Potato seeds cultivation method

Abstract

Method and system for cultivating potato plants for the purpose of harvesting tubers are provided. The potato plants are grown in a cultivation assembly that comprises two light-sealed chambers that include a bottom, root chamber and a top crop chamber, separated by a dividing wall. The crop chamber has a plurality of first openings formed in the dividing wall, and a plurality of second openings formed in the top wall. Potato plantlets are introduced into the top chamber while permitting the roots to extend into the root chamber through the first openings, and a stem of the plant grown from the plantlet is permitted to extend through the second openings. Irrigation solution is introducing to the bottom chamber and potato tuners are periodically harvested from the top chamber.

Description

[0001] Potato Seeds Cultivation Method

[0002] TECHNOLOGICAL FIELD

[0003] The present disclosure concerns cultivation methods for growing potato plants from potato seeds.

[0004] BACKGROUND ART

[0005] References considered to be relevant as background to the presently disclosed subject matter are listed below:

[0006] - United States patent publication no. 10,058,040

[0007] - United States patent publication no. 8,887,439

[0008] - European patent publication no. EP 3102022

[0009] Acknowledgement of the above references herein is not to be inferred as meaning that these are in any way relevant to the patentability of the presently disclosed subject matter.

[0010] BACKGROUND

[0011] Potato plants are traditionally grown in fields and each plant typically produces 4-10 potatoes, which develop on stolons extending underground. To grow potato plants, potato tubers (also customary referred to as “potato seeds”) are introduced into the soil at a depth below the soil surface. Within a period of time after seeding, roots develop and a stem extends upward from the seeded mother-tuber, that eventually pierces the soil surface to produce the above-ground plant body (stems, leaves, flowers, etc.). In parallel stolons develop underground and new tubers grow thereon, also underground. The mother-tuber eventually decomposes and, after a cultivation period when the tubers reach sufficient size, these are harvested for use as ware- or industrial-potatoes.

[0012] For various reasons there is a growing world-wide shortage in potato seeds, typically produced through several repeating cycles of traditional cultivation methods. This shortage is aggravated by increased production costs, as well as increased pest infestation consequent of global warming. Cultivation methods of potato tubers using a two-chamber arrangement, comprising a bottom, root chamber and a top, crop chamber are known from US 8,887,439, US 10,058,040 and EP 3102022. In such arrangements, the roots of the plants extend into the bottom chamber through first openings formed in a wall disposed between the two chambers, the stems extend through second openings at the top of the top chamber, and crops are harvested from the crop chamber by periodically opening and closing of the chamber during harvesting.

[0013] GENERAL DESCRIPTION

[0014] Provided herewith are methods and systems for cultivating potato tubers, particularly (but not only) such intended to be used as potato seeds, namely as a breeding material that may be seeded in the ground, grown in a greenhouse, etc. for obtaining subsequent generations of plants, which may be plants that serve for the generation of tubers intended to be used as seeds or serve for the generation of ware potatoes or potatoes for industrial processing.

[0015] In general, the methods and systems disclosed herein utilize a two-compartment growth arrangement, such as those disclosed in US 10,058,040, US 8,887,439 and EP 3102022, the content of which being incorporated herein by reference for some of the embodiments of this disclosure. Various elements described in these documents are also applicable in some embodiments of this disclosure. Accordingly, the systems disclosed herein may comprise device of the kind described in US 10,058,040 or EP 3102022 with modifications that include elements of certain embodiments of this disclosure.

[0016] In such two-compartment growth arrangement arrangements, there are two chambers: a bottom chamber that houses the roots of the plants, and a top chamber that houses the stolons and the tubers that grow on the plants and from which the tubers are periodically harvested. The stems and the upper part of the potato plants extend to the space above the top chamber. The methods and systems of this disclosure may be hydroponic growth methods and systems, where the roots in the bottom chamber are immersed in the irrigation solution; or may be aeroponic growth methods and systems, where the roots in the bottom chamber are not immersed in any medium and the irrigation solution is sprayed into the bottom chamber, typically as a mist. A mist has an advantage in that it spreads relatively evenly in the chamber circumventing obstacles, even to regions that are behind (with the respect to spraying nozzle) an element in the chamber, e.g. behind another plant, whereby the irrigation solution would reach all plant elements in the chamber.

[0017] The terms “bottom chamberfsj" and “root chamberfsj" may be used interchangeably, both referring to the bottom of the two chambers. Similarly, the terms “top chamberfsj" and “crop chamberfsj" may be used interchangeably, both referring to the top of the two chambers.

[0018] The terms “starter potato planllels". “potato planllels". “planllels" or the like may be used, interchangeably, to denote the small potato plants that are introduced into the top chamber at a start of a growth period.

[0019] The term “growth period' may be used to denote the period from introducing potato plantlets into the top chamber, through cultivation of tubers and one or more harvests of tubers until the end of the cultivation period.

[0020] Provided by one aspect, is a method for cultivating potato plants for purpose of harvesting tubers, the method comprises growing potato plants in a cultivation assembly. The cultivation assembly comprises two light-sealed chambers, comprising a bottom, root chamber and a top crop chamber, separated by a dividing wall, the crop chamber being defined between said dividing wall and a top wall; a plurality of first openings formed in the dividing wall; and a plurality of second openings formed in the top wall. In the method, the growing comprises placing potato plantlets (namely small potato plants, typically with one, mother tuber, having one or small stems and some roots) in the top chamber while permitting the roots to extend into the root chamber through the first openings, and stems of the plants stem to extend through the second openings, and introducing an irrigation solution, continuously or in a defined schedule comprising one or more nutrients to the bottom chamber; and periodically harvesting potato tubers from the top chamber. In some embodiments, as a potato plant may develop more than one stem, the number of second openings may be larger than the number of the first openings, different stem permitted to extend out of different second openings.

[0021] The term “nutrient” denotes chemical elements that may be added to the irrigation solution for delivery to the potato plant. It may include the standard NPK element that are used in fertilizers as well as other elements. As will be explained also below, there may be different nutrients in the irrigation solution delivered the top chamber and that delivered to the bottom chamber. Also, the introduction of the irrigation solution (that may also be referred to herein as "irrigation" may, for example, be continuous, or may be in short pulses separated by longer dry (i.e. non-irrigates) periods. The irrigation schedule may include different irrigation schedules for different times of day; may be an irrigation schedule that depends on the season or the time of year; may be at a schedule that depends on temperature, humidity or other environmental factors; etc. Similarly, the irrigation solutions may depend on various factors including environmental-related, seasonal, growth-related, and others.

[0022] The method has a few embodiments, each with one or more of the following added features (1) to (8):

[0023] (1) spraying an irrigation solution to the top chambers, the composition of the irrigation solution in the two chambers being different from one another,

[0024] (2) cooling the irrigation solution introduced into the bottom chamber and intended to irrigate the roots,

[0025] (3) growing potato plant matter to obtain a starter potato plant with a mother tuber and introducing the starter potato plant to the top chamber over one of the first openings to permit the starter potato plants roots to extend into the bottom chamber,

[0026] (4) after said placing, keeping one or both of the sidewalls of the top chamber open for a time sufficient to expose the plantlets to light and to permit each plantlet to develop a stem of sufficient length with leaves, then extending each stem out of a second opening, and after said extending closing any open side wall,

[0027] (5) permitting plant parts that are above the top wall to grow upwards to trail a general upwards path, this being done typically by providing an upwards growth support arrangement,

[0028] (6) spraying the irrigation solution into is the bottom chamber in the form of a mist,

[0029] (7) trimming the roots in the bottom chamber at least once during a growth period, and

[0030] (8) preparing the irrigation solution by mixing a first solution of water treated by reverse osmosis, a second solution of network water and optionally also a third, nutrient-containing solution.

[0031] Different embodiments of the method will now be described and further explained. These will be described by their serial number in the above list of features, as “embodiment (1)”, “embodiment (2)”, etc. Each of these embodiments may be implemented in a variety of different ways which may be referred to also by the term “ embodiment' for example, “by one embodiment of embodiment (1) . . Embodiments (1) to (8) may be embodied individually in the method of this disclosure or in any combination of one or more of these embodiments.

[0032] In the following description the terms “spraying", “spray irrigation", or “aeroponic irrigation", etc. will be used to denote the introduction of irrigation solution into a chamber in the form of sprayed droplets, mostly in the form of a mist where the droplets have an average diameter that is below about 100 pm, 90 pm, 80 pm, 70 pm, 60 pm, 50 pm and even below about 40 pm, typically in the range of about 10-25 pm. The term “mist” may be used to refer to the irrigation solution that is introduced in such manner. In aeroponic irrigation the roots are suspended in the air without the use of any medium and are periodically sprayed with a fine mist of nutrient-containing irrigation solution.

