JP7637508B2 - Plant growth regulator and method for inhibiting plant growth - Google Patents

Description

The present invention relates to a plant growth inhibitor, a resin molded body for inhibiting plant growth, a method for inhibiting plant growth, and soil.

In parks, plazas, farmland including unused farmland, coasts, reclaimed land, road slopes, roadsides or median strips, vacant lots, etc., manual, chemical or mechanical weeding work is carried out by hand or with a harvester, spraying herbicides or pesticides, covering with weed control sheets, etc., in order to prevent weeds from impairing crop growth, stabilize crop yields and beautify the environment.

Herbicides that use glyphosate are commonly known (e.g., Patent Document 1), but because these herbicides kill weeds by killing them, there are concerns that they may have a negative impact on the natural environment. Therefore, there is a strong demand for herbicides that not only reduce the time and cost required for weeding, but also reduce the negative impact of weeding on the natural environment.

Special Publication No. 2005-521700

Therefore, the present invention aims to provide a plant growth inhibitor that can inhibit plant growth and is environmentally friendly, a resin molded body for inhibiting plant growth, and a method for inhibiting plant growth.

As a result of intensive research into solving the above problems, the inventors have found that plant growth can be suitably inhibited by using a triester of carboxylic acid and glycerin, glycerin, or sorbitol. That is, one aspect of the present invention is a plant growth inhibitor containing at least one selected from the group consisting of a triester of carboxylic acid and glycerin, glycerin, and sorbitol. This growth inhibitor does not kill plants, but rather inhibits plant growth, thereby reducing adverse effects on nature.

Another aspect of the present invention is a resin molded body for inhibiting plant growth, which contains the above-mentioned growth inhibitor and a resin. Another aspect of the present invention is a method for inhibiting plant growth, which comprises applying the above-mentioned resin molded body to soil. Another aspect of the present invention is soil, which contains the above-mentioned resin molded body of a plant.

The present invention provides a plant growth inhibitor that can inhibit plant growth and is environmentally friendly, a resin molded body for inhibiting plant growth, and a method for inhibiting plant growth.

FIG. 2 is a perspective view showing a stake-shaped growth retarder in one embodiment. FIG. 2 is a perspective view showing a granular growth inhibitor in one embodiment. FIG. 2 is a perspective view showing a sheet-shaped growth inhibitor in one embodiment.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings as appropriate. Note that the present invention is not limited to the following embodiment.

In one embodiment, the plant growth inhibitor (hereinafter also simply referred to as "growth inhibitor") contains at least one selected from the group consisting of a triester of carboxylic acid and glycerin (hereinafter also simply referred to as "triester"), glycerin, and sorbitol.

The carboxylic acid constituting the triester may be, for example, a fatty acid. The fatty acid may include a saturated fatty acid or an unsaturated fatty acid. The fatty acid includes one or more types selected from the group consisting of saturated fatty acids and unsaturated fatty acids. When the fatty acid includes two or more types of these fatty acids, the fatty acid may include both saturated fatty acids and unsaturated fatty acids.

The number of carbon atoms in the fatty acid may be, for example, 12 or more, 14 or more, or 16 or more. The number of carbon atoms in the fatty acid may be 30 or less, 25 or less, or 18 or less. The number of carbon atoms in the fatty acid may be 12-30, 12-25, 12-18, 14-30, 14-25, 14-18, 16-30, 16-25, or 16-18, preferably 12-30, more preferably 14-25, and particularly preferably 16-18.

The fatty acid having 16 to 18 carbon atoms may be linoleic acid, oleic acid, palmitic acid, linolenic acid (α-linolenic acid or γ-linolenic acid), stearic acid, etc. The fatty acid preferably contains at least one selected from the group consisting of linoleic acid, oleic acid, palmitic acid, linolenic acid, and stearic acid, and may contain all of linoleic acid, oleic acid, palmitic acid, linolenic acid, and stearic acid. Triesters composed of these fatty acids are contained in soybean oil, for example. Therefore, the growth inhibitor may contain soybean oil.

