Method for regulating growth of plant

Abstract

The present invention addresses the problem of providing a method capable of effectively regulating the growth of a plant. The growth of a plant can be effectively regulated by this method comprising: (A) a step for growing the plant in the presence of hematite; and (B) a step for growing the plant in substantially the absence of hematite.

Description

Methods for regulating plant growth

[0001] The present invention relates to a method for regulating plant growth, and the like.

[0002] In the agricultural field, regulating plant growth is an important technique for improving plant productivity. Currently, various types of plant growth regulation methods and plant growth regulators are in practical use, contributing to increased crop yields and improved product quality. In regulating plant growth, non-natural organic compounds are mainly used as so-called pesticides. However, since non-natural organic compounds may raise concerns about their safety for humans and animals and their impact on the environment, various research efforts are being conducted to improve and devise cultivation methods, use useful microorganisms, use light of specific wavelengths, and utilize organic agricultural materials.

[0003] Specific surface area (BET) is 70 to 200 m ２ / g, hematite (ALPHA-Fe ２ O ３ It is known that iron oxides such as hematite and ferric iron oxides such as ferric iron oxides (Patent Document 1) can be used as inhibitors of plant diseases. However, it was not known what effects, for example, the timing of growing plants in the presence and substantial absence of hematite would have on the plants.

[0004] Japanese Patent Application Laid-Open No. 2019-167338

[0005] An objective of the present invention is to provide a method capable of effectively regulating plant growth.

[0006] As a result of extensive research, the present inventors have found that plant growth can be effectively regulated by a method comprising the steps of growing a plant in the presence of hematite and growing the plant substantially in the absence of hematite. The present invention was completed based on this finding.

[0007] That is, the present invention is as specified by the following features: [1] A method for regulating plant growth, comprising: (A) growing the plant in the presence of hematite; and (B) growing the plant substantially in the absence of hematite. [2] The method for regulating plant growth according to [1] above, wherein step (B) is carried out after step (A). [3] The method for regulating plant growth according to [2] above, wherein regulating plant growth comprises suppressing the plant growth by step (A) and then promoting the plant growth by step (B). [4] The method for regulating plant growth according to [2] or [3] above, wherein regulating plant growth comprises increasing the mass of the plant body. [5] The method for regulating plant growth according to [1] above, wherein step (A) is carried out after step (B). [6] The method for regulating plant growth according to [5] above, wherein regulating plant growth comprises promoting acclimatization of the plant to the growth environment. [7] The method for regulating plant growth according to [5] or [6] above, wherein regulating plant growth is one or more selected from the group consisting of promoting flowering of the plant, increasing plant width, increasing plant height, increasing root mass, and improving heat tolerance. [8] A plant growth regulator containing hematite for use in the methods described in any one of [1] to [7] above and

[11] to

[19] and

[21] to

[22] below. [9] A culture medium containing hematite for use in the methods described in any one of [1] to [7] above and

[11] to

[19] and

[21] to

[22] below.

[10] A method for producing a plant, comprising regulating plant growth by the method described in any one of [1] to [7] above and

[11] to

[19] and

[19] below.

[0008] Other embodiments of the present invention include, for example, the following.

[11] The method for regulating plant growth according to any one of [2] to [4] above, further comprising a step of sowing the plant in the presence of hematite before step (A).

[12] The method for regulating plant growth according to any one of [2] to [4] and

[11] above, wherein regulating plant growth is promoting the growth of the plant compared to a case in which step (A) is not included.

[13] The method for regulating plant growth according to any one of [2] to [4] and

[11] to

[12] above, wherein the plant is a plant whose leaves are edible.

[14] The method for regulating plant growth according to any one of [2] to [4] and

[11] to

[13] above, wherein the plant is Chinese cabbage, cabbage, Nozawana, Komatsuna, Bok Choy, kale, Garland chrysanthemum, lettuce, spinach, onion, or leek.

[15] The method for regulating plant growth according to any one of [5] to [7] above, further comprising the step of sowing the plant in the substantial absence of hematite before step (B).

[16] The method for regulating plant growth according to any one of [5] to [7] and

[15] above, wherein regulating plant growth promotes acclimatization of the plant to the growth environment compared to a case in which step (A) is not included.

[17] The method for regulating plant growth according to any one of [5] to [7] and

[15] to

[16] above, wherein the plant is cultivated for the purpose of obtaining flowers, fruits, seeds, or roots.

[18] The method for regulating plant growth according to any one of [5] to [7] and

[15] to

[17] above, wherein the plant is a pansy, petunia, cyclamen, orchid, tulip, lily, chrysanthemum, rose, gentian, gypsophila, statice, gerbera, bellflower, alstroemeria, carnation, turnip, radish, wasabi, tomato, eggplant, potato, bell pepper, chili pepper, rice, wheat, barley, corn, burdock, carrot, lotus root, taro, konjac, Chinese yam, Chinese yam, cucumber, watermelon, pumpkin, melon, bitter melon, zucchini, soybean, pea, or strawberry.

[19] The method for regulating plant growth according to any one of [1] to [7] and

[11] to

[18] above, wherein step (A) is growing a plant in a culture medium containing hematite, and / or step (B) is growing a plant in a culture medium substantially free of hematite.

