Method for accelerating growth of plants

Abstract

The invention disclosed herein relates to methods for growing plants, in particular methods for growing a plant under such conditions that a young plant with a better quality is obtained and / or a young plant is obtained sooner, as compared to a standard outdoors-grown plant. The disclosure also relates to a plant per se, an arrangement to carry out said methods, a plant cultivation facility comprising said arrangement, as well as a use of artificial light to accelerate the growth of a plant.

Description

[0001] Title: METHOD FOR ACCELERATING GROWTH OF PLANTS

[0002] TECHNOLOGICAL FIELD

[0003] The invention disclosed herein relates to methods for growing plants, plants perse, arrangements to cany out said methods, plant cultivation facilities comprising said arrangement, and the use of artificial light to accelerate growth of plants.

[0004] BACKGROUND

[0005] The process of growing plants is usually lengthy. Typically, seed is sown in an outdoors nursery bed or in a tunnel or greenhouse, and the resulting seedlings grow slowly until they are large enough to be transferred to the field. When a plant is ready to be transferred to the field, it is typically referred to as a “young plant”

[0006] For example, for forestry plants it typically takes about 125-180 days (including germination) to obtain a young plant, for mangrove about 150 days (including germination), for potato plants grown from real seeds in a tunnel or greenhouse about 42 days, and for strawberry plants grown from real seeds, e.g. in a tunnel or greenhouse, about 65-90 days.

[0007] Moreover, during the outdoors nursery stage the conditions are not well-controlled, as the weather conditions are not constant Furthermore, there may be an undesired degree of variation between different plants, and / or the plants may be exposed to pests and diseases.

[0008] As such, it is desired that methods arc developed that accelerate the growth of plants, in particular such that young plants can be transferred sooner to the field, shortening the production cycle. In particular, it is desired that such a method be provided that can be readily carried out, allows employing controlled conditions (including controlled environmental conditions such as light, CO2, relative humidity, and the like; pest control; and / or disease control), may reduce the variation between plants, and / or is economical.

[0009] Some efforts have been made in this respect For example, the plants may be exposed to growth hormones and / or the plant material may be genetically enhanced. However, the use of chemicals such as growth hormones is undesired as it may lead to water pollution, and genetic enhancement maybe cumbersome. Moreover, both procedures are typically expensive. As such, it is still desired to further accelerate the growth of plants, to achieve said acceleration at an early stage, to achieve said acceleration without using genetic enhancement and / or growth hormones, and / or to faster obtain significant differences as compared to reference examples such as outdoor-grown plants.

[0010] SUMMARY

[0011] The methods, arrangements, facilities, plants, and uses as disclosed herein meet one or more of the abovementioned desires. In particular, one or more of the abovementioned desires are achieved by the method, arrangement, facility, plant, and use as claimed.

[0012] BRIEF DESCRIPTION OF THE FIGURES

[0013] Figure 1 depicts Acacia nilotica plants of about 60-80 cm grown using methods of the invention. It is also indicated that under conventional, traditional conditions it would take about 120-180 days (including germination) to obtain a young plant. “DAS” means “days after sowing”.

[0014] Figure 2 depicts mangrove plants grown using traditional conditions (top), and mangrove plants grown using methods of the invention (middle and bottom).

[0015] Figure 3 depicts potato plants grown from real seeds. The plant on the left is a reference example, which was grown in a greenhouse / tunnel. The plants in the middle and on the right of Figure 3 were grown using a method of the invention in 21 and 34 days (including germination), respectively.

[0016] Figure 4 depicts strawberry plants (variety Limore One) grown from real seeds as obtained in Example 4.2 using a method of the invention. The plants are type B plants, and are pictured on day 70 after sowing.

[0017] Figure 5 depicts strawberry plants (variety Limore One) grown from real seeds as obtained in Example 4.2 using a method of the invention. The plants are type C plants, and are pictured on day 70 after sowing.

[0018] DETAILED DESCRIPTION

[0019] In a general sense, the invention is based on the judicious insight that providing artificial light to a plant in its early stages of development accelerates and / or improves the growth and development of said plant. As such, the invention relates to a method for growing a plant, wherein the method comprises the steps of: a) providing plant material selected from the group consisting of a seedling, a cutting, and a plant obtained from a tissue culture; wherein preferably the seedling is obtained by providing a seed and germinating said seed; and b) exposing said plant material to light, wherein said light is substantially exclusively artificial grow light. In particular, the plant is preferably grown under such conditions that a young plant with a better quality is obtained and / or a young plant is obtained sooner, as compared to a standard outdoors-grown plant As used in this phrase, “such conditions" may refer to any one of the preferred features as mentioned herein, and combinations thereof, in particular to the artificial grow light.

[0020] As is known to the skilled person, a plant is of improved quality if it has for example a higher dry weight a better root structure, a higher survival rate, a lower susceptibility to plagues and / or diseases, and / or a faster production rate when grown outdoors.

[0021] As used herein, “a young plant is obtained sooner" means that the time for obtaining a young plant is reduced. Naturally, it will depend on the plant or the plant variety to exactly what extent the process is accelerated. Typically, “sooner*' in this context means that when using a method of the invention, a young plant is obtained in less than 95%, preferably less than 90%, more preferably less than 80%, more preferably less than 75%, even more preferably less than 70%, of the time required to typically obtain a young plant under traditional outdoor conditions.

[0022] In particular, methods as disclosed herein enable that a young plant is obtained more quickly, such that young plants can be transferred sooner to the field, shortening the production cycle. Moreover, the methods can be readily carried out, allow employing controlled conditions, may reduce the variation between plants, and / or are economical.

[0023] In the methods of the disclosure plant material is provided. It will be understood that the plant material is subjected to the method of the invention to obtain a (young) plant. Especially, the term “plant material” may refer to any stage of growth, at any moment starting from seed, seedling, cutting, or tissue culture plant, up to a young plant and even a mature plant. In principle, at any stage of growth a plant can benefit from methods of the invention. Preferably, however, the plant material is selected from the group consisting of a seedling, a cutting, and a tissue culture plant.

[0024] In principle, the method of the invention can be applied to any plant species. Preferably, the plant is selected from the group consisting of mangrove, a forest plant, a potato plant, a strawberry plant, a cacao plant, a palm plant, a tomato plant, an orchid, and Pautowma tomentosa. More preferably, the plant is selected from the group consisting of mangrove, a finest plant, a potato plant, and a strawberry plant

[0025] Preferably, the plant is a mangrove. As used herein, “mangrove” indicates a plant of the family Rhizophoraceae, preferably of the genus Rhizophore, most preferably of the species Rluzophora mangle.

[0026] In other preferred embodiments, the plant is a forest plant. Preferably, the forest plant is selected from the group consisting of fruit-producing plants, food-producing plants, gumproducing plants, timber trees, rubber trees, medicinal plants, oil-producing plants, resinproducing plants, fiber-producing trees, paper-producing trees, and Paulownia tomentosa (also known as a princess tree, empress tree, or foxglove-tree). Preferably, the timber tree is selected from the group consisting of teak (Tectona grandis), mahogany (Staetenfe spp.), eucalyptus (Eucalyptus spp.), pine (Pinus spp.), and douglas fir (Pseudotsuga menziesif). Preferably, the medicinal plant is selected from the group consisting of ginseng (Panax spp.), neem (Azadirachta indica), and cinchona (Cinchona spp.). Preferably, the rubber tree is

[0027] Hevea brasiliensis. Preferably, the food-producing tree is a cocoa plant (Theobroma cacao), or a palm tree (i.e. a plant of the family Palmae or Arecaceae). More preferably, the foodproducing tree is a date palm (i.e. a plant of the genus Phoenix, preferably of the species Phoenix dactylifera or Phoenix canarensis). Preferably, the oil- and / or resin-producing plant is selected from the group consisting of oil palm (Elaeis guineensis), frankincense (Boswellia spp.), pi™ trees (Pinus spp.), sandalwood (Santalum album), and agarwood (Aquilaria spp.). Preferably, the fiber- and / or paper-producing trees are bamboo (Bambusoideae spp.), or mulberry (Moras spp.).

[0028] Most preferably, the forest plant is an acacia. As used herein, “acacia” refers to a plant of the genus Acacia or Vachellia. Preferably, the acacia is Acacia niiotica (also known as Vachellia niiotica, gum Arabic tree, babul, thorn mimosa, Egyptian acacia, and thorny acacia).

[0029] In other preferred embodiments, the plant is a potato plant As used herein, “potato plant” refers to a plant of the species Sokmum tuberosum.

[0030] In other preferred embodiments, the plant is a strawberry plant. As used herein, “strawberry plant" or “strawberry” refers to a plant of the genus Fragaria, preferably of the species Fragaria x ananassa.

[0031] Preferably, the plant material is a seedling. Seedlings are readily obtained from seeds of a plant. As used herein, “seedling” refers to a plant at the developmental stage between gemination and being a young plant. The seedling typically has a height of at most 39 cm, preferably at most 35 cm, more preferably at most 30 cm, more preferably at most 25 cm, more preferably at most 20 cm, more preferably at most 15 cm, more preferably at most 10 cm, and most preferably at most about 8 cm. Preferably, a seedling is used directly after gemination.

[0032] Preferably, the seedling is obtained by providing a seed and geminating said seed. As such, the method of the invention may also start with providing a seed of a plant; and geminating said seed. Preferred methods of geminating said seed are mentioned below.

[0033] In particular, if the plant to be grown is a potato plant or a strawberry plant, it is preferred that the plant material is a seedling. Then, the method of the invention preferably starts with a step of providing a seed, preferably a true seed, and gemination said seed to obtain a seedling. As used herein, “true seed” or “real seed” refers to a fertilized mature ovule that typically has an embryo, stored food material, and / or a protective coat or coats. For example, for potatoes a true seed can be distinguished from a tuber that is traditionally used for germination or sprouting. For potatoes, it is preferred that the true seed is a hybrid seed, for example True Hybrid Potato Seed (HPTS).

[0034] The plant material may also be a cutting or a tissue culture plant, in particular when the plant is a forestiy plant. The advantage of using a cutting or a tissue culture plant is that substantial or even complete genetic homogeneity may be achieved between various plants. The skilled person is aware how to obtain cuttings and / or tissue culture plants. The cutting or tissue culture plant typically has a height of at most 39 cm, preferably at most 35 cm, more preferably at most 30 cm, more preferably at most 25 cm, more preferably at most 20 cm, more preferably at most 15 cm, more preferably at most 10 cm, and most preferably at most about 8 cm.

[0035] In the method of the invention, the plant material is exposed to light, wherein said light is substantially exclusively artificial grow light.

[0036] Artificial grow light is non-naiural light that induces the growth of plants, in particular induces photosynthesis in plants. Artificial grow light has a different composition in terms of wavelength and / or intensity than sunlight. An advantage of using artificial grow light is that more control can be achieved, in the sense that a constant spectrum and intensity can be maintained throughout the day, whereas the composition and intensity of sunlight changes during the day.

[0037] With “substantially exclusively" it is typically meant that at least 95%, preferably at least 97%, more preferably at least 98%, more preferably at least 99%, more preferably at least 99.9%, and most preferably 100%, of the light to which the plant is exposed is artificial grow light. Consequently, it is preferred that the plant material is not exposed to natural sunlight, and more preferably that the plant material is not exposed to any other light than said artificial grow light. In particular, it is preferred that the plant material is shielded from natural sunlight, and more preferably that the plant material is shielded from to any other light than said artificial grow light Preferably, the method of the invention is carried out indoors. As used herein, “indoors” typically refers to a substantially sunlight-free conditioned cultivation environment. This environment may also be configured to control the relative humidity of the air, the space temperature, the substrate temperature, and / or the carbon dioxide concentration of the air.

[0038] Below, preferred features of the artificial grow light are described. In particular, the photosynthetic flux density of various components of said artificial grow light are mentioned. Herein, the photosynthetic flux density is expressed in units of μmol / m2 / s. Therein, the area (m2) refers to the surface area at the top of the plant material, typically one or more leaves of said plant material. The skilled person will understand that to maintain a specific photosynthetic flux density or to remain within a range of photosynthetic flux densities throughout the method of the invention, the height of the one or more lighting devices that are typically used to produce the artificial grow light and / or the height of the surface on which the plant material are kept, may be adjusted, if necessary, while the plant material grows. In other words; the distance between said lighting device and the plant material may be held substantially constant by for example increasing the height at which the lighting device is kept as the plant material grows and / or lowering the surface on which the plant material are kept, if necessary. Alternatively, said distance may be fixed for a certain room, and the plant material may be moved to a different room with a different fixed distance between the lighting device and the plant material.

[0039] For all of the artificial grow light components listed herein it holds that no upper limit needs to be specified for the photosynthetic flux density, since exposing the plant material to more light is not detrimental to the growth of the plant However, preferably an as low as possible photosynthetic flux density is used, so as to reduce costs, and / or provide a more environmentally friendly method.

[0040] Preferably, the artificial grow light comprises a red component having a wavelength in a range of from 600 to 700 nm. Preferably, the red component comprises substantially all wavelengths within a range of from 600 to 700 nm, with a peak between 650 and 670 nm, preferably at 660 nm, and wherein the light intensities at 600 nm and 700 nm are less than 5%, preferably less than 2%, more preferably less than 1% of the intensity at said peak.

[0041] Preferably, the red component has a photosynthetic flux density of at least 30 μmol / m2 / s; more preferably at least 50 μmol / m2 / s; more preferably at least 75 μmol / m2 / s; more preferably at least 100 μmol / m2 / s; more preferably at least 125 μmol / m2 / s; more preferably at least 150 μmol / m2 / s; more preferably at least 175 μmol / m2 / s; more preferably at least 190 μmol / m2 / s; more preferably at least 200 μmol / m2 / s; and most preferably at least 210 μmol / m2 / s.

[0042] Preferably, the red component has a photosynthetic flux density of at most 1000 μmol / m2 / s; more preferably at most 750 μmol / m2 / s; more preferably at most 600 μmol / m2 / s; more preferably at most 500 μmol / m2 / s; more preferably at most 450 μmol / m2 / s; more preferably at most 400 μmol / m2 / s; more preferably at most 350 μmol / m2 / s; more preferably at most 300 μmol / m2 / s; more preferably at most 250 μmol / m2 / s; and most preferably at most 230 μmol / m2 / s.

[0043] Preferably, the red component has a photosynthetic flux density in a range of from 30 to 1000 μmol / m2 / s; more preferably in a range of from 50 to 750 μmol / m2 / s; more preferably in a range of from 75 to 600 μmol / m2 / s; more preferably in a range of from 100 to 500 μmol / m2 / s; more preferably in a range of from 125 to 450 μmol / m2 / s; more preferably in a range of from 150 to 400 μmol / m2 / s; more preferably in a range of from 175 to 350 μmol / m2 / s; more preferably in a range of from 190 to 300 μmol / m2 / s; more preferably in a range of from 200 to 250 μmol / m2 / s; and most preferably of from 210 to 230 μmol / m2 / s.

[0044] Most preferably, the red component has a photosynthetic flux density of about 220 μmol / m2 / s.

[0045] Preferably, the artificial grow light comprises a blue component having a wavelength in a range of from 400 to 500 nm, preferably in a range of from 420 to 495 nm. Preferably, the blue component comprises substantially all wavelengths within a range of from 420 to 495 nm, with a peak between 440 and 460 nm, preferably at 450 nm, and wherein the light intensities at 420 nm and 495 nm are less than 5%, preferably less than 2%, more preferably less than 1% of the intensity at said peak. More preferably, the blue component comprises substantially all wavelengths within a range of from 400 to 500 nm, with a peak between 440 and 460 nm, preferably at 450 nm, and wherein the light intensities at 400 nm and 500 nm are less than 5%, preferably less than 2%, more preferably less than 1% of the intensity at said peak Preferably, the blue component has a photosynthetic flux density of at least 10 μmol / m2 / s; more preferably at least 20 μmol / m2 / s; more preferably at least 25 μmol / m2 / s; more preferably at least 30 μmol / m2 / s; more preferably at least 40 μmol / m2 / s; more preferably at least 45 μmol / m2 / s; more preferably at least 50 μmol / m2 / s; more preferably at least 55 μmol / m2 / s; more preferably at least 60 μmol / m2 / s; and most preferably at least 65 μmol / m2 / s.