[0033] In the following description the term “hydroponic irrigation" will be used to denote an irrigation where the introduction of the irrigation solution is intended and performed such that the roots or at least a portion thereof are immersed in the irrigation solution. For hydroponic irrigation the roots may grow in an inert medium like perlite, rock wool, clay pellets, peat moss, vermiculite, etc., which medium is wetted by the irrigation solution or may be immersed directly in the irrigation solution.

[0034] According to embodiment (1), an irrigation solution with or without nutrients is applied, through spraying, to the top chamber and typically also to the bottom chamber. The solutions applied to the two chambers may be different from one another. While the irrigation of the irrigation solution to the bottom chamber is typically aeroponic irrigation, the irrigation of the bottom chamber may also be hydroponic in nature. For example, the bottom chamber with the roots may be irrigated with a nutrient solution, e.g. comprising the typical NPK and other fertilizers that may be employed in tubers cultivation, for a period and then irrigated with a solution similar to that applied in the top chamber. By certain embodiments of embodiment (1) one or both of the bottom or of the top chambers may be irrigated in pulses of irrigation separated by intermittent periods of non-irrigation. One or both of the irrigation solutions may be circulated for reuse. For that, the bottom chamber and the top chamber have each a drainage for collecting the respective irrigating solutions from each of the chambers. Any value given in this disclosure, other than if specifically understood otherwise from the context, should be understood as meaning a value that is about the indicated value, whether the term “about” is indicated before the value or not. A value that is about the indicated value means a value that may be in a range of ±10% of the indicated value (namely a value that deviates from the indicated value by up to 20%). For example, a value of 100 pm denotes a value that may be equal or lower than 90 or equal or higher than 110 pm.

[0035] In accordance with embodiment (2), the irrigation solution introduced, such as by spraying, e.g. in the form of a mist, into the bottom chamber is cooled to thereby cool the roots in the bottom chamber. This was found to positively affect the tubers cultivation, particularly during cultivation that occurs in a hot climate or during a relatively hot time of year. Such cooling may increase the tubers yield. The irrigation solution is cooled such that the temperature in which the solution is sprayed at the bottom chamber is between about 14 to 18 °C, typically about 16°C. For that purpose, the irrigation solution may have to be cooled at source to a lower temperature since, even if the pipes through which the irrigation solution flows are thermally insulated, they may heat up before their introduction into the bottom chamber.

[0036] The term "yield" may mean one or more of (i) total number of harvested tubers, (ii) number of harvested tubers in a defined time period, (iii) number of harvested tubers that meet predefined criteria such as (but not only) minimum weight or size, (iv) total weight of harvested tubers, (v) total weight of harvested tubers in a defined time period.

[0037] According to embodiment (3) potato plant matter, which may be a plantlet obtained from tissue culture, a potato plant cutting, a potato tuber or minitubers, is grown, typically on a porous substrate, e.g. rock wool, to obtain a starter potato plant with a mother tuber and some roots. Where cuttings are used, this can occur with about 2 weeks from cutting and placing the cutting on the substrate. The starter potato plant is then introduced into the top chamber over one of the first openings to the roots of the starter plants to extend into the bottom chamber. By one embodiment of embodiment (3) said mother-tuber is fitted in a porous substrate such that the mother-tuber is at a bottom portion of the substrate, occasionally at the very bottom of the substrate and permit the roots to extend into the bottom chamber.

[0038] According to embodiment (4), after placing of plants in the top chamber, at least one of its sidewalls are kept open for a time to expose the plantlets to light and permitting each plantlet to develop a stem of sufficient length with leaves, and then extending each stem out of a second opening. Thereafter, the side walls are closed and are only opened occasionally (typically for a short while once every few days) for harvesting minitubers from the top chamber. Said time in which the side wall is kept open to permit an initial growth boost to the potato plants, may be between about 15 to about 30 days.

[0039] According to embodiment (5), upper plant parts, namely the stem and the leaves of the plant that extend out of the top chamber through the second openings, are permitted to grow upwards in a general upwards direction. This is contrary to the general acceptable practice of trimming the vegetative parts of potato plants grown in an incubator or nursery, which is believed to improve the yield. In accordance with this disclosure it was found that such extension, which brings to a taller and generally upwards or upright directed vegetative parts, increases yield of the harvested tubers. To achieve that, by an embodiment of embedment (5), the vegetative parts are supported in a manner permitting their upward growth. This support may be by tying the stems to strings, cables, bands, etc., that may be tied directly or by means of rings, strings, bands, clips, etc. to a support structure above the upper chamber and gradually pulling the strings upwards, in keeping with the growth and extension of the stem. Alternatively, a growth supporting installation, e.g. in the form of one or more net or grid structures above the plants, typically several such structures that are parallel to one another at various heights above the chamber. The support may also be a combination of these solutions.

[0040] In accordance with embodiment (6) the irrigation solution into one or both of the chambers is sprayed as a mist. The droplet size may be below about 100 pm, 90 pm, 80 pm, 70 pm, 60 pm or even below about 50 pm, and typically in the range of about 10 pm to 25 pm. It was found in accordance with this disclosure that the use of such a small droplet size does not hamper the ability to provide fertilizers and other nutritional substance to the plants, particularly the roots and their absorption by the roots.

[0041] In accordance with embodiment (7) at least one time during cultivation the roots in the bottom chamber are trimmed. It was surprisingly found in accordance with this disclosure that such trimming, which may at times be of more than about 10%, 20%, 30%, 40%, 50%, 60%, 70% or even more than about 80% of the roots’ length, increases the overall number of harvested tubers. Such trimming may be conducted once, twice or more during a cultivation cycle, the first being about 30, 40 or 50 days after placing the starter potato plants in the top chamber. For example, the roots may be trimmed by about 10-30 cm, 2-3 times during a growth period.

[0042] In accordance with embodiment (8) a unique solution for preparing at least one of the irrigation solutions is provided. It involves mixing a first solution that consists of water (or an aqueous solution) treated by reverse osmosis, mixed with a second solution consisting of network or running water, namely water that is untreated. It was found in accordance with this disclosure that such a mixture is suitable for mixing with a nutrientcontaining aqueous solution, e.g. one containing standard NPK or other fertilizer solutions, to achieve optimal effect on the cultivated plants. The mixture of the first and second solutions is typically controlled to have an EC of about 0.1 to 0.7 mS / cm, 0.2 to 0.6 mS / cm or even about 0.4 mS / cm. When mixing with the third solution the EC is typically controlled to be within about 0.8 to 1.5 mS / cm, e.g. about 1.2 mS / cm. The pH of the first and the second solution is typically above 5 and usually about 5.4 and changes to a small extent upon the addition of the third solution.

[0043] In the following some embodiments are described, all being optional embodiments of each of embodiments (1) to (8).

[0044] In accordance with some embodiments, light opaque discs are placed around each plant stem such as to substantially block light penetration into the top chamber through the second openings.

[0045] In accordance with some embodiments, the tubers that are harvested are intended for use as potato seeds, and are typically such that are classified as minitubers and have a diameter of less than about 25 mm.

[0046] In accordance with some embodiments, spraying of the irrigation solutions may be carried out in intermitted spraying bursts.

[0047] In accordance with some embodiments, the mother-tuber is removed from the plant after growth of tubers on the potato plant.

[0048] Provide by another aspect of this disclosure is a system for cultivating potato plants for the purpose of harvesting tubers, comprising one or more cultivation assemblies. Each such assemblies, comprises two light-sealable chambers (namely can be sealed from light to maintain darkness therein), each having a bottom, root chamber and a top crop chamber, separated by a dividing wall, the crop chamber being defined between said dividing wall and a top wall. Formed in the dividing wall are a plurality of first openings and formed in the top wall are a plurality of second openings. The system also comprises an irrigation arrangement configured for independently spraying of different irrigation solutions into the root chamber and the crop chamber. The root chamber is configured for receiving roots of a potato plantlet that extend from the first chamber through the first openings into the second chamber. The crop chamber is intended or configured to maintain a stem of the potato plant during growth thereof and permit its extension through the second opening, and permit growth therein of stolons and growth of tubers on the stolons. The system has several embodiments with one or more of the following added features (a) to (f):

[0049] (a) having separate irrigation sub-systems for irrigating the bottom chambers and the top chambers;

[0050] (b) having at least one cooling sub-system configured for cooling the irrigation solution intended for the bottom chamber;

[0051] (c) having at least one installation for growing potato plant matter to obtain a starter potato plant with a mother tuber;

[0052] (d) having at least one support system above the top chambers for supporting upwards growth of the potato plants;

[0053] (e) having at least one pump and a plurality of sprayers disposed in the irrigation arrangement configured for mist irrigation, and

[0054] (f) having at least one irrigation solution preparation sub-system configured for mixing at least one first solution of water treated by reverse osmosis, at least one second solution of network water and a at least one third, element-containing solution.

