CN114073217A

CN114073217A - Strawberry cultivation method and plant activator for strawberry cultivation

Info

Publication number: CN114073217A
Application number: CN202110942207.0A
Authority: CN
Inventors: 斋藤信; 内田博; 藤田一郎
Original assignee: Showa Denko KK
Current assignee: Resonac Holdings Corp
Priority date: 2020-08-18
Filing date: 2021-08-17
Publication date: 2022-02-22
Also published as: JP2022034181A

Abstract

The invention provides a method for improving yield and quality of strawberry harvest. The solution is a cultivation method of strawberries, comprising the following steps: a plant vigor agent comprising an exogenous elicitor and an endogenous elicitor is applied to the seedling at least 1 time.

Description

Strawberry cultivation method and plant activator for strawberry cultivation

Technical Field

The present invention relates to a method for cultivating strawberries using an exogenous exciton and an endogenous exciton, and a plant activator for cultivating strawberries.

Background

The yield of plants is reduced by abiotic stress such as sunshine duration, air temperature and rainfall, and biotic stress such as insect pests. For example, strawberries are suitable for a relatively cool climate with an optimum temperature of 17 to 25 ℃ because of a great amount of sunlight, and are prone to suffer from growth inhibition, flower bud differentiation inhibition, and the like at high temperatures. In addition, the defects of root rot, poor fruit set, easy occurrence of diseases and the like are generated under the condition of poor drainage and over-wet. In particular, in order to increase the yield of agricultural crops, various fertilizers and agricultural chemicals have been used so far. Fertilizers are a nutrient source required for the growth of plants but do not have a stress-mitigating function. Although pesticides directly repel plant diseases and pests and eliminate biotic stress, when pesticides are used, although safety is sufficiently confirmed, there is a concern that excessive ingestion may affect the human body and the environment, and particularly, pesticides produced by chemical synthesis may remain in the soil for a long time if they are spread, and if they are possible, it is desired to impart tolerance to biotic stress by other methods. Therefore, in addition to these, use of a bio-stimulant (biostimulant) has recently been attracting attention as a substance safe to the human body and the environment.

"biological growth promoter" is also referred to as "biostimulant", "plant vigor agent" or the like, and means a substance containing any substance group/microorganism, which, when applied to a plant or its root system, can improve nutrient absorption, fertilizer efficiency, or quality by stimulating a series of processes that occur also in a natural crop, or impart stress tolerance, and does not exhibit a direct effect on pests, and therefore, is not classified into any insecticidal/fungicidal substance. That is, it refers to a substance that is present in the natural world (including microorganisms), and that, although not a plant hormone or nutrient, stimulates the vigor of a plant and promotes growth and development even in a very small amount. It is considered that by applying the bio-stimulant to a plant, the nutrient absorption and nutrient utilization of the plant are improved, the growth and development are promoted, and the yield and quality of crops are improved. Among the agricultural bio-stimulants, various formulations including compounds, substances and other products applied to plants or soil are included in order to control/enhance physiological processes of crops. In order to improve the vigor, yield, quality and post-harvest preservability of crops, bio-stimulants act on plant physiology by a different pathway than nutrients.

Thus, the growth of plants can be promoted by stimulating the inherent ability of plants without causing problems caused by conventional agricultural chemicals and fertilizers.

As substances related to such a bio-stimulant, a plant activator obtained by combining a chitin oligosaccharide with chitosan having an antibacterial activity or the like (patent document 1), a plant activator obtained by blending an oligosaccharide and a plant extract component with vinegar (patent document 2), a plant growth promoter containing cellulose (patent document 3), a plant growth regulator containing a hexose furan derivative (patent document 4), a method for improving the disease resistance of a plant by using a low-molecular-weight chitin or chitosan (patent document 5), and a fertilizer containing chitin and/or chitosan (patent document 6) have been reported.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 9-143013

Patent document 2: japanese patent laid-open No. 2001-64112

Patent document 3: japanese laid-open patent publication No. 2002-114610

Patent document 4: japanese patent laid-open publication No. 2013-151438

Patent document 5: japanese laid-open patent publication (Kokai) No. 2015-48436

Patent document 6: japanese patent laid-open publication No. 2017-95352

Patent document 7: international publication No. 2017/104687

Disclosure of Invention

Problems to be solved by the invention

However, in the cultivation of plants, studies to improve the expression of the effect of a plant-activating agent by adjusting the application method thereof according to the plant species have not been completed so far. In particular, methods of application of plant vigor agents suitable for strawberries are not known.

