the internodes).

The conditions of growth and irrigation are traditional:

• temperature ranging between 20 and 25 °C,
• watering according to the needs for the seedlings,
• foliar fertilization by watering with a manure.

Selected manure must be adapted to the developmental stage of the plant with an important content phosphate just after the catch of the roots such as a manure NPK 10-52-10 and with a more important nitrogen contribution during the phases of strong growth such as a manure classically used in greenhouse of type NPK 10-10-10. The first harvests of herbaceous stems are possible between one and two months after the setting in greenhouse.

Only fresh stems, in full growth and of a diameter of about 1 to 2 mm will be cut.

The harvest of the grafts is carried out at the last time, right before the operation of grafting.

The branch previously collected is brought back in the room of grafting. It is cut out in elements including/understanding at least a node with, if necessary, its principal sheet and two segments of herbaceous stem located on both sides at less the one node. Preferably, the green graft comprises only one prolonged node, on both sides of two segments of herbaceous stem. The surface of the possible sheet presents to the level of a node is advantageously reduced from 30 to 50% according to the conditions of illumination available in the climatic room where the growth will be carried out.

Each one of these elements constitutes a graft then.

It is recommended not to use the 3 or 4 mérithalles higher whose physiological maturity is usually not sufficient.

The grafts thus obtained are maintained wet, preferably, by vaporization and in the shade, throughout all grafting. They are then ready for the grafting.

The understock is already present tightens some in a traditional mixture of compost-peat culture, for example.

One leaves him a period of annual rest preferably. One will then make him take again his cycle of vegetation while waiting for the season or by forcing the conditions of culture of the greenhouse so necessary. It receives a foliar fertilization adapted and balanced in manure of the type NPK, preferably of type 10-10-10.

Just like in the culture of the graft, the branches are trained vertically on wire. This operation is all the more important here that one wants to obtain stems presenting of the internodes from 10 to 15 cm. Indeed, the length of internode is a good indicator of vitality of the plant: more the internode is long, better is the aptitude for the clerk's office of the branch.

The branch is output in sections from 15 to 30 cm length, comprising between node at least, but rather two to three in practice.

The base of the understock is consisted the lower node to which one removed the bud. It is starting from this node that enraciner goes the cutting. At the time of the Clerc's Office, the entirely herbaceous or green understock can not present a root.

The top of the understock is approximately 3 cm above the higher node.

One removes the buds and the sheets of the second node and all the sheets except one with the third node or failing this with the preceding node. When it is present, the surface of this sheet is reduced by 30 to 50%, as for the graft.

During all these operations, the vegetable material is maintained wet, for example, by brumisation.

The preferred process described here requires the preparation of a nutritive plug intended for the graft.

The plug is, for example, a cube of 1 cm on side cut out in conventional floral foam such as one usually finds it in the florists and the nursery gardeners.

Before its use, this plug will be put to soak a few minutes in a nutritive and hormonal solution (second nutritive solution within the meaning of the process according to the present invention) whose mass composition preferred for one liter of water is the following one:

• solution of manure 10-52-10: 2500 Mg (out of crude),
• hormone AIB (acid 3-indolbutyric): 1 Mg,
• ANNA hormone (acid 1-naphtaleneacetic): 1 Mg,
• cytokinine BAP (benzylaminopurine): 1 Mg.

One supplements the volume of the mixture obtained with one liter with water demineralized such as usually used in the laboratories.

The concentration in active substances of the nutritive solution, its type and balance between the various hormones are defined and adjusted on a case-by-case basis, according to the vegetation, of the period of the year and the material available to the operator. For example, the increase in the quantities of hormones AIB and ANNA support the development of the roots whereas the increase in the amount of cytokinine contributes to a better formation of the cal on the level of the Clerc's Office. In all the cases, balance between the various hormones is as important as their concentrations in absolute value.

This solution must be preserved cold during 24 hours.

In a mode of particularly advantageous realization, this plug soaked with nutritive and hormonal solution is placed at the top of the graft, just after the Clerc's Office.

Its role is on the one hand, to slow down the desiccation of the graft and to nourish it while waiting for that the roots of the understock are functional and take over, and on the other hand, to ensure a hormonal balance at the level of the point of grafting to support the formation of cal.