The growth inhibitor may contain at least two of glycerin, sorbitol, and a triester. Such combinations include glycerin and sorbitol, glycerin and a triester, sorbitol and a triester, and glycerin, sorbitol, and a triester.

The growth inhibitor may consist of at least one active ingredient (growth inhibitor) selected from the group consisting of triester, glycerin, and sorbitol, or may contain other ingredients in addition to the active ingredient. When the growth inhibitor contains other ingredients, the content of the growth inhibitor may be, for example, 0.7% by mass or more, or 1.0% by mass or more, based on the total amount of the growth inhibitor.

The growth inhibitor may be a solid or liquid at 23°C. When the growth inhibitor is a liquid, for example, the growth inhibitor may further contain water or a specified solvent. From the viewpoint of being able to prevent the growth inhibitor from flowing out from a specified location when the growth inhibitor is applied to the specified location, the growth inhibitor is preferably a solid. When the growth inhibitor is a solid, the shape of the growth inhibitor is not particularly limited.

Another embodiment of the present invention may be a resin molded body for suppressing plant growth, containing the above-mentioned growth inhibitor and a resin. The shape of the resin molded body is not particularly limited.

1 is a perspective view showing a resin molded body according to one embodiment. As shown in FIG. 1(a), the resin molded body 1 according to one embodiment is molded into a pile shape. The resin molded body 1 includes, for example, a substantially disk-shaped pile head 2 and an elongated pile main body 3 extending from one surface of the pile head 2 in a direction substantially perpendicular to the surface. The cross-sectional shape of the pile main body 3 may be, for example, a cross shape. By being molded into such a shape, the resin molded body 1 can be inserted into soil 5 as shown in FIG. 1(b). The tip of the pile main body 3 (the end opposite the pile head 2) may be pointed so as to facilitate insertion into soil 5.

The diameter d1 of the pile head 2 (the length in the short direction of the resin molding 1) may be, for example, 2.0 to 4.0 cm. The length d2 in the long direction of the resin molding 1 may be, for example, 5.0 to 15.0 cm.

The content of the growth inhibitor may be, for example, 0.7 mass% or more, or 1.0 mass% or more, based on the total amount of the resin molding.

The resin may contain a thermoplastic resin, a thermosetting resin, or both. From the viewpoint of excellent moldability, the resin preferably contains a thermoplastic resin.

The thermoplastic resin may contain a biodegradable thermoplastic resin, may contain a non-biodegradable thermoplastic resin, or may contain both. From the viewpoint of exerting the plant growth inhibitory effect more sustainably (excellent sustained release properties), the thermoplastic resin preferably contains a biodegradable thermoplastic resin.

Examples of biodegradable thermoplastic resins include aliphatic polyesters, polyvinyl alcohol, polyalkylene glycols, etc.

The resin content may be, based on the total amount of the resin molded body, 10% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, or 98% by mass or more. When the resin molded body contains a binder as described below, the resin content may be, for example, 10% by mass or more, 60% by mass or more, or 70% by mass or more, based on the total amount of the resin molded body. When the resin molded body does not contain a binder, the resin content may be, for example, 95% by mass or more, or 98% by mass or more, based on the total amount of the resin molded body.

The content of the thermoplastic resin may be 10% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, or 98% by mass or more based on the total amount of the resin molded body. When the resin molded body contains a binder as described below, the content of the thermoplastic resin may be, for example, 60% by mass or more, or 70% by mass or more based on the total amount of the resin molded body. When the resin molded body does not contain a binder, the content of the thermoplastic resin may be, for example, 95% by mass or more, or 98% by mass or more based on the total amount of the resin molded body.

Examples of aliphatic polyesters include polylactic acid, poly(3-hydroxybutyric acid), polybutylene succinate, polybutylene adipate, polyethylene succinate, polyethylene adipate, polypropylene succinate, polypropylene adipate, polyhexylene succinate, polyhexylene adipate, polyhydroxybutyrate, copolymers of polybutylene succinate and polybutylene adipate, copolymers of polybutylene succinate and polycarbonate, polycaprolactone, polyhydroxybutyric acid, polyhydroxyvaleric acid, polybutylene succinate, polybutylene adipate, polymalic acid, polyglycolic acid, polysuccinic acid esters, polyoxalic acid esters, polybutylene diglycolate, and polydioxanone.