Means for solving the problems

The present invention has been made in view of the above circumstances, and intensive studies have been made on a method for applying a plant-energizing agent to strawberry cultivation. As a result, they have found that yield and quality are significantly improved by applying a plant activator containing an exogenous exciton and an endogenous exciton to strawberry seedlings, and have completed the present invention.

That is, the present invention includes the following [1] to [26 ].

[1] A strawberry cultivation method comprises the following steps: a plant vigor agent comprising an exogenous elicitor and an endogenous elicitor is applied to the seedling at least 1 time.

[2] The method for cultivating strawberries according to [1], comprising the steps of: the plant vigor agent is applied to the seedlings 2-15 days after germination for at least 1 time.

[3] The method for cultivating strawberries according to [1] or [2], comprising the steps of: the plant vigor agent is further applied to the plant body after the seedling stage at least 1 time.

[4] The method for cultivating a strawberry according to any one of [1] to [3], wherein the young seedling is a daughter plant that germinates from an aerial branch of a parent plant.

[5] The method for cultivating strawberries according to [4], comprising the steps of: further applying said plant vigor agent to said parent plant at least 1 time during the period before the 1 st daughter plant sprouts from the growing runners.

[6] The method for cultivating a strawberry according to any one of [1] to [5], wherein the exogenous elicitor is a chitin oligosaccharide, and the endogenous elicitor is at least 1 oligosaccharide selected from the group consisting of cellooligosaccharides and xylooligosaccharides.

[7] The method for cultivating strawberry according to any one of [1] to [6], wherein a mass ratio of the exogenous elicitor to the endogenous elicitor in the plant energizing agent is 0.1 to 5.

[8] The method for cultivating strawberry according to any one of [1] to [7], wherein the endogenous elicitor comprises xylooligosaccharide.

[9] The method for cultivating strawberry according to [8], wherein the endogenous elicitor includes both cellooligosaccharide and xylooligosaccharide.

[10] The method for cultivating strawberry according to item [9], wherein a mass ratio of the cellooligosaccharide to the xylooligosaccharide in the plant activator is 0.2 to 5.

[11] The method for cultivating strawberry according to any one of [1] to [10], wherein the plant activator is applied to the plant at a concentration at which the total content of the exogenous elicitor and the endogenous elicitor is 0.1 to 500 mass ppm.

[12] The method for cultivating strawberry according to any one of [1] to [11], wherein the plant-activating agent is applied to the plant through foliar application.

[13] The method for cultivating strawberries according to any one of [1] to [12], wherein the strawberries are of a single-season variety.

[14] A plant activator, which is a plant activator comprising an exogenous elicitor and an endogenous elicitor used in the cultivation of strawberries, is applied to seedlings at least 1 time.

[15] The plant activator according to [14], which is applied at least 1 time to seedlings 2 to 15 days after germination.

[16] The plant-vigor agent according to [14] or [15], which is further applied to a plant body after a seedling stage at least 1 time.

[17] The plant activating agent according to any one of [14] to [16], wherein the seedling is a daughter plant that sprouts from a fibrous branch of a parent plant.

[18] The plant vigor agent according to [17], which is further applied to the parent plant at least 1 time during the period before the 1 st subsidiary plant sprouts from the growing runners.

[19] The plant activating agent according to any one of [14] to [18], wherein the exogenous elicitor is a chitin oligosaccharide, and the endogenous elicitor is at least 1 oligosaccharide selected from cellooligosaccharides and xylooligosaccharides.

[20] The plant activator according to any one of [14] to [19], wherein the mass ratio of the exogenous exciton to the endogenous exciton in the plant activator is 0.1 to 5.

[21] The plant energizing agent according to any one of [14] to [20], wherein the endogenous elicitor comprises xylooligosaccharide.

[22] The plant activator according to [21], which is an endogenous exciton, comprising both cellooligosaccharide and xylooligosaccharide.

[23] The plant vigor agent according to [22], wherein the mass ratio of the cellooligosaccharide to the xylooligosaccharide in the plant vigor agent is 0.2 to 5.