The pots intended to receive the young grafted seedlings are filled with a culture medium adapted, for example consisted of the usual compost-peat mixture.

Right before the use, they are put to soak in a vat containing the first nutritive solution within the meaning of the process according to the invention (approximately 1 liter of solution for 15 pots). This solution will impregnate by capillarity the substrate of the pots.

This first solution of steeping is made up in weight of:

• solution of manure 10-52-10: 2500 Mg (out of crude),
• hormone AIB: 0,05 Mg with 5 Mg, preferably 1,6 Mg,
• ANNA hormone: 0,05 Mg with 5 Mg, preferably 1 Mg.

One supplements the volume of the mixture obtained with one liter with water demineralized such as usually used in the laboratories.

The pots are withdrawn from steeping after having received the grafted seedlings.

To carry out the grafting, one will provide oneself preferably with the following instruments: clothes pins, machine to be grafted in green, for example according to the French patent FR 86 01117, scalpel, container containing of hormone AIB pure or slightly diluted (with a factor of dilution of 2), pots in the course of steeping, understocks prepared, prepared grafts and nutritive plugs for soaked grafts.

Of course, the Clerc's Office can also be completely realized with the hand with the corresponding material.

One carries out a slit in the understock above the node carrying the sheet, or if no sheet is present, in the free segment of stem near to the node on the side of the bud. This can be made with the machine or the hand using a scalpel.

To the hand one cuts in bevel the graft to approximately 1,5 cm in lower part of the eye (or node).

One inserts the point of the graft cut in the slit previously practised in the understock.

To maintain the unit, one tightens the zone of contact with a small clothes pin. Other means of maintenance can also be appropriate (adhesive tape, wire, clips…).

Optionnellement, the bottom of the stem of the understock is soaked during approximately 2 to 20 seconds in a more or less concentrated mixture of hormones supporting the growth of the roots (first solution within the meaning of this patent). It goes without saying that this treatment, for example by steeping can also be carried out with several “first” solutions, for example with a succession of more or less concentrated baths.

The young grafted seedling is then planted in a pot which one packs well the compost around the foot.

One then pricks a plug soaked with nutritive and hormonal solution at the top of the stem of the graft crossed to approximately 3 cm of the node.

The pot thus prepared is transferred in climatic room for incubation.

The patent application FR 2.613.581 A1 of April 8th, 1987 describes the conditions of a process of herbaceous cutting which can be adapted or begun again for the process of grafting according to the present invention.

The incubation period in the climatic room will be led in hot and wet conditions:

• moisture ranging between 75 and 90%,
• temperature maintained between 25 and 30 °C,
• lighting are equivalent in the light of the day with an alternation day and night (of 8 with 10:00) regular,
• watering in fine rain every 3 hours the day and every 5 hours the night.

However, any watering making it possible to maintain the vegetation slightly wet but without excess will also be appropriate.

No fertilization is necessary at this stage of the development, taking into account the preliminary steeping of the pot in the bath of nutritive solution.

This incubation period will generally last from 14 to 15 days, until the appearance of the first roots and the higher buds. The summit nutritive plug can then be removed graft referred to above and the pot can then be transported in a traditional greenhouse.

The culture of the young Clerc's Office is then led under conditions much less constraining:

• moisture ranging between 50 and 70%,
• temperature of about 22 to 26 °C,
• lighting: the Clerc's Offices are protected from the sun, especially in summer period, for example by nets of shade.

This passage in greenhouse also will last a fifteen or so days, until the development of 4 sheets above the graft.

Then, the seedlings will live a phase of acclimatization outside or inside according to the time. It must make it possible the plant to adapt to the conditions external of rain, of wind,…

Between 15 and 30 days can be necessary to conclude this phase of transition and to obtain seedlings able to face the external conditions without problems.

The plantation with the vineyard can finally take place.

The preceding technique can still be improved as a practitioner the Clerc's Office of a branch green (or entirely herbaceous) on a wood growth.

The culture and the preparation of the graft are identical to those described in a) part above.