[0055] Different embodiments of the system will now be described and further explained. These will be described by their serial number from the above list of features, as “embodiment (a)”, “embodiment (b)”, etc. Each of these embodiments may be implemented in a variety of different ways which may be referred to also by the term “embodiment”; for example, “by one embodiment of embodiment () ...”. Embodiments (a) to (f) may be embodied individually in the method of this disclosure or in any combination of one or more of these embodiments.

[0056] By some embodiments of the system of this disclosure, the same irrigation system can be used to irrigate both the root chamber and the crop chamber, directing the irrigation to either one of the chambers, making use of an appropriate valving arrangement for drawing the right irrigation composition at each time and directing the irrigation to either of the chambers or occasionally to both. According to embodiment (a), there are separate irrigation sub-systems, the irrigation arrangement comprising at least one first irrigation sub-system for irrigation of the root chambers and at least one second irrigation subsystem for irrigation of the crop chambers. The system of embodiment (a) may be useful for carrying out the method of embodiment (1). The first irrigation sub-system may comprise a first control utility for operating it in an irrigation cycle comprising pulses of irrigation separated by intermittent periods of non-irrigation. The second irrigation subsystem may also comprise a second control utility, which may be the same or different than the first control utility, for operating it in an irrigation cycle comprising pulses of irrigation separated by intermittent periods of non-irrigation. The pulses of irrigation controlled by the control utility may be in synch in the two chambers but may also be out of synch with one another. The irrigation solutions may, typically, circulated for reuse, for which purpose the bottom chambers and the top chambers may have each a drainage for collecting the respective irrigating solutions from each of the chambers.

[0057] By an embodiment of embodiment (b) a cooling sub-system is employed for cooling the irrigated solution, particularly that intended for the bottom, root chamber. The temperature may be controlled such that the temperature of the solution once reaching the root chamber is in the range of 14°C to 18°C, typically about 16°C. The system of embodiment (b) may be useful for carrying out the method of embodiment (2).

[0058] The system of embodiment (c) comprises at least one installation for growing potato plant matter to obtain a starter potato plant with a mother tuber. The system of embodiment (c) may be useful for carrying out the method of embodiment (5). By an embodiment of embodiment (c), the starter potato plant be obtained from tissue culture. By another embodiment of embodiment (c), the starter potato plant is obtained from a plant cutting. It was found in accordance with this disclosure that a plant shoot cut from the top of potato plant and including at least, typically at least 2 leaves, when placed with its stem in an inert porous substrate, as noted for embodiment (3) growth medium, such as rock wool, develops roots and a mother tuber and becomes a starter potato plant within about 2 weeks.

[0059] According to embodiment (d) the system comprises at least one support system above the top chambers for supporting upwards growth of the potato plants. The system of this embodiment (c) may be useful for carrying out the method of embodiment (5). Exemplary elements of such a support system have been described above. According to embodiment (e) the irrigation sub-system comprises at least one pump and a plurality of sprayers disposed within the chambers that are configured for mist irrigation. This embodiment is useful for carrying out the method of embodiment (6). The system is typically configured to produce a mist with droplet size in the range as noted above.

[0060] The system of embodiment (f) comprises at least one irrigation solution preparation sub-system for an irrigation solution that is configured for mixing at least one first solution of water treated by reverse osmosis, at least one second solution of network water and at least one third, nutrient-containing solution. This system is useful for carrying out the method of embodiment (8).

[0061] The system of some embodiments of this disclosure may make use of light-opaque discs that are configured for placing around each plant stem such as to substantially block light penetration into the top chamber through the second openings. The discs may typically each have a slit extending from its center to the periphery and have a central void dimensioned to snugly fit around a potato plant stem.

[0062] In some embodiments of this disclosure, the light-sealed chambers are configured as elongated elements. The crop chamber, in such embodiments, may have side walls that made of a light-opaque sheet material that can be lifted or downfolded to open said channel. The root channel may be defined between said dividing wall, that has a first width and an elongated flexible sheet light-opaque of a second width larger than first width extending between two sheet edges that are attached to edges of the dividing wall. This sheet, thus, forms a slack below the dividing wall providing a space for root growth and extension. Such embodiments may be referred to herein as the “channel embodiment” .

[0063] In some other embodiments, the crop chambers are configured as pots, each with a base that defines the dividing wall and having one or more openings in it, the pot having a side wall that can be opened. The pot is positioned on a rack with the root chamber being defend by a light sealed chamber below the rack. Such embodiments may be referred to herein as the “pot embodiment” .

[0064] In general, some embodiments of the methods and systems disclosed herein are improvements over the methods and systems described in US 10,058,040, US 8,887,439 and EP 3102022, which are being incorporated herein by reference. Various elements described in these documents may also be applicable in embodiments of this disclosure. EMBODIMENTS

[0065] In the following sections embodiments will be listed in numbered passages intended to add onto the above description and not limit it in any way. The embodiments include such drafted in an independent format and other that dependent from such independent embodiments and may add additional elements to or modify embodiments from which they depend. Embodiments that are depended on one or more embodiments may also constitute elements that add to or modify other embodiments from which they do not depend.

[0066] 1. A method for cultivating potato plants for the purpose of harvesting tubers, comprising: growing potato plants in a cultivation assembly that comprises: two light-sealed chambers, comprising a bottom, root chamber and a top crop chamber, separated by a dividing wall, the crop chamber being defined between said dividing wall and a top wall, a plurality of first openings formed in the dividing wall, and a plurality of second openings formed in the top wall; said growing comprising placing potato plantlets in the top chamber while permitting the roots to extend into the root chamber through the first openings, and a stem of the plant grown from the plantlet to extend through the second openings, and introducing an irrigation solution comprising one or more nutrients to the bottom chamber; periodically harvesting potato tubers from the top chamber; and comprising spraying an irrigation solution to the top chambers, the composition of the irrigation solution in the top and bottom chambers being different from one another.

[0067] 2. The method of embodiment 1, wherein the irrigation to the bottom chamber is aeroponic irrigation and said introducing comprises spraying said irrigation solution to the bottom chambers.

[0068] 2 A. The method of embodiment 1, wherein the irrigation of the bottom chamber is hydroponic irrigation. 3. The method of any one of embodiment 1, 2 or 2 A, wherein the irrigation of the bottom chamber is in pulses of irrigation separated by intermittent periods of nonirrigation.

[0069] 4. The method of any one of embodiments 1 to 3, wherein the irrigation of the top chamber is in pulses of irrigation separated by intermittent periods of nonirrigation.

[0070] 5. The method of any one of embodiments 1 to 4, wherein one or both of the irrigation solutions are circulated for reuse.

[0071] 6. The method of embodiment 5, wherein the bottom chamber and the top chamber have each a drainage for collecting the respective irrigating solutions from each of the chambers.

[0072] 7. The method of any one of embodiments 1 to 6, wherein the irrigation solution introduced into the bottom chamber is cooled.

[0073] 8. A method for cultivating potato plants for the purpose of harvesting tubers, comprising: growing potato plants in a cultivation assembly that comprises: two light-sealed chambers, comprising a bottom, root chamber and a top, crop chamber, separated by a dividing wall, the crop chamber being defined between said dividing wall and a top wall, a plurality of first openings formed in the dividing wall, and a plurality of second openings formed in the top wall; said growing comprising placing potato plantlets in the top chamber while permitting the roots to extend into the root chamber through the first openings, and a stem of the plant grown from the plantlet to extend through the second openings, and introducing an irrigation solution comprising one or more nutrients to the bottom chamber; periodically harvesting potato tubers from the top chamber; and comprising cooling the irrigation solution introduced into the bottom chamber.

[0074] 9. The method of embodiment 8, wherein the irrigation to the bottom chamber is aeroponic irrigation and said introducing comprises spraying said irrigation solution to the bottom chambers. 9A. The method of embodiment 8, wherein the irrigation of the bottom chamber is hydroponic irrigation.