[20] A plant cultivation kit containing hematite for use in the method according to any one of [1] to [7] and

[11] to

[19] above.

[21] A method for producing a plant whose growth is regulated, comprising: (A) growing the plant in the presence of hematite, and (B) growing the plant substantially in the absence of hematite.

[22] The method according to

[21] above, having the characteristics according to any one of [2] to [7] and

[11] to

[19] above.

[0009] Further, other embodiments of the present invention can include, for example, the following. 1) Use of hematite for the method described in any one of [1] to [7],

[11] to

[19] , and

[21] to

[22] above. 2) Use of a plant growth regulator containing hematite for the method described in any one of [1] to [7],

[11] to

[19] , and

[21] to

[22] above. 3) Use of a culture medium containing hematite for the method described in any one of [1] to [7],

[11] to

[19] , and

[21] to

[22] above. 4) Use of a plant cultivation kit containing hematite for the method described in any one of [1] to [7],

[11] to

[19] , and

[21] to

[22] above. 5) Use of hematite for producing a plant growth regulator for use in the method described in any one of [1] to [7],

[11] to

[19] , and

[21] to

[22] above. 6) Use of hematite for producing culture soil for use in any of the methods described above in [1] to [7],

[11] to

[19] , and

[21] to

[22] . 7) Use of hematite for producing a plant cultivation kit for use in any of the methods described above in [1] to [7],

[11] to

[19] , and

[21] to

[22] .

[0010] According to the present invention, plant growth can be effectively regulated.

[0011] This is an image of sunny lettuce taken on November 22nd (33 days after sowing) in a sunny lettuce cultivation test. This is an image of sunny lettuce taken on January 6th (78 days after sowing) in a sunny lettuce cultivation test. This is an image of sunny lettuce taken on February 5th (108 days after sowing) in a sunny lettuce cultivation test. This is an image of cos lettuce taken on February 27th (32 days after sowing) in a cos lettuce cultivation test. This is an image of the cross-section of cos lettuce harvested on May 10th (104 days after sowing) in a cos lettuce cultivation test. This is an image of pansies (variety name: cranberry) taken on December 20th (113 days after sowing) in a pansy cultivation test (2).

[0012] (Method for regulating plant growth) The method for regulating plant growth of the present invention (hereinafter sometimes simply referred to as the "method of the present invention") comprises the steps of (A) growing the plant in the presence of hematite, and (B) growing the plant substantially in the absence of hematite. The method of the present invention may also include steps other than step (A) and step (B), as appropriate. Furthermore, the method of the present invention may be used in combination with other methods.

[0013] (Hematite) In the present invention, hematite (ALPHA-Fe), which is a type of iron oxide, is used. ２ O ３ ) is used. Hematite may be natural or industrially produced as long as the desired effect is obtained. Hematite can be obtained, for example, from natural ores. Also, for example, goethite (ALPHA-FeOOH) can be dehydrated by heating (2FeOOH → Fe ２ O ３ +H ２ Hematite is stable even when in contact with water, so the effects of the present invention can be maintained for a long period of time. In addition, hematite is safe for humans and animals, and has low environmental impact and is safe.

[0014] Hematite, for example, has a specific surface area (BET) of 70 m ２ / g or more, and ２ / g, and hematite, 70 to 170m ２ / g, and hematite with a value of 70 to 140 m ２ / g, and hematite with a 70-120m ２ / g, and hematite, 80-110m ２ Hematite having a specific surface area (BET) of 1 / g can be used. Here, the specific surface area (BET) is the surface area per unit mass (m ２ When hematite having a relatively large specific surface area (BET) is used, the active sites per unit mass become larger, and the effect can be exerted more efficiently.

[0015] The size of the hematite particles is not particularly limited as long as the desired effect is obtained, but examples thereof include an average particle diameter of 10 μm or less. The shape of the hematite is not particularly limited as long as the desired effect is obtained, but examples thereof include powder, granules, needles, spindles, and spheres.

[0016] In addition to hematite, other iron oxides include goethite (ALPHA-FeOOH), maghemite (GAMMA-Fe ２ O ３ ), magnetite (Fe ３ O ４ ), acacia (BETA-FeOOH), lepidocrocite (GAMMA-FeOOH), wustite (FeO), limonite (FeOOH.nH ２ O), and the like, and although it is possible to use iron oxides of these, hematite is preferred.

[0017] (In the Presence of Hematite) In step (A) of the present invention, "in the presence of hematite" refers to conditions in which hematite is present. The conditions are not particularly limited as long as the desired effect is obtained. For example, hematite can be applied using the usual methods for applying pesticides and fertilizers. It may be applied to the plant itself, to the medium in which the plant is grown, or a combination thereof. That is, hematite may be present in the plant itself, in the medium in which the plant is grown, or a combination thereof. Application to the plant may be by spraying or coating the plant, or by immersing the plant. Hematite may be applied to the entire plant or to a part of the plant. Hematite may be applied to, for example, the entire above-ground or underground part of the plant. Examples of parts of the plant include leaves, stems, trunks, roots, flowers, fruits, seeds, or two or more thereof. When hematite is applied to leaves, it may be applied to only one or both of the upper and lower surfaces of the leaves. Specific examples of application to plants include foliage spraying and root immersion. The medium for plant cultivation can be appropriately selected depending on various conditions, such as the type of plant and the cultivation method, and examples include potting soil, hydroponic culture solution, and solid medium. The medium may also contain, for example, sand, soil, fiber, glass beads, resin, foam, sponge, rock wool, solidifying agents (e.g., agar, xanthan gum, etc.), water, fertilizer, pesticides, and other chemicals. Application to the medium can be by spraying, irrigating, or mixing. Application to the medium should be carried out so that hematite is present or reaches the rhizosphere of the plant, i.e., the area where the roots extend and come into contact. The effects of the present invention are presumed to be produced by the reaction between the active sites of hematite and the plant's secretions (substrate). Specific examples of "in the presence of hematite" include "medium containing hematite," "culture soil containing hematite," "culture solution containing hematite," "solid medium containing hematite," "under irrigation with hematite," and / or "under spraying with hematite."