[24] The plant activator according to any one of [14] to [23], which is applied to a plant at a concentration at which the total content of the exogenous exciton and the endogenous exciton is 0.1 to 500 ppm by mass.

[25] The plant-energizing agent according to any one of [14] to [24], which is applied to a plant by foliar application.

[26] The plant activating agent according to any one of [14] to [25], wherein the strawberry is a single cropping variety.

ADVANTAGEOUS EFFECTS OF INVENTION

The method for cultivating strawberries according to the present invention can improve the yield and quality of the harvest by applying a plant activator containing an exogenous exciton and an endogenous exciton to the seedling of strawberries.

Detailed Description

Hereinafter, embodiments of the present invention will be described. The embodiments described below are representative examples of the present invention, and are not limited to these examples.

The strawberry cultivation method of the present embodiment includes the steps of: a plant vigor agent comprising an exogenous elicitor and an endogenous elicitor is applied to seedlings of strawberries. The "plant vigor agent" includes not only substances having an effect of alleviating abiotic stresses such as temperature, light, water, and salt associated with the growth and development of plants, but also substances having an effect of alleviating biotic stresses such as diseases and pests.

The elicitor is a generic term for substances that induce a defense response of a living body against tissues or cultured cells of a higher plant, and induces disease resistance in the immune mechanism of a plant. Plants initiate pathogen resistance responses by sensing elicitors through receptors present on leaf surfaces and the like. This causes a biological defense effect (immunity) against various pathogenic bacteria, which secretes various compounds. It is considered that when an elicitor acts on a plant, defense reactions such as synthesis and accumulation of phytochemicals and infection-specific proteins, production of active oxygen, production of active nitrogen, plant hypersensitive reactive cell death, and changes in gene expression are induced, and thus the plant itself is protected from pathogenic bacteria by these reactions, thereby improving disease tolerance.

Phytochemicals are antimicrobial compounds synthesized and accumulated in plants by the action of excitons, and the antimicrobial compounds produced by each plant species are different. Typical examples of the plant protecting agent include flavonoids, terpenes, and fatty acid derivatives. Active oxygen has a function of killing pathogenic microorganisms, and further, active oxygen and active nitrogen act individually or in concert as signals for initiating various defense reactions. Disease resistance due to such an exciton effect is expected to be used in agriculture because resistance to a wide range of diseases is enhanced.

[ exogenous exciton ]

In the present specification, the term "exogenous elicitor" refers to a substance derived from an organism other than a plant, for example, elicitors derived from components of fungi, insects, and crustaceans, and is not particularly limited as long as it has an elicitor effect, and typically includes chitin, chitosan, oligosaccharides thereof, and various biomolecules derived from insects.

The plant activator used in the strawberry cultivation method according to the present embodiment preferably includes chitin oligosaccharide as an exogenous elicitor.

Chitin oligosaccharides are oligosaccharides comprising a partially deacetylated chitosan oligosaccharide and a plurality of N-acetylglucosamines linked together, and are generally obtained by hydrolyzing chitin derived from crustaceans or the like, and are also referred to as oligo-N-acetylglucosamines.

That is, chitin oligosaccharide is obtained by chemically or enzymatically partially hydrolyzing chitin prepared by a conventional method from shells of crustaceans such as crabs and shrimps. As the chitin oligosaccharide, it is preferable to use one or more mixtures selected from N-acetylchitobiose, N-acetylchitotriose, N-acetylchitetraose, N-acetylchitopentaose, N-acetylchitohexaose, N-acetylchitoheptaose, N-acetylchitoctaose, etc. Among them, N-acetylchitopentaose, N-acetylchitohexaose, and N-acetylchitopentaose have particularly high elicitor effects.

The chitin oligosaccharide used in the present embodiment is particularly preferably one having the following chemical structure.

Further, acetyl (-COCH) in the formula₃) Partial abscission, -NHCOCH₃to-NH₂The substance of (1).

[ endogenous elicitor ]

In the present specification, the "endogenous elicitor" refers to an elicitor that is a plant-derived substance, and is not particularly limited as long as it has an elicitor effect, and typically cellulose, xylan, oligosaccharides thereof, and the like produced from plants.

The plant vigor agent used in the strawberry cultivation method of the present embodiment preferably includes at least 1 oligosaccharide selected from cellooligosaccharides and xylooligosaccharides as an endogenous elicitor.