[0046] Preferably, the blue component has a photosynthetic flux density of at most 250 μmol / m2 / s; more preferably at most 200 μmol / m2 / s; more preferably at most 150 μmol / m2 / s; more preferably at most 125 μmol / m2 / s; more preferably at most 100 μmol / m2 / s; more preferably at most 95 μmol / m2 / s; more preferably at most 90 μmol / m2 / s; more preferably at most 85 μmol / m2 / s; more preferably at most 80 μmol / m2 / s; and most preferably at most 75 μmol / m2 / s.

[0047] Preferably, the blue component has a photosynthetic flux density in a range of from 10 to 250 μmol / m2 / s; more preferably of from 20 to 200 μmol / m2 / s; more preferably of from 25 to 150 μmol / m2 / s; more preferably of from 30 to 125 μmol / m2 / s; more preferably of from 40 to 100 μmol / m2 / s; more preferably of from 45 to 95 μmol / m2 / s; more preferably of from 50 to 90 μmol / m2 / s; more preferably of from 55 to 85 μmol / m2 / s; more preferably of from 60 to 80 μmol / m2 / s; and most preferably of from 65 to 75 μmol / m2 / s.

[0048] Most preferably, the blue component has a photosynthetic flux density of about 70 μmol / m2 / s.

[0049] Preferably, the artificial grow light comprises a far-red component having a wavelength in a range of from 680 to 800 nm, more preferably in a range of from 680 to 770 nm, more preferably in a range of from 701 to 770 nm. Preferably, the far-red component comprises substantially all wavelengths within a range of from 701 to 770 nm, with a peak in a range of from 720 to 750 nm, preferably in a range of from730 to 740 nm, and wherein the light intensities at 701 nm is less than 30%, preferably less than 25%, and more preferably less than 23% of the intensity at said peak; and the light intensity at 770 nm is less than 5%, preferably less than 4%, more preferably less than 3% of the intensity at said peak. More preferably, the far-red component comprises substantially all wavelengths within a range of from 680 to 770 nm, with apeak between 730 and 750 nm, preferably in a range of from 730 to 740 nm, and wherein the light intensities at 680 nm and 770 nm are less than 6%, preferably less than 5%, more preferably less than 4% of the intensity at said peak.

[0050] Preferably, the far-red component has a photosynthetic flux density of at least 1 μmol / m2 / s; more preferably at least 2 μmol / m2 / s; more preferably at least 5 μmol / m2 / s; more preferably at least 8 μmol / m2 / s; more preferably at least 10 μmol / m2 / s; more preferably at least 12 μmol / m2 / s; more preferably at least 15 μmol / m2 / s; more preferably at least 18 μmol / m2 / s; more preferably at least 20 μmol / m2 / s; and most preferably at least 25 μmol / m2 / s.

[0051] Preferably, the far-red component has a photosynthetic flux density of at most 100 μmol / m2 / s; more preferably at most 75 μmol / m2 / s; more preferably at most 60 μmol / m2 / s; more preferably at most 50 μmol / m2 / s; more preferably at most 47 μmol / m2 / s; more preferably at most 45 μmol / m2 / s; more preferably at most 42 μmol / m2 / s; more preferably at most 40 μmol / m2 / s; more preferably at most 37 μmol / m2 / s; and most preferably at most 35 μmol / m2 / s.

[0052] Preferably, the far-red component has a photosynthetic flux density in a range of from 1 to 100 μmol / m2 / s; more preferably of from 2 to 75 μmol / m2 / s; more preferably of from 5 to 60 μmol / m2 / s; more preferably of from 8 to 50 μmol / m2 / s; more preferably of from 10 to 47 μmol / m2 / s; more preferably of from 12 to 45 μmol / m2 / s; more preferably of from 15 to 42 μmol / m2 / s; more preferably of from 18 to 40 μmol / m2 / s; more preferably of from 20 to 37 μmol / m2 / s; and most preferably of from 25 to 35 μmol / m2 / s.

[0053] Most preferably, the far-red component has a photosynthetic flux density of about 30 μmol / m2 / s.

[0054] If the plant is a strawberry plant, it is preferred that the artificial grow light does not contain a far-red component.

[0055] Preferably, the artificial grow light comprises the red component and the blue component In some preferred embodiments, the artificial grow light essentially consists of the red component and the blue component. For example, for strawberry plants it is preferred that the artificial grow light essentially consists of the red component and the blue component.

[0056] If plants with a larger internode length and / or taller plants are desired, it is however desired that the artificial grow light comprises the far-red component. As such, in some preferred embodiments the artificial grow light comprises the red component, the blue component, and the far-red component More preferably, the artificial grow light essentially consists of the red component, the blue component, and the far-red component.

[0057] If the artificial grow light comprises said red component and said far-red component, it is preferred that the ratio of the photosynthetic flux density of said red component over the photosynthetic flux density of the far-red component is in a range of from 1:1 to 60:1. More preferably, said ratio is of from 2:1 to 40:1; more preferably of from 3:1 to 30:1; more preferably of from 4: 1 to 20:1 ; more preferably of from 5: 1 to 15:1 ; more preferably of from 5.5:1 to 12:1; more preferably of from 6:1 to 9:1; even more preferably of from 7:1 to 8:1. Most preferably, said ratio is about 7.3:1.

[0058] For all of the artificial grow light components listed herein it holds that while lighting devices can be used that produce a single wavelength within the defined range, the best results are obtained when using one or more lighting devices that produce a range of wavelengths. Typically, the peak intensity of such light sources is at or around a specific wavelength, and the light intensity gradually decreases towards the lower and upper wavelengths of the range provided, typically forming a bell curve or a skewed distribution around said specific wavelength. At the lower and upper wavelengths of the range provided, the light intensity is typically less than 5%, preferably less than 2%, more preferably less than 1% of the intensity at said specific wavelength.

[0059] For example, for the red light component a light source can be used producing light with wavelengths in a range of from 600-700 nm with a peak between 650 and 670 nm, preferably at 660 nm. Likewise, for the blue light component a lighting device can be used producing light with wavelengths in a range of from 420-495 nm with a peak between 440 and 460 nm, preferably at 450 nm. Similarly, for light having a far-red component a light source can be used producing light with wavelengths in a range of from 701-770 nm, preferably in a range of from 680-770 nm, with a peak in a range of from 720 to 750 nm, preferably in a range of from 730 to 740 nm.

[0060] Preferably, in the methods of the invention the plant material is exposed to the artificial grow light for at least 8 hours per day; preferably for at least 9 hours a day, more preferably at least 10 hours per day, more preferably at least 11 hours a day, and most preferably at least 12 hours a day.

[0061] Preferably, in the methods of the invention the plant material is exposed to the artificial grow light for at most 24 hours per day; preferably for at most 23 hours a day, more preferably at most 22 hours per day, more preferably at most 21 hours a day, more preferably at most 20 hours a day.

[0062] Preferably, in the methods of the invention the plant material is exposed to the artificial grow light for a duration in a range of from 8 to 24 hours a day, more preferably of from 9 to 22 hours a day, and most preferably of from 12 to 20 hours a day. If the plant is a forest plant, in particular an Acacia plant, the plant material is preferably exposed to the artificial grow light for a chiration in a range of from 12 to 18 hours a day, more preferably of from 13 to 15 hours a day, and most preferably for about 14 hours a day.

[0063] If the plant is a mangrove plant, in particular Rhizophora, the plant material is preferably exposed to the artificial grow light for a duration in a range of from 10 to 16 hours a day, more preferably of from 11 to 13 hours a day, and most preferably for about 12 hours a day.

[0064] If the plant is a potato plant, the plant material is preferably exposed to the artificial grow light for a duration in a range of from 12 to 22 hours a day, more preferably of from 16 to 20 hours a day, and most preferably for about 16 or about 20 hours a day.

[0065] If the plant is a strawberry plant, the plant material is preferably exposed to the artificial grow light for a duration in a range of from 14 to 18 hours a day, more preferably of from 15 to 17 hours a day, and most preferably for about 16 hours a day.

[0066] It will be understood that the exposure of the plant material to the artificial grow light may be continuous or discontinuous throughout the day. However, it is preferred that the plant material is continuously exposed to the artificial grow light during the time periods mentioned herein.

[0067] When the plant material is not exposed to artificial grow light during the methods of the disclosure, it is preferred that the plant material is not exposed to any visible light, more preferably that said plant material is kept in the dark.

[0068] In principle, the growth of and / or flowering in the plant may be accelerated further by other means than exposing said plant to artificial growth light, such as by pruning at a folk from which an orthotropic shoot and at least one plagiotropic branch have developed by removing at least the orthotropic shoot and maintaining the at least one plagiotropic branch; contacting the plant material with growth hormones (in particular synthetic and / or artificial growth hormones); and / or genetically enhancing the plant material. However, one advantage of the methods of the disclosure is that such means are not necessary, thus making the process easier, more economical, and / or more readily available. Thus, the methods of the disclosure preferably do not comprise pruning the plant material at a fork from which an orthotropic shoot and at least one plagiotropic branch have developed by removing at least the orthotropic shoot and maintaining the at least plagiotropic branch. Likewise, the methods of the disclosure preferably do not comprise the step of bringing the plant material into contact with growth hormones, in particular artificial and / or synthetic growth hormones. Moreover, the methods of the disclosure preferably do not comprise genetically enhancing the plant material.

[0069] It will be understood, however, that the methods of the invention optionally comprise pruning plant material having at least one plagiotropic branch by removing said at least one plagiotropic branch.

[0070] Duration of method

[0071] In principle, any plant can benefit from the method of the invention for any length of time, whether it be short or for the entire lifetime of said plant On the one hand, the longer the method of the invention is applied, the stronger and healthier a plant may become.

[0072] Therefore, it is preferred that the method of the invention is carried out for at least one day, more preferably at least 2 days; more preferably at least 5 days; more preferably at least 10 days; more preferably at least 15 days; and most preferably at least 20 days.

[0073] On the other hand, however, it may be more cost-effective and more friendly to the environment to apply the method of the invention not longer than necessary, and to transfer the young plant obtained with the method of the invention to the field as soon as possible. Therefore, it is preferred that the method of the invention is carried out for at most 300 days, more preferably at most 270 days; more preferably at most 240 days; more preferably at most 220 days; more preferably at most 200 days; more preferably at most 180 days; more preferably at most 170 days; more preferably at most 160 days; more preferably at most 150 days; more preferably at most 140 days; more preferably at most 130 days; more preferably at most 110 days; and most preferably at most 120 days.

[0074] If the plant is a forest plant, in particular an Acacia plant, the method of the invention is preferably carried out for of from 50 to 160 days.

[0075] If the plant is a mangrove plant, in particular Rhizophora, the method of the invention is preferably carried out for of from 60 to 140 days, preferably of from 70 to 125 days, and most preferably for of from 75 to 120 days.

[0076] If the plant is a potato plant, the method of the invention is preferably carried out for of from 16 to 40 days, preferably of from 18 to 37 days, and most preferably for of from 20 to 35 days.

[0077] If the plant is a strawberry plant, preferably a strawberry plant of the variety Dellizimo, the method of the invention is preferably carried out for of from 34 to 46 days, preferably of from 36 to 44 days, and most preferably for of from 38 to 42 days. In other preferred embodiments, if the plant is a strawberry plant, preferably a strawberry plant of the variety Limore One, the method of the invention is carried out for of from 63 to 83 days, more preferably for of from 65 to 80 days, and most preferably for of from 71 to 75 days.

[0078] These periods relate to when the starting material is a seed of a plant, and a seedling is obtained therefrom by germinating said seed. As such, said periods include time for germination. When starting with a seedling directly, or when starting with a cutting or a tissue culture plant, the same periods apply minus said time for germination.

[0079] Typically, (hiring the method of the disclosure the root of the plant material will be kept in a substrate. The substrate may be soil or an aqueous solution, but it is preferred that the substrate is soil.

[0080] However, it will be understood that during the method of the disclosure the plant material can be repotted if necessary, and thus the root may temporarily not be kept in a substrate. Likewise, horticultural substrates and horticultural nutrient solutions suitable for the growth of plants are known to the skilled person.

[0081] Other parameters

[0082] In principle, the methods of the disclosure work well, and accelerate the growth of plants. However, even better results are obtained if one or more other parameters are within certain ranges as well. These parameters are selected from the group consisting of space temperature, substrate temperature, relative humidity, CO2concentration, electric conductivity of the substrate, and the pH of the substrate. The preferred values of these parameters are detailed below.

[0083] In particular, improved results are obtained if the temperature and relative humidity are within the ranges as disclosed herein. Without wishing to be bound by theory, the inventors believe that the combination of temperature and relative humidity as disclosed herein advantageously allows to control the waler evaporation by the plant, thereby stimulating plant growth, in particular to increase the diy weight of both the shoot and the root while obtaining a relatively low ratio of the dry weight of the root over the dry weight of the shoot. Still without wishing to be bound by theory, the inventors believe that this relatively low ratio, while still obtaining relatively high values for the dry weight of the root, contributes to the improved quality of the plant. A further parameter that the inventors believe may positively influence the water evaporation of the plant is the CO2concentration as disclosed herein. URIS, to obtain improved plant quality, it is preferred that the methods of the invention combine the temperature (viz. space and substrate temperature) and relative humidity as disclosed herein, and more preferably further combine the temperature and relative humidity with the CO2concentration as disclosed herein.

[0084] In the methods of the disclosure the best results are obtained if for all of these parameters (viz. space temperature, substrate temperature, relative humidity, CO2concentration, electric conductivity of the substrate, and the pH of the substrate) the preferred values are used.

[0085] The temperature of the plant material can be measured and adjusted using standard techniques known to the skilled person.

[0086] Preferably, the plant material is kept at a temperature of at least 15°C; more preferably at least 16°C; more preferably at least 18°C; more preferably at least 19°C; more preferably at least 20 °C; more preferably at least 21°C; and most preferably at least 22°C,

[0087] Preferably, the plant material is kept at a temperature of at most 40°C; more preferably at most 37°C; more preferably at most 36°C; more preferably at most 35°C; more preferably at most 34°C; more preferably at most 33°C; more preferably at most 32°C; more preferably at most 31 °C; more preferably at most 30°C; more preferably at most 29 °C; and most preferably of at most 28°C.

[0088] Preferably, the plant material is kept at a temperature in a range of from 15 to 40 °C; more preferably in a range of from 16 to 37 °C; more preferably in a range of from 18 to 36 °C; more preferably in a range of from 19 to 35 °C; more preferably in a range of from 20 to 34 °C; more preferably in a range of from 21 to 33 °C; and most preferably in a range of from 22 to 32 °C.

[0089] More preferably, if the plant is a forest plant, in particular Acacia, or a mangrove plant, the plant material is kept at a temperature in a range of from 23 to 31 °C; more preferably in a range of from 24 to 30 °C; more preferably in a range of from 25 to 29 °C; and even more preferably in a range of from 26 to 28 °C. Most preferably, if the plant is a forest plant, in particular Acacia, the plant material is kept at a temperature of about 27 °C. Most preferably, if the plant is a mangrove plant, the plant material is kept at a temperature of about 28 °C.