[0018] The application amount (amount present) of hematite is not particularly limited as long as the desired effect is obtained, and can be appropriately selected depending on the type of target plant, cultivation method, growth stage, cultivation purpose, type and level of environmental stress, plant condition, etc. The appropriate application amount of hematite can be found without undue experimentation by referring to the examples described below and / or by experimenting with several conditions. For example, when hematite is applied to (present in) a medium in which a plant is cultivated, the medium (e.g., culture soil, hydroponic culture solution, solid medium, etc.) contains hematite in an amount of, for example, 0.1% (w / v) or more, 0.2% (w / v) or more, 0.3% (w / v) or more, 0.5% (w / v) or more, 0.7% (w / v) or more, 1% (w / v) or more, 2% (w / v) or more, 3% (w / v) or more, 4% (w / v) or more, or 5% (w / v) or more. The hematite content may be, for example, 10% (w / v) or less, 8% (w / v) or less, 6% (w / v) or less, 5% (w / v) or less, 4% (w / v) or less, 3% (w / v) or less, 2% (w / v) or less, or a combination thereof, for example, 0.1-10% (w / v), 0.5-8% (w / v), 0.7-7% (w / v), 1-5% (w / v), 2-5% (w / v), 1-4% (w / v), 1-3% (w / v), etc. Note that when calculating the hematite content, the dry weight of hematite is used. The medium may be considered in its normal state of use. For example, when using a commercially available product (e.g., commercially available potting soil or a mixture thereof) as the medium, the content may be calculated based on the labeled volume of the product.

[0019] Furthermore, for example, when hematite is applied to a plant (to be present in the plant itself), the hematite may be applied as is or as a composition containing hematite. The composition may contain hematite, for example, at 0.01 to 10% (w / v), 0.05 to 5% (w / v), 0.1 to 3% (w / v), or 0.15 to 2% (w / v). The composition may optionally contain one or more other components. The other components are not particularly limited as long as the desired effect is achieved, and examples thereof include additives such as carriers, excipients, binders, disintegrants, lubricants, stabilizers, antioxidants, diluents, dispersants, adjuvants, surfactants, spreading agents, pH adjusters, colorants, UV absorbers, antistatic agents, preservatives, water, alcohol, vitamins, and minerals. The formulation of the composition may be, for example, a dust, wettable powder, emulsifiable concentrate, flowable concentrate, suspension, water-soluble concentrate, water-dispersible granule, tablet, granule, SE agent (Suspo Emulsion), OD agent (Oil Dispersion), EW agent (Emulsion oil in water), etc., or may be, for example, a water suspension, etc. During the step (A), the hematite may be applied once or twice or more times.

[0020] (Substantially in the absence of hematite) In step (B) of the present invention, "substantially in the absence of hematite" refers to conditions in which hematite is substantially absent, and the conditions are not particularly limited as long as the desired effect is obtained. This can also be referred to as conditions other than the above-mentioned "in the presence of hematite." Specific examples include "substantially hematite-free medium," "substantially hematite-free culture soil," "substantially hematite-free culture solution," "substantially hematite-free solid medium," "substantially without irrigation of hematite," and / or "substantially without spraying of hematite."

[0021] Here, "substantially" hematite-free means that hematite may be present in small amounts, but not in effective amounts, and also encompasses the complete absence of hematite. "Small amounts" refers to, for example, the hematite content in a medium (e.g., culture soil, hydroponic culture solution, solid medium, etc.) in which plants are grown being less than 0.1% (w / v), less than 0.05% (w / v), less than 0.01% (w / v), or less than 0.005% (w / v). Because hematite is a naturally occurring substance, it may be unintentionally contained in a medium (e.g., culture soil, hydroponic culture solution, solid medium, etc.) in which plants are grown. However, the amount contained in a typical medium is usually small, even if present. Therefore, when hematite is intentionally not present (not added), it can usually be said to be "substantially hematite-free." Also, when a plant is repotted from an area where hematite is present (e.g., a soil containing hematite), for example, some hematite may be attached to the roots of the plant, but most of the roots will then grow into an area where hematite is substantially absent (e.g., a soil containing no hematite), so that the plant can be said to be substantially hematite-free after repotting.