Cellooligosaccharides are oligosaccharides in which a plurality of glucose groups are polymerized by β -glycosidic bonds, and recently, they have found functionalities such as moisture retention, stickiness inhibition, fresh taste addition, starch retrogradation reduction, and protein denaturation inhibition, and are expected to be used in the fields of medicines, cosmetics, foods, and feeds. Particularly, cellooligosaccharides having a degree of polymerization of glucose of 3 or more are expected to have a greater increase in the functionality described above and to provide new functionalities. Cellooligosaccharides that are currently used industrially are produced by an enzymatic reaction, but glucose and cellobiose that is a dimer are the main components, and oligomers of cellotriose or more that are trimers are hardly contained. However, in recent years, the applicant and others have reported a method for producing cellooligosaccharides containing oligomers having a degree of polymerization of glucose of 3 to 6 by controlling a temperature rise rate, a cooling rate, a reaction temperature, and a reaction time in a hydrolysis reaction of plant biomass using a carbon catalyst to cause a hydrothermal reaction (patent document 7).

The cellooligosaccharide used in the present embodiment is particularly preferably a cellooligosaccharide having the following chemical structure.

Xylooligosaccharides are oligosaccharides in which several kinds of xylose are polymerized by β -glycosidic bonds, are generally obtained by hydrolysis of xylan, which is a main component of hemicellulose, and are sold mainly for food use.

The xylooligosaccharide used in the present embodiment is particularly preferably a substance having the following chemical structure.

[ plant-activating agent ]

The plant vigor agent used in the strawberry cultivation method according to the present embodiment contains at least the exogenous exciton and the endogenous exciton as active ingredients. The mass ratio of the exogenous exciton to the endogenous exciton (i.e., exogenous exciton content/endogenous exciton content) in the plant activator is preferably 0.1 to 5, more preferably 0.2 to 2, and still more preferably 0.3 to 0.6.

More preferably, the plant vigor agent comprises xylo-oligosaccharides as endogenous elicitors, most preferably both cello-and xylo-oligosaccharides. The mass ratio of cellooligosaccharide to xylooligosaccharide (i.e., cellooligosaccharide content/xylooligosaccharide content) in the plant activator is preferably 0.2 to 5, more preferably 0.3 to 3, and still more preferably 0.4 to 1.2.

When the plant activator contains chitin oligosaccharide as an exogenous exciton and both cellooligosaccharide and xylooligosaccharide as endogenous excitons, the ratio of each oligosaccharide to the total content of chitin oligosaccharide, cellooligosaccharide and xylooligosaccharide is preferably 10 to 50 mass% of chitin oligosaccharide and 10 to 50 mass% of cellooligosaccharide and 10 to 60 mass% of xylooligosaccharide. The ratio of each oligosaccharide is more preferably 20 to 40 mass% of chitin oligosaccharide, 20 to 40 mass% of cellooligosaccharide and 20 to 55 mass% of xylooligosaccharide.

The plant-vigor agent may further comprise other components in addition to the exogenous elicitor and the endogenous elicitor as active ingredients, for example, preservatives, spreading agents, precipitation preventing agents, thickening agents, excipients, solvents. Examples of the preservatives include potassium sorbate, paraben, benzoin, sodium dehydroacetate, 4-isopropylcycloheptadienone, phenoxyethanol, polyaminopropyl biguanide, polylysine, and the like. The spreading agent is a viscous liquid containing a surfactant as a main component, and is not particularly limited as long as it can be used as a spreading agent for a plant vigor agent, and examples thereof include polyoxyethylene nonylphenyl ether, sorbitan fatty acid ester, polyoxyethylene hexitol anhydride fatty acid ester, and the like. Examples of the precipitation inhibitor include polyphosphoric acid or a salt of polyphosphoric acid, and a polycarboxylic acid type polymer surfactant. Examples of the thickener include water-soluble polymers such as carboxymethyl cellulose (CMC), polyacrylamide, and starch, and molasses, alcohol fermentation concentrated waste liquid, and amino acid fermentation concentrated waste liquid. Examples of the excipient include lactose and starch. The solvent is used for the purpose of diluting the active ingredient to an appropriate concentration to prepare a liquid, and for the purpose of facilitating the dispersion of the solvent on plants. As the solvent, water is preferable.