[0090] More preferably, if the plant is a potato plant, the plant material is kept at a temperature in a range of from 16 to 29 °C; more preferably in a range of from 17 to 28 °C; more preferably of from 18 to 27 and most preferably of from 20 to 25 °C.

[0091] More preferably, if the plant is a strawberry plant, the plant material is kept at a temperature in a range of from 18 to 26 °C; more preferably in a range of from 20 to 24 °C; and most preferably at a temperature of about 22 °C.

[0092] In the methods of the disclosure, it is also possible to separately control the space temperature (viz. the air temperature) and the substrate temperature. Thus, the temperature of the root of the plant material can be controlled by the substrate temperature, and the temperature of the shoot of the plant material can be controlled by the space temperature. Although some variation between the space temperature and the substrate temperature is allowed, it is preferred that the space temperature and the substrate temperature are substantially the same.

[0093] Preferably, the root of the plant is kept at a temperature of at least 15°C; more preferably at least 16°C; more preferably at least 18°C; more preferably at least 19°C; more preferably at least 20°C; more preferably at least 21 °C; and most preferably at least 22°C.

[0094] Preferably, the root of the plant is kept at a temperature of at most 40°C; more preferably at most 37°C; more preferably at most 36°C; more preferably at most 35°C; more preferably at most 34°C; more preferably at most 33°C; more preferably at most 32°C; more preferably at most 31°C; more preferably at most 30°C; more preferably at most 29°C; and most preferably of at most 28°C.

[0095] Preferably, the root of the plant is kept at a temperature in a range of from 15 to 40 °C; more preferably in a range of from 16 to 37 °C; more preferably in a range of from 18 to 36 °C; more preferably in a range of from 19 to 35 °C; more preferably in a range of from 20 to 34 °C; more preferably in a range of from 21 to 33 °C; and most preferably in a range of from 22 to 32 °C.

[0096] More preferably, if the plant is a forest plant, in particular Acacia, or a mangrove plant, the root of the plant is kept at a temperature in a range of from 23 to 31 °C; more preferably in a range of from 24 to 30 °C; more preferably in a range of from 25 to 29 °C; and even more preferably in a range of from 26 to 28 °C. Most preferably, if the plant is a forest plant, in particular Acacia, the root of the plant is kept at a temperature of about 27 °C. Most preferably, if the plant is a mangrove plant, the root of the plant is kept at a temperature of about 28 °C.

[0097] More preferably, if the plant is a potato plant, the root of the plant is kept at a temperature in a range of from 16 to 29 °C; more preferably in a range of from 17 to 28 °C; more preferably of from 18 to 27 and most preferably of from 20 to 25 °C. More preferably, if the plant is a strawberry plant, the root of the plant is kept at a temperature in a range of from 18 to 26 °C; more preferably in a range of from 20 to 24 °C; and most preferably at a temperature of about 22 °C.

[0098] Preferably, the shoot of the plant is kept at a temperature of at least 15°C; more preferably at least 16°C; more preferably at least 18°C; more preferably at least 19°C; more preferably at least 20°C; more preferably at least 21°C; and most preferably at least 22°C.

[0099] Preferably, the shoot of the plant is kept at a temperature of at most 40°C; more preferably at most 37°C; more preferably at most 36°C; more preferably at most 35°C; more preferably at most 34°C; more preferably at most 33°C; more preferably at most 32°C; more preferably at most 31 °C; more preferably at most 30°C; more preferably at most 29°C; and most preferably of at most 28°C.

[0100] Preferably, the shoot of the plant is kept at a temperature in a range of from 15 to 40 °C; more preferably in a range of from 16 to 37 °C; more preferably in a range of from 18 to 36 °C; more preferably in a range of from 19 to 35 °C; more preferably in a range of from 20 to 34 °C; more preferably in a range of from 21 to 33 °C; and most preferably in a range of from 22 to 32 °C.

[0101] More preferably, if the plant is a forest plant, in particular Acacia, or a mangrove plant, the shoot of the plant is kept at a temperature in a range of from 23 to 31 °C; more preferably in a range of from 24 to 30 °C; more preferably in a range of from 25 to 29 °C; and even more preferably in a range of from 26 to 28 °C. Most preferably, if the plant is a forest plant, in particular Acacia, the shoot of the plant is kept at a temperature of about 27 °C. Most preferably, if the plant is a mangrove plant, the shoot of the plant is kept at a temperature of about 28 °C.

[0102] More preferably, if the plant is a potato plant, the shoot of the plant is kept at a temperature in a range of from 16 to 29 °C; more preferably in a range of from 17 to 28 °C; more preferably of from 18 to 27 and most preferably of from 20 to 25 °C.

[0103] More preferably, if the plant is a strawberry plant, the shoot of the plant is kept at a temperature in a range of from 18 to 26 °C; more preferably in a range of from 20 to 24 °C; and most preferably at a temperature of about 22 °C.

[0104] The relative humidity of air can be measured and adjusted using standard techniques known to the skilled person. As used herein, “relative humidity** indicates a present state of absolute humidity relative to a maximum humidity given the same temperature. Therein, “absolute humidity” is the actual water content of the air, and is typically expressed as either mass of water vapor per volume of moist air (in grams per cubic meter) or as mass of water vapor per mass of dry air (usually in grams per kilogram)

[0105] Preferably, the plant material is subjected to a relative humidity of at least 45%, and more preferably at least 60%. Preferably, the plant material is subjected to a relative humidity of at most 100%, and more preferably of at most 95%. Preferably, the plant material is subjected to a relative humidity in a range of from 45 to 100%.

[0106] If the plant is a forest plant, in particular an Acacia plant, the plant material is preferably subjected to a relative humidity in a range of from 65 to 90%, preferably of from 70 to 85%, and most preferably of about 80%.

[0107] If the plant is a mangrove plant, in particular Rhizophora, the plant material is preferably subjected to a relative humidity in a range of from 60 to 85%, preferably of from 65 to 80%, and most preferably of about 70%.

[0108] If the plant is a potato plant, the plant material is preferably subjected to a relative humidity in a range of from 45 to 75%, preferably of from 47 to 70%, and most preferably of from 52 to 65%.

[0109] If the plant is a strawberry plant, the plant material is preferably subjected to a relative humidity in a range of from 50 to 100%, preferably of from 50 to 90%, more preferably of from 55 to 85%, and most preferably of from 60 to 75%.

[0110] The CO2concentration in air can be measured and adjusted using standard techniques known to the skilled person.

[0111] Preferably, the plant material is subjected to air having a CO2concentration of at least 250 ppm; more preferably at least 400 ppm; more preferably at least 500 ppm; more preferably at least 600 ppm; more preferably at least 700 ppm; more preferably at least 800 ppm; more preferably at least 900 ppm; more preferably at least 1000 ppm; more preferably at least 1100 ppm; more preferably at least 1200 ppm; more preferably at least 1300 ppm; and most preferably at least 1400 ppm.

[0112] Preferably, the plant material is subjected to air having a CO2concentration of at most 2750 ppm; more preferably at most 2600 ppm; more preferably at most ppm; more preferably at most 2500 ppm; more preferably at most 2400 ppm; more preferably at most 2300 ppm; more preferably at most 2200 ppm; more preferably at most 2100 ppm; more preferably at most 2000 ppm; more preferably at most 1900 ppm; more preferably at most 1800 ppm; more preferably at most 1700 ppm; and most preferably at most 1600 ppm. Preferably, the plant material is subjected to air having a CO2concentration in a range of from 250 to 2750 ppm; more preferably in a range of from 400 to 2600 ppm; more preferably in a range of from 500 to 2500 ppm; more preferably in a range of from 600 to 2400 ppm; more preferably in a range of from 700 to 2300 ppm; more preferably in a range of from 800 to 2200 ppm; and more preferably in a range of from 900 to 2100 ppm.

[0113] If the plant is a forest plant, in particular Acacia, the plant material is preferably subjected to air having a CO2concentration in a range of from 500 to 2000 ppm; more preferably in a range of from 1100 to 1900 ppm; more preferably in a range of from 1200 to 1800 ppm; more preferably in a range of from 1300 to 1700 ppm; more preferably in a range of from 1400 to 1600 ppm; and most preferably about 1500 ppm.

[0114] If the plant is a mangrove plant, a potato plant, or a strawberry plant, the plant material is preferably subjected to air having a CO2concentration in a range of from 1000 to 2750 ppm; more preferably in a range of from 1500 to 2500 ppm; more preferably in a range of from 1750 to 2250 ppm; and most preferably about 2000 ppm.

[0115] The dectrical conductivity of the substrate can be measured and adjusted using standard techniques known to the drilled person.

[0116] Preferably, the electrical conductivity of the substrate in which the plant material of the plants grows is maintained at a value of at least 1.0 mS / cm2, more preferably at least 1.2 mS / cm3, more preferably at least 1.3 mS / cm2, more preferably at least 1.4 mS / cm2, and more preferably at least 1.5 mS / cm2.

[0117] Preferably, the electrical conductivity of the substrate in which the plant material of the plants grows is maintained at a value of at most 3.0 mS / cm2, more preferably at most 2.9 mS / cm2, more preferably at most 2.8 mS / cm2, more preferably at most 2.7 mS / cm2, more preferably at most 2.6 mS / cm2, more preferably at most 2.5 mS / cm2, more preferably at most 2.4 mS / cm2, more preferably at most 2.3 mS / cm2, more preferably at most 2.2 mS / cm2, and most preferably at most 2.1 mS / cm2.

[0118] Preferably, the electrical conductivity of the substrate in which the plant material of the plants grows is maintained from 1.1 to 2.8 mS / cm2, more preferably of from 1.2 to 2.4 mS / cm2, more preferably of from 1.3 to 2.3 mS / cm2, more preferably of from 1 ,4 to 2.2 mS / cm2, and most preferably in a range of from 1.5 to 2.1 mS / cm2.

[0119] If the plant is a forest plant, in particular Acacia, a mangrove plant, or a potato plant, the dectrical conductivity of the substrate in which the plant material of the plants grows is preferably maintained in a range of from 12 to 2.8 mS / cm2, more preferably of from 1.8 to 2.2 mS / cm2; more preferably of from 1.9 to 2.1 mS / cm2; and most preferably ata value of about 2.0 mS / cm2.

[0120] If the plant is a strawberry plant, the electrical conductivity of the substrate in which the plant material of the plants grows is preferably maintained in a range of from 1.2 to 2.0 mS / cm2, more preferably of from 1.3 to 1.9 mS / cm2; more preferably of from 1.5 to 1.7 mS / cm2; and most preferably at a value of about 1.6 mS / cm2.

[0121] The pH of the soil can be measured and adjusted using standard techniques known to the skilled person.

[0122] Preferably, the pH of the substrate in which the plant material of the plants grows is maintained at a value of at least 4.5, more preferably at least 4.8, more preferably at least 5.0, more preferably at least 5.1, more preferably at least 5.2, and more preferably at least 5.3.

[0123] Preferably, the pH of the substrate in which the plant material of the plants grows is maintained at a value of at most 7.0, more preferably at most 6.8, more preferably at most 6.7, even more preferably at most 6.6, and more preferably at most 6.5.

[0124] Preferably, the pH of the substrate in which the plant material of the plants grows is maintained in a range of from 4.5 to 7.0, more preferably of from 4.7 to 6.9, more preferably of from 4.9 to 6.7, more preferably of from 5.1 to 6.5.

[0125] If the plant is a forest plant, in particular an Acacia plant, the pH of the substrate in which the plant material of the plants grows is preferably maintained in a range of from 5.2 to 6.3, more preferably of from 5.4 to 6.2, more preferably of from 5.6 to 6.1, more preferably of from 5.8 to 6.0, and most preferably about 5.9,

[0126] If the plant is a mangrove plant, the pH of the substrate in which the plant material of the plants grows is preferably maintained in a range of from 5.6 to 7.4, more preferably of from 5.8 to 7.2, more preferably of from 6.1 to 6.9, more preferably of from 6.4 to 6.6, and most preferably about 6.5.

[0127] If the plant is a potato plant, the pH of the substrate in which the plant material of the plants grows is preferably maintained in a range of from 5.2 to 6.4, more preferably of from 5.3 to 6.2, more preferably of from 5.5 to 6.0, more preferably of from 5.7 to 5.9, and most preferably about 5.8.

[0128] If the plant is a strawberry plant, preferably of the variety Dellizimo, the pH of the substrate in which the plant material of the plants grows is preferably maintained in a range of from 4.8 to 5.9, more preferably of from 5.0 to 5.7, more preferably of from 5.1 to 5.5, more preferably of from 5.2 to 5.4, and most preferably about 5.3. In other embodiments, if the plant is a strawberry plant, preferably of the variety Limore One, the pH of the substrate in which the plant material of the plants grows is preferably maintained in a range of from 4.8 to 6.5, more preferably of from 5.0 to 6.5, more preferably of from 5.3 to 6.3, more preferably of from 5.6 to 6.0, and most preferably about 5.8,

[0129] When multiple plants are grown simultaneously using a method of the invention, it is preferred that the leaf area index is at most 4, more preferably at most 3.7. In this way, the plant material can be optimally exposed to the artificial grow light.

[0130] First days of a cutting or tissue culture plant

[0131] If in a method of the disclosure the starting material is a cutting or a tissue culture plant, then in the first 8 days, and most preferably the first 7 days it is preferred that the below values are used for the temperature, the relative humidity, and / or the artificial grow light. After said first days, it is preferred that the conditions as listed above are applied. If in a method of the disclosure the starting material is a seedling, it is preferred that the conditions as listed above are applied throughout conducting said method.

[0132] If in a method of the disclosure the starting material is a cutting or a tissue culture plant, then in the first about 1 day, the artificial grow light preferably comprises a red component as defined herein. Then, the red component preferably has a photosynthetic flux density of at least 30 μmol / m2 / s; more preferably at least 60 μmol / m2 / s; more preferably at least 80 μmol / m2 / s; and most preferably at least 100 μmol / m2 / s. Then, the red component preferably has a photosynthetic flux density of at most 190 μmol / m2 / s; more preferably at most 160 μmol / m2 / s; more preferably at most 130 μmol / m2 / s; and most preferably at most 120 μmol / m2 / s. Then, preferably the red component has a photosynthetic flux density in a range of from 30 to 190 μmol / m2 / s; more preferably of from 60 to 160 μmol / m2 / s; more preferably of from 80 to 140 μmol / m2 / s; more preferably of from 90 to 130 μmol / m2 / s; and most preferably of from 100 to 120 μmol / m2 / s. Then, most preferably the red component has a photosynthetic flux density of about 110 μmol / m2 / s.

[0133] If in a method of the disclosure the starting material is a cutting or a tissue culture plant, then on days 2 to 3 of carrying out said method, the artificial grow light preferably comprises a red component as defined herein. Then, the red component preferably has a photosynthetic flux density of at least 100 μmol / m2 / s; more preferably at least 115 μmol / m2 / s; and most preferably at least 125 μmol / m2 / s. Then, the red component preferably has a photosynthetic flux density of at most 185 μmol / m2 / s; more preferably at most 170 μmol / m2 / s; and most preferably at most 155 μmol / m2 / s. Then, preferably the red component has a photosynthetic flux density in a range of from 100 to 185 μmol / m2 / s; more preferably of from 115 to 170 μmol / m2 / s; and most preferably of from 125 to 155 μmol / m2 / s. Then, most preferably the red component has a photosynthetic flux density of about 140 μmol / m2 / s.