Examples of polyalkylene glycols include methylene glycol, ethylene glycol, propylene glycol, diethylene glycol, etc.

Examples of non-biodegradable thermoplastic resins include polyolefins, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl acetate, etc. Examples of polyolefins include polyethylene, polypropylene, polymethylpentene, polybutene, polybutadiene, polystyrene, etc. Polyolefins may be homopolymers or copolymers of α-olefins such as polyethylene and polypropylene, or copolymers of α-olefins and other comonomers.

Even the above-mentioned thermoplastic resins that do not have biodegradability can be imparted with biodegradability by using them together with additives that promote the depolymerization of the thermoplastic resin. Specifically, for example, polyolefins containing homopolymers or copolymers of α-olefins such as polyethylene and polypropylene, or copolymers of α-olefins and other comonomers, are imparted with biodegradability by using them together with a metal compound containing at least one selected from the group consisting of metal salts, metal oxides, and metal hydroxides. In this specification, even if a thermoplastic resin does not have biodegradability by itself, a resin that has been imparted with biodegradability by an additive that promotes the depolymerization is defined as a thermoplastic resin having biodegradability. In one embodiment, a resin molded product containing a thermoplastic resin that has biodegradability by itself contains a thermoplastic resin that does not have biodegradability by itself and an additive that promotes the depolymerization of the thermoplastic resin, and in another embodiment, contains the above-mentioned polyolefin and a metal compound containing at least one selected from the group consisting of metal salts, metal oxides, and metal hydroxides.

The resin molded body 1 may further contain a natural polymer compound. Examples of the natural polymer compound include polysaccharides. The natural polymer compounds may be used alone or in combination of two or more. Examples of the polysaccharides include cellulose, starch, chitosan, dextran, cellulose acetate, starch-modified resins, and cellulose-modified resins.

The resin molded body 1 may further contain a binder. The binder may be, for example, processed food residue. Examples of processed food residue include compost made by fermenting and decomposing organic waste such as food residue discharged from households, food processing waste, fish iliac bones, leftover food, and expired food discharged from food processing plants, supermarkets, restaurants, convenience stores, hotels, etc., using microorganisms to ferment and decompose the waste and adjust the salt concentration.

The resin molded body 1 described above contains a plant growth inhibitor and is therefore suitable for use as a resin molded body for inhibiting plant growth. The resin molded body 1 is applied to the soil 5 by inserting the pile main body 3 so that part or all of it is buried in the soil 5, as shown in FIG. 1(b), for example. This allows the resin molded body 1 to be suitably held in the desired location in the soil 5, even if rain falls on the soil 5.

The pile-shaped resin molded body 1 is molded, for example, by injection molding. In injection molding, for example, a raw material containing a growth inhibitor and resin is heated to a temperature at which the resin softens, and the heated raw material is poured into a mold and cooled for a certain period of time to harden the resin.

The resin molded body may take other embodiments. FIG. 2 is a perspective view showing a resin molded body according to another embodiment. As shown in FIG. 2, the resin molded body 11 according to another embodiment is molded into a granular shape. The resin molded body 11 may be, for example, an elliptical sphere as shown in FIG. 2, or may be another fixed shape such as a sphere, a cylinder, or an elliptical cylinder, or may be an irregular shape. By being molded into such a shape, the resin molded body 11 can be spread on the soil 15 as shown in FIG. 2. The maximum length d3 of the resin molded body 11 may be, for example, 0.5 to 5.0 mm.

This resin molded body 11 is also preferably used as a resin molded body for suppressing plant growth, and is applied to the soil 15 by being sprayed on the soil 15 as shown in Figure 2. This resin molded body 11 can also be preferably retained in a desired location in the soil 15, for example, even if rain falls on the soil 15.

The granular resin molded body 11 is molded, for example, by resin pellet granulation. In resin pellet granulation, for example, raw materials containing a growth inhibitor and a resin extruded from an extruder are granulated into pellets while being cooled with cooling water or after being cooled.

