WO2003003815A1

WO2003003815A1 - Method and apparatus for propagating plants by cuttings and/or raising plants, in particular roses

Info

Publication number: WO2003003815A1
Application number: PCT/NL2002/000442
Authority: WO
Inventors: Hendrik Jan Van Telgen
Original assignee: Praktijkonderzoek Plant En Omgeving B.V.
Priority date: 2001-07-05
Filing date: 2002-07-05
Publication date: 2003-01-16
Also published as: NL1018467C2; AP2004002967A0; EP1404171A1

Abstract

The invention relates to a method for propagating plants by cuttings and/or raising plants, in particular roses, wherein cuttings are formed, which cuttings are brought into contact by at least one cut surface with a growth hormone solution, while a supra-optimal hormone time is used, and also relates to an apparatus for propagating plants by cuttings and raising plants, in particular roses, comprising a synchronization space in which a method according to any one of the preceding claims can be used and a number of spaces for raising and further treatment of the plants, wherein in or at the synchronization space, means are provided for regulating at least the temperature and the lighting.

Description

Title: Method and apparatus for propagating plants by cuttings and/or raising plants, in particular roses.

The invention relates to a method for propagating roses by cuttings and/or raising roses.

It is known that plants such as roses can be propagated by cuttings by taking cuttings from flower branches consisting of at least a length of stem internode, one leaf and at least one axillary bud. Generally, the axillary bud lies dormant, i.e. is not yet budding. By the lower end, at least the cut surface, these cuttings are inserted into a growth medium such as a substrate, after at least the cut surface has been treated with a growth hormone such as a (synthetic) root growth hormone, for instance a mixture of an auxin and talcum powder. As a result, root growth is initiated on the cutting, whereupon the plant can grow and be brought to flower formation. Also, in the treatment, growth hormone can be offered in a solution, while, as a rule, concentrations of growth hormone are used in the order of 0.5 - 1 % by weight of auxin, for instance indole butyric acid (IBA). Also, for instance, indol acetic acid (IAA) and naphthyl acetic acid (NAA) are used. Customary is the use of the "quick- dip", i.e. the underside of the cuttings are dipped for 3 - 10 seconds into a highly concentrated (10,000 ppm, 1%) auxin solution. Thus, a relatively good, constant root development is obtained.

A disadvantage of these known methods is that different cuttings will develop at different times. The axillary buds will bud at intervals of, for instance, a week or longer and, moreover, will lead to very different yield times of flowers.

The invention contemplates providing a method with which in a better synchronized manner, cuttings can be brought to development and/or flower formation can be synchronized. To that end, a method according to the invention is characterized by the features of claim 1. Surprisingly, it has appeared that upon increase of the hormone time to supra-optimal, i.e. to a value higher than the optimal value for root formation, budding of the axillary buds is decelerated or even temporarily prevented. With a method according to the invention this insight is used in a surprising manner. Root formation is induced without the axillary buds already budding. It has appeared that the root formation then occurs virtually evenly and the cuttings can be hardened-off more rapidly than usually by, inter alia, reduction of the relative air humidity before budding of the axillary buds. It has appeared that thereupon, the budding and flower formation of the cuttings, at least the plants grown therefrom, proceeds synchronously to a large extent. Without wishing to be bound to any theory, this seems to be the result of the fact that the time between the start of the budding of the axillary buds and flower formation is relatively constant for cuttings, irrespective of the position where they have been taken in a plant, leaf formation and the like, while the moment of budding with a method according to the invention can be largely controlled as a result of the inhibitory action of the supra- optimal hormone time. As a result of the improved synchronization, the advantage is achieved that cultivating and harvesting becomes less labor- intensive, that flowers, at least plants are obtained with a greater homogeneity, thereby increasing their value. Moreover, with a method according to the invention, the rooting time and the hardening-off time can be shortened, so that the available space can be utilized in a more efficient manner. Further, the flowers, at least the plants, can be harvested in a simpler manner. Use is then made of low-concentration auxin solutions (0.2 -1.0*10"⁴%) in which the bottom of the cuttings are dipped for some time, for instance a few minutes. Experiments have shown that the maximum root development percentage is achieved with an optimal treatment, i.e. an optimal combination of duration of dip (in minutes) and concentration of the solution (in μmol/1 = μM). For this, the term "hormone time" is used, being the product of duration (min) and concentration (μM). Thus, it has been estabhshed that, at least for roses as mentioned in the experiments, for maximum root development, a hormone time of 3,000 μM.min is optimal.