[0075] 10. The method of any one of embodiments 7 to 9A, wherein the irrigation solution introduced into the bottom chamber has a temperature of about 14-18°C (Typically 16°C; e.g. 7-8°C at source).

[0076] 11. The method of any one of embodiments 1 to 10, further comprising growing (e.g. on a porous growth substrate) potato plant matter (e.g. a potato plantlet from tissue culture, a potato minitubers, a potato plant cutting, etc.) to obtain a starter potato plant with a mother tuber, and introducing the starter potato plant to the top chamber over one of the first openings to permit the starter potato plants roots to extend into the bottom chamber.

[0077] 12. A method for cultivating potato plants for the purpose of harvesting tubers, comprising: growing potato plants in a cultivation assembly that comprises: two light-sealed chambers, comprising a bottom, root chamber and a top crop chamber, separated by a dividing wall, the crop chamber being defined between said dividing wall and a top wall, a plurality of first openings formed in the dividing wall, a plurality of second openings formed in the top wall; said growing comprising placing potato plantlets in the top chamber while permitting the roots to extend into the root chamber through the first openings, and a stem of the plant grown from the plantlet to extend through the second openings, and introducing an irrigation solution comprising one or more nutrients to the bottom chamber; periodically harvesting potato tubers from the top chamber; and comprising growing potato plant matter to obtain a starter potato plant with a mother tuber, and introducing the starter potato plant to the top chamber over one of the first openings to permit the starter potato plants roots to extend into the bottom chamber.

[0078] 13. The method of embodiment 12, wherein the irrigation to the bottom chamber is aeroponic irrigation and said introducing comprises spraying said irrigation solution to the bottom chambers. 13A. The method of embodiment 12, wherein the irrigation of the bottom chamber is hydroponic irrigation.

[0079] 14. The method of embodiment 11 to 13 A, wherein said mother-tuber is fitted in a porous substrate such that the mother-tuber is at a bottom portion of the substrate and permitting the roots to extend into the bottom chamber.

[0080] 15. The method of embodiment 14, wherein said mother tuber is embedded within said porous substrate.

[0081] 16. The method of embodiment 14 or 15, wherein said porous substrate is rock wool.

[0082] 17. The method of any one of embodiments 11 to 16, wherein the mother tuber is at the bottom portion of said substrate.

[0083] 18. The method of any one of embodiments 1 to 17, further comprising after said placing, keeping at least one of the sidewalls of the top chamber open for a time to expose the plantlets to light and permit each plantlet to develop a stem of sufficient length with leaves, extending each stem out of a second opening, and after said extending closing the open side wall.

[0084] 19. A method for cultivating potato plants for the purpose of harvesting tubers, comprising: growing potato plants in a cultivation assembly that comprises: two light-sealed chambers, comprising a bottom, root chamber and a top crop chamber, separated by a dividing wall, the crop chamber being defined between said dividing wall and a top wall, a plurality of first openings formed in the dividing wall, and a plurality of second openings formed in the top wall; said growing comprising placing potato plantlets in the top chamber while permitting the roots to extend into the root chamber through the first openings, and a stem of the plant grown from the plantlet to extend through the second openings, and introducing irrigation an irrigation solution comprising one or more nutrients to the bottom chamber; periodically harvesting potato tubers from the top chamber; and comprising after said placing, (i) keeping at least one of the sidewalls of the top chamber open for a time to expose the plantlets to light and permit each plantlet to develop a stem of sufficient length with leaves, (ii) extending each stem out of a second opening, and (iii) after said extending closing the at least one open side wall.

[0085] 20. The method of embodiment 19, wherein the irrigation to the bottom chamber is aeroponic irrigation and said introducing comprises spraying said irrigation solution to the bottom chambers.

[0086] 20 A. The method of embodiment 19, wherein the irrigation of the bottom chamber is hydroponic irrigation.

[0087] 21. The method of any one of embodiments 18 to 20A, wherein said time is between about 15 to about 30 days.

[0088] 22. The method of any one of embodiments 1 to 21, further comprising permitting or inducing upper plant parts above said second openings to grow upwards to trail a general upwards growth path.

[0089] 23. A method for cultivating potato plants for the purpose of harvesting tubers, comprising: growing potato plants in a cultivation assembly that comprises: two light-sealed chambers, comprising a bottom, root chamber and a top crop chamber, separated by a dividing wall, the crop chamber being defined between said dividing wall and a top wall, a plurality of first openings formed in the dividing wall, and a plurality of second openings formed in the top wall; said growing comprising placing potato plantlets in the top chamber while permitting the roots to extend into the root chamber through the first openings, and a stem of the plant grown from the plantlet to extend through the second openings to define upper plant parts, and introducing an irrigation solution comprising one or more nutrients to at least the bottom chamber; periodically harvesting potato tubers from the top chamber; and comprising permitting or inducing upper plant parts to grow upwards to trail a general upwards growth path. 24. The method of embodiment 22, wherein the irrigation to the bottom chamber is aeroponic irrigation and said introducing comprises spraying said irrigation solution to the bottom chambers.

[0090] 24A. The method of embodiment 22, wherein the irrigation of the bottom chamber is hydroponic irrigation.

[0091] 25. The method of any one of embodiments 22 to 24A, comprising physically supporting said upper plan parts.

[0092] 26. The method of any one of embodiments 1 to 25, wherein said introducing comprises spraying the irrigation solution into the bottom chamber in the form of a mist.

[0093] 27. A method for cultivating potato plants for the purpose of harvesting tubers, comprising: growing potato plants in a cultivation assembly that comprises: two light-sealed chambers, comprising a bottom, root chamber and a top crop chamber, separated by a dividing wall, the crop chamber being defined between said dividing wall and a top wall, and a plurality of first openings formed in the dividing wall, a plurality of second openings formed in the top wall; said growing comprising placing potato plantlets in the top chamber while permitting the roots to extend into the root chamber through the first openings, and a stem of the plant grown from said plantlet to extend through the second openings, and spraying an irrigation solution comprising one or more nutrients to the bottom chamber; periodically harvesting potato tubers from the top chamber; and comprising spraying the irrigation solution into the bottom chamber in the form of a mist.

[0094] 28. The method of embodiment 27 or 28, comprising spraying a solution in the upper chamber in the form of a mist.

[0095] 29. The method of any one of embodiments 26 to 28, wherein the mist is comprised of droplets in the range of 10 to 25 pM. (contrary to common wisdom of 60- 80)

[0096] 30. The method of any one of embodiments 1 to 32, and further comprising trimming the roots in the bottom chamber at least once during a cultivation cycle. 31. A method for cultivating potato plants for the purpose of harvesting tubers, comprising: growing potato plants in a cultivation assembly that comprises: two light-sealed chambers, comprising a bottom, root chamber and a top crop chamber, separated by a dividing wall, the crop chamber being defined between said dividing wall and a top wall, a plurality of first openings formed in the dividing wall, and a plurality of second openings formed in the top wall; said growing comprising placing potato plantlets in the top chamber while permitting the roots to extend into the root chamber through the first openings, and a stem of the plant grown from said plantlet to extend through the second openings, and introducing an irrigation solution comprising one or more nutrients to the bottom chamber; periodically harvesting potato tubers from the top chamber; and comprising trimming the roots in the bottom chamber at least once during a cultivation cycle.

[0097] 31 A. The method of embodiment 30 or 31, wherein the rimming comprises one or more for the following: (i) trimming about 1 / 3 to 2 / 3 of the root at least once during a growth period, (ii) cutting about 10 cm, 20 cm, or 30 cm from the when the roots extend to above 50 cm, (iii) trimming the roots 2-3 times during a growth period.

[0098] 32. The method of embodiment 31, wherein the irrigation to the bottom chamber is aeroponic irrigation and said introducing comprises spraying said irrigation solution to the bottom chambers.

[0099] 32A. The method of embodiment 31, wherein the irrigation of the bottom chamber is hydroponic irrigation.

[0100] 33. The method of any one of embodiments 1 to 32 A, further comprising preparing the irrigation solution by mixing a first solution of water treated by reverse osmosis and a second solution of network water.