Figure 3 is a perspective view showing a resin molded body according to another embodiment. As shown in Figure 3(a), the resin molded body 21 according to another embodiment is molded into a sheet shape. Because the resin molded body 21 is molded into such a shape, it can be laid in soil 25 as shown in Figure 3(b).

The resin molded body 21 has, for example, a substantially rectangular planar shape. The lengths of one side of the rectangle (the maximum length of the resin molded body 21 in the main surface direction) d4 and d5 may be, for example, 0.5 to 50 m. The thickness d6 of the resin molded body 21 may be, for example, 7 to 100 μm.

This resin molded body 21 is also preferably used as a resin molded body for suppressing plant growth, and is applied to the soil 25 by laying it so that one main surface is in contact with the soil 25, as shown in FIG. 3(b). The resin molded body 21 may be partially or entirely buried in the soil 25. This resin molded body 21 can also be preferably retained in a desired location in the soil 25, for example, even if rain falls on the soil 25.

The sheet-shaped resin molded body may have voids (holes) penetrating the sheet in the thickness direction, unevenness in the thickness direction of the sheet, etc. The sheet-shaped resin molded body may be, for example, a net-like body having a mesh structure.

The sheet-shaped resin molded body 21 is formed, for example, by extrusion molding. In extrusion molding, for example, raw materials containing a growth inhibitor and a resin are melted and plasticized in an extruder, then extruded from a die, cooled and solidified, and given a predetermined shape and dimensions.

One embodiment of the present invention may be a method for inhibiting plant growth. This method includes a step of applying the above-mentioned growth inhibitor or the above-mentioned resin molded body to soil. This makes it possible to inhibit the growth of plants present in the soil. The method of applying the growth inhibitor or resin molded body in this step is appropriately selected depending on, for example, the state and shape of the growth inhibitor or resin molded body. In this step, the growth inhibitor or resin molded body may be inserted, spread, or laid in the soil.

In one embodiment, the application amount of the growth inhibitor or resin molded body is preferably 500 g or more, more preferably 1000 g or more, per square meter of soil, from the viewpoint of more suitably suppressing plant growth. The application amount of the growth inhibitor or resin molded body may be, for example, 2500 g or less per square meter of soil.

In another embodiment, the application amount of the growth inhibitor or resin molded body is such that the application amount of the above-mentioned active ingredient is preferably 0.01 g or more, more preferably 0.1 g or more, even more preferably 2.6 g or more, and particularly preferably 5.2 g or more per square meter of soil, from the viewpoint of more suitably suppressing plant growth. The application amount of the growth inhibitor or resin molded body may be, for example, such that the application amount of the above-mentioned active ingredient is 400 g or less, preferably 200 g or less, and more preferably 10.4 g or less per square meter of soil.

The plant to which the growth inhibitor or resin molding is applied (to inhibit its growth) may be an annual plant or a perennial plant, preferably an annual plant. The plant may be a plant of the Poaceae family or a plant other than the Poaceae family, preferably a Poaceae family. The plant is particularly preferably an annual Poaceae plant.

Plants to which the growth inhibitor or resin molded body is applied may be, for example, annual bluegrass, chickweed, knotweed, lamb's paw, dandelion, dayflower, crabgrass, Japanese crabgrass, goosegrass, paspalum, purslane, amplexicaule, cornflower, mugwort, ragweed, nutsedge, green foxtail, wood sorrel, sedge, clover, Japanese knotweed, daisy, annual bluegrass, annual foxtail, dwarf sorrel, dock, fleabane, clover, earwort, phillyraeoides, mugwort, common mugwort, sowberry, persimmon, barnyard millet, solidago altissima, komatsuna, shepherd's purse, or dog mustard. The above-mentioned resin molded article and the above-mentioned method are suitably used when the plants are weeds (annual plants and perennial plants).

One embodiment of the present invention may be soil 5, 15, 25 containing the resin molded body 1, 11, 21 of the above-mentioned plant, as shown in Figures 1 (b), 2, and 3 (b). The resin molded body may be present in the soil 5 as shown in Figure 1 (b), or may be present on the surface of the soil 15, 25 as shown in Figures 2 and 3 (b). By containing the resin molded body 1, 11, 21, this soil 5, 15, 25 becomes soil capable of suppressing plant growth. Therefore, the resin molded body 1, 11, 21 can also be said to be a resin molded body for soil modification that can be modified to soil capable of suppressing plant growth.