In a further advantageous embodiment, a method according to the invention is characterized by the features of claim 3. By selecting the temperature of the substrate the cuttings are put into for root growth to be relatively high, preferably above room temperature, for instance between 23° and 30°C, the root growth is even more accelerated, while budding of buds remains inhibited. In particular when a temperature of approximately 26°C is maintained, an optimal root growth will be obtained. It is then preferred that immediately after the first onset of root growth, in particular the first root primordia, is visible, the temperature of the substrate is lowered, for instance by approximately 5°C, which improves further growth of the cuttings. The substrate temperature is then for instance reduced to approximately 21°C. Hardening-off of the cuttings can then begin, immediately when the first root primordia are visible, at reduction of the relative air humidity to, for instance, between 50 and 70% RH.

With a method according to the invention, preferably, use is made of a supra-optimal hormone time between 3,000 and 15,000 μM.min. More in particular use is made of a hormone time between 5,000 and 12.000 μM.min, more in particular between 8,000 and 11,000 μM.min. With roses as the cultivar "First Red", preferably, use is made of a hormone time of approximately 9,000 μM.min, while as growth hormone, at least an auxin is used, in particular indole butyric acid (IBA). It will, for that matter, be immediately clear to the skilled person, at least it can be simply determined, what a supra-optimal hormone-time is for other plants, at least flowers and/or other root hormones to be used. This will be selected such that the hormone time is higher than the one at which maximal root growth occurs, but not so high that undesired ethylene formation occurs.

With a method according to the invention, preferably, a growth hormone solution is used, in particular an auxin solution in a phosphate buffer. Preferably, use is then made of a low concentration of growth hormone, in particular a concentration of less than 0.1 % by weight, more in particular a concentration of less than 3,000 μM. Notably with roses, it has surprisingly appeared that it is preferred to use a solution of a concentration between 100 and 1,000 μM, preferably approximately 700 μM. This corresponds approximately to 1.5 x 10' % by weight. As such particularly low concentrations can be used, the advantage is achieved that the use of auxin is considerably reduced in relation to the current methods, while a particularly good dosing, and hence uptake of growth hormone can be obtained. It has appeared that the growth of the cuttings can be controlled and synchronized still better by lighting the cuttings, while the lighting is reduced as soon as the first root primordia become visible. Until that moment, preferably, the air humidity is kept relatively high, for instance higher than 75% RH, more in particular between approximately 85 and 90% RH. In a method according to the invention, after sufficient root formation has occurred, the cuttings can be directly put into the soil or a different growth medium for further development and growth. However, it has appeared that, surprisingly, cuttings according to the invention can also be stored after they have been caused to root and hardened-off, by storing the cuttings in a cold room at a relatively low temperature, for instance below 8°C, more in particular a temperature between 2 and 6°C. For roses, a storage temperature of approximately 4°C appears optimal. It has appeared that in such a manner, cuttings can be stored relatively long, for instance a few weeks, without the .desired synchronization being lost. Moreover, the synchronicity is also preserved when these roses are raised further. At decreasing synchronicity, it suffices to then store the plants with roots cold for some time, at conditioned lighting. It is advantageous then to store the plants, at least roses, with root development during approximately two weeks at approximately 4°C and a relatively low light intensity, for instance approximately 4 Watt/m². The invention further relates to an apparatus for propagating and raising plants, in particular roses, characterized by the features of claim 12.

In such an apparatus, plants, in particular roses, can be propagated and raised, while a particularly good synchronization can be obtained in the- budding of the roses, so that controlling and harvesting can be carried out in a little labor-intensive manner. Moreover, thus, roses can be raised having a particularly high homogeneity in appearance. Moreover, as a result of the use of a method according to the invention, the available space can be utilized in a particularly efficient manner, so that for instance energy costs, investments and the Uke can be Hmited to a minimum. A further advantage is that the roses in such an apparatus have a relatively short cycle, so that the efficiency is even more increased.

It is preferred that in an apparatus according to the invention plants such as roses are propagated in moveable, in particular wheelable propagating cases, with which they can be wheeled through the different spaces in the apparatus, between the different phases. This facilitates logistics and management even more. Optionally, the plants, in particular the roses, can be harvested automatically.