[0101] 34. A method for cultivating potato plants for the purpose of harvesting tubers, comprising: growing potato plants in a cultivation assembly that comprises: two light-sealed chambers, comprising a bottom, root chamber and a top crop chamber, separated by a dividing wall, the crop chamber being defined between said dividing wall and a top wall, a plurality of first openings formed in the dividing wall, and a plurality of second openings formed in the top wall; said growing comprising placing potato plantlets in the top chamber while permitting the roots to extend into the root chamber through the first openings, and a stem of the plant grown from said plantlet to extend through the second openings, and introducing an irrigation solution comprising one or more nutrients to the bottom chamber; periodically harvesting potato tubers from the top chamber; and comprising preparing the irrigation solution by mixing a first solution of water treated by reverse osmosis and a second solution of network water.

[0102] 35. The method of embodiment 33 or 34, wherein the irrigation to the bottom chamber is aeroponic irrigation and said introducing comprises spraying said irrigation solution to the bottom chambers.

[0103] 35A. The method of embodiment 33 or 34, wherein the irrigation of the bottom chamber is hydroponic irrigation.

[0104] 36. The method of any one of embodiments 33 to 35A, wherein the irrigation solution is prepared by mixing said first solution, said second solution and a third, nutrient-containing solution.

[0105] 37. The method of any one of embodiments 33 to 36, wherein the mixture of said first and said second solutions gives rise to a mixture with an EC of about 0.1 to 0.7 mS / cm, typically about 0.4 mS / cm.

[0106] 38. The method of embodiment 37, wherein the mixture of said first solution, said second solution and said third solution has an EC of about 1.2 to 1.6 mS / cm.

[0107] 39. The method of any one of embodiments 33 to 39, wherein the pH of the irrigation solution is above about 5, typically about 5.5 to 6.0.

[0108] 40. A method for cultivating potato plants for the purpose of harvesting tubers, comprising: growing potato plants in a cultivation assembly that comprises: two light-sealed chambers, comprising a bottom, root chamber and a top crop chamber, separated by a dividing wall, the crop chamber being defined between said dividing wall and a top wall, a plurality of first openings formed in the dividing wall, and a plurality of second openings formed in the top wall; said growing comprising placing potato plantlets in the top chamber while permitting the roots to extend into the root chamber through the first openings, and a stem of the plant grown from said plantlet to extend through the second openings, and introducing an irrigation solution comprising one or more nutrients to at least the bottom chamber; periodically harvesting potato tubers from the top chamber; and comprising one or more of the following:

[0109] (1) spraying an irrigation solution to the top chambers, the composition of the irrigation solution in the two chambers being different from one another,

[0110] (2) cooling the irrigation solution introduced into the bottom chamber,

[0111] (3) growing potato plant matter to obtain a starter potato plant with a mother tuber and introducing the starter potato plant to the top chamber over one of the first openings to permit the starter potato plants roots to extend into the bottom chamber,

[0112] (4) after said placing, (i) keeping at least one of the sidewalls of the top chamber open for a time to expose the plantlets to light and permit each plantlet to develop a stem of sufficient length with leaves, (ii) extending each stem out of a second opening, and (iii) after said extending closing the at least one open side wall,

[0113] (5) permitting or inducing plant parts that are above the top wall to grow upwards to trail a general upwards path,

[0114] (6) spraying the irrigation solution into the bottom chamber in the form of a mist,

[0115] (7) trimming the roots in the bottom chamber at least once during a cultivation cycle, and

[0116] (8) preparing the irrigation solution by mixing a first solution of water treated by reverse osmosis, a second solution of network water and a third, nutrientcontaining solution. 41. The method of any one of embodiments 1 to 40, comprising placing a light-opaque disc around each plant stem such as to substantially block light penetration into the top chamber through the second openings.

[0117] 42. The method of any one of embodiments 1 to 41, comprising harvesting the potato tubers when reaching a diameter of less than about 25 mm.

[0118] 43. The method of any one of embodiments 1 to 42, wherein the introduction of the irrigation solution into the bottom chamber is in intermittent bursts.

[0119] 44. The method of any one of embodiments 1 to 43, wherein the mother-tuber is removed from the plant after growth of tubers on the potato plant.

[0120] 45. The method of any one of embodiments 1 to 44, wherein the tubers are intended to be used as potato seeds, (namely breeding material)

[0121] 46. A system for cultivating potato plants for the purpose of harvesting tubers, comprising: one or more cultivation assemblies, each comprising: two light-sealed chambers, comprising a bottom, root chamber and a top crop chamber, separated by a dividing wall, the crop chamber being defined between said dividing wall and a top wall, a plurality of first openings formed in the dividing wall, and a plurality of second openings formed in the top wall; an irrigation arrangement configured for introducing an irrigation solution into the root chamber and into the crop chamber; the root chamber being configured for receiving roots of a potato plant extending through said first openings; the crop chamber being configured or intended to maintain a stem of the potato plant during growth thereof and permit extension of the stem through the second opening, and to permit growth therein of stolons and growth of tubers on the stolons; and the irrigation arrangement being configured for separate irrigation of the bottom chamber and of the top chamber.

[0122] 47. The system of embodiment 46, wherein the irrigation solution into the two chambers is introduced by spraying, e.g. in the form of a mist.

[0123] 47A. The system of embodiment 46 or 47, comprising at least one first irrigation sub-system for irrigating the bottom chambers and at least one second irrigation subsystem, separate from said first sub-system, for irrigating the top chambers. 48. The system of embodiment 47A, wherein the first irrigation sub-system is configured for introducing the irrigation solution into the bottom chambers by spraying.

[0124] 49. The system of embodiment 47A or 48, wherein the first irrigation subsystem is configured for introducing the irrigation solution into the bottom chambers in the form of a mist.

[0125] 50. The system of any one of embodiments 47A to 49, wherein the second irrigation sub-system is configured for introducing the irrigation solution into the top chambers by spraying.

[0126] 51. The system of embodiment 50, wherein the second irrigation sub-system is configured for introducing the irrigation solution into the top chambers in the form of a mist.

[0127] 52. The system of any one of embodiments 47 to 51, wherein the first and second irrigation subsystems comprise each (i) at least one high pressure pump for pumping the irrigation solution in the respective irrigation sub-system and (ii) mist- generating nozzles disposed in the bottom and top chambers.

[0128] 53. The system of embodiment 52, wherein the mist produced by the mist- generating nozzles has an average drop size in the range of 10-25 pm.

[0129] 54. The system of any one of embodiments 47 to 53, wherein the first irrigation sub-system comprises a control utility for operating it in an irrigation cycle comprising pulses of irrigation separated by intermittent periods of non-irrigation.

[0130] 55. The system of any one of embodiments 47 to 54, wherein the second irrigation sub-system comprises a control utility for operating it in an irrigation cycle comprising pulses of irrigation separated by intermittent periods of non-irrigation.

[0131] 56. The system of any one of embodiments 46 to 55, wherein at least one of the irrigation solutions is circulated for reuse.

[0132] 57. The system of embodiment 56, wherein the bottom chambers and the top chambers have each a drainage for collecting the respective irrigating solutions from each of the chambers.

[0133] 58. The system of any one of embodiments 46 to 57, further comprising at least one cooling sub-system configured for cooling the irrigation solution intended for the bottom chamber.

[0134] 59. A system for cultivating potato plants for the purpose of harvesting tubers, comprising: one or more cultivation assemblies, each comprising: two light-sealed chambers, comprising a bottom, root chamber and a top crop chamber, separated by a dividing wall, the crop chamber being defined between said dividing wall and a top wall, a plurality of first openings formed in the dividing wall, and a plurality of second openings formed in the top wall; and an irrigation arrangement configured for introducing an irrigation solution into the root chamber; the root chamber being configured for receiving roots of a potato plant extending through said first openings; the crop chamber being configured to maintain a stem of the potato plant during growth thereof and permit extension of the stem through the second opening, and to permit growth therein of stolons and growth of tubers on the stolons; the system further comprises at least one cooling sub-system configured for cooling the irrigation solution intended for the bottom chamber.

[0135] 60. The system of embodiment 58 or 59, wherein the temperature reaching the bottom chamber has a temperature of about 14-18°C.

[0136] 61. The system of any one of embodiments 46 to 60, further comprising at least one installation for growing potato plant matter to obtain a starter potato plant with a mother tuber.