In this case, one uses as source of understock, the right cuttings greffables bought in the trade. It is about the traditional material of the nursery gardeners.

One cuts out these cuttings in sections from 20 to 30 cm, comprising, for example 2 to 3 nodes.

These elements are put to soak in a commercial solution of hormone AIB, containing 0,16 g/l AIB, during 2 hours (first nutritive solution within the meaning of the process according to the present invention).

After being drained, the cuttings are planted in pots which one places in hot room until the catch of the roots.

Then the development of the air parts proceeds in greenhouse under standard conditions of growth, with a sufficient watering and a foliar fertilization rich in phosphate.

The understock is ready when the growth reached 10 to 20 cm.

As in the case of the above mentioned herbaceous Clerc's Office, the graft receives after the grafting a nutritive plug.

The preparation of this plug is the same one as that presented in a) part referred to above. However, the formulation of the nutritive and hormonal solution of the known as plug (second nutritive solution within the meaning of the process according to the present invention), preferably, is modified a little. It is the following one:

• solution of manure 10-52-10: 2500 Mg (out of crude),
• hormone AIB: 0,05 Mg with 5 Mg, preferably 1,7 Mg,
• ANNA hormone: 0,05 Mg with 5 Mg, preferably 1 Mg,
• cytokinine: 1 Mg.

One also supplements the volume of the mixture obtained with one liter of demineralized water.

In this case since the seedlings are already enracinés, one does not proceed to the operation of steeping of the pots in a nutritive bath.

To carry out the grafting, one will use a material identical or similar to that described in the process of a) part.

The Clerc's Office is preferably carried out primarily with the hand. Initially, one shortens to approximately 2 cm, the herbaceous stem (green) in phase of growth of the understock marbled wood on which one will carry out the Clerc's Office. Then one practises in this stem a right incision with the scalpel. Then one inserts in this slit the graft cut in bevel into the hand or the machine.

To maintain the unit, one uses a small clothes pin to tighten the zone of contact between the graft and the understock.

A plug soaked with nutritive and hormonal solution is placed at the top of the stem of the graft.

The pot can then be placed in climatic room.

The incubation period in hot climatic room will last in this case only one about eight days until the appearance of the first bud. The conditions are identical or similar to those described for the above-mentioned process A).

The seedling is then transferred in greenhouse from culture for 8 to 15 days until the appearance of 4 sheets above the graft.

The phase of acclimatization of the seedling in the external conditions is then launched for one duration going from 8 to 15 days.

Then, the seedling is ready to be replanted in the vineyard.

The contribution of one second nutritive solution, for example via a plug soaked with a nutritive and hormonal solution makes reliable the resumption of the graft and is effective for the Clerc's Office herbaceous cutting as for the Clerc's Office cutting wood.

Its principal advantages are:

• it facilitates survival independent of the graft while waiting for that the understock develops its roots and is able to nourish says it graft,
• it makes it possible to adjust the hormonal balance of the graft independently of that of the roots. It is thus possible to add hormones more specifically favorable to the manufacture of cal to accelerate the process of cicatrization of the point of grafting,
• he prevents the drying of the graft, the level of moisture to be maintained in the room of culture after the grafting thus which can be appreciably reduced. This has as an additional positive consequence to limit the fungic attacks.

The use of budding cutting wood makes it possible to reduce on the one hand, the duration of the cycle of production and on the other hand, the basic investment grace, in particular with needs for surfaces of less greenhouses.

Indeed, the cutting wood being bought in the trade, it is not produced any more under in situ greenhouse. Moreover, it is available all the year because it can be stored cold.

The understock is in this case in a phase of strong growth. It is marbled and can nourish the graft more quickly. The resumption of the growth is thus facilitated, the cycle of production is shortened of as much and the rate of success of the considerably increased grafting.

The cutting wood with the advantage of having nutritive reserves in the wood which the seedling can mobilize to face the conditions of growth in full field. The seedling is then more robust and can be left earlier.

Of course, the invention is not limited to the described modes of realization. Modifications remain possible, in particular from the point of view of the constitution of the various elements or by substitution of technical equivalents, without leaving for all that the field protection of inventions.