In the further subclaims, advantageous further elaborations of a method and apparatus according to the invention are further described. In clarification of the invention, embodiments of a method an apparatus according to the invention will be further elucidated with reference to the drawing and examples. In the drawing:

Fig. 1 shows four phases of a rose, from a cutting to a harvestable plant, at least rose;

Fig. 2 schematically shows the lay-out of an apparatus for propagating and raising roses;

Fig. 3 shows a graphic plot of the effect of the hormone time on root development percentage and number of roots for cuttings of roses of the type "First Red"; Fig. 4 shows a graphic plot of the effect of hormone time on number of roots, measured 21 days after propagating and budding of axillary buds, 28, 42 and 49 days, respectively, after propagating, for cuttings of roses of the type "First Red"; and Fig. 5 shows a graphic plot of the effects of the use of a synchronization method according to the invention at the time of appearance of a flower bud and harvesting, while the comparison is shown between cuttings of roses of the type "First Red" either treated with a supra-optimal hormone time or non-treated, traditionally hardened-off. In this description, the starting point are roses as plants, at least roses, to be propagated by cuttings and to be raised. However, also other plants, in particular cut flowers can be propagated by cuttings and be raised in the same or in a comparable manner. In the examples to be described hereinbelow, the starting point is the use of a solution of a root development hormone IBA, made with a 0.1 MK H2PO4 buffer, so as to give all solutions an identical pH and ion strength. Concentrations of IBA between 0 and 3 mM were used. However, it will be clear that also other root development growth hormones can be used, for instance comparable solutions of NAA or IAA.

According to the invention, cuttings were taken from roses, while each cutting consisted of a piece of stem internode 1, a leaf 2 and an axillary bud 3, in particular a dormant axillary bud. After having been cut, the cutting was dipped into the hormone solution, while different hormone times to be described further, expressed in μM.min, were used.

Four experiments were carried out, which, insofar as necessary, will be described and discussed. Experiment 1:

Cuttings were taken from branches of First Red roses, ready for auctioning, which were pre-watered in a cold room for one day. From three positions (highest five-leaf, lowest five-leaf and an intermediately positioned five-leaf) cuttings were taken. The three groups of cuttings were kept apart and caused to root. To that end, the bottom side of the cuttings were put into the described root development hormone solutions (IBA) having concentrations between 0 and 3 N for a number of minutes, whereupon the cuttings were inserted into coco plugs. Seven days after the cuttings were inserted, for all ^' treatments, the quality of the cutting leaf and any shifting of the axillary bud were visually examined. Three weeks after the cuttings were inserted, they were sampled and destructively examined for roots, number of roots and visual quality of the cutting leaf. After four, six and seven weeks, number and length of the budded axillary buds were measured. Experiment two:

Cuttings were taken from branches ready for auctioning of the cultivar "First Red", as described at experiment 1. Only the highest and lowest five-leaves present were used as cuttings. After dipping in the IBA-solution during 4,000 μM.min, the cuttings were inserted into coco plugs with the axillary bud 3 approximately 1 cm above the plug. After four weeks of root development, and two weeks of hardening-off, the cuttings were planted in Tempex troughs filled with pearlite in densities of 48 or 96 cuttings per m². Experiment three: Cuttings were taken from branches ready for auctioning of the cultivar "Lambada". The upper and lower five-leaves were not used for cuttings. Cuttings from the intermediate positions were mixed and used as one population. During 2,000 or 5,000 μM.min, the cuttings were dipped in the IBA-solution and caused to root. Additional lighting took place from 48 hours after insertion of the cuttings, during maximally 16 hours per 24 hours, between 06.00 and 22.00 hours. Half of the cuttings were lighted at 10 Watt/m² at cutting level, the other half at 20 Watt/m². After three weeks of root development and two weeks of hardening-off, the cuttings were sorted according to length of the budded shoot and planted in Tempex troughs filled with pearlite in a density of 12 cuttings per m². Experiment four: Cuttings were taken as in experiment 1. The upper and lower five- leaves were not used for cuttings. The remaining cuttings were mixed and used as one population. After the cuttings were taken, they were dipped in a 1 mM IBA-solution. Thereupon, the cuttings were planted in Tempex troughs^' filled with pearlite in densities of 18 cuttings per m². Root development conditions.