The plant-activating agent used in the method for cultivating strawberries according to the present embodiment may be in any form of powder, granule, liquid, etc., but is preferably in a liquid form that is easily dispersed. When a liquid plant activator is used, the concentration of the active ingredient in the plant activator at the time of application to a plant is preferably 0.1 to 500 mass ppm, more preferably 0.5 to 200 mass ppm, and still more preferably 1 to 100 mass ppm. The concentration of the active ingredient in the plant-activating agent is the total content of the exogenous exciton and the endogenous exciton in the plant-activating agent. If the dispersion concentration is 0.1 mass ppm or more, the effect as a plant-energizing agent is efficiently exhibited. If the dispersion concentration is 500 ppm by mass or less, the plant growth can be prevented and the disease resistance can be exhibited.

The plant-vigor agent may be a commercially available product in which the concentration of the active ingredient is adjusted to the above-mentioned concentration in advance, but in general, a stock solution of the plant-vigor agent containing the exogenous elicitor and the endogenous elicitor in a high concentration is diluted with water and used. When the plant activator stock solution is diluted (for example, 1000-fold) and used, the total content of the exogenous exciton and the endogenous exciton in the plant activator stock solution is preferably 0.05 to 10% by mass, more preferably 0.1 to 8% by mass, and still more preferably 0.5 to 6% by mass.

[ strawberry ]

The strawberry cultivated by the cultivation method of the present embodiment is preferably a strawberry classified into the genus strawberry. The type is not particularly limited, and any of the season varieties can be used, but among them, the season variety is preferable.

[ cultivation method ]

The cultivation form of the strawberry is not particularly limited, and includes open field cultivation, greenhouse cultivation, hydroponic cultivation, and the like. In the cultivation of strawberries, it is important to grow seedlings in a sufficient manner to ensure high-quality fruits and yield. The seeds may be directly sown in the field, but for the purpose of growing a seedling at full depth, it is preferable to perform inoculation/seedling raising separately, and the seedling is more preferably picked up from a fine runner grown from the parent plant. Preferably, the seedlings obtained by collecting the seedlings are transplanted to a seedbed, a seedling box, or a seedling pot to grow seedlings, and the grown seedlings are planted in a large field.

For example, when a plant is cultivated from a fine runner grown from a parent plant, the following method is exemplified.

In the case of the vicinity of kanto area in japan, the field for the fertilized parent plant was transplanted with the parent seedling for about 4 months, and the field was sufficiently watered for about 1 week to promote survival. Alternatively, the parent plant may be transplanted without replanting the plant, and the plant harvested in the previous season may be directly cultivated as the parent plant. The fibrous runners grow out from parent plants in 6-7 months, and the fibrous runners grow out to sprout in sequence to form sub-plants (seedlings). The seed plants germinated from the fibrous stolons are guided to a seedbed, a pot, a seedling box and the like for fixation, so that the seed plants can root and survive. The surviving daughter plants were cut from the parent plants at about 8 months to collect seedlings, and the seedlings obtained by the seedling collection were grown for about 1 month. The seedlings are protected from direct sunlight until they survive while retaining soil moisture slightly more, and it is preferable to gradually reduce watering so that no root rot occurs after survival. Avoids extreme high temperature and excessive humidity during seedling raising, and is planted in a large field in about 10 months. In the management of the established seedlings, it is preferable to maintain soil moisture slightly more until the seedlings survive, and to gradually reduce watering so that root rot does not occur after the seedlings survive. In order to enrich the established plants, it is preferable to remove fibrous runners and axillary buds which are generated during vegetative growth for about 11 months. Entering winter dormancy stage about 12-2 months, after winter dormancy, if watering and topdressing are carried out properly along with the rise of air temperature, reproductive growth is vigorous, and flowering is carried out. After flowering, a harvest occurred around 1 month.

The strawberry cultivation method of the present embodiment includes the steps of: applying the plant activator to the seedling. In the present specification, the term "seedling" refers to a seedling from germination to 3 weeks when seeds are directly sown in a field, and refers to a seedling from germination to permanent planting when seeds are separately inoculated and raised. In addition, the term "pick-up" as used herein refers to a process from the germination of a parent plant to the pick-up of a seedling to the permanent planting of the parent plant.