[0137] 62. A system for cultivating potato plants for the purpose of harvesting tubers, comprising: one or more cultivation assemblies, each comprising: two light-sealed chambers, comprising a bottom, root chamber and a top crop chamber, separated by a dividing wall, the crop chamber being defined between said dividing wall and a top wall, a plurality of first openings formed in the dividing wall, and a plurality of second openings formed in the top wall; an irrigation arrangement configured for introducing an irrigation solution into the root chamber; the root chamber being configured for receiving roots of a potato plant extending through said first openings; the crop chamber being configured to maintain a stem of the potato plant during growth thereof and permit extension of the stem through the second opening, and to permit growth therein of stolons and growth of tubers on the stolons; and comprising at least one installation for growing potato plant matter to obtain a starter potato plant with a mother tuber.

[0138] 63. The system of any one of embodiments 46 to 62, further comprising at least one support system above the top chambers for supporting upwards growth of the potato plants.

[0139] 64. A system for cultivating potato plants for the purpose of harvesting tubers, comprising: one or more cultivation assemblies, each comprising: two light-sealed chambers, comprising a bottom, root chamber and a top crop chamber, separated by a dividing wall, the crop chamber being defined between said dividing wall and a top wall, a plurality of first openings formed in the dividing wall, and a plurality of second openings formed in the top wall; an irrigation arrangement configured for introducing an irrigation solution into the root chamber; the root chamber being configured for receiving roots of a potato plant extending through said first openings; the crop chamber being configured to maintain a stem of the potato plant during growth thereof and permit extension of the stem through the second opening, and to permit growth therein of stolons and growth of tubers on the stolons; and comprising at least one support system above the top chambers for supporting upwards growth of the potato plants.

[0140] 64A. The system of any one of embodiments 46 to 64, having at least one pump and a plurality of sprayers disposed in the irrigation arrangement configured for mist irrigation.

[0141] 64B. A system for cultivating potato plants for the purpose of harvesting tubers, comprising: one or more cultivation assemblies, each comprising: two light-sealed chambers, comprising a bottom, root chamber and a top crop chamber, separated by a dividing wall, the crop chamber being defined between said dividing wall and a top wall, a plurality of first openings formed in the dividing wall, and a plurality of second openings formed in the top wall; an irrigation arrangement configured for introducing an irrigation solution into the root chamber; the root chamber being configured for receiving roots of a potato plant extending through said first openings; the crop chamber being configured to maintain a stem of the potato plant during growth thereof and permit extension of the stem through the second opening, and to permit growth therein of stolons and growth of tubers on the stolons; and having at least one pump and a plurality of sprayers disposed in the irrigation arrangement configured for mist irrigation.

[0142] 65. The system of any one of embodiments 46 to 64B, further comprising at least one irrigation solution preparation sub-system configured for mixing at least one first solution of water treated by reverse osmosis, at least one second solution of network water and at least one third, nutrient-containing solution.

[0143] 66. A system for cultivating potato plants for the purpose of harvesting tubers, comprising: one or more cultivation assemblies, each comprising: two light-sealed chambers, comprising a bottom, root chamber and a top crop chamber, separated by a dividing wall, the crop chamber being defined between said dividing wall and a top wall, a plurality of first openings formed in the dividing wall, and a plurality of second openings formed in the top wall; and an irrigation arrangement configured for introducing an irrigation solution into the root chamber; the root chamber being configured for receiving roots of a potato plant extending through said first openings, and the crop chamber being configured to maintain a stem of the potato plant during growth thereof and permit extension of the stem through the second opening, and to permit growth therein of stolons and growth of tubers on the stolons; the system being characterized in that it comprises at least one irrigation solution preparation sub-system for feeding the irrigation solution to the root chamber and configured for mixing at least one first solution of water treated by reverse osmosis, at least one second solution of network water and at least one third, nutrient-containing solution.

[0144] 67. A system for cultivating potato plants for the purpose of harvesting tubers, comprising: one or more cultivation assemblies, each comprising: two light-sealed chambers, comprising a bottom, root chamber and a top crop chamber, separated by a dividing wall, the crop chamber being defined between said dividing wall and a top wall, a plurality of first openings formed in the dividing wall, and a plurality of second openings formed in the top wall; an irrigation arrangement configured for independently introducing different irrigation solutions into the root chamber and the crop chamber; the root chamber being configured for receiving roots of a potato plant extending through said first openings; the crop chamber being configured to maintain a stem of the potato plant during growth thereof and permit extension of the stem through the second opening, and to permit growth therein of stolons and growth of tubers on the stolons; the system further comprising one or more of the following (a) to (f):

[0145] (a) having separate irrigation sub-systems for irrigating the bottom chambers and the top chambers,

[0146] (b) having at least one cooling sub-system configured for cooling the irrigation solution intended for the bottom chamber,

[0147] (c) having at least one installation for growing potato plant matter to obtain a starter potato plant with a mother tuber,

[0148] (d) having at least one support system above the top chambers for supporting upwards growth of the potato plants,

[0149] (e) having at least one pump and a plurality of sprayers disposed in the irrigation sub-system configured for mist irrigation,

[0150] (f) having at least one irrigation solution preparation sub-system configured for mixing at least one first solution of water treated by reverse osmosis, at least one second solution of network water and a at least one third, nutrient-containing solution.

[0151] 68. The system of any one of embodiments 46 to 67, comprising light-opaque discs configured for placing around each plant stem such as to substantially block light penetration into the top chamber through the second openings.

[0152] 69. The System of any one of embodiments 46 to 68, wherein at least one of the said light-sealed chambers are configured as an elongated element.

[0153] 70. The system of embodiment 69, wherein said elongated element is defined between a top, a bottom wall and lateral side wall, having a plurality of first openings in the bottom wall and a plurality of second opening in the top wall, and having a side wall portion that may be opened permitting access into the top chamber.

[0154] 71. The system of embodiment 69 or 70, wherein said crop channel has side walls made of a light-opaque sheet that can be lifted or downfolded to open said channel.

[0155] 72. The system of any one of embodiments 69 to 71 , wherein said root channel is defined between said dividing wall that has a first width, and an elongated flexible sheet light-opaque of a second width larger than first width extending between two sheet edges that are attached to edges of the dividing wall.

[0156] 73. The System of any one of embodiments 46 to 72, wherein at least one the crop chambers is configured as a pot, each with a top wall and a base that defines the dividing wall and having one or more openings in it, the pot having a side wall that can be opened, and said pot being positioned on a rack with the root chamber being defined by a light sealed chamber below the rack.

[0157] BRIEF DESCRIPTION OF THE DRAWINGS

[0158] In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

[0159] Figs. 1 is a schematic diagram of the irrigation sub-system of an exemplary embodiment of a system of this disclosure. Figs. 2A-7 are graphical renderings of photographs of actual systems of this disclosure in experimental setting, illustrating examples of the channel embodiment of this disclosure, wherein:

[0160] Figs. 2A-2B show the system with the top chamber opened, immediately after introducing potato plantlets into the top chamber;

[0161] Figs. 3A-3B show the system with the top chamber opened, in a more advanced stage of growth in which the stems of the potato plants are made to extend out through the second openings;

[0162] Figs. 4A-4C show the system with the top chamber opened, in a more advanced stage of growth in which the stems of the potato plants are made to extend out through the second openings;

[0163] Figs. 5A-5B shows the system with the bottom chamber opened, showing the roots after being trimmed;

[0164] Figs. 6A-6D shows the system with the top chamber opened, showing the stolons and the many tubers grown on them; and

[0165] Fig- 7 shows the system with the top chamber opened, showing the stolons and the many tubers grown on them of a variety other than that of Figs. 6A-6D.

[0166] Figs. 8A-8D are schematic illustrations of an example of a pot for use in the pot embodiment of this disclosure; wherein Fig 8A is an isometric view of the pot, Fig. 8B shows the upper member, Fig. 8C shows the upper member with the closure of the top chamber and Fig. 8D shows the bottom member in isolation.

[0167] DETAILED DESCRIPTION OF EMBODIMENTS

[0168] Reference is first made to Fig. 1 showing a schematic diagram of an irrigation assembly 100 of an exemplary embodiment of this disclosure. The greenhouse cultivation area, represented schematically by rectangle 102, has a plurality of cultivation assemblies with corresponding plurality of top chambers and bottom chambers schematically represented by rectangles 104 and 106, respectively.