Root development of the cuttings took place in trays with coco plugs which, prior to cutting, were watered once with standard nutrient solution for roses (EC=2), while the trays were placed in polyethylene cutting tents. In the experiments 1, 2 and 3, as substrate temperature in the cutting tent, approximately 23°C was maintained, at 100% relative humidity. Additional lighting took place from 48 hours after the cuttings were inserted, for 18 hours per day. The lighting level was 10 Watt/m² at cutting level for the total root development and hardening-off period. During the lighting period, 800 ppm CO2 was dosed.

In experiment 4, as substrate temperature in the cutting tent approximately 26°C was maintained, at 85-90% RH. Additional lighting took place from 48 hours after the cuttings were inserted, for maximally 16 hours per day, at a lighting level of 10 Watt/m² at cutting level. Additional lighting occurred between 06.00 and 22.00 hours, when the outside radiation was less than 180 Watt/m². During the total root development and hardening-off period, 800 ppm CO2 was dosed. Seven days after the cuttings were inserted, the substrate temperature was brought to 21°C, while the additional lighting was switched off. Root formation was then just visible. After 12 days, hardening-off was started, which took place in five days at approximately 60% RH. In this period, virtually no budding of axillary buds had occurred.

A quarter of the cuttings of experiment 4 were directly planted in a greenhouse, a quarter remained standing under the hardening-off conditions, while the remaining cuttings were stored at approximately 4°C, 60% RH, at a lighting of approximately 4 Watt/m² (SON-T). Two weeks after planting of the first series of cuttings, the cuttings kept under hardening-off conditions were planted, and so were half of the cuttings stored at 4°C. After another two weeks, the remaining cuttings stored at 4°C were planted.

Cultivating conditions. The temperature in the greenhouses during cultivation was set to a

24-hour average of approximately 20°C. During cultivation, between 02.00 and 20.00 hours, lighting took place with 11 or 22 Watt/m² assimilation lighting. Watering and fertilizing occurred via trickle tubes.

In experiment 4, the temperature in the greenhouses during cultivation was set to a 24-hour average of 20°C. The additional lighting here was as described hereinabove, however only when the outside radiation was less than 200 Watt/m². Again, watering and fertilizing occurred via trickle tubes.

The budding of the axillary buds was monitored and the day of appearance of the flower buds and the day of harvesting were registered. As a measure for synchronicity in development was taken the number of days between the appearance of the first and last flower bud in a trial field.

In experiment 1, the relation hormone time - root development percentage — number of roots — budding was examined. It showed that (21 days after the treatment) from a hormone time of 10 μM.min, the root development percentage increased, reached a maximum about 1,000 — 2,000 μM.min, and, at longer hormone times, decreased again (Fig. 3).

The number of roots exhibits a similar curve, however, the optimum has shifted, o & value between 10,000 and 30.000 μM.min. When the budding of axillary bud is considered, this runs substantially parallel to number of roots, but an optimum is reached sooner (about 5,000 μM.min); at higher hormone times the budding decreases again; budding is apparently inhibited by auxin (Fig. 4). The hormone time best for inhibiting budding is supra- optimal for root development percentage. Root development with a supra-optimal concentration for root development percentage, but sub-optimal for inhibition of budding gave a not much smaller spread in appearance of the flower bud and eventual harvest time: on average about 21- 28 days. In experiment 3 it appeared that further increase of the hormone time to 5,000 μM.min yielded a considerable increase in synchronous growth and development. Cuttings whose axillary buds had not budded in the cutting period, subsequently developed very uniformly, while an influence of cultivation conditions was measurable. The conclusion from this was that for better synchronization, budding in the cutting-root development phase is undesired.

In experiment 4, a hormone time of 10,000 μM.min was used, in combination with a temporarily increased substrate temperature during the first 7 — 8 days, decrease of substrate temperature and light intensity after appearance of root primordia and rapid hardening-off (15 days). After the hardening-off, % was planted directly, % was hardened-off further in a traditional manner (slowly), and 2 x % were stored at 4°C (for 2 and 4 weeks, respectively). Subsequently, after planting, the synchronicity in growth and development was examined. Plants hardened-off in a traditional manner (i.e. planting with budded axillary bud) were relatively highly a-synchronous, having a spread in flower bud appearance of several weeks (21 to 28 days, Fig. 5). Planting of synchronized cuttings (with non-budded axillary bud and rapid hardening-off) yielded a uniform growth and development, with appearance of 90% of the flower buds within a time period of approximately 5 days (Fig. 5). Storage at 5°C actually seemed to reinforce this, albeit that at storage longer than two weeks, possibly, a wider spread seemed to occur.