In an embodiment, the plant vigor agent is preferably applied at least 1 time to seedlings 2-15 days after germination, more preferably at least 1 time to seedlings 2-10 days, and even more preferably at least 1 time to seedlings 3-7 days after germination, in order to obtain a filled seedling. The number of uses of the plant activator in a period of 2 to 15 days after germination is preferably 1 to 2 times, and more preferably 1 time.

In other embodiments, in the case of separate inoculation/seedling raising or in the case of picking seedlings from the fine runners of parent plants, it is preferable to use the seedlings from 16 days after germination to the time of permanent planting at least 1 time. The number of uses of the plant vigor agent from 16 days after germination to the time of permanent planting is related to the period of seedling raising, but is preferably 1 time for 5 to 30 days, and more preferably 1 time for 10 to 20 days.

Further, in other embodiments, in the case where seeds are directly sown in a field, it is preferable to use at least 1 time to seedlings from 16 days to 3 weeks after germination.

In order to obtain a more full seedling, it is further preferable that the plant activator is applied to a seedling 2 to 15 days after germination at least 1 time, and to the following seedling at a frequency of 5 days to 30 days 1 time at least 1 time.

In the method for cultivating strawberries according to the present embodiment, when seedlings are harvested from the fine runners of the parent plant, it is preferable to use the plant-activating agent in the parent plant in addition to the seedlings. In the case of planting parent plants, it is preferable to use the plant-activating agent 1 week after the time when the 1 st child plant sprouts from the growing fibrous runners, and it is more preferable to use the plant-activating agent further until the fibrous runners are cut for picking. In addition, when the plant harvested in the previous season is directly used as a parent plant, the plant vigor agent is preferably used from after harvesting until the 1 st child plant sprouts from the growing fibrous runners, more preferably, further, until the fibrous runners are cut for seedling collection. The frequency of use is preferably 5 to 30 days and 1 time, more preferably 10 to 20 days and 1 time. Further, it is more preferable that the plant vigor agent is used at the above-described frequency for both parent and child plants after the 1 st, 2 nd and 3 rd child plants germinate from the runners.

In another embodiment of the strawberry cultivation method according to the present embodiment, the plant vigor agent is preferably applied to the plant body after the seedling stage. The term "plant body after seedling stage" as used herein means a plant body after the lapse of the period of "seedling". Specifically, the case where seeds are directly sown in a field means plant bodies after 3 weeks from germination, and the case where the seeds are separately inoculated and grown, means plant bodies after permanent planting. In addition, the term "plant body" as used herein refers to a plant body on which seedlings picked from fibrous branches of parent plants are planted.

In one embodiment, in the case of separate inoculation/seedling raising or in the case of picking seedlings from the fibrous runners of the parent plant, the permanent planting is preferably carried out in about 10 months, with about 5 to 8 seedlings being spread with the true leaves. In order to ensure sunshine and avoid close planting, shallow planting is carried out, and watering is carried out after planting to promote survival.

The plant vigor agent is preferably applied to a plant body after 1 to 2 weeks of permanent planting at least 1 time. Then, the composition is used preferably at a rate of 1 time for 5 to 30 days, more preferably at a rate of 1 time for 10 to 20 days until the sleep period is entered. In the dormancy stage, the plant-activating agent is preferably used at a rate of 10 to 40 days for 1 time, more preferably at a rate of 20 to 30 days for 1 time. Further, the plant-activating agent is preferably used at a rate of 1 time in 5 to 40 days, more preferably at a rate of 1 time in 10 to 30 days, from the end of the resting period to the end of the harvesting period.

In other embodiments, in the case where seeds are directly sown in a field, it is preferable that the plant vigor agent is applied to the plant body at least 1 time after 3 weeks from germination. The agent is preferably used at a rate of 1 time in 5 to 30 days, more preferably at a rate of 1 time in 10 to 20 days, from 3 weeks after germination to before entering the dormancy stage. In the dormancy stage, the plant-activating agent is preferably used at a rate of 10 to 40 days for 1 time, more preferably at a rate of 20 to 30 days for 1 time. Further, the plant-activating agent is preferably used at a rate of 1 time in 5 to 40 days, more preferably at a rate of 1 time in 10 to 30 days, from the end of the resting period to the end of the harvesting period.