[0169] Fresh, line water is introduced at 108 passing through a filer 110 to reach a bifurcation 112, a first portion of the water flowing through reverse osmosis arrangement 114, having a brine drain 116 and propelled by a pressure pump 117, a second portion flowing through a parallel, free flow line 118 (the flow being propelled by the pressure of the introduced water 108). The first solution egressing from the reverse osmosis arrangement and the free-flowing line water (also referred herein as the "second solution") are then mixed at 120 and the mixture can then flow through line 122 into tank 124

[0170] Fitted on line 122 is an EC sensor 126 that is connected to a control utility 128 (to avoid cluttered illustration, electrical and data connections between elements are not shown), which is in turn connected to and controls electric valve 130 on line 118. Through this control, the relative flow of untreated water through line 118 is regulated to achieve an EC of the mixture of the first and second solutions to be between about 0.1 to about 0.7 mS / cm, typically 0.2 to 0.6 mS / cm or even about 0.4 mS / cm. The pH of the mixture is typically above 5 and usually about 5.4.

[0171] The tank 124 has a level gauge 132 that controls an electrical valve 134 fitted on line 122 such that when the level reaches a maximum level the valve 134 is closed to prevent overflow. Gauge 132 may also be connected to controller 128 and when the level in tank 124 reaches a maximum, the reverse osmosis arrangement may be shut. Once the level of the mixture in tank 124 is reduced, valve 134 opens and the reverse osmosis arrangement is activated.

[0172] The irrigation assembly 100 has two subassemblies 136 and 138, for preparation of the irrigation solution by the addition of one or more nutrients and delivering it to the respective top and bottom chambers 104 and 106. Subassemblies 136 and 138 may be similar, the main difference being the type of nutrients that may be added. While Subassembly 138 is typically configured to deliver several nutrients to the bottom chambers and, hence, to the roots, subassembly 136 may be configured to deliver different nutrients, for example such that are effective in hardening the skin of the tubers, or no nutrients at all.

[0173] The subassembly 138 will not be described. The corresponding elements in subassembly 136 are denoted with a prime (‘) indication and have a similar function to the corresponding elements of subassembly 138.

[0174] Subassembly 138 has an irrigation solution preparation arrangement 140 that includes a pump 142 a plurality of nutrient reservoirs 144 (3 in this example) and a tank 146. The mixture from tank 124 is drawn by pump 142, through feeding line 143, into tank 146 where it is mixed with nutrients from reservoirs 144. The nutrient solutions, referred to above as “third solution”, may be drawn into tank 146 by individual pumps (not shown), may be fed gravitationally into tank 146 through lines with a flow control valve, pump 142 may be configured to draw solutions from all sources - namely from tank 124 and from each of reservoirs 144, etc. An irrigation solution is, thus, produced, which is fed to the bottom chambers 106. The mixing arrangement may also have an EC sensor, similar to element 126, to control the amount of the one or more third solutions so that the EC will be within about 0.8 to 1.5 mS / cm, e.g. about 1.2 mS / cm. Under such conditions, the irrigation solution will mostly have a pH that is similar to that of the mixture of the first and second solution.

[0175] Subassembly 138 also comprises an irrigation solution reservoir 150 and a pump 152 that feeds the irrigation solution from reservoir 150, through feed line 154, to the bottom chambers 106. Where the irrigation is an aeroponic irrigation, pump 152 needs to be high pressure pumps. Subassembly 138 also comprises a return line 156 that feeds unused irrigation solution back to reservoir 150. However, the recycling of the irrigation solution is not complete as some water may evaporate, nutrients may be depleted as they are absorbed by the roots, etc., the irrigation solution in the in reservoir 150 is periodically supplemented from arrangement 140, for example by a pump (not shown). Additionally, to ensure a consistent composition of the irrigation solution in reservoir 150 a portion of it (e.g. 5-20%) may be periodically discarded, e.g. once daily, and replaced by fresh irrigation solution from arrangement 140. All this is controlled by controller 128 through pumps and / or electrically controlled valves, as know per se.

[0176] Reservoir 150 has an associated cooling unit 160 for cooling the irrigation solution within the reservoir. Typically, the feed line 154 is thermally isolated such that the temperature in which the solution is sprayed at the bottom chamber is between about 14 to 18 °C, typically about 16°C.

[0177] The pump 152 may be used to control the irrigation schedule. As noted above, it may, for example, be operated in an irrigation cycle that includes bursts of irrigation separated by idle periods with not irrigation.

[0178] Reference is now made to Figs. 2A-2B showing potato plantlets 204 that are placed in the top chamber 202 of a cultivation assembly 200 of an exemplary channel embodiment, that is shown open with its side walls 206, made of a light-opaque flexible polymeric sheet, being down-folded. The side walls 206 can be seen in their closed state in Figs. 5B and 6A. As can be seen in Figs. 2A-2B, each of the plantlets 204 extends from a tuber (mother tuber, not seen) that is embedded in bottom portion of a porous inert substrate 208 having a major, upper portion 210 and a small, bottom portion 212. The substrate 208 may, for example, be rock wool. The substrate is placed over a first opening (not seen) in the dividing wall 214. In other embodiments, the mother tuber may be placed at the bottom of substrate 208 with the growing roots extending directly into the bottom chamber through the first openings. The bottom chamber is defined between the dividing wall 214 and a flexible elongated sheet 216 that has a width that is larger than that of the dividing wall 214, whereby the sheet assumes the general form of a trough or that of an elongated sack, providing a space for elongation of the roots that extend through the first openings into the bottom chamber.

[0179] The top chamber is defined between the dividing wall 214, a top wall 215 and two side walls constituted by the two flexible sheets 206. A plurality of second openings 217 are formed in the top wall 215.

[0180] As can also be seen in Figs. 2A-2B, feed lines 154, 154’ (the prime indication of some elements in the top chamber is done consistent with such indication made in Fig. 1) that are wrapped together by a thermal isolation material, have branched-off lines 218, 218’ that feed cooled irrigation solution into the respective bottom and top chambers. Both chambers have a plurality of spraying nozzles for spraying a mist. Such nozzles 220’ in the top chamber, that can best be seen in Fig. 6C-6D, are fitted on an irrigation line 222’. Similar spraying nozzles are also found in the bottom chamber.

[0181] Figs. 3 A-3B show the system after an additional growth period, for example, after about 1-3 weeks, typically about 2 weeks, in which the side walls are kept open, i.e. down- folded, until the stems of the plants can be extended out of the second openings 217. As can best be seen in Fig. 4C, once the stems 224 extend to a significant extent, they are inserted through the second openings 217 such that the upper plant parts 226 continue to develop and grow above the second chamber 106. As can further be seen, particularly in Fig. 4C, the second openings 217 are sealed by light-opaque discs 228 that are configured for placing around each plant stem such as to substantially block light penetration into the top chamber through the second openings. The discs 228, in this example, have a slit extending from its center to the periphery and have a central void dimensioned to snugly fit around a potato plant stem 224. As can further be seen in Figs. 3 A-3B, there is a support system 230 above the top chamber for supporting upwards growth of the potato plants. The support system 230 in this exemplary embodiment has several parallel and horizontally oriented wire nets 232 that support the vegetative parts of the plants from leaning sideways such that they grow substantially upwards, as can be seen in Figs. 4A-4B, 5B and 6A. As noted above, this is contrary to the general acceptable practice of yield improvement that involves trimming the vegetative parts of potato plants grown in an incubator or nursery.

[0182] One of the findings of this disclosure is that trimming of the roots one to several times during a growth period, typically 2-3 times, increases the yield of the tubers that may be harvested during a growth period. For example, the roots may be trimmed by about 10-30 cm, 2-3 times during a growth period. Figs. 5A-5B show the exposed roots that were trimmed by cutting of about a 1 / 3 of their length, with the sheet 216 that defines the bottom chamber being lowered to expose the roots that were trimmed a day earlier. As can be seen, the roots 240 rapidly begin to produce new hyperactive root extension 242 and without wishing to be bound by theory, it is believed that it is these root extensions that provide new vigor to the plant or generates a stress signal that causes an increase in tuber production.

[0183] As can be seen for one potato variety in Figs. 6A-6D and another potato variety in Fig. 7, each of the plants produces many tubers 244, that grow primarily on stolons 246 that can be seen in their initial growth stage in Figs. 2A, 4B and 4C and in their more advanced growth stages, each carrying many tubers, in Figs. 6A-6D and Fig. 7. As can be seen in Fig. 6A, for harvesting, one of the sheets 206 constituting the sides walls of the upper chamber 202 is opened and tubers of appropriate size, typically such having a diameter that is between about 15 to 25 mm, may be harvested, the sheet 206 can then be pulled upwards to close the upper chamber for another 1 or a few days by which it can be opened for another harvest.