[0134] If in a method of the disclosure the starting material is a cutting or a tissue culture plant, then on days 4 to 7 of carrying out said method, the artificial grow light preferably comprises a red component as defined herein. Then, the red component preferably has a photosynthetic flux density of at least 130 μmol / m2 / s; more preferably at least 150 μmol / m2 / s; and most preferably at least 170 μmol / m2 / s. Then, the red component preferably has a photosynthetic flux density of at most 250 μmol / m2 / s; more preferably at most 230 μmol / m2 / s; and most preferably at most 210 μmol / m2 / s. Then, preferably the red component has a photosynthetic flux density in a range of from 130 to 250 μmol / m2 / s; more preferably of from 150 to 230 μmol / m2 / s; and most preferably of from 170 to 210 μmol / m2 / s. Then, most preferably the red component has a photosynthetic flux density of about 190 μmol / m2 / s.

[0135] If in a method of the disclosure the starting material is a cutting or a tissue culture plant, then in the first about 1 day, the artificial grow light preferably comprises a blue component as defined herein. Then, the blue component preferably has a photosynthetic flux density of at least 20 μmol / m2 / s; more preferably at least 25 μmol / m2 / s; and most preferably at least 30 μmol / m2 / s. Then, the blue component preferably has a photosynthetic flux density of at most 50 μmol / m2 / s; more preferably at most 45 μmol / m2 / s; and most preferably at most 40 μmol / m2 / s. Then, preferably the blue component has a photosynthetic flux density in a range of from 20 to 50 μmol / m2 / s; more preferably of from 25 to 45 μmol / m2 / s; and most preferably of from 30 to 40 μmol / m2 / s. Then, most preferably the blue component has a photosynthetic flux density of about 35 μmol / m2 / s.

[0136] If in a method of the disclosure the starting material is a cutting or a tissue culture plant, then on days 2 to 3 of carrying out said method, the artificial grow light preferably comprises a blue component as defined herein. Then, the blue component preferably has a photosynthetic flux density of at least 30 μmol / m2 / s; more preferably at least 35 μmol / m2 / s; and most preferably at least 40 μmol / m2 / s. Then, the blue component preferably has a photosynthetic flux density of at most 60 μmol / m2 / s; more preferably at most 55 μmol / m2 / s; and most preferably at most 50 μmol / m2 / s. Then, preferably the blue component has a photosynthetic flux density in a range of from 30 to 60 μmol / m2 / s; more preferably of from 35 to 55 μmol / m2 / s; and most preferably of from 40 to 50 μmol / m2 / s. Then, most preferably the blue component has a photosynthetic flux density of about 45 μmol / m2 / s.

[0137] If in a method of the disclosure the starting material is a cutting or a tissue culture plant, then on days 4 to 7 of carrying out said method, the artificial grow light preferably comprises a blue component as defined herein. Then, the blue component preferably has a photosynthetic flux density of at least 40 μmol / m2 / s; more preferably at least 50 μmol / m2 / s; and most preferably at least 60 μmol / m2 / s. Then, the blue component preferably has a photosynthetic flux density of at most 90 μmol / m2 / s; more preferably at most 80 μmol / m2 / s; and most preferably at most 70 μmol / m2 / s. Then, preferably the blue component has a photosynthetic flux density in a range of from 40 to 90 μmol / m2 / s; more preferably of from 50 to 80 μmol / m2 / s; and most preferably of from 60 to 70 μmol / m2 / s. Then, most preferably the blue component has a photosynthetic flux density of about 65 μmol / m2 / s.

[0138] If in a method of the disclosure the starting material is a cutting or a tissue culture plant, then during the first about 3 days, the artificial grow light preferably comprises a far-red component as defined herein. Then, the far-red component preferably has a photosynthetic flux density of at least 1 μmol / m2 / s; more preferably at least 3 μmol / m2 / s; more preferably at least 5 μmol / m2 / s; more preferably at least 7 μmol / m2 / s; more preferably at least 10 μmol / m2 / s; and most preferably at least 12 μmol / m2 / s. Then, the far-red component preferably has a photosynthetic flux density of at most 30 μmol / m2 / s; more preferably at most 25 μmol / m2 / s; more preferably at most 22 μmol / m2 / s; more preferably at most 20 μmol / m2 / s; more preferably at most 19 μmol / m2 / s; and most preferably at most 17 μmol / m2 / s. Then, preferably the far-red component has a photosynthetic flux density in a range of from 1 to 30 μmol / m2 / s; more preferably of from 3 to 25 μmol / m2 / s; more preferably of from 5 to 22 μmol / m2 / s; more preferably of from 7 to 20 pmol / m2 / s; more preferably of from 10 to 19 μmol / m2 / s; and most preferably of from 12 to 17 pmol / m2 / s. Then, most preferably the far-red component has a photosynthetic flux density of about 15 μmol / m2 / s.

[0139] If in a method of the disclosure the starting material is a cutting or a tissue culture plant, then on days 4 to 7 of carrying out said method, the artificial grow light preferably comprises a far-red component as defined herein. Then, the far-red component preferably has a photosynthetic flux density of at least 15 μmol / m2 / s; more preferably at least 20 μmol / m2 / s; and most preferably at least 22 μmol / m2 / s. Then, the far-red component preferably has a photosynthetic flux density of at most 35 μmol / m2 / s; more preferably at most 30 μmol / m2 / s; and most preferably at most 28 μmol / m2 / s. Then, preferably the far-red component has a photosynthetic flux density in a range of from 15 to 35 μmol / m2 / s; more preferably of from 20 to 30 μmol / m2 / s; and most preferably of from 22 to 28 μmol / m2 / s. Then, most preferably the far-red component has a photosynthetic flux density of about 25 μmol / m2 / s.

[0140] If in a method of the disclosure the starting material is a cutting or a tissue culture plant, then in the first about 3 days, the relative humidity of the air is preferably at least 75%, more preferably at least 80%, more preferably at least 85%, and most preferably at least 88%. Then, the relative humidity of the air is preferably at most 99%, more preferably at most 97%, more preferably at most 95%, and most preferably at most 92%. Then, the relative humidity of the air is preferably of in a range from 75 to 99%, more preferably of from 80 to 97%, more preferably of from 85 to 95%, and most preferably of from 88 to 92%. Then, most preferably the relative humidity of the air is about 90%.

[0141] If in a method of the disclosure the starting material is a cutting or a tissue culture plant, then on days 4 to 7 of carrying out said method, the relative humidity of the air is preferably at least 75%, more preferably at least 78%, more preferably at least 81% and most preferably at least 83%. Then, the relative humidity of the air is preferably at most 95%, more preferably at most 92% more preferably at most 89%, and most preferably at most 87%, Then, the relative humidity of the air is preferably of in a range from 75 to 95%, more preferably of from 78 to 92%, more preferably of from 81 to 89%, and most preferably of from 83 to 87%. Then, most preferably the relative humidity of the air is about 85%.

[0142] If in a method of the disclosure the starting material is a cutting or a tissue culture plant, then during the first about 1 day of carrying out said method, it is preferred that the cutting or the tissue culture plant is kept at a temperature of at least 17°C; more preferably at least 18°C; and most preferably at least 19°C. Then, preferably the cutting or the tissue culture plant is kept at a temperature of at most 23°C; more preferably at most 22°C; and most preferably at most 21 °C. Then, preferably the cutting or the tissue culture plant is kept at a temperature in a range of from 17 to 23°C; more preferably of from 18 to 22°C; and most preferably of from 19 to 21°C. Then, most preferably the cutting or the tissue culture plant is kept at a temperature of about 20°C. If in a method of the disclosure the starting material is a cutting or a tissue culture plant, then on days 2 to 3 of carrying out said method, it is preferred that the cutting or the tissue culture plant is kept at a temperature of at least 19°C; more preferably at least 20°C; and most preferably at least 21°C. Then, preferably the cutting or the tissue culture plant is kept at a temperature of at most 25°C; more preferably at most 24°C; and most preferably at most 23°C. Then, preferably the cutting or the tissue culture plant is kept at a temperature in a range of from 19 to 25°C; more preferably of from 20 to 24°C; and most preferably of from 21 to 23°C. Then, most preferably the cutting or the tissue culture plant is kept at a temperature of about 22°C.

[0143] If in a method of the disclosure the starting material is a cutting or a tissue culture plant, then on days 4 to 7 of carrying out said method, it is preferred that the cutting or the tissue culture plant is kept at a temperature of at least 22°C; more preferably at least 23°C; and most preferably at least 24°C. Then, preferably the cutting or the tissue culture plant is kept at a temperature of at most 28°C; more preferably at most 27°C; and most preferably at most 26°C. Then, preferably the cutting or the tissue culture plant is kept at a temperature in a range of from 22 to 28°C; more preferably of from 23 to 27°C; and most preferably of from 24 to 26°C. Then, most preferably the cutting or the tissue culture plant is kept at a temperature of about 25°C.

[0144] If in a method of the disclosure the starting material is a cutting or a tissue culture plant, then for the first about 7 days of carrying out said method, it is preferred that the substrate temperature and the space temperature are substantially the same.

[0145] Methods for manerove plants

[0146] Several preferred features for methods of the invention for growing mangrove plants are already indicated above. Furthermore, when growing mangrove plants using methods of the invention, it is also preferred that the leaf area index about 75 days after sowing is in a range of from 0.6 to 1.5, preferably about 1.1. Preferably, the leaf area index about 120 days after sowing is in a range of from 1.2 to 2.1, preferably about 1.8.

[0147] Methods for potato plants

[0148] Several preferred features for methods of the invention for growing potato plants are already indicated above. Furthermore, when growing potato plants using methods of the invention, the following features are also preferred.

[0149] Preferably, the artificial grow light comprises a red component and a blue component. Preferably, from about day 6 until about day 20 after sowing the artificial grow light essentially consists of a red component and a blue component. Preferably, from about day 21 onwards the artificial grow light comprises a red component, a blue component, and a far-red component; and more preferably essentially consists of a red component, a blue component, and a far-red component

[0150] Preferably, when growing a potato plant using a method of the invention the red component has a photosynthetic flux density of at least 125 μmol / m2 / s; more preferably at least 150 μmol / miVs; and most preferably at least 175 μmol / m2 / s. Preferably, when growing a potato plant using a method of the invention the red component has a photosynthetic flux density of at most 300 μmol / m2 / s; more preferably at most 250 μmol / m2 / s; and most preferably at most 225 μmol / m2 / s. Preferably, when growing a potato plant using a method of the invention the red component has a photosynthetic flux density in a range of from 125 to 300 μmol / m2 / s; more preferably in a range of from 150 to 250 μmol / m2 / s; and most preferably of from 175 to 225 μmol / m2 / s. Most preferably, when growing a potato plant using a method of the invention the red component has a photosynthetic flux density of about 200 μmol / m2 / s.

[0151] Preferably, from about day 6 until about day 20 after sowing the blue component has a photosynthetic flux density of at least 20 μmol / m2 / s; more preferably at least 30 μmol / m2 / s; and most preferably at least 40 μmol / m2 / s. Preferably, from about day 6 until about day 80 after sowing the blue component has a photosynthetic flux density of at most 70 μmol / m2 / s; more preferably at most 60 μmol / m2 / s; and most preferably at most 42 μmol / m2 / s. Preferably, from about day 6 until about day 20 after sawing the blue component has a photosynthetic flux density in a range of from 20 to 80 μmol / m2 / s; more preferably in a range of from 30 to 70 μmol / m2 / s; and most preferably of from 40 to 60 μmol / m2 / s. Most preferably, from about day 6 until about day 20 after sowing the blue component has a photosynthetic flux density of about 50 μmol / m2 / s.

[0152] Preferably, from about day 21 onwards after sowing the blue component has a photosynthetic flux density of at least 85 μmol / m2 / s; more preferably at least 80 μmol / m2 / s; and most preferably at least 85 μmol / m2 / s. Preferably, from about day 21 onwards after sowing the blue component has a photosynthetic flux density of at most 110 μmol / m2 / s; more preferably at most 100 μmol / m2 / s; and most preferably at most 95 μmol / m2 / s. Preferably, from about day 21 onwards after sowing the blue component has a photosynthetic flux density in a range of from 70 to 110 μmol / m2 / s; more preferably in a range of from 80 to 100 μmol / m2 / s; and most preferably of from 85 to 95 μmol / m2 / s. Most preferably, from about day 21 onwards after sowing the blue component has a photosynthetic flux density of about 90 μmol / m2 / s.

[0153] Preferably, from about day 21 onwards after sowing the far-red component has a photosynthetic flux density of at least 15 μmol / m2 / s; more preferably at least 20 μmol / m2 / s; and most preferably at least 25 μmol / m2 / s. Preferably, from about day 21 onwards after sowing the far-red component has a photosynthetic flux density of at most 50 μmol / m2 / s; more preferably at most 40 μmol / m3 / s; and most preferably at most 35 μmol / m2 / s. Preferably, from about day 21 onwards after sowing the far-red component has a photosynthetic flux density in a range of from 15 to 50 μmol / m2 / s; more preferably in a range of from 20 to 40 μmol / m2 / s; and most preferably of from 25 to 35 μmol / m2 / s. Most preferably, from about day 21 onwards after sowing the far-red component has a photosynthetic flux density of about 30 μmol / m2 / s.

[0154] Preferably, from about day 6 until about day 20 the leaf area index is in a range of from 3 to 4, preferably about 3.7. Preferably, from about day 26 onwards the leaf area index is in a range of from 0.6 to 1.0, preferably about 0.8.

[0155] Methods fbr strawberry plants

[0156] Several preferred features for methods of the invention for growing strawberry plants are already indicated above. Furthermore, when growing strawberry plants using methods of the invention, the following features are also preferred.

[0157] Preferably, the artificial grow light comprises a red component and a blue component, and more preferably essentially consists of a red component and a blue component.

[0158] The following conditions may be applied for strawberry plants in general, but are in particular preferred for strawberry plants of the variety Dellizimo.

[0159] Preferably, from about day 8 until about day 14 after sowing the red component has a photosynthetic flux density of at least 90 μmol / m2 / s; more preferably at least 100 μmol / m2 / s; and most preferably at least 110 μmol / m2 / s. Preferably, from about day 8 until about day 14 after sowing the red component has a photosynthetic flux density of at most 150 μmol / m2 / s; more preferably at most 140 μmol / m2 / s; and most preferably at most 130 μmol / m2 / s. Preferably, from about day 8 until about day 14 after sowing the red component has a photosynthetic flux density in a range of from 90 to 150 μmol / m2 / s; more preferably in a range of from 100 to 140 μmol / m2 / s; and most preferably of from 110 to 130 μmol / m2 / s. Most preferably, from about day 8 until about day 14 after sowing the red component has a photosynthetic flux density of about 122 μmol / m2 / s.

[0160] Preferably, from about day 8 until about day 14 after sowing the blue component has a photosynthetic flux density of at least 25 μmol / m2 / s; more preferably at least 30 μmol / m2 / s; and most preferably at least 32 μmol / m2 / s. Preferably, from about day 8 until about day 14 after sowing the blue component has a photosynthetic flux density of at most 60 μmol / m2 / s; more preferably at most 50 μmol / m2 / s; and most preferably at most 42 μmol / m2 / s. Preferably, from about day 8 until about day 14 after sawing the blue component has a photosynthetic flux density in a range of from 25 to 60 μmol / m2 / s; more preferably in a range of from 30 to 50 μmol / m2 / s; and most preferably of from 32 to 42 μmol / m2 / s. Most preferably, from about day 8 until about day 14 after sowing the blue component has a photosynthetic flux density of about 37 μmol / m2 / s.

[0161] Preferably, from about day 15 until about day 40 after sowing the red component has a photosynthetic flux density of at least 220 μmol / m2 / s; more preferably at least 230 μmol / m2 / s; and most preferably at least 235 μmol / m2 / s. Preferably, from about day 15 until about day 40 after sowing the red component has a photosynthetic flux density of at most 275 μmol / m2 / s; more preferably at most 260 μmol / m2 / s; and most preferably at most 250 μmol / m2 / s. Preferably, from about day 15 until about day 40 after sowing the red component has a photosynthetic flux density in a range of from 220 to 275 μmol / m2 / s; more preferably in a range of from 230 to 260 μmol / m2 / s; and most preferably of from 235 to 250 μmol / m2 / s. Most preferably, from about day 15 until about day 40 after sawing the red component has a photosynthetic flux density of about 245 μmol / m2 / s.