The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to the following examples.

(Examples 1 to 3)
The plant growth regulators shown in Table 1 were evaluated for their plant growth inhibitory effects by the Plant Regulator Research Association, a public interest incorporated foundation, using the evaluation method described below.
That is, first, three pots (with five holes on the bottom) with a diameter of 8 cm, height of 9 cm, and area of 0.005 ^m2 were prepared, and volcanic ash clay loam (pH: 5.8, humus content: 13.02%, maximum water capacity: 115%) was spread in the pots to a height of 6.5 cm from the bottom. Next, the volcanic ash clay loam was disinfected and dried with chloropicrin separately from the spread soil, and then sieved with a sieve with 2-4 mm openings to obtain disinfected and dried volcanic ash clay loam. The obtained disinfected and dried volcanic ash clay loam was spread on top of the volcanic ash clay loam spread in the pots to a height of 1.5 cm, and about 3 cc of barnyard grass seeds were sown. The barnyard grass seeds were then covered with disinfected and dried volcanic ash clay loam, and a growth inhibitor was applied at 150 g/ ^m2 . After 15 and 22 days, the number and height of germinated barnyard grass plants were measured for each pot. After 30 days, the above-ground parts of the germinated barnyard grass were harvested and the mass of the above-ground parts of the barnyard grass was measured. The average values of the measurement results for the three pots are shown in Table 1.

As the triester in Example 1, soybean oil containing a triester of fatty acid and glycerin was used. The fatty acids constituting the triester included palmitic acid, stearic acid, oleic acid, linoleic acid, and linolenic acid.

(Comparative Example 3)
The plant growth retardant effect was evaluated in the same manner as in Examples 1 to 3, except that no growth retardant was applied.

The evaluation results show that comparing Example 1, in which a triester was used as a growth retarder, with Comparative Example 1, in which no growth retarder or comparative component was applied, in Example 1, the number of germinated plants after 15 days was 11, about one-sixth of the number in the comparative example, and the number of germinated plants after 22 days was similar, but the plant height was low both after 15 and 22 days, and the mass after above-ground cutting was also low. Therefore, it can be said that the triester used in Example 1 can inhibit plant growth.

Comparing Example 2, in which glycerin was used as a growth retardant, with Comparative Example 1, in which no growth retardant or comparative component was applied, Example 2 showed smaller values in all respects, including the number of sprouted plants and plant height after 15 and 22 days, and the mass of the aboveground parts after cutting after 30 days. Therefore, it can be said that the glycerin used in Example 2 can inhibit plant growth.

Comparing Example 3, in which sorbitol was used as a growth retardant, with Comparative Example 1, in which no growth retardant or comparative component was applied, in Example 3, the plant height after 15 days was similar, but the number of sprouted plants after 15 days, the plant height and number of sprouted plants after 22 days, and the mass of the aboveground parts after cutting were smaller. Therefore, it can be said that the sorbitol used in Example 3 can inhibit plant growth.

In Examples 1 to 3, no withering of plants was observed, demonstrating that the growth retardant merely inhibits growth and is environmentally friendly.

1, 11, 21...resin molding, 2...pile head, 3...pile body, 5, 15, 25...soil.

Claims (6)

It consists only of triesters of carboxylic acids and glycerin,
A plant growth regulator wherein said triester is derived from soybean oil, except where said triester is cottonseed oil. A plant growth inhibitor consisting of only glycerin, only sorbitol, or only glycerin and sorbitol that inhibits the growth of grasses. The plant growth inhibitor according to claim 2, which consists solely of glycerin. The plant growth inhibitor according to claim 2, which consists solely of sorbitol. The plant growth inhibitor according to claim 2, which consists only of the glycerin and the sorbitol. A method for inhibiting plant growth, comprising applying the plant growth inhibitor according to any one of claims 1 to 5 to soil.

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