These experiments show that use of a supra-optimal hormone time, between 3,000 and 15,000 μM.min, leads to an improved synchronization of budding of cuttings of, in particular, roses, since the budding of the axillary buds seems to be at least temporarily suppressed by the relatively long hormone times, while particularly good root development is obtained with a particularly high percentage of the cuttings. It has appeared that, particularly the use of hormone times between 8,000 and 11,000 μM.min lead to higher synchronization. An optimum appears to lie, at least for the roses used in these experiments, at approximately 9,000 to 10,000 μM.min. By moreover selecting the temperature of the substrate in which the cuttings, after being dipped in the hormone, are planted to be relatively high, i.e. for instance between approximately 23 and 30°C, the root development phase is accelerated, so that the efficiency is increased still further. For the roses used in these experiments, an optimum appeared to lie at a substrate temperature of approximately 26°C, until the first root tips became visible, whereupon the temperature was reduced, for instance to approximately 21°C, at the start of hardening-off by, at least with reduction of the air humidity to between approximately 50 and 70% RH, while, in these experiments, approximately 65% RH seemed optimal. For different plants, in particular roses or similar ligneous or semi-ligneous plants than used in these experiments, a skilled person can simply determine a comparable set of optimal conditions, starting from the present inventive concept, while, moreover, in a comparable manner, also for different root development growth hormones or solutions optima can be determined.

Further, it appears from these experiments that according to the invention plants, in particular roses, can be stored for relatively long periods of time without the synchronicity being lost, by storing the cuttings relatively cool, for instance at a temperature of approximately 4°C. Surprisingly, it has appeared that in the cycle of harvesting and, once again, budding of pretreated cuttings, the desired synchronicity is preserved a number of times without specific further treatment. When the synchronicity falls, storage at the relatively low temperature mentioned, for instance between 2 and 8°C, more in particular at approximately 4°C for approximately two weeks at a lower amount of light, is sufficient for regaining the desired synchronicity. This effect also appeared to occur already with optimal hormone times, albeit less optimally, due to the light/temperature treatments mentioned. Without wishing to be bound to any theory, this seems to result from the fact that the axillary bud, in principle, contains a complete rose and needs to have sufficient time to develop before the axillary bud buds. As under equal conditions, the duration of time of budding from the completely developed axillary bud to harvestable rose seems to be fixed, the synchronicity at harvesting can be improved, in an above-described manner, by causing the axillary bud to bud only when this development is fully completed. When all plants are in the same phase of development, which can be effected for instance in the above- described manner, and optimal combinations of temperature and light have been created for the separate development phases from axillary bud to harvestable rose, an optimal cultivation treatment is possible. This leads to a reduced cultivation duration, lower production costs and energy savings. Moreover, in a particularly accurate and simple manner, cultivation can be planned on the basis of desires of customers. The fact is that as the time between the taking of cuttings and completely harvestable rose is virtually fixed and it can be provided that the different roses develop simultaneously, roses are virtually simultaneously harvestable. With a method according to the present invention, the time between development of the first and last harvestable rose in a batch can be reduced from, normally, approximately 21 to 28 days to less than 8 days. As a result, for instance, harvesting only has to take place 4 to 8 times every six weeks, instead of every day. Thus, it is additionally achieved that in a simple manner, automated harvesting means such as harvesting robots can be used.