[0162] Preferably, from about day 15 until about day 40 after sowing the blue component has a photosynthetic flux density of at least 60 μmol / m2 / s; more preferably at least 65 μmol / m2 / s; and most preferably at least 70 μmol / m2 / s. Preferably, from about day 15 until about day 40 after sowing the blue component has a photosynthetic flux density of at most 100 μmol / m2 / s; more preferably at most 85 μmol / m2 / s; and most preferably at most 80 μmol / m2 / s. Preferably, from about day 15 until about day 40 after sowing the blue component has a photosynthetic flux density in a range of from 60 to 100 μmol / m2 / s; more preferably in a range of from 65 to 85 μmol / m2 / s; and most preferably of from 70 to 80 μmol / m2 / s. Most preferably, from about day 15 until about day 40 after sowing the blue component has a photosynthetic flux density of about 75 μmol / m2 / s.

[0163] Preferably, from about day 8 until about day 14 after sowing the leaf area index is in a range of from 2 to 3, preferably about 2.5, Preferably, from about day 15 onwards the leaf area index is in a range of from 2.5 to 4, preferably about 3.

[0164] The following conditions may be applied for strawberry plants in general, but are in particular preferred for strawberry plants of the variety Limore One.

[0165] Preferably, from about day 0 until about day 23 after sowing the red component has a photosynthetic flux density of at least 60 μmol / m2 / s; more preferably at least 70 μmol / m2 / s; and most preferably at least 85 μmol / m2 / s. Preferably, from about day 0 until about day 23 after sowing the red component has a photosynthetic flux density in a range of from 60 to 125 μmol / m2 / s; more preferably in a range of from 70 to 115 μmol / m2 / s; and most preferably of from 85 to 105 μmol / m2 / s. Most preferably, from about day 0 until about day 23 after sowing the red component has a photosynthetic flux density of about 95 μmol / m2 / s.

[0166] Preferably, from about day 0 until about day 23 after sowing the blue component has a photosynthetic flux density of at least 20 μmol / m2 / s; more preferably at least 25 μmol / m2 / s; and most preferably at least 30 μmol / m2 / s. Preferably, from about day 0 until about day 23 after sowing the blue component has a photosynthetic flux density in a range of from 20 to 55 μmol / m2 / s; more preferably in a range of from 25 to 45 μmol / m2 / s; and most preferably of from 30 to 35 μmol / m2 / s. Most preferably, from about day 0 until about day 23 after sowing the blue component has a photosynthetic flux density of about 32 μmol / m2 / s.

[0167] Preferably, from about day 23 after sowing the red component has a photosynthetic flux density of at least 160 μmol / m2 / s; more preferably at least 170 μmol / m2 / s; and most preferably at least 180 μmol / m2 / s. Preferably, from about day 23 after sowing the red component has a photosynthetic flux density in a range of from 160 to 220 μmol / m2 / s; more preferably in a range of from 170 to 210 μmol / m2 / s; and most preferably of from 180 to 200 μmol / m2 / s. Most preferably, from about day 23 after sowing the red component has a photosynthetic flux density of about 190 μmol / m2 / s.

[0168] Preferably, from about day 23 after sowing the blue component has a photosynthetic flux density of at least 40 μmol / m2 / s; more preferably at least 50 μmol / m2 / s; and most preferably at least 60 μmol / m2 / s. Preferably, from about day 23 after sowing the blue component has a photosynthetic flux density in a range of from 40 to 90 μmol / m2 / s; more preferably in a range of from 50 to 80 μmol / m2 / s; and most preferably of from 60 to 70 μmol / m2 / s. Most preferably, from about day 23 after sowing the blue component has a photosynthetic flux density of about 63 μmol / m2 / s.

[0169] Preferably, from about day 0 until about day 9 after sowing the relative humidity is in a range of from 95% to 100%. Most preferably, from about day 0 until about day 9 after sowing the relative humidity is about 100%.

[0170] Preferably, from about day 9 until about day 23 after sowing the relative humidity is in a range of from 70% to 100%, more preferably of from 75% to 95%, and even more preferably of from 80% to 90%. Most preferably, from about day 9 until about day 23 after sowing the relative humidity is about 85%.

[0171] Preferably, from about day 24 until about day 62 after sowing the relative humidity is in a range of from 60% to 90%, more preferably of from 65% to 85%, and even more preferably of from 70% to 80%. Most preferably, from about day 24 until about day 62 after sowing the relative humidity is about 75%.

[0172] Preferably, from about day 63 after sowing the relative humidity is in a range of from 45% to 75%, more preferably of from 50% to 70%, and even more preferably of from 55% to 65%. Most preferably, from about day 9 until about day 23 after sawing the relative humidity is about 61.5%.

[0173] Preferably, from about day 0 to about day 23 after sowing the strawberry plant is kept in a container having a volume in a range of from 20 to 40 mL, preferably of from 25 to 35 mL, and most preferably the volume is about 30 mL.

[0174] In some embodiments, from about day 24 to about day 31 after sowing the strawberry plant is kept in a container having a volume in a range of from 20 to 40 mL, preferably of from 25 to 35 mL, and most preferably the volume is about 30 mL; and from about day 32 after sowing the strawberry plant is kept in a container having a volume in a range of from 70 to 90 mL, preferably of from 75 to 85 mL, and most preferably the volume is about 80 mL.

[0175] In other embodiments, from about day 24 to about day 31 after sowing the strawberry plant is kept in a container having a volume in a range of from 70 to 90 mL, preferably of from 75 to 85 mL, and most preferably the volume is about 80 mL; and from about day 32 after sowing the strawberry plant is kept in a container having a volume in a range of from 230 to 270 mL, preferably of from 240 to 260 mL, and most preferably the volume is about 250 mL.

[0176] Preferably, from about day 0 to about day 23 after sawing the strawberry plants are kept at a density in a range of from 550 to 750 plants per m2, preferably of from 600 to 700 plants per m2, and most preferably about 649 plants per m2.

[0177] In some embodiments, from about day 24 to about day 31 after sowing the strawberry plants are kept at a density in a range of from 550 to 750 plants per m2, preferably of from 600 to 700 plants per m2, and most preferably about 649 plants per m2; and from about day 32 after sowing the strawberry plants are kept at a density in a range of from 50 to 250 plants per m2, preferably of from 100 to 200 plants per m2, and most preferably about 145 plants per m2.

[0178] In other embodiments, from about day 24 to about day 31 after sowing the strawberry plants are kept at a density in a range of from 50 to 250 plants per m2, preferably of from 100 to 200 plants per m2, and most preferably about 145 plants per m2; and from about day 32 after sowing the strawberry plants are kept at a density in a range of from 15 to 150 plants per m2, preferably of from 25 to 125 plants per m2, and most preferably about 75 plants per m2.

[0179] Preferably, from about day 63 after sowing the leaf area index is in a range of from 2.5 to 5.0. In some embodiments, from about day 63 after sowing the leaf area index is in a range of from 4.0 to 5.0, preferably about 4.4. In other embodiments, from about day 63 after sowing the leaf area index is in a range of from 2.5 to 3.5, preferably about 2.8.

[0180] Germination methods

[0181] Herein, preferred methods for germinating a seed of a plant are described. The steps of these methods may precede the steps of the method of the invention, if the starting material in the latter method is a seed.

[0182] Preferably, the method for germinating a seed of a plant so as to obtain a seedling comprises the steps of: (a) providing a seed of a plant; (b) covering said seed with soil; preferably burying said seed in soil; wherein said soil is in contact with air; and (c) allowing the seed to germinate.

[0183] When germinating seed from a forest plant, in particular a plant of the genus Acacia, preferably one or more of the following conditions are applied for about 30 days: (i) maintaining the soil temperature in a range of from 25 to 35 °C; preferably in a range of from 27 to 33 °C; more preferably in a range of from 29 to 31 °C; and most preferably at about 30 °C; (ii) maintaining the relative humidity of the air in a range of from 85 to 95%; preferably in a range of from 87 to 92%; and most preferably at about 90%; (iii) maintaining the CO2concentration in the air in a range of from 300 to 700 ppm; preferably of from 320 to 650 ppm; more preferably of from 350 to 550 ppm; more preferably of from 370 to 470 ppm; more preferably of from 400 to 440 ppm; and most preferably at about 420 ppm. When germinating seed from a potato plant, preferably one or more of the following conditions are applied for about 5 days: (i) maintaining the soil temperature in a range of from 17 to 20 °C; and most preferably at about 18.5 °C; (ii) maintaining the relative humidity of the air in a range of from 85 to 95%; and most preferably at about 90%; (iii) maintaining the CO2concentration in the air in a range of from 300 to 700 ppm; and most preferably at about 420 ppm; and (iv) a plant density of from 600-700 plants per m2; most preferably about 666 plants per m2.

[0184] When germinating seed from a strawberry plant, preferably one or more of the following conditions are applied for about 5 days: (i) maintaining the soil temperature in a range of from 20 to 24 °C; and most preferably at about 22 °C; (ii) maintaining the relative humidity of the air in a range of from 85 to 100%; and most preferably at about 90% to about 95%; (iii) maintaining the CO2concentration in the air in a range of from 1500 to 2500 ppm; and most preferably at about 2000 ppm; and (iv) a plant density of from 900-960 plants per m2; most preferably about 937 plants per m2. Preferably, at the end of the germination phase the leaf area index is in a range of from 2.5 to 4, preferably about 3.

[0185] Preferably, in the germination method the seed is not exposed to artificial grow light. More preferably, in the germination method the seed is kept in the dark.

[0186] Preferably, in the germination method the seed is sowed in a container, preferably a pot, having a volume in a range of from 20 to 90 mL, most preferably about 25 mL, about 30 mL, or about 75 mL.

[0187] Plants

[0188] The invention also relates to plants per se. Preferably, the plant is obtainable by a method as disclosed herein. Plants of the invention are distinguishable from known plants, in particular when grown outdoors using traditional conditions, by being of better quality. In particular, plants of the invention have a larger total dry weight, a larger total leaf area, lower susceptibility to plagues and diseases, faster production rate after transfer to an outdoor field, and / or higher survival rate after transfer to an outdoor field. Moreover, plants of the invention have better storage quality. For example, strawberry plants of the invention can be stored for a relatively long period of time at low temperatures, e.g. -1ºC, without a significant decrease in plant quality. Several preferred plants are indicated below.

[0189] In a preferred embodiment, the plant is a forest plant, more preferably a plant of the species Acacia mlotica. Preferably, the forest plant has a total leaf area of at least 725 cm2; more preferably at least 1000 cm2; more preferably at least 1100 cm2; more preferably at least 1150 cm2; more preferably at least 1200 cm2; and most preferably at least 1225 cm2. Preferably, the forest plant has a total leaf area of at most 4000 cm2; more preferably at most 3500 cm2; more preferably at most 3000 cm2; more preferably at most 2750 cm2; more preferably at most 2600 cm2; and most preferably at most 2200 cm2. Preferably, the forest plant has a total leaf area in a range of from 900 to 4000 cm2; more preferably of from 1000 to 3500 cm2; more preferably of from 1100 to 3000 cm2; more preferably of from 1150 to 2750 cm2; more preferably of from 1150 to 2600 cm2; and most preferably of from 1200 to 2200 cm2. Preferably, the forest plant has a total leaf area of about 1225 cm2, or about 1750 cm2.

[0190] Preferably, the forest plant has a total dry weight of at least 6.0 gram; more preferably at least 6.5 gram; more preferably at least 7.0 gram; more preferably at least 10 gram; more preferably at least 15 gram; and most preferably at least 17 gram. Preferably, the forest plant has a total dry weight of at most 50 gram; more preferably at most 45 gram; more preferably at most 40 gram; more preferably at most 35 gram; more preferably at most 30 gram; and most preferably at most 25 gram. Preferably, the forest plant has a total dry weight in a range of from 6.0 to 50 gram; more preferably of from 6.5 to 45 gram; more preferably of from 7.0 to 40 gram; more preferably of from 10 to 35 gram; more preferably of from 15 to 30 gram; and most preferably of from 17 to 25 gram. Preferably, the forest plant has a total dry weight of about 20 gram. In other embodiments, however, the forest plant has a total dry weight of about 8.0 gram.

[0191] Preferably, the forest plant has an average internode length of at least 3.5 cm; more preferably at least 4.0 cm; more preferably at least 4.5 cm; more preferably at least 5.0 cm; more preferably at least 5.5 cm; and most preferably at least 6.0 cm. Preferably, the forest plant has a average internode length of at most 17 cm; more preferably at most 15 cm; mote preferably at most 14 cm; more preferably at most 13 cm; more preferably at most 12 cm; and most preferably at most 11 cm. Preferably, the finest plant has a average internode length in a range of from 3.5 to 17 cm; more preferably of from 4.0 to 15 cm; more preferably of from 4.5 to 14 cm; more preferably of from 5.0 to 13 cm; more preferably of from 5.5 to 12 cm; and most preferably of from 6.0 to 11 cm. Preferably, the forest plant has a average internode length of about 6.4 cm, or about 10 cm.

[0192] Preferably, the forest plant has a height of at least 20 cm; more preferably at least 25 cm; more preferably at least 30 cm; more preferably at least 35 cm; more preferably at least 40 cm; and most preferably at least 45 cm. Preferably, the forest plant has a height of at most 200 cm; more preferably at most 175 cm; more preferably at most 150 cm; more preferably at most 130 cm; more preferably at most 125 cm; and most preferably at most 120 cm. Preferably, the forest plant has a height in a range of from 20 to 200 cm; more preferably of from 25 to 175 cm; more preferably of from 30 to 150 cm; more preferably of from 35 to 130 cm; more preferably of from 40 to 125 cm; and most preferably of from 45 to 120 cm. Preferably, the forest plant has a height of about 45 cm, about 65 cm, or about 100 cm.

[0193] Preferably, the forest plant has a ratio of the dry weight of the shoot over the dry weight of the root of at least 1 :0.6, more preferably at least 1 :0.5, more preferably at least 1 :0.4, and most preferably at least 1 :0,35. Preferably, the forest plant has a ratio of the dry weight of the shoot over the dry weight of the root of at most 1:0.05, more preferably at most 1:0.1, more preferably at most 1 :02, and most preferably at most 1:0,25. Preferably, the forest plant has a ratio of the dry weight of the shoot over the dry weight of the root in a range of from 1:0.6 to 1:0.05, more preferably of from 1:0.5 to 1:0.1, more preferably of from 1:0.4 to 1:0.2, and most preferably of from 1:0.35 to 1 :0,25. Most preferably, the forest plant has a ratio of the dry weight of the shoot over the dry weight of the root of about 1 :0.3.

[0194] Preferably, the forest plant has a number of leaf pairs on the main stem of at least 6, more preferably at least 7, more preferably at least 8, and most preferably at least 9. Preferably, the forest plant has a number of leaf pairs on the main stem of at most 18, more preferably at most 16, more preferably at most 13, and most preferably at most 11, Preferably, the forest plant has a number of leaf pairs on the main stem in a range of from 6 to 18, more preferably of from 7 to 16, more preferably of from 8 to 13, and most preferably of from 9 to 11. Most preferably, the forest plant has a number of leaf pairs on the main stem of about 10. In other embodiments, the forest plant has a number of leaf pairs on the main stem of about 7.

[0195] In another preferred embodiment, the plant is a mangrove plant, more preferably a plant of the species Rhizophora mangle.