[0184] Reference is now made to Figs. 8A-8D showing an exemplary pot useful in the pot embodiment of this disclosure. The pot 300 consists of a top member 302 with a top opening that is closed by a cover 304 to define a top chamber 306 and a bottom member 308 that can be snapped into engagement with the top member and, thus, jointly with the bottom wall 310 of member 302 defines a bottom chamber, wall 310 being the dividing wall between the two chambers. The top chamber has a closure 312 that can be opened by sliding it in the direction represented by arrow 314 with the aid of grip 316 and closed in the opposite direction, this sliding opening and closing being guided by a track 317 in the periphery of bottom wall 310 and a corresponding track (not shown) in the inner face of the cover 304.

[0185] Formed in wall 310 are a plurality of first openings 318 (three in this example) and formed in closure 304 are a plurality of second opening 320, the former opening permitting extension of the routes into the bottom chamber and the latter extension of the stem and the vegetative parts of the plant above the cover 304. The tubers can be periodically harvested by opening closure 312, picking the tubers that meet predefined size, typically a diameter between about 15mm to about 25mm, closing closure 312 and repeating this every few days.

[0186] By other embodiments, the top member may be placed on a rack with the bottom chamber defined by an installation below the rack. Such a rack may be configured to receive a plurality of such top members, all having separate or common bottom chamber.

Claims

CLAIMS:

1. A method for cultivating potato plants for the purpose of harvesting tubers, comprising: growing potato plants in a cultivation assembly that comprises: two light-sealed chambers, comprising a bottom, root chamber and a top crop chamber, separated by a dividing wall, the crop chamber being defined between said dividing wall and a top wall, a plurality of first openings formed in the dividing wall, a plurality of second openings formed in the top wall; said growing comprising placing potato plantlets in the top chamber while permitting the roots to extend into the root chamber through the first openings, and a stem of the plant grown from said plantlet to extend through the second openings, and introducing an irrigation solution comprising one or more nutrients to at least the bottom chamber; periodically harvesting potato tubers from the top chamber; and comprising one or more of the following:(1) spraying an irrigation solution to the top chambers, the composition of the irrigation solution in the two chambers being different from one another,(2) cooling the irrigation solution introduced into the bottom chamber,(3) growing potato plant matter to obtain a starter potato plantlets with a mother tuber and introducing the starter potato plantlets to the top chamber over one of the first openings to permit the starter potato plantlets roots to extend into the bottom chamber,(4) after said placing, (i) keeping at least one of the sidewalls of the top chamber open for a time to expose the plantlets to light and permit each plantlet to develop a stem of sufficient length with leaves, (ii) extending each stem out of a second opening, and (iii) after said extending closing the at least one open side wall,(5) permitting or inducing plant parts that are above the top wall to grow upwards to trail a general upwards path,(6) spraying the irrigation solution into the bottom chamber in the form of a mist,(7) trimming the roots in the bottom chamber at least once during a cultivation cycle, and(8) preparing the irrigation solution by mixing a first solution of water treated by reverse osmosis, a second solution of network water and a third, nutrient-containing solution.

2. The method of claim 1, wherein said introducing comprises spraying said irrigation solution to the bottom chambers.

3. The method of any one of claim 1 or 2, wherein the irrigation of the bottom chamber is in pulses of irrigation separated by intermittent periods of non-irrigation.

4. The method of any one of claims 1 to 3, wherein the irrigation solutions are circulated for reuse.

5. The method of any one of claims 1 to 4, wherein the irrigation solution introduced into the bottom chamber is cooled.

6. The method of any one of claims 1 to 5, wherein the irrigation solution introduced into the bottom chamber has a temperature within the bottom chamber of about 14-18°C.

7. The method of any one of claims 1 to 6, wherein a mother tuber of said plantlet is fitted in a bottom portion of a porous substrate and the roots are permitted to extend into the bottom chamber.

8. The method of claim 7, wherein said mother tuber is embedded within said porous substrate.

9. The method of any one of claims 1 to 8, wherein one or both of the side walls are kept open after said placing for about 15 to about 30 days.

10. The method of any one of claims 1 to 9, comprising physically supporting said upper plan parts to cause them to grow upwards.

11. The method of any one of claims 1 to 10, wherein said introducing comprises spraying the irrigation solution into the bottom chamber in the form of a mist.

12. The method of claim 11, wherein the mist is comprised of droplets in the range of 10 to 25 pM.

13. The method of any one of claims 1 to 12, and further comprising trimming the roots in the bottom chamber at least once during a cultivation cycle.

14. The method of any one of claims 1 to 13, comprising irrigating the bottom chamber with an irrigation solution prepared by mixing said first and said second solution to obtain a mixture with an EC of about 0.1 to 0.7 mS / cm and mixing said mixture withsaid third solution to obtain said irrigation solution having an EC of about 1.2 to 1.6 mS / cm.

15. The method of any one of claim 14, wherein the pH of the irrigation solution is above about 5.

16. The method of any one of claims 1 to 15, comprising placing a light-opaque disc around each plant stem such as to substantially block light penetration into the top chamber through the second openings.

17. The method of any one of claims 1 to 16, comprising harvesting the potato tubers when reaching a diameter of up to about 25 mm.

18. The method of any one of claims 1 to 17, wherein the mother-tuber is removed from the plant after growth of tubers on the potato plant.

19. A system for cultivating potato plants for the purpose of harvesting tubers, comprising: one or more cultivation assemblies, each comprising: two light-sealed chambers, comprising a bottom, root chamber and a top crop chamber, separated by a dividing wall, the crop chamber being defined between said dividing wall and a top wall, a plurality of first openings formed in the dividing wall, and a plurality of second openings formed in the top wall; an irrigation arrangement configured for independently introducing different irrigation solutions into the root chamber and the crop chamber; the root chamber being configured for receiving roots of a potato plant extending through said first openings; and the crop chamber being intended or configured to maintain a stem of the potato plant during growth thereof, permit extension of the stem through the second opening, and to permit growth therein of stolons and growth of tubers on the stolons; the system further comprising one or more of the following (a) to (f):(a) having separate irrigation sub-systems for irrigating the bottom chambers and the top chambers,(b) having at least one cooling sub-system configured for cooling the irrigation solution intended for the bottom chamber,(c) having at least one installation for growing potato plant matter to obtain a starter potato plant with a mother tuber,(d) having at least one support system above the top chambers for supporting upwards growth of the potato plants,(e) having at least one pump and a plurality of sprayers disposed in the irrigation arrangement configured for mist irrigation,(f) having at least one irrigation solution preparation sub-system configured for mixing at least one first solution of water treated by reverse osmosis, at least one second solution of network water and a at least one third, nutrient-containing solution.

20. The system of claim 19, configured for introducing the irrigation solution into the bottom chamber by spraying.

21. The system of claim 20, configured for introducing the irrigation solution into the bottom chamber in the form of a mist.

22. The system of any one of claims 19 to 21 , configured for introducing the irrigation solution into the top chamber by spraying.

23. The system of claim 22, configured for introducing the irrigation solution into the top chamber in the form of a mist.

24. The system of any one of claims 20 to 23, comprising first irrigation subsystem for irrigation of the root chamber and a second irrigation subsystem for for irrigation of the crop chamber, the two irrigation subsystems comprise each (i) at least one high pressure pump for pumping the irrigation solution in the respective irrigation sub-system and (ii) mist-generating nozzles disposed in the bottom and top chambers.

25. The system of claim 24, wherein the mist produced by the mist-generating nozzles has an average drop size in the range of 10-25 pm.

26. The system of any one of claims 19 to 25, comprising a control utility controlling introduction of irrigation solution into the bottom chamber in an irrigation cycle comprising pulses of irrigation separated by intermittent periods of non-irrigation.

27. The system of any one of claims 19 to 26, comprising a control utility controlling introduction of irrigation solution into the top chamber in an irrigation cycle comprising pulses of irrigation separated by intermittent periods of non-irrigation.

28. The system of any one of claims 19 to 27, wherein the irrigation solutions are circulated for reuse.

29. The system of any one of claims 19 to 28, wherein the irrigation solution introduced into the bottom chamber has a temperature of about 14-18°C.

30. The system of any one of claims 19 to 29, further comprising at least one support system above the top chambers for supporting upwards growth of the potato plants.

31. The system of any one of claims 19 to 30, comprising light-opaque discs configured for placing around each plant stem such as to substantially block light penetration into the top chamber through the second openings.

32. The System of any one of claims 19 to 31, wherein the said light-sealed chambers are configured as elongated elements.

33. The system of any one of claims 19 to 31, wherein the said light-sealed chambers are configured as pots.

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