In Fig. 2, schematically, an apparatus is shown for use of a method according to the present invention. This apparatus, for instance a greenhouse, comprises a number of spaces through which wheelable cultivating trays 6 can be moved, for the different phases of development. This apparatus will be further discussed hereinbelow. The apparatus 8 comprises a synchronization space 10, a budding space 12, a processing space 14, a first straightening space 16, a second straightening space 18 and a maturing space 20. The spaces 10 - 20 are separated from each other, such that in the different spaces temperature, relative air humidity and/or level of lighting can be individually controlled. The cultivating trays 6 with cuttings therein, at least plants for traversing the different phases can be wheeled through the spaces 10 — 20. The trays 6 have for instance a size of 6 — 20 square meters and travel through the spaces mentioned via an automatic transport system. In the budding space, budding of the axillary buds takes place, whereupon the plants can be brought to the processing space 14, in which, manually, superfluous buds are broken off. Then, the budded plants are moved to the first straightening space 16, where optimal light and temperature conditions prevail for straightening of the shoot until a flower bud becomes visible. Then, the trays 6 are wheeled to the second straightening space 18, where, as described, optimal conditions prevail for a cultivation phase for straightening after the flower buds have become visible. Then, the plants in the trays 6 are wheeled to the maturing space 20, where further growth is effected. Then, the trays can be wheeled from the maturing space 20 to the central processing space 14, where harvestable plants can be harvested, in particular while using a robot with pattern recognition means or the like. After a harvesting action, the plants are returned to the maturing space 20 each time flowers can still be expected on the plants straightening in the respective tray 6. Afterwards, cuttings can be taken from the relevant plants which, after having been dipped in the earlier mentioned hormone solution for a desired hormone time, can be brought into the synchronization space 10, cooled and in artificial fighting, for obtaining and preserving the desired synchronization.

Preferably, in the trays, each plant contains one or more outward bent branches which provide assimilates and one or more straight flower branches. The plants are topped as much as possible, so that a neatly arranged working environment is obtained which allows, at least facilitates harvesting with the robot mentioned.

The invention is not limited in any manner to the exemplary embodiments of methods and apparatuses represented in the description and the drawing. Many variations thereon are possible within the framework of the invention as outlined by the claims.

Claims

1. A method for propagating plants by cuttings and/or raising plants, in particular roses, wherein cuttings are formed, which cuttings are brought into contact by at least one cut surface with a growth hormone solution, while a supra-optimal hormone time is used.

2. A method according to claim 1, wherein such a length of hormone time is used that root growth is induced and accelerated w ile budding of buds is at least temporarily delayed.

3. A method according to claim 1 or 2, wherein the cuttings are placed in a substrate of a temperature over 18°C, more in particular over 21°C, preferably a temperature between 23 and 30°C, more in particular a temperature of approximately 26°C, until root formation occurs, in particular until the first root primordia become visible.

4. A method according to claim 3, wherein, after the first root primordia are visible, the temperature of the substrate in which the cuttings are cultivated is lowered, preferably below 26°C, more in particular to approximately 21°C, at least is reduced by approximately ό°C.

5. A method according to any one of the preceding claims, wherein the cuttings are hardened-off after the first root primordia become visible.

6. A method according to any one of the preceding claims, wherein a hormone time is used between 3,000 and 15,000 μM.min, more in particular between 5,000 and 12,000 μM.min, more in particular between 8,000 and 11,000 μM.min, and preferably about 10,000 μM.min.

7. A method according to any one of the preceding claims, wherein as growth hormone at least an auxin is used, in particular indole butyric acid (IBA).

8. A method according to any one of the preceding claims, wherein a growth hormone solution is used, in particular an auxin solution in a phosphate buffer, wherein a low concentration of growth hormone is present, in particular a concentration of less than 0.1 % by weight, more in particular a concentration of less than 3,000 μM, preferably a concentration between 100 and 1,000 μM and more preferably approximately 700 μM.

9. A method according to any one of the preceding claims, wherein the cuttings are lighted, while the lighting is reduced when the first root primordia become visible.

10. A method according to any one of the preceding claims, wherein the cuttings, at least until the first root primordia become visible, are kept at an air humidity higher than75% RH, more in particular at an air humidity between 80 and 95% RH and preferably between 85 and 90% RH.

11. A method according to any one of the preceding claims, wherein the cuttings, after these have been caused to root and are hardened-off, are stored in a cold room at a temperature below 8°C, more in particular a temperature between 2 and 6°C and preferably a temperature of approximately 4°C.

12. An apparatus for propagating plants by cuttings and raising plants, in particular roses, comprising a synchronization space in which a method according to any one of the preceding claims can be used and a number of spaces for raising and further treatment of the plants, while in or at the synchronization space, means are provided for regulating at least the temperature and the lighting.

13. An apparatus according to claim 12, wherein propagating trays are provided for cultivating the plants, which propagating trays are movable, in particular wheelable, through the different spaces.

14. An apparatus according to any one of claims 12 or 13, wherein at least an automatic device is provided for automatically harvesting plants.