[0196] Preferably, the mangrove plant has a total leaf area of at least 80 cm2; more preferably at least 100 cm2; and most preferably at least 150 cm2. Preferably, the mangrove plant has a total leaf area of at most 400 cm2; more preferably at most 350 cm2; and most preferably at most 300 cm2. Preferably, the mangrove plant has a total leaf area in a range of from 80 to 400 cm2; more preferably of from 100 to 350 cm2; and most preferably of from 150 to 325 cm2. Preferably, the mangrove plant has a total leaf area of about 180 cm2, or about 300 cm2.

[0197] Preferably, the mangrove plant has a total dry weight of at least 12 gram, more preferably at least 14 gram; and most preferably at least 15 gram. Preferably, the mangrove plant has a total dry weight of at most 25 gram; more preferably at most 21 gram; and most preferably at most 19 gram. Preferably, the mangrove plant has a total dry weight in a range of from 12 to 25 gram; more preferably of from 14 to 21 gram; and most preferably of from 15 to 19 gram. Preferably, the mangrove plant has a total dry weight of about 17 gram.

[0198] Preferably, the mangrove plant has an average internode length of at least 3.5 cm; more preferably at least 4.0 cm; and most preferably at least 5.0 cm. Preferably, the mangrove plant has an average internode length of at most 11 cm; more preferably at most 9 cm; and most preferably at most 7.0 cm. Preferably, the mangrove plant has an average internode length in a range of from 3.5 to 11 cm; more preferably of from 4.0 to 9 cm; and most preferably of from 5.0 to 7.0 cm. Preferably, the mangrove plant has a average internode length of about 6.0 cm.

[0199] Preferably, the mangrove plant has a height of at least 25 cm; more preferably at least 30 cm; and most preferably at least 35 cm. Preferably, the mangrove plant has a height of at most 65 cm; more preferably at most 60 cm; and most preferably at most 55 cm. Preferably, the mangrove plant has a height in a range of from 25 to 65 cm; more preferably of from 30 to 60 cm; and most preferably of from 35 to 55 cm. Preferably, the mangrove plant has a height of about 40 cm, or about 50 cm.

[0200] Preferably, the mangrove plant has a ratio of the dry weight of the shoot over the dry weight of the root of at least 2.0, more preferably at least 2,5, and most preferably at least 3.0. Preferably, the mangrove plant has a ratio of the dry weight of the shoot over the dry weight of the root of at most 5.0, more preferably at most 4.5, and most preferably at most 4.0. Preferably, the mangrove plant has a ratio of the dry weight of the shoot over the dry weight of the root in a range of from 2.0 to 5.0, more preferably of from 2.5 to 4.5, and most preferably of from 3.0 to 4.0. Most preferably, the mangrove plant has a ratio of the dry weight of the shoot over the dry weight of the root of about 3.5 or 3.8.

[0201] Preferably, the mangrove plant has a number of leaf pairs on the main stem of at least 1, and most preferably at least 2. Preferably, the mangrove plant has a number of leaf pairs on the main stem of at most 6, and most preferably at most 5. Preferably, the mangrove plant has a number of leaf pairs on the main stem in a range of from 1 to 6, and most preferably of from 2 to 5. Most preferably, the mangrove plant has a number of leaf pairs on the main stem of about 3 or about 4.

[0202] In another preferred embodiment, the plant is a potato plant, more preferably a plant of tire species Solanum tuberosum. Preferably, the potato plant has a total leaf area of at least 35 cm2; more preferably at least 46 cm2; and most preferably at least 50 cm2. Preferably, the potato plant has a total leaf area of at most 600 cm2; more preferably at most 550 cm2; and most preferably at most 500 cm2. Preferably, the potato plant has a total leaf area in a range of from 35 to 600 cm2; more preferably of from 46 to 550 cm2; and most preferably of from 50 to 500 cm2. Preferably, the potato plant has a total leaf area of about 55 cm2, or about 456 cm2.

[0203] Preferably, the potato plant has a total dry weight of at least 0.10 gram, more preferably at least 0.14 gram; and most preferably at least 0.16 gram. Preferably, the potato plant has a total dry weight of at most 3.0 gram; more preferably at most 2.4 gram; and most preferably at most 2.3 gram. Preferably, the potato plant has a total dry weight in a range of from 0.10 to 3.0 gram; more preferably of from 0.14 to 2.4 gram; and most preferably of from 0.16 to 2.3 gram. Preferably, the potato plant has a total diy weight of about 0.17 gram or about 2.19 gram.

[0204] Preferably, the potato plant has a height of at least 3.5 cm; more preferably at least 4.0 cm; and most preferably at least 4.2 cm. Preferably, the potato plant has a height of at most 6.0 cm; more preferably at most 5.0 cm; and most preferably at most 4.7 cm. Preferably, the potato plant has a height in a range of from 3.5 to 6.0 cm; more preferably of from 4.0 to 5.0 cm; and most preferably of from 4.2 to 4.7 cm. Preferably, the potato plant has a height of about 4.5 cm.

[0205] Preferably, the potato plant has a number of leaf pairs on the main stem of at least 4, and most preferably at least 5. Preferably, the potato plant has a number of leaf pairs on the main stem of at most 10, and most preferably at most 9. Preferably, the potato plant has a number of leaf pairs on the main stem in a range of from 4 to 10, and most preferably of from 5 to 9. Most preferably, the potato plant has a number of leaf pairs on the main stem of about 6, or about 8.

[0206] In another preferred embodiment, the plant is a strawbeny plant, preferably of the species Fragaria × ananassa. Preferably, the strawbeny plant is an F1 hybrid strawbeny plant, and more preferably the strawbeny plant is of the variety Dellizimo. In other preferred embodiments, the strawbeny plant is of the variety Limore One.

[0207] Preferably, the strawberry plant, preferably a plant of the variety Limore One, has a total leaf area per plant in a range of from 200 to 500 cm2. In some embodiments, the total leaf area of the strawbeny plant, preferably of the variety Limore One, is in a range of from 200 to 400 cm2, preferably of from 250 to 350 cm2, more preferably of from 275 to 325 cm2. In other embodiments, the total leaf area of the strawberry plant, preferably of the variety Limore One, is in a range of from 300 to 500 cm2, preferably of from 325 to 425 cm2, more preferably of from 350 to 400 cm2.

[0208] Preferably, the strawberry plant, preferably a plant of the variety Limore One, has a total dry weight in a range of from 3.8 to 9.0 gram. In some embodiments, the total diy weight of the strawberry plant, preferably of the variety Limore One, is in a range of from 3.8 to 8.0 gram, preferably of from 4.5 to 7.5 gram, more preferably of from 5.50 to 6.50 gram. In other embodiments, the total diy weight of the strawberry plant, preferably of the variety Limore One, is in a range of from 4.8 to 9.0 gram, preferably of from 5.5 to 7.5 gram, more preferably of from 6.0 to 7.0 gram.

[0209] Preferably, the strawberry plant, preferably a plant of the variety Limore One, has a total dry weight of the shoot in a range of from 2.0 to 5.0 gram. In some embodiments, the total dry weight of the shoot of the strawberry plant, preferably of the variety Limore One, is in a range of from 2.0 to 4.0 gram, preferably of from 2.5 to 3.5 gram, more preferably of from 2.75 to 3.25 gram. In other embodiments, the total dry weight of the shoot of the strawberry plant, preferably of the variety Limore One, is in a range of from 3.0 to 5.0 gram, preferably of from 3.75 to 4.75 gram, more preferably of from 4.0 to 4.5 gram.

[0210] Preferably, the strawberry plant, preferably a plant of the variety Limore One, has a total dry weight ofthe roots in a range of from 1.8 to 4.0 gram, more preferably of from 2.0 to 3.5 gram, even more preferably of from 2.2 to 3.1 gram.

[0211] Preferably, the strawberry plant, preferably a plant ofthe variety Limore One, has a ratio of the dry weight of the shoot over the diy weight of the root in a range of from 1.00 to

[0212] 1.85. In some embodiments, the strawberry plant, preferably a plant of the variety Limore One, has a ratio of the dry weight of the shoot over the diy weight of the root in a range of from 1.00 to 1.20, preferably about 1.07. In other embodiments, the strawberry plant, preferably a plant of the variety Limore One, has a ratio of the dry weight ofthe shoot over the dry weight of the root in a range of from 1.60 to 1.85, preferably about 1.75.

[0213] Preferably, the strawberry plant, preferably a plant of the variety Limore One, has a number of leaf pairs on the main stem in a range of from 8 to 12, more preferably of from 9 to

[0214] 11 , most preferably of from 10 to 11.

[0215] Preferably, the strawberry plant, preferably a plant of the variety Limore One, has a truss length in a range of from 0.1 to 0.7 cm. In some embodiments, the strawberry plant, preferably a plant ofthe variety Limore One, has a truss length in a range of from 0.1 to 0.5 cm, preferably of from 0.2 to 0.4 cm. In other embodiments, the strawberry plant, preferably a plant of the variety Limore One, has a trass length in a range of from 0.3 to 0.7 cm, preferably of from 0.4 to 0.6 cm.

[0216] Arrangement

[0217] The disclosure also relates to an arrangement for carrying out the method of the invention, in particular for growing a plant under such conditions that a young plant with a better quality is obtained and / or a young plant is obtained sooner, as compared to a standard outdoors-grown plant The arrangement comprises the plant material and a lighting device configured to provide artificial grow light to the plant material. The artificial grow light is preferably as defined herein.

[0218] Preferably, the lighting device is configured to communicate with a light controller configured to control the lighting device.

[0219] In principle, any suitable light source can be used. However, preferably the lighting device comprises one or more light-emitting diodes (LEDs). More preferably, the lighting device comprises a light-emitting diode configured to provide the red component as defined herein. More preferably, the lighting device comprises a light-emitting diode configured to provide the blue component as defined herein. More preferably, the lighting device comprises a light-emitting diode configured to provide the far-red component as defined herein. Even more preferably, the lighting device comprises a light-emitting diode configured to provide the red component as defined herein, and a light-emitting diode configured to provide the blue component as defined herein. Most preferably, the lighting device comprises a light-emitting diode configured to provide the red component as defined herein, a light-emitting diode configured to provide the blue component as defined herein, and a light-emitting diode configured to provide the far-red component as defined herein.

[0220] The arrangement preferably further comprises an air temperature adjustment device configured to adjust the air temperature. During operation the air temperature adjustment device may be used to maintain the air temperature at a temperature as defined above. Temperature adjustment devices such as heating and cooling adjustment devices are well- known to the skilled person.

[0221] Preferably, the air temperature adjustment device is configured to communicate with an air temperature controller. The air temperature controller is configured to control the air temperature adjustment device.

[0222] Preferably, the arrangement further comprises an air temperature sensor configured to measure the air temperature. Preferably, the air temperature sensor is configured to communicate with the air temperature adjustment device and / or the air temperature controller. Preferably, the air temperature controller is configured to control the air temperature adjustment device in dependence of communication received by the air temperature controller from the air temperature sensor.

[0223] The arrangement preferably further comprises a substrate temperature adjustment device configured to adjust the substrate temperature. During operation the substrate temperature adjustment device may be used to maintain the substrate temperature at a temperature as defined above. Temperature adjustment devices such as heating and cooling adjustment devices arc well-known to the skilled person.

[0224] Preferably, the substrate temperature adjustment device is configured to communicate with a substrate temperature controller. The substrate temperature controller is configured to control the substrate temperature adjustment device.

[0225] Preferably, the arrangement further comprises a substrate temperature sensor configured to measure the substrate temperature. Preferably, the substrate temperature sensor is configured to communicate with the substrate temperature adjustment device and / or the substrate temperature controller. Preferably, the substrate temperature controller is configured to control the substrate temperature adjustment device in dependence of communication received by the substrate temperature controller from the substrate temperature sensor.

[0226] Preferably, the arrangement further comprises a humidity adjustment device configured to adjust the relative humidity. During operation the humidity adjustment device may be used to maintain the relative humidity as defined above. For example, the humidity adjustment device may absorb and / or release moisture from the air to adjust the relative humidity.

[0227] Preferably, the humidity adjustment device is configured to communicate with a humidity controller. The humidity controller is configured to control the humidity adjustment device as defined herein. During operation, the humidity controller and the humidity adjustment device may be used to maintain the relative humidity as defined above.

[0228] Preferably, the arrangement further comprises a humidity sensor configured to measure the relative humidity. Preferably, the humidity sensor is configured to communicate with the humidity adjustment device and / or the humidity controller. Preferably, the humidity controller is configured to control the humidity adjustment device in dependence of communication received by the humidity controller from the humidity sensor.

[0229] Preferably, the arrangement comprises a CO2adjustment device configured to adjust the CO2concentration of air. During operation the CO2adjustment device may be used to maintain the CO2concentration of air as defined above. For example, the CO2adjustment device may absorb and / or release carbon dioxide from or to the air to adjust the CO2concentration of the air.

[0230] Preferably, the CO2adjustment device is configured to communicate with a CO2controller. The CO2controller is configured to control the CO2adjustment device as defined herein. During operation, the CO2controller and the CO2adjustment device may be used to maintain the CO2concentration in the air as defined above.

[0231] Preferably, the arrangement further comprises a CO2sensor configured to measure the CO2concentration in the air. Preferably, the CO2sensor is configured to communicate with the CO2adjustment device and / or the CO2controller. Preferably, the CO2controller is configured to control the CO2adjustment device in dependence of communication received by the CO2controller from the CO2sensor.

[0232] Preferably, the arrangement comprises a conductivity adjustment device configured to adjust the electrical conductivity of the substrate. It will be understood that if herein reference is made to “conductivity*’ without the adjective “electrical", “electrical conductivity” is nevertheless meant. During operation the conductivity adjustment device may be used to maintain the electrical conductivity of the substrate as defined above. For example, the conductivity adjustment device may absorb and / or release water and / or salts from or to the substrate to adjust the electrical conductivity. Preferably, the conductivity adjustment device adjusts the electrical conductivity of the water that is provided to the substrate.

[0233] Preferably, the conductivity adjustment device is configured to communicate with a conductivity controller. The conductivity controller is configured to control the conductivity adjustment device as defined herein. During operation, the conductivity controller and the conductivity adjustment device may be used to maintain the electrical conductivity as defined above.

[0234] Preferably, the arrangement further comprises a conductivity sensor configured to measure the electrical conductivity. Preferably, the conductivity sensor is configured to communicate with the conductivity adjustment device and / or the conductivity controller. Preferably, the conductivity controller is configured to control the conductivity adjustment device in dependence of communication received by the conductivity controller from the conductivity sensor.

[0235] Preferably, the arrangement comprises a pH adjustment device configured to adjust the pH of the substrate. During operation the pH adjustment device may be used to maintain the pH of the substrate as defined above. For example, the pH adjustment device may absorb and / or release water, acidic substances, and / or basic substances from or to the substrate to adjust the pH. It will be understood that “basic" as used herein refers to Brensted bases. Preferably, the pH adjustment device adjusts the pH of the water that is provided to the substrate.

[0236] Preferably, the pH adjustment device is configured to communicate with a pH controller. The pH controller is configured to control the pH adjustment device as defined herein. During operation, the pH controller and the pH adjustment device may be used to maintain the pH of the substrate as defined above.

[0237] Preferably, the arrangement further comprises a pH sensor configured to measure the pH of the substrate. The pH of the substrate can be measured directly on the substrate, but it is preferred that the pH of the substrate is determined by measuring the pH of the water provided to or obtained from the substrate. Preferably, the pH sensor is configured to communicate wife the pH adjustment device and / or the pH controller. Preferably, the pH controller is configured to control the pH adjustment device in dependence of communication received by the pH controller from the pH sensor.

[0238] Most preferably, the arrangement further comprises the air temperature adjustment device, the substrate temperature adjustment device, the humidity adjustment device, the CO2adjustment device, the conductivity adjustment device, and the pH adjustment device.