[0022] (Plants) The plants targeted in the present invention are not particularly limited as long as the desired effect can be obtained, and may be herbaceous or woody. Herbaceous plants include annual herbs, biennial herbs, and perennial herbs, while woody plants include deciduous trees and evergreen trees. Examples include Brassicaceae plants, Solanaceae plants, Amaryllidaceae plants, Poaceae plants, Asteraceae plants, Umbelliferae plants, Nelumbaceae plants, Araceae plants, Dioscoreae plants, Cucurbitaceae plants, Leguminosae plants, Amaranthaceae plants, Rosaceae plants, Euphorbiaceae plants, Musaceae plants, Boraginaceae plants, Palmaceae plants, Oleaceae plants, Cupressaceae plants, Pinaceae plants, Fagaceae plants, etc. However, any one or more of these may or may not be included. For example, it may not include Brassicaceae plants or Solanaceae plants.

[0023] Examples of Brassicaceae plants include Chinese cabbage, cabbage, rapeseed, broccoli, turnip, cauliflower, mizuna, nozawana, komatsuna, bok choy, kale, radish, and wasabi. Examples of Solanaceae plants include tomato, eggplant, potato, bell pepper, chili pepper, and tobacco. Examples of Amaryllidaceae plants include leeks, onions, chives, garlic, and rakkyo. Examples of Gramineae plants include rice, wheat, barley, and corn. Examples of Asteraceae plants include chrysanthemum, garland chrysanthemum, burdock, lettuce, and mugwort. Examples of Umbelliferae plants include carrots, celery, mitsuba, cilantro, parsley, Japanese parsley, and angelica tree. Examples of Nelumbaceae plants include lotus root. Examples of Araceae plants include taro and konjac. Examples of Dioscoreaceae plants include Chinese yam and Chinese yam. Examples of Cucurbitaceae plants include cucumber, watermelon, pumpkin, melon, bitter melon, zucchini, etc. Examples of Leguminosae plants include soybean, pea, gum arabic, and licorice. Examples of Amaranthaceae plants include spinach. Examples of Rosaceae plants include rose, strawberry, apple, pear, plum, and peach. Examples of Euphorbiaceae plants include Hevea brasiliensis. Examples of Musaceae plants include banana. Examples of Boraginaceae plants include purple lily. Examples of Palmaceae plants include oil palm. Examples of Oleaceae plants include olive. Examples of Cupressaceae plants include cedar, cypress, and Japanese cypress. Examples of Pinaceae plants include red pine, larch, and fir. Examples of Fagaceae plants include beech, oak, and Castanopsis cuspidata. However, any one or more of these may or may not be included. For example, it may not include one or more selected from the group consisting of Chinese cabbage, cabbage, rapeseed, broccoli, turnip, tomato, and potato.

[0024] (Regulating plant growth) In the present invention, "regulating plant growth" refers to affecting the growth of all or a part of a plant, and is not particularly limited to, for example, improving the growth rate of a plant, increasing the mass of a plant (e.g., above-ground parts, underground parts, leaves, stems, trunks, roots, flowers, fruits, seeds, or the sum of two or more thereof), increasing the mass of the edible parts of a plant, increasing the harvest (yield) of a plant, promoting acclimation of a plant to its growing environment, promoting flowering, promoting fruit setting, increasing the number of flowers, increasing the number of fruits or seeds, accelerating the flowering time, accelerating the fruit setting time, increasing plant width, increasing plant height, promoting tillering, increasing root mass, improving the (environmental) stress resistance of a plant (e.g., improving cold tolerance, improving heat tolerance, improving drought tolerance, improving salt tolerance, etc.), improving plant quality, and the like.

[0025] (Growing a plant) In the present invention, the conditions for "growing a plant" are not particularly limited as long as the desired effect is obtained, and can be appropriately selected depending on the type of target plant, cultivation method, growth stage, cultivation purpose, type and level of environmental stress, plant condition, etc. For example, the plant can be grown in the same manner as a normal plant cultivation method, except that the plant is grown in the presence of hematite and substantially in the absence of hematite. Examples of plant cultivation methods include soil cultivation, nutrient solution cultivation, and nutrient solution soil cultivation. Examples of nutrient solution cultivation include hydroponics and solid medium cultivation. Examples of hydroponics include nutrient film technique (NFT) and deep flow technique (DFT).

[0026] The timing and duration of steps (A) and (B) can be appropriately selected depending on the type of plant, cultivation method, growth stage, cultivation purpose, type and level of environmental stress, plant condition, etc. Appropriate conditions can be found without undue experimentation by referring to the examples described below and / or by trying several conditions. The duration of steps (A) and (B) may be, for example, independently 1 day or more, 1 week or more, 2 weeks or more, 3 weeks or more, 4 weeks or more, 5 weeks or more, 6 weeks or more, 7 weeks or more, 8 weeks or more, 3 months or more, 4 months or more, 5 months or more, or 6 months or more, or may be, for example, 6 months or less, 5 months or less, 4 months or less, 3 months or less, 8 weeks or less, 7 weeks or less, 6 weeks or less, 5 weeks or less, 4 weeks or less, 3 weeks or less, 2 weeks or less, or a combination thereof.

[0027] In the method of the present invention, the order in which steps (A) and (B) are performed can be appropriately selected depending on the purpose. However, the method of the present invention can be divided into a first method and a second method described below depending on the order in which steps (A) and (B) are performed. That is, the method of the present invention includes the first method and the second method.