[0239] It will be understood that one adjustment device may be configured to adjust more than one parameter. As such, the CO2adjustment device may for example also be configured to adjust the relative humidity, and / or the air temperature. Likewise, the pH adjustment device may for example also be configured to adjust the electrical conductivity of the substrate. In other words: the various adjustment devices as disclosed herein may be combined, preferably integrated.

[0240] Most preferably, the arrangement further comprises the air temperature sensor, the substrate temperature sensor, the humidity sensor, the CO2sensor, the conductivity sensor, and the pH sensor.

[0241] It will be understood that the aforementioned adjustment devices and the aforementioned sensors may be integrated, in particular such that a respective sensor is integrated with a respective adjustment device. For example, the pH sensor may be comprised in tiie pH adjustment device. Alternatively, the sensor and the adjustment device are physically separated. This may reduce the influence of the adjustment device on the measurements of the sensor, e.g. if the adjustment device releases acid to adjust the pH the concentration of acid close to the adjustment device may be temporarily high as the acid diffuses into the substrate.

[0242] Preferably, the arrangement further comprises the air temperature controller, the substrate temperature controller, the humidity controller, the CO2controller, the conductivity controller, and / or the pH controller. More preferably, the arrangement further comprises the air temperature controller, the substrate temperature controller, the humidity controller, the CO2controller, the conductivity controller, and the pH controller.

[0243] It will be understood that the communication between the controller and the respective (adjustment) device and / or sensor may be via wires or wireless, wherein wireless communication is preferred. Preferably, the (adjustment) device and / or the sensor are provided with telecommunication means configured to exchange signals and / or message with the controller. As such, the controller may be able to communicate with the (adjustment) device and / or sensor from a remote location. It is however preferred that the controller is at the same location as the (adjustment) device and / or sensor, viz. that the controller and the (adjustment) device and / or sensor are at most 500 meters away from each other, more preferably at most 250 meters, more preferably at most 100 meters, and most preferably at most 50 meters.

[0244] Plant cultivation facility

[0245] The invention also relates to a plant cultivation facility comprising the arrangement of the invention. Preferably, the plant cultivation facility comprises a controlled condition environment that is substantially daylight-free. Preferably, the plant material, the one or more adjustment devices, and / or the one or more sensors as defined herein are kept within said controlled condition environment.

[0246] Preferably, the controlled condition environment comprises one or more of daylight shielding, heat insulation, and moisture shielding. It will be understood that it is not required that the one or more controllers as defined herein are also present in the plant cultivation facility. The one or more controllers may communicate with the one or more adjustment devices via wires or wirelessly, and therefore may communicate remotely.

[0247] The invention also pertains to the use of artificial light to accelerate the growth of a plant; wherein preferably substantially exclusively artificial grow light is used; wherein preferably said artificial grow light is as defined herein. Preferably, the plant is selected from the group consisting of selected from the group consisting of mangrove, a forest plant, a potato plant, a strawberry plant, a cacao plant, a palm plant, a tomato plant, and an orchid; more preferably the plant is selected from the group consisting of mangrove, a forest plant, a potato plant, and a strawberry plant; and even more preferably from the group consisting of mangrove, an acacia, a potato plant, and a strawberry plant.

[0248] In some preferred embodiments, in the use the plant is a plant of the germs Rhizophora. In other preferred embodiments, in the use the plant is a plant of the genus Acacia or Vachellia. In other preferred embodiments, in the use the plant is a plant of the species Solatium tuberosum, wherein preferably said plant is a seedling of the species Solatium tuberosum, wherein the seedling is obtained by providing a seed and germinating said seed. In other preferred embodiments, in the use the plant is a plant of the genus Fragaria, wherein preferably said plant is a seedling of the genus Fragaria, wherein the seedling is obtained by providing a seed and germinating said seed.

[0249] Preferably, the other conditions of the method of the invention are used in the use of artificial grow light to accelerate the growth of a plant, in particular the carbon dioxide concentration of the air, the pH of the substrate, the electric conductivity of the substrate, the relative humidity of the air, and the temperature, in particular the substrate temperature and / or the space temperature.

[0250] Definitions

[0251] The term “about” as used herein preferably indicates a deviation of 25% or less from the given value, more preferably 20% or less, more preferably 15% or less, more preferably 10% or less, and most preferably 5% or less.

[0252] In particular, when referring to the “first about 2 days” or “first about 4 days” and the like when the starting material is a cutting or a tissue culture plant, “about” preferably means a deviation of 25% or less.

[0253] In particular, when referring to specific values for the air temperature, substrate temperature, pH of the substrate, carbon dioxide concentration of the air, the electric conductivity of the substrate, or the relative humidity of the air, "about" preferably means a deviation of 10% or less, most preferably 5% or less.

[0254] Herein, “dry weight" refers to the weight of a plant or a part thereof after said plant or part thereof has been dried. Usually, the residual moisture level in said plant or part thereof after drying is at most 10 wt%, preferably at most 5 wt%, as compared to the total weight of the dried plant or dried part.

[0255] Herein, the “total dry weight" refers to the dry weight of the entire plant (viz. both shoot and root).

[0256] A “young plant" as referred to herein is a plant that is not mature (yet), but has all the typical parts of a plant, such as a root, a stem, and one or more leaves. Typically, as used herein “young plant” refers to a plant that is of sufficient quality and / or has sufficient weight to be (further) grown outdoors. The skilled person is able to use common general knowledge and / or simple experiments to assess whether a plant has said sufficient quality and / or sufficient weight

[0257] The young plants as described herein typically comprise a stem having a leaf pair, preferably multiple leaf pairs. Herein, “a leaf pair" is defined as two leaves on opposite sides of the stem.

[0258] Herein, “shoot" refers to the part of the plant that is above ground, including the stem, leaves, fruit, and the like. By contrast, “root” refers to the part of the plant that is below ground. Said ratio can be determined by harvesting said plant, drying said plant, separating the shoot from the root, and measuring the dry weight of the shoot and the root, and comparing the dry weights. Alternatively, the shoot and the root are first separated, and then dried separately.

[0259] As used herein, “leaf area index" refers to the total leaf area present within a certain area divided by the ground surface area of said area.

[0260] Herein, the “leaf area" is the amount of surface area of leaves of plants (e.g. one plant may have 1000 cm2of leaf area divided over 8 leaves).

[0261] Herein, the “total leaf area" indicates the leaf area of all leaves of a plant combined. There are several ways in which the leaf area of a leaf can be determined, which all yield substantially the same result

[0262] For instance, the area of a leaf can be measured manually, for example by using millimeter graph paper, or by other means. For instance, a photograph can be taken of one or more leaves on a contrasting background with a known scale object. Software such as Image! can then be used to apply a scale using the known object, locate the contours) of the one or more leaves, and measure the leaf area.

[0263] Furthermore, the leaf area can be determined automatically using handheld or portable leaf area meters that measure leaf area by scanning the surface of the leaf. This is a nondestructive method that the skilled person can readily use, also to measure the total leaf area of a plant.

[0264] Alternatively, a destructive method can also be employed if desired. In that case, all leaves of a plant may be harvested and dried, and the total weight of the dried leaves may be determined. The total leaf area can then be obtained from multiplying the total dry weight with a certain conversion factor. This conversion factor can be obtained from literature, and / or by measuring the dry weight of a sample of leaves with a known area. An alternative to drying and weighing the leaves is to scan the leaves and analyze their surface area digitally.

[0265] For determining the total leaf area per plant of a large number of plants, only a small number of plants (e.g. at most 5% of all plants; or about 10 plants) may need to be examined. The average of the results obtained in this way can be considered to be representative for all plants. This is in particular useful when employing the destructive method, as it may not be necessary to harvest the leaves of all plants.

[0266] The skilled person will understand that all of these methods to determine the (total) leaf area yield the same result within the appropriate limit of measurement accuracy.

[0267] Examples

[0268] The invention is illustrated below using several examples. It will be understood that the invention is not limited thereto, and other embodiments such as those listed above are also capable of achieving the technical effects and benefits of the invention.

[0269] Unless indicated otherwise, the following conditions were applied for the methods of the invention in the below examples.

[0270] The plants were kept indoors, in a controlled condition environment that was substantially daylight-free. This controlled condition environment comprised a lighting device (in particular lighting devices comprising one or more light-emitting diodes), an air temperature adjustment device; a substrate temperature adjustment device; a humidity adjustment device; a CO2adjustment device; a pH adjustment device; a conductivity adjustment device; an air temperature sensor; a substrate temperature sensor, a humidity sensor, a CO2sensor, a pH sensor; and a conductivity sensor. All (adjustment) devices and sensors are as defined herein, and were configured to communicate with one or more controllers.

[0271] A suitable horticultural substrate was used, and a suitable horticultural nutrient solution was applied when necessary. Optionally, one or more of the side branches were pruned.

[0272] Moreover, if in the examples reference is made to light having a red component, it is meant that a light source was used producing light with wavelengths in a range of from 600- 700 nm with apeak at 660 nm, wherein the light intensities at 600 and 700 nm are less than 2% of the light intensity at said peak. Likewise, for light having a blue component a light source was used producing light with wavelengths in a range of from 400-500 nm with a peak at 450 nm, wherein the light intensities at 400 and 500 nm are less than 1% of the light intensity at said peak. Finally, for light having a far-red component a light source was used producing light with wavelengths in a range of from 680-800 nm with a peak at 730-740 nm, wherein the light intensity at 680 nm is less than 6% of the light intensity at said peak, and the light intensity at 800 nm is less titan 2% of the light intensity at said peak.

[0273] During light periods wherein artificial grow light (having a red, blue, and / or far-red component) was applied, the artificial grow light was shone continuously during said light period with the components and flux densities as indicated.

[0274] Unless indicated otherwise, for plants grown from seeds day 0 is the day of sowing.

[0275] Example 1 - Forestry plant

[0276] This Example relates to foreshy plants, of which Acacia nilotica was chosen as an example. Multiple procedures according to the invention were used to grow young plants of Acacia nilotica. Procedures 2A and 2B start with a cutting or a tissue culture plant of a plant. By contrast, procedures 1 A and IB start with providing a seed of a plant, sowing said seed in a suitable horticultural substrate, and allowing the seed to germinate. The germinating seed was kept indoors under controlled conditions.

[0277] Germination was carried out using the following conditions. Both the space temperature and the substrate temperature were maintained in a range of from 27 to 33 °C, typically at about 30°C. The relative humidity of the air was maintained in a range of from 85 to 95%, typically at about 90%. The carbon dioxide concentration in the air was maintained in a range of from 300 to 650 ppm, typically at about 420 ppm. The seed was sowed in a pot having a volume in a range of from 65-90 mL, typically 75 mL. No artificial grow light was applied. Germination took about 30 days, after which a seedling was obtained.

[0278] Unless indicated otherwise, the following conditions were applied for the rest of procedures 1 A and IB, and throughout procedures 2A and 2B.

[0279] The plants were exposed to artificial grow light for about 12-18 hours a day, typically 14 hours a day, for a total duration of up to 210 days. The CO2concentration was kept within the range of from 420-2000 ppm, typically at about 1500 ppm. A suitable horticultural substrate was used, and a suitable horticultural nutrient solution was applied when necessary. The electrical conductivity of the soil in which the plants grew was maintained in a range of from 1.2-2.8 mS / cm2, typically at about 2.0 mS / cm2; and the pH of said soil was maintained in a range of from S.2-6.6, typically at about pH 5.9. The temperature of both the soil and the (shoots of the) plant were maintained in a range of from 25-30 °C, typically at about 27 or 29 °C. The relative humidity of the air was maintained in a range of from 75-85%, typically at about 80%.

[0280] For procedures 1 A and IB, the plants were kept in a pot with a volume in a range of from 65-90 mL, typically 75 mL, for the first about 58-64 days (not including germination). On about day 58-64, the plants were repotted to a pot with a volume in a range of from 500- 1400 mL, typically 700 mL, or to a pot with a volume in a range of from 1500-3000 mL, typically 2000 mL. If the plants were first repotted to a pot with a volume of from 500-1400 mL, the plants were transferred again on about day 101 to a pot with a volume in a range of from 1500-3000 mL, typically 2000 mL. A plant density of about 500-600 (typically 558) plants per m2was maintained for the first about 58-64 days (not including germination). If the plants were potted in a pot of a volume of from 500-1400 mL, the plant density was about 150-250, typically 204, plants per m2, If the plants were potted in a pot of a volume of from 1500-3000 mL, the plant density was about 30-80, typically 60, plants per m2. After germination, a leaf area index of about 2-4, typically about 3, was maintained.

[0281] For procedures 2A and 2B, the plants were kept in a pot with a volume in a range of from 65-90 mL, typically 75 mL, for the first about 39-45 days. On about day 39-45, the plants were repotted to a pot with a volume in a range of from 500-1400 mL, typically 700 mL, or to a pot with a volume in a range of from 1500-3000 mL, typically 2000 mL. If the plants were first repotted to a pot with a volume of from 500-1400 mL, the plants were transferred again on about day 61 to a pot with a volume in a range of from 1500-3000 mL, typically 2000 mL.

[0282] Below, procedures 1A, 1B, 2A, and 2B according to the invention are presented. In each procedure, the growth of a plant is accelerated by exposing said plant substantially exclusively to artificial grow light. In procedures 1 A and 2A, the artificial grow light consists essentially of a red component and a blue component, while in procedures 1 B and 2B the artificial grow light consists essentially of a red component, a blue component, and a far-red component Table 1 lists the composition of the artificial grow light used in procedures 1 A and IB. Likewise, Table 2 lists the further conditions used in procedures 2A and 2B.

[0283] As explained above, procedures 1 A and 1B use seeds or seedlings as a starting material, while Procedures 2A and 2B use cuttings or tissue culture plants as a starting material.

[0284] Table 1. Composition of artificial grow light used in procedures 1A and 1B.

[0285] Table 2. Composition of artificial grow light, temperatures, and relative humidity, used in procedures 2A and 2B.

[0286] Below, the results are shown of the Procedures 1 A, 2A, 1B, and 2B of the invention. Table 3 summarizes the growth methods and their differences as compared to a reference example. Table 4 shows the plant quality obtained when applying the procedures of the invention for various amounts of time.

[0287] Table 3. Comparison of the reference procedure and procedures of the invention used to grow young plants of Acacia nilotica, and the time required to obtain a young plant.

[0288] Table 4. Results front procedures 1A, 1B, 2A, and 2B of the invention when growing young plants of the species Acacia nilotica, and the characteristics of the plants obtained after a certain number of days following the procedure. The number of days for procedures 1A and 1B includes 30 days for germination. Typical ranges are given for certain plant properties, and the typical values are indicated between parentheses.

[0289] Example 2 - Manerove

[0290] In this example, young plants of the species Rhizophora mangle were grown from seeds. The conditions of Table 5 shown below were applied for 75 days to obtain a young plant, or for 120 days to obtain a larger young plant. Table 5. Conditions to grow young plants of the species Rhizophora mangle using methods of the invention. “Day 51 onwards “ indicates the conditions until the end of the procedure (either 75 days or 120 days). The characteristics of the plants obtained using the procedures of Table 5 for 75 days or for 120 days are shown in Table 6.

[0291] Table & Results from the procedures of Table 5 of die invention when growing young plants of die species Rhizophora mangle, and die characteristics of the plants obtained after a certain number of days following the procedure. Typical ranges are given for certain plant properties, and die typical values are indicated between parentheses.

[0292] Example 3 - Potato plants

[0293] In this example, young plants of the species Solanum tuberosum were grown from real seeds that were sown in a substrate. The conditions for growing a reference plant in a greenhouse or tunnel are shown in Table 7, and the conditions for growing young plants using methods of the invention are shown in Tables 8 (short procedure for growing young plants) and 9 (longer procedure for growing larger young plants). Table 7. Conditionsfor growing a reference plant of the species Solanum tuberosum in a greenhouse or tunnel, wherein the plant is not exposed to artificial grow light. It took 42 days to produce a young plant using this procedure.