[0028] (First Method) The first method of the present invention is a method for regulating plant growth, comprising (A) a step of growing the plant in the presence of hematite, followed by (B) a step of growing the plant substantially in the absence of hematite. As long as step (A) is performed before step (B) and step (B) is performed after step (A), other steps may be appropriately included before, after, or between them. For example, a step of sowing plants, preferably a step of sowing plants in the presence of hematite from the viewpoint of work efficiency, may be included before step (A).

[0029] In the first method of the present invention, regulating plant growth may involve suppressing the growth of the plant in step (A) and then promoting the growth of the plant in step (B). More specifically, it may involve promoting the growth of the plant compared to a case in which step (A) is not included. In the first method of the present invention, promoting plant growth may involve, for example, one or more actions selected from the group consisting of improving the growth rate of the plant, increasing the mass of the plant body, increasing the mass of the edible part of the plant, and increasing the yield of the plant.

[0030] Considering that the first method of the present invention ultimately promotes plant growth, the temporary suppression of plant growth by step (A) is not ultimately disadvantageous and may even be beneficial in itself. For example, performing step (A) during the seedling raising stage suppresses seedling growth, resulting in compact seedlings. Compact seedlings improve seedling transportation efficiency, reduce transportation costs, facilitate irrigation management, reduce seedling tangles and planting damage, and improve the efficiency of tasks such as transplanting seedlings. Furthermore, gently suppressing the seedling growth rate eliminates limitations on the timing of tasks such as transplanting seedlings. For example, delays in seedling transplantation due to bad weather or other factors can generally lead to seedling elongation, which can result in seedling lodging and reduced seedling quality. However, the first method of the present invention makes it easy to prevent such situations. As such, the first method of the present invention is an excellent method for achieving various plant growth regulation effects.

[0031] In the first method of the present invention, for example, step (A) is preferably carried out from the time of sowing to the seedling raising period, and step (B) is preferably carried out from the time of planting (transplanting) to the time of harvesting. For example, step (A) may be carried out from the time of sowing, and step (B) may be carried out from the time of planting (transplanting). In this case, for example, a plant may be sown in a culture medium containing hematite, grown, and then planted (transplanted) in a culture medium substantially free of hematite, and grown.

[0032] The plant to be subjected to the first method of the present invention can be appropriately selected depending on the purpose of cultivating the plant, but for example, plants cultivated for the purpose of obtaining leaves or stems, specifically plants whose leaves or stems are used for ornamental purposes or plants whose leaves or stems are edible (vegetables, etc.) are preferred, such as Chinese cabbage, cabbage, Nozawana, Komatsuna, Bok choy, kale, Garland chrysanthemum, lettuce, spinach, onion, welsh onion, etc. However, any one or more of these may or may not be contained.

[0033] (Second Method) The second method of the present invention is a method for regulating plant growth, and includes a step (B) of growing the plant substantially in the absence of hematite, followed by a step (A) of growing the plant in the presence of hematite. As long as step (B) precedes step (A) and step (A) follows step (B), other steps may be appropriately included before, after, or between them. For example, a step of sowing plants may be included before step (B), preferably a step of sowing plants substantially in the absence of hematite from the viewpoint of work efficiency.

[0034] In the second method of the present invention, regulating plant growth may mean promoting acclimatization of the plant to the growth environment. More specifically, it may mean promoting acclimatization of the plant to the growth environment compared to a case in which step (A) is not included. The acclimatization may be, for example, acclimatization to (environmental) stress such as temperature stress, chemical stress, light stress, drought stress, pH stress, salt stress, hypoxic stress, or physical stress.

[0035] In the second method of the present invention, regulating plant growth may be one or more selected from the group consisting of, for example, promoting flowering, promoting fruit set, increasing the number of flowers, increasing the number of fruits or seeds, accelerating flowering, accelerating fruit set, increasing plant width, increasing plant height, promoting tillering, increasing root mass, increasing plant mass, increasing edible plant mass, increasing plant yield, and improving plant (environmental) stress tolerance (e.g., improving cold tolerance, heat tolerance, drought tolerance, salt tolerance, etc.), and is preferably one or more selected from the group consisting of promoting plant flowering, increasing plant width, increasing plant height, increasing root mass, and improving heat tolerance. Thus, the second method of the present invention is an excellent method for achieving various plant growth regulation effects.

[0036] In the second method of the present invention, for example, step (B) is preferably carried out from the time of sowing to the seedling raising period, and step (A) is preferably carried out from the time of planting (transplanting) to the time of harvesting. For example, step (B) may be carried out from the time of sowing, and step (A) may be carried out from the time of planting (transplanting). In this case, for example, a plant may be sown in a culture medium that is substantially free of hematite, grown, and then planted (transplanted) in a culture medium that contains hematite, and grown.