[0294] Table 8. Conditions for growing a young plant of the species Solomon tuberosum within 21 days using a method according to the invention. Table 9. Conditions for growing a large young plant of the species Solanum tuberosum within 34 days using a method according to the invention.

[0295] The results of the procedures of Tables 7-9 are shown below in Table 10. A plant obtained using the procedure of Table 7 is shown on the left ofFigure 3, a plant obtained using the procedure of Table 8 is shown in the middle ofFigure 3, and a plant obtained using the procedure of Table 9 is shown on the right ofFigure 3.

[0296] Table 10. Young plants of the species Solatium tuberosum obtained using the procedures of Table 7 (plant A), Table 8 (plant B), or Table 9 (plant C). Typical ranges are green for certain plant properties, and the typical values are indicated between parentheses.

[0297] Example 4 - Strawb y plants

[0298] In this Example strawberry plants of two varieties (Dellizimo, Example 4.1 ; and Limore One, Example 4.2) were grown using methods of the invention and compared to plants that were grown outdoors. The costs for producing the plants using a method of the invention were much lower than for conventional, outdoors-grown plants. Additionally, a higher quality of plants (in particular a combination of a higher dry weight, in particular of the roots, as compared to outdoors-grown plants; and a higher ratio of the dry weight of the shoot over the dry weight of the shoot, as compared to outdoors-grown plants), was achieved in a shorter period of time. Furthermore, the strawberry plants obtained using the method of the invention had a better storage quality, viz. could be stored at -1 °C (typical storage temperature for strawberry plants) for a longer period of time without significant quality loss.

[0299] Finally, the strawberry plants obtained using the method of the invention also showed a better production, and lower susceptibility and / or better resistance to diseases, in particular mildew.

[0300] Example 4.1 - variety Dellizimo

[0301] In this example, young plants of the species Fragaria x ananassa (variety Dellizimo) were grown from real seeds that were sown in a substrate. Using a method of the invention, applying the conditions shown in Table 11, young strawberry plants were typically obtained within 40 days (typical range of from 35-45 days). The plants grown using the method of the invention within about 40 days had a height of about 8 cm (typically in a range of from 6-10 cm), and had about 8 leaf pairs on the main stem (typically in a range of from 6-10).

[0302] Table 11. Conditions for growing a young plant of the species Fragaria × ananassa (variety Dellizimo) withut 40 days using a method according to the invention.

[0303] As a comparative example, young plants of the species Fragaria x ananassa (variety Dellizimo) were grown outdoors from real seeds that were sown in a substrate. Thus, the plant material was subjected to outdoor conditions, such as fluctuating temperatures, day-night cycles, wind, and other weather-related conditions. In this comparative example it typically took 70-84 days (in a range of from 65-90 days) to obtain a young plant.

[0304] Example 4.2 — Variety Limore One

[0305] In this example, young plants of the species Fragaria × ananassa (variety Limore One) were grown from real seeds that were sown in a substrate. Using a method of the invention young strawberry plants of types B and C were typically obtained within 73 days (typical range of from 60-80 days).

[0306] A comparative example was also carried out, wherein the plant was grown outdoors from real seeds that were sown in a substrate. Thus, the plant material was subjected to outdoor conditions, such as fluctuating temperahires, day-night cycles, wind, and other weather- related conditions. In this comparative example a plant of type A was obtained within typically 112 days (in a range of from 100-130 days) to obtain a young plant. The characteristics of plants of types A, B, and C as obtained in Example 4.2 are shown in Table 12. The conditions under which plants of type B and C were grown are shown in Tables 13 and 14, respectively.

[0307] Figure 4 shows strawberry plants of type B on day 70 after sowing. Figure 5 shows strawberry plants of type C on day 70 after sowing.

[0308] Table 12. Characteristics of strawberry plants (variety Limore One) of types A-C as obtained in Example 4.2.

[0309] Table 13. Conditions for growing a young plant of the species Fragaria × ananassa (variety Limore One) of type B within about 73 days using a method according to the invention.

[0310] Table 14. Conditions for growing a young plant of the species Fragaria × ananassa (variety Limore One) of type C within about 73 days using a method according to the invention.

Claims

Claims1. A method for growing a plant under such conditions that a young plant with a better quality is obtained and / or a young plant is obtained sooner, as compared to a standard outdoors-grown plant, wherein the method comprises the steps of: a) providing plant material selected from the group consisting of a seedling, a cutting, and a plant obtained from a tissue culture; wherein preferably the seedling is obtained by providing a seed and germinating said seed; and b) exposing said plant material to light, wherein said light is substantially exclusively artificial grow light2. The method according to claim 1, wherein the leaf area index is maintained at a value of at most 4, preferably in a range of from 2 to 4, more preferably at about 3.

3. The method according to any one of the preceding claims, wherein the the plant material is continuously exposed to the artificial grow light for a duration of at least 8 hours a day.

4. The method according to any one of the preceding claims, wherein the artificial grow light comprises a red component having a wavelength in a range of from 600 to 700 nm, and wherein the red component has a photosynthetic flux density of at least 30 μmol / m2 / s; preferably in a range of from 30 to 1000 μmol / m2 / s.

5. The method according to any one of the preceding claims, wherein the artificial grow light comprises a far-red component having a wavelength in a range of from 680 to 800 nm, preferably of from 680 to 770 nm, and wherein the far-red component has a photosynthetic flux density of at least 1 μmol / m2 / s; preferably a range of from 1 to 100 μmol / m2 / s.

6. The method according to claims 4 and 5, wherein the artificial grow light comprises said red component and said far-red component, wherein the ratio of the photosynthetic flux density of said red component over the photosynthetic flux density of the far-red component is ina range of from 1:1 to 60:1.

7. The method according to any one of the preceding claims, wherein the artificial grow light comprises a blue component having a wavelength in a range of from 400 to 500 nm, preferably of from 420 to 495 nm, and wherein the blue component has a photosynthetic flux density of at least 10 μmol / m2 / s; preferably in a range of from 10 to 250 μmol / m2 / s.

8. The method according to any one of the preceding claims, wherein said plant is selected from the group consisting of mangrove, a forest plant, a potato plant, a strawberry plant, a cacao plant, a palm plant, a tomato plant, an orchid, and Paulownia tomentosa.

9. The method according to any one of the preceding claims, wherein said plant is a plant of the genus Rhizophora.

10. The method according to claim 9, wherein the artificial grow light comprises a red component having a wavelength in a range of from 600 to 700 nm, and wherein the red component has a photosynthetic flux density of at least 90 μmol / m2 / s; and wherein the artificial grow light comprises a blue component having a wavelength in a range of from 400 to 500 nm, and wherein the blue component has a photosynthetic flux density of at least 10 μmol / m2 / s.

11. The method according to any one of claims 1 to 8, wherein said plant is a plant of the genus Acacia or Vachellia.

12. The method according to claim 11 , wherein the artificial grow light cornprises a red component having a wavelength in a range of from 600 to 700 nm, and wherein the red component has a photosynthetic flux density of at least 90 μmol / m2 / s; and wherein the artificial grow light comprises a blue component having a wavelength in a range of from 400 to 500 nm, and wherein the blue component has a photosynthetic flux density of at least 10 μmol / m2 / s.

13. The method according to any one of claims 1 to 8, wherein said plant is a plant of the species Solanum tuberosum.

14. The method according to claim 13, wherein the method comprises the steps of:al) providing a true seed of a plant of the species Solatium tuberosum; a2) germinating said true seed so as to obtain a seedling; and b) exposing said seedling to light, wherein said light is substantially exclusively artificial grow light.

15. The method according to any one of claims 13 and 14, wherein the artificial grow light comprises a red component having a wavelength in a range of from 600 to 700 nm, and wherein the red component has a photosynthetic flux density of at least 150 μmol / m2 / s; and wherein the artificial grow light comprises a blue component having a wavelength in a range of from 400 to 500 nm, and wherein the blue component has a photosynthetic flux density of at least 30 μmol / m2 / s.

16. The method according to any one of claims 1 to 8, wherein said plant is a plant of the genus Fragaria.

17. The method according to claim 16, wherein the method comprises the steps of: al) providing a seed of a plant of the genus Fragaria; a2) germinating said seed so as to obtain a seedling; and b) exposing said seedling to light, wherein said light is substantially exclusively artificial grow light.

18. The method according to any one of claims 16 and 17, wherein the artificial grow light comprises a red component having a wavelength in a range of from 600 to 700 nm, and wherein the red component has a photosynthetic flux density of at least 100 μmol / m2 / s; and wherein the artificial grow light comprises a blue component having a wavelength in a range of from 400 to 500 nm, and wherein the blue component has a photosynthetic flux density of at least 30 μmol / m2 / s.

19. The method according to any one of claims 16 and 17, wherein the artificial grow light comprises a red component having a wavelength in a range of from 600 to 700 nm, and wherein the red component has a photosynthetic flux density of at least 80 μmol / m2 / s; and wherein the artificial grow light comprises a blue component having a wavelength in a rangeof from 400 to 500 nm, and wherein the blue component has a photosynthetic flux density of at least 25 μmol / m2 / s.

20. The method according to any one of claims 18 and 19, wherein the the plant material is continuously exposed to the artificial grow light for a duration in a range of from 14 to 18 hours a day.

21. The method according to any one of the preceding claims, wherein the method is carried out indoors; preferably for at least the first 70 days, more preferably at least the first 80 days.

22. The method according to any one of the preceding claims, wherein the method is carried out for at most 80 days; preferably at most 70 days.

23. The method according to any one of the preceding claims, wherein the method is continued at least until the plant bears fruit.

24. The method according to any one of the preceding claims, wherein when the plant has become a young plant, said plant is transferred to an outdoor field.

25. The method according to any one of claims 1 to 23, wherein the method is carried out indoors at least until said plant bears fruit.

26. The method according to any one of the preceding claims, wherein said plant material is exposed to the light for at least 8 hours per day; preferably at least 8 hours per day, and most preferably for a duration in a range of from 8 to 24 hours per day.

27. The method according to any one of the preceding claims, wherein said plant material is kept at a temperature in a range of from 15 to 40 °C; preferably in a range of from 17 to 35 °C; more preferably in a range of from 18 to 32 °C; most preferably in a range of from 25 to 30 °C.

28. The method according to any one of the preceding claims, wherein said plant material is subjected to a relative humidity in a range of from 60 to 100%; preferably in a range offrom 65 to 97%; more preferably in a range of from 67 to 95%; and most preferably in a range offrom 70 to 85%.

29. The method according to any one of the preceding claims, wherein said plant material is subjected to air having a CO2concentration of at least 250 ppm; preferably in a range of from 250 to 2750 ppm.

30. A plant obtainable by the method according to any one of the preceding claims.

31. A plant according to claim 30, wherein said plant is a plant of the genus Acacia or Vachellia; wherein said plant has: a) a total leaf area per plant in a range of from 900 to 2750 cm2; b) a total dry weight in a range of from 6.0 to 30 gram; c) an average internode length in a range of from 4 to 14 cm; d) an average leaf area per leaf pair in a range of from 150 to 250 cm2; e) a height in a range of from 30 to 125 cm; f) a ratio of the dry weight of the shoot over the dry weight of the root in a range of from 1:0.4 to 1:0.2 and g) a number of leaf pairs on the main stem in a range of from 6 to 11.

32. A plant according to claim 30, wherein said plant is a plant of the genus Rhizophora; wherein said plant has; a) a total leaf area per plant in a range of from 50 to 70 cm2; b) a total dry weight in a range of from 12 to 21 gram; c) an average internode length in a range of from 4 to 9 cm; d) an average leaf area per leaf pair in a range of from 50 to 70 cm2; e) a height in a range of from 30 to 55 cm; f) a ratio of the dry weight of the shoot over the dry weight of the root in a range of from 1:0.4 to 1:0.2; and g) a number of leaf pairs on the main stem in a range of from 2 to 5.

33. A plant according to claim 30, wherein said plant is a plant of the species Solatium tuberosum; wherein said plant has: a) a total leaf area per plant in a range of from 46 to 550 cm2; b) a total dry weight in a range of from 0.14 to 2.4 gram; c) a height in a range of from 4 to 5 cm; and d) a number of leaf pairs on the main stem in a range of from 5 to 9.

34. A plant according to claim 30, wherein said plant is a plant of the species Fragaria x ananassa, wherein said species is preferably of the variety Limore One, wherein said plant has: a) a total leaf area per plant in a range of from 200 to 500 cm2; b) a total dry weight in a range of from 3.8 to 9.0 gram; c) a total dry weight of the shoot in a range of from 2.0 to 5.0 gram; d) a total dry weight of the roots in a range of from 1.8 to 4.0 gram; e) a ratio of the dry weight of the shoot over the dry weight of the root in a range of from 1.00 to 1.85; f) a number of leaf pairs on the main stem in a range of from 8 to 12; and g) a trass length in a range of from 0.1 to 0.7 cm.

35. An arrangement for growing a plant under such conditions that a young plant with a better quality is obtained and / or a young plant is obtained sooner, as compared to a standard outdoors-grown plant; wherein the arrangement comprises: a) the plant material as defined in any one of claims 1 to 29; and b) a lighting adjustment device configured to provide artificial grow light to the plant material, wherein the artificial grow light is as defined in any one of claims 1 to 29; and optionally an air temperature adjustment device configured to adjust the air temperature; a substrate temperature adjustment device configured to adjust the substrate temperature; a humidity adjustment device configured to adjust the relative humidity; a CO2adjustment device configured to adjust the CO2concentration of air; a pH adjustment device configuredto adjust the pH of the substrate on which the plant material is kept; and / or a conductivity adjustment device configured to adjust the electrical conductivity of the substrate on which the plant material is kept; and optionally an air temperature sensor configured to measure the air temperature; a substrate temperature sensor configured to measure the substrate temperature; a humidity sensor configured to measure the relative humidity; a CO2sensor configured to measure the CO2concentration of air; a pH sensor configured to measure the pH of the substrate on which the plant material is kept; and / or a conductivity sensor configured to measure the electrical conductivity of the substrate on which the plant material is kept; and optionally an air temperature controller configured to control the air temperature adjustment device; a substrate temperature controller configured to control the substrate temperature adjustment device; a humidity controller configured to control the humidity adjustment device; a CO2controller configured to control the CO2adjustment device; a pH controller configured to control the pH adjustment device; and / or a conductivity controller configured to control the conductivity adjustment device.

36. A plant cultivation facility comprising the arrangement of claim 35, wherein preferably the plant cultivation facility is a substantially sunlight-free conditioned cultivation environment.

37. Use of artificial light to accelerate the growth of a plant selected from the group consisting of mangrove, a forest plant, a potato plant, a strawberry plant, a cacao plant, a palm plant, a tomato plant, and an orchid; wherein preferably substantially exclusively artificial grow light is used; wherein preferably said artificial grow light is as defined in any one of claims 1 to 29.

38. The use according to claim 37, wherein said plant is a plant of the genus Rhizophora.

39. The use according to claim 37, wherein said plant is a plant of the genus Acacia or Vachellia.

40. The use according to claim 37, wherein said plant is a plant of the species Solatium tuberosum.

41. The use according to claim 40, wherein said plant is a seedling of the species Solanum tuberosum, wherein the seedling is obtained by providing a seed and germinating said seed.

42. The use according to claim 37, wherein said plant is a plant of the genus Fragaria.

43. The use according to claim 42, wherein said plant is a seedling of the genus Fragaria, wherein the seedling is obtained by providing a seed and germinating said seed.

Images