[0037] The plant to be subjected to the second method of the present invention can be appropriately selected depending on the purpose of cultivating the plant. For example, plants cultivated for the purpose of obtaining flowers, fruits, seeds, or roots, such as ornamental plants, vegetables, and grains, and specifically plants whose flowers, fruits, seeds, or roots are used for ornamental purposes or whose flowers, fruits, seeds, or roots are edible, are preferred. Examples of such plants include pansies, petunias, cyclamen, orchids, tulips, lilies, chrysanthemums, roses, gentians, baby's breath, statice, gerberas, bellflowers, alstroemerias, carnations, turnips, radishes, wasabi, tomatoes, eggplants, potatoes, bell peppers, chili peppers, rice, wheat, barley, corn, burdock, carrots, lotus roots, taro, konjac, Chinese yam, cucumbers, watermelons, pumpkins, melons, bitter melons, zucchinis, soybeans, peas, and strawberries. However, any one or more of these may or may not be included. For example, the plants on which the second method of the present invention is performed may not include Solanaceae plants, or may not include tomatoes or potatoes.

[0038] (Plant Growth Regulator) The plant growth regulator of the present invention is a plant growth regulator specified for use in the method of the present invention. According to the method of the present invention, as described above, hematite can be used to effectively regulate the growth of various plants. Therefore, a plant growth regulator specified for use in the method of the present invention is provided. The plant growth regulator of the present invention must contain hematite, but may or may not contain one or more other components. The other components are not particularly limited as long as the desired effect is obtained, and examples thereof include additives such as carriers, excipients, binders, disintegrants, lubricants, stabilizers, antioxidants, diluents, dispersants, adjuvants, surfactants, spreading agents, pH adjusters, colorants, UV absorbers, antistatic agents, preservatives, water, alcohol, vitamins, and minerals. The formulation of the composition may be, for example, a dust, wettable powder, emulsifiable concentrate, flowable concentrate, suspension, water-soluble concentrate, water-dispersible granule, tablet, granule, SE (Suspo Emulsion), OD (Oil Dispersion), EW (Emulsion oil in water) or the like, or may be, for example, a water suspension, etc. The plant growth regulator may contain hematite in an amount of, for example, 0.01 to 10% (w / v), 0.05 to 5% (w / v), 0.1 to 3% (w / v), 0.15 to 2% (w / v), etc.

[0039] (Culture soil) The culture soil of the present invention is a culture soil specified for use in the method of the present invention. The culture soil of the present invention must contain hematite, but may optionally contain one or more other components. The other components are not particularly limited as long as the desired effect is obtained, and may be components normally contained in culture soil, such as red soil, Akadama soil, Kanuma soil, Arakida soil, leaf mold, Kiryu sand, river sand, sea sand, beach sand, mountain sand, perlite, vermiculite, rock wool, zeolite, slag, peat moss, coco peat, sphagnum moss, leaf mold, bark compost, rice husk, rice husk charcoal, lignite, charcoal, bran, charcoal powder, etc. Alternatively, the culture soil of the present invention may be a culture soil normally used (for example, a commercially available culture soil or a mixture thereof) to which hematite has been added. The content of hematite in the culture medium is not particularly limited as long as the desired effect is obtained, and may be, for example, 0.1% (w / v) or more, 0.2% (w / v) or more, 0.3% (w / v) or more, 0.5% (w / v) or more, 0.7% (w / v) or more, 1% (w / v) or more, 2% (w / v) or more, 3% (w / v) or more, 4% (w / v) or more, or 5% (w / v) or more, and may be, for example, 10% (w / v) or less , 8% (w / v) or less, 6% (w / v) or less, 5% (w / v) or less, 4% (w / v) or less, 3% (w / v) or less, 2% (w / v) or less, or a combination thereof, for example, 0.1 to 10% (w / v), 0.5 to 8% (w / v), 0.7 to 7% (w / v), 1 to 5% (w / v), 2 to 5% (w / v), 1 to 4% (w / v), 1 to 3% (w / v), etc. According to the culture soil of the present invention, the method of the present invention can be carried out more easily.

[0040] (Plant Cultivation Kit) The plant cultivation kit of the present invention is a plant cultivation kit specified for use in the method of the present invention. The kit of the present invention must contain hematite, but may optionally contain one or more other components. Examples of other components include, but are not limited to, instructions on the method and procedure for use, instructions on the method of the present invention, other package inserts, media for cultivating plants (e.g., culture soil, hydroponic culture solution, solid medium, etc.), plant seeds or seedlings, fertilizer, pesticides, other chemicals, containers, tools, and other plant cultivation materials. The plant cultivation kit of the present invention allows the method of the present invention to be carried out more easily.

[0041] (Plant Production Method) The plant production method of the present invention comprises regulating plant growth by (using) the method of the present invention. The plant production method of the present invention can also be described as a method for producing a plant whose growth is regulated, comprising the steps of (A) growing the plant in the presence of hematite, and (B) growing the plant substantially in the absence of hematite. The plant production method of the present invention may also have the same features as those described above for the method of the present invention. The plant production method of the present invention may optionally include steps other than steps (A) and (B). Examples of such steps include, but are not limited to, harvesting the plant. The plant harvesting step may involve harvesting all or part of the plant (e.g., above-ground parts, underground parts, leaves, stems, trunks, roots, flowers, fruits, seeds, or two or more thereof). The plant production method of the present invention may also be used in combination with other methods. According to the method of the present invention, it is possible to effectively regulate the growth of various plants, and therefore, according to the plant production method of the present invention, it is possible to produce plants whose growth is effectively regulated, which can, for example, increase plant yields, improve plant quality, and make plant cultivation easier and more efficient.

[0042] The present invention will be described in more detail below using examples, although the technical scope of the present invention is not limited to these examples.

[0043] [Test by First Method] An investigation was conducted to determine the effect on plants of a method that involves (A) a step of growing the plant in the presence of hematite, followed by (B) a step of growing the plant substantially in the absence of hematite.

[0044] 1-1. Cultivation test of sunny lettuce. "Limonide" manufactured by Nippon Limonite Co., Ltd. (natural product from Aso City, Kumamoto Prefecture; contains 72% goethite; sun-dried) was calcined at 250°C to obtain hematite powder (hematite purity 78%; identified by powder X-ray analysis; BET = 90.5 m ２ / g; average particle size 7 μm). This hematite powder was added to seedling culture medium (Takii Tanemaki Culture Medium, manufactured by Takii Seed Co., Ltd.) at 1% (w / v), 3% (w / v), 5% (w / v), or 10% (w / v). The contents of hematite powder were calculated based on the dry weight, and those of the seedling culture medium were calculated based on the labeled volume of the sealed packaged product. These seedling culture mediums were placed in cell trays, and sunny lettuce (variety name: Red Fire) was sown on October 20th. The sunny lettuce seedlings were grown in the usual manner. The groups were designated as the no-addition group, 1%-addition group, 3%-addition group, 5%-addition group, and 10%-addition group, respectively. Observations on November 22nd (33 days after sowing) showed that the higher the concentration of hematite powder added, the more suppressed the seedling growth (Figure 1). These seedlings were planted in the field on November 30th (41 days after sowing) and grown in the usual manner. The potting soil used for planting (Takii Tanemaki Potting Soil, manufactured by Takii Seed Co., Ltd.) did not contain hematite. Although some of the potting soil adhered to the roots at the time of planting, most of the roots subsequently extended into the area of ​​the potting soil without hematite (i.e., essentially hematite-free). Therefore, after planting, the roots were essentially hematite-free. When observed on January 6th of the following year (78 days after sowing), the growth of the sunny lettuce plants in the 1% potting soil group caught up with that of the non-potting soil group (Figure 2). Furthermore, when observed on February 5th (108 days after sowing), the sunny lettuce plants in the 3% potting soil group showed the best growth, followed by the 1% potting soil group, which also outgrew the non-potting soil group (Figure 3).

[0045] 1-2. Cultivation Test of Cos Lettuce The same hematite powder as above was added to seedling culture medium (Takii Tanemaki Culture Medium, manufactured by Takii Seed Co., Ltd.) at 1% (w / v), 3% (w / v), or 5% (w / v) without addition. These seedling culture mediums were placed in cell trays, and cos lettuce (variety: Romalia) seeds were sown on January 26. The cos lettuce seedlings were grown in the usual manner. These were designated the untreated, 1%, 3%, and 5% treated groups, respectively. Observations on February 27 (32 days after sowing) showed that the higher the concentration of hematite powder added, the more suppressed the seedling growth (Figure 4). These seedlings were planted in the field on March 10 (43 days after sowing) and grown in the usual manner. The culture medium used for planting (Takii Tanemaki Culture Medium, manufactured by Takii Seed Co., Ltd.) did not contain hematite. Although some of the culture medium adhered to the roots at planting, most of the roots subsequently expanded into the hematite-free culture medium (i.e., essentially hematite-free), meaning that the hematite was essentially absent after planting. Cos lettuce was harvested on May 10 (104 days after sowing), and the yield (kg / plant) was measured. The mean and standard error were calculated (n = 35 per plot). As shown in Table 1, the yields in the 1% and 3% added plots were significantly higher than those in the control plot (Tukey's Multiple Test, p < 0.05). Furthermore, cross-sections of the harvested cos lettuce revealed high head formation and densely packed edible leaves (Figure 5).

[0046]

[0047] 1-3. Summary These results demonstrate that, according to the first method of the present invention, although initially growing a plant in a culture medium containing hematite temporarily inhibits plant growth, subsequently growing the plant in a culture medium substantially free of hematite promotes plant growth, and the degree of growth is even greater than that of a plant that has not undergone the process of growing in a culture medium containing hematite. Thus, it was surprising that, even though plant growth is temporarily inhibited by growing the plant in the presence of hematite, subsequent growth in a culture medium substantially free of hematite ultimately resulted in a higher yield.

[0048] [Test by Second Method] An investigation was conducted to determine what effect a method of carrying out (B) the step of growing the plant substantially in the absence of hematite, followed by (A) the step of growing the plant in the presence of hematite would have on the plant.

[0049] 2-1. Pansy Cultivation Test (1) Seeding soil (BM-2, manufactured by Berger; hereinafter referred to as "Soil A") consisting of peat moss, perlite, and vermiculite was placed in a cell tray (200 holes, 15 mL / hole), and pansies (variety name: sweet potato) were sown on September 10. The pansy seedlings were grown in the usual manner. The soil A used here did not contain hematite. These seedlings were planted on September 30 (20 days after sowing) into 3.5-inch pots (500 mL capacity) filled with soil (hereinafter referred to as "Soil B") that was purchased from Sanyo Chip Industries Co., Ltd. and mixed in a ratio of bark compost, red soil, Akadama soil, and rice husk charcoal (volume ratio: 4:2:3:1). The seedlings were grown in the usual manner. The culture medium used for planting (culture medium B) was the same as that used in the first method, but was either unadded, 1% (w / v), or 3% (w / v) hematite powder. These were referred to as the no-addition, 1%-addition, and 3%-addition groups, respectively. On January 20th of the following year (132 days after sowing), plant width and height were measured, and the number of flowering rings was counted. The average and standard error were calculated (n = 5 per group). As shown in Table 2, the higher the concentration of hematite powder added, the greater the plant width and the more promoted flowering, i.e., the more promoted the growth of the pansies.

[0050]

[0051] 2-2. Pansy Cultivation Test (2) A test (2) similar to the pansy cultivation test (1) was conducted, except that the number of pansy varieties was increased and a 5% addition group was also added. Culture medium A was placed in a cell tray (200 holes, 15 mL / hole), and pansies (varieties: Sweet Potato, Clear Mix, Lemon, and Cranberry) were sown on August 29. The pansy seedlings were grown in the usual manner. The culture medium A used in this study did not contain hematite. These seedlings were planted in 3.5-inch pots (500 mL capacity) on October 7 (39 days after sowing) and grown in the usual manner. The culture medium (culture medium B) used for planting contained the same hematite powder used in the first method, either without addition or at 1% (w / v), 3% (w / v), or 5% (w / v). These plots were referred to as the untreated, 1%, 3%, or 5% hematite treatment groups, respectively. On December 20 (113 days after sowing), plant width and height were measured, the number of flowering rings was counted, and the average and standard error were calculated (n = 8 per plot). As shown in Table 3, for all cultivars, increasing the concentration of hematite powder increased pansy plant width and height, promoting flowering and pansy growth (Tukey's Multiple Test, p < 0.05). Furthermore, increasing the concentration of hematite powder increased pansy root mass (Figure 6).

[0052]

[0053] 2-3. Field Wasabi Cultivation Test Field wasabi (variety: Kamo Jiko) was sown in seedling culture medium (Takii Tanemaki Culture Medium, manufactured by Takii Seed Co., Ltd.) on July 31st, and field wasabi seedlings were grown in the usual manner. The seedling culture medium used in this study did not contain hematite. These seedlings were replanted in 128-hole cell trays on August 31st (31 days after sowing) and grown in the usual manner under high temperature conditions (conditions with an average daytime temperature exceeding 25°C). The same hematite powder used in the first method was either not added, or was mixed in at 1.5% (w / v) or 2.5% (w / v) to the culture medium (Takii Tanemaki Culture Medium, manufactured by Takii Seed Co., Ltd.). Note that these contents were calculated based on the dry weight for hematite powder and the labeled volume of the sealed packaged product for the seedling culture medium. These plots are referred to as the no-addition plot, the 1.5%-addition plot, and the 2.5%-addition plot, respectively. The number of surviving seedlings was counted on November 1st (93 days after sowing), approximately two months after transplanting, and the survival rate was calculated (n = 640 per plot). As shown in Table 4, the higher the concentration of hematite powder added, the higher the survival rate of field wasabi, i.e., the improved heat tolerance. In response to global warming in recent years, efforts are being made to improve heat tolerance in crops, and the second method of the present invention is a useful tool.

[0054]

[0055] 2-4. Summary These results demonstrate that the second method of the present invention, in which a plant is initially grown in a culture medium substantially free of hematite and then grown in a culture medium containing hematite, produces various beneficial effects compared to plants not grown in a culture medium containing hematite. These results are believed to be due to the hematite inducing the plant's latent functions and promoting acclimatization. Therefore, since the method of the present invention can produce various acclimatization effects in the same way, it is expected that the method of the present invention will be a means for adapting plants to a wide range of growing environments.

[0056] Furthermore, it has been found that the first and second methods of the present invention each produce different plant growth regulating effects, and therefore, by appropriately selecting either the first or second method depending on the target plant, purpose, etc., it is possible to more effectively regulate the growth of a wide range of plants.

Claims

1. A method for regulating plant growth, comprising: (A) growing said plant in the presence of hematite; and (B) growing said plant substantially in the absence of hematite.

2. The method for regulating plant growth according to claim 1, wherein step (B) is carried out after step (A).

3. The method for regulating plant growth according to claim 2, wherein regulating plant growth comprises suppressing the growth of the plant by step (A) and then promoting the growth of the plant by step (B).

4. The method for regulating plant growth according to claim 2, wherein regulating plant growth comprises increasing the mass of the plant body.

5. The method for regulating plant growth according to claim 1, wherein step (A) is carried out after step (B).

6. The method for regulating plant growth according to claim 5, wherein regulating plant growth comprises promoting acclimatization of the plant to a growth environment.

7. The method for regulating plant growth according to claim 5, wherein regulating plant growth is one or more selected from the group consisting of promoting flowering of the plant, increasing plant width, increasing plant height, increasing root volume, and improving heat tolerance.

8. A plant growth regulator comprising hematite for use in the method according to any one of claims 1 to 7.

9. A culture medium containing hematite for use in the method according to any one of claims 1 to 7.

10. A method for producing a plant, comprising regulating plant growth by the method according to any one of claims 1 to 7.

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