(use of plant-activating agent)

The application of the plant vigor agent to the strawberry can be performed by a method customary in the art, and the method of application is not particularly limited, and may be any of a method of directly applying the agent to a leaf, stem, or the like of a plant, a method of applying the agent to a culture medium in which a plant is cultivated, a method of applying the agent to soil, a method of applying the agent to a culture medium in which a fertilizer is mixed, and a method of applying the agent to soil. When the fertilizer is blended with a fertilizer, the fertilizer may be a chemical fertilizer containing nitrogen, phosphoric acid, and potassium, an organic fertilizer such as oil residue, fish residue, bone meal, seaweed powder, amino acids, sugars, and vitamins, and the like, and the type of the fertilizer is not limited. As the method of spreading, it is particularly preferable to carry out the spreading by leaf surface in order to effectively express the inducer activity. Foliar application may be effected by methods customary in the art, for example, power sprayers, shoulder sprayers, spreaders, sprayers, manned or unmanned helicopters, foggers, hand sprayers, and the like.

The spreading amount of the plant vigor agent is preferably 1cm per active ingredient²The amount of the active ingredient spread on the leaf surface is 0.1 ng-100 ng, and more preferably per 1cm²The spread amount on the leaf surface is 1ng to 20 ng. In an actual field, it is difficult to selectively spread only on the leaf surface and to attach all the spread substances to the leaf surface, and therefore it is preferable to apply the spread substances to every 100m²The active ingredient having a cultivation area of 0.01 to 20g is diluted so that the concentration in the plant activator becomes 1 to 100 mass ppm, and is uniformly dispersed from the plant body. More preferably, it will be preferred that every 100m²The active ingredient having a cultivation area of 0.1g to 10g is diluted so that the concentration in the plant activator becomes 10 mass ppm to 500 mass ppm.

In the method for cultivating strawberries according to the present embodiment, the soil is preferably managed by a conventional cultivation method.

(Effect of plant-activating agent)

The strawberry cultivation method of the present embodiment includes the steps of: a plant vigor agent comprising an exogenous elicitor and an endogenous elicitor is applied to seedlings of strawberries. Further, it is preferable that the plant-vigor agent comprising the exogenous elicitor and the endogenous elicitor is continuously applied to the plant body after the seedling stage of the strawberry. The reason why the plant growth stimulant having such a structure exerts its effect by being applied at that time is not completely elucidated. It is considered that the application of an exogenous elicitor (for example, derived from chitin oligosaccharide) imparts disease resistance and the like derived from a phytophage to a plant body, but if the exogenous elicitor excessively acts, growth inhibition occurs. On the other hand, it is expected that by administering endogenous elicitors (for example, derived from cellooligosaccharide or xylooligosaccharide), plants recognize their own cell destruction or disruption components (DAMPs: Damage-associated molecular patterns), and that acquisition of immunity, cell repair, and self-growth are promoted. In the method for cultivating strawberry of the present embodiment, it is considered that a tough seedling to which disease resistance is imparted while suppressing growth inhibition can be cultivated by applying a plant vigor agent containing an exogenous exciton and an endogenous exciton particularly at the initial seedling stage. It is considered that by continuing the use of the plant vigor agent to the strong plant bodies grown by the above operation, the growth promoting effect of the endogenous elicitor is exerted without being strongly inhibited by the growth of the exogenous elicitor thereafter, and finally, a high development effect in which both of them act complementarily can be achieved. Therefore, it is presumed that when strawberry is cultivated, the plant vigor agent is applied to the young plants at least 1 time and to the plant bodies after the young plants at least 1 time, whereby the plant bodies grow strongly and the yield and quality of the harvested products are improved.

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

Examples

[1. preparation of oligosaccharides ]

(1) Chitin oligosaccharide

10g of chitin powder (purified chitin available from Wako pure chemical industries, Ltd.) was dispersed in 30mL of water containing 1.2g of 85% phosphoric acid (special grade reagent available from Wako pure chemical industries, Ltd.), and then dried under reduced pressure, and the obtained powder was charged into an alumina pot having a capacity of 250mL together with 100g of alumina balls having a diameter of 5mm, and the mixture was placed in a planetary ball mill (available from フリッチュ, PULVERISTEE 6) and continuously treated at 500rpm for 6 hours to obtain a reaction product. In addition, as for the temperature, the temperature rise due to shear heat generation is natural at room temperature.

The reaction mixture was suspended in water and neutralized with calcium hydroxide, the resulting slurry was filtered through a suction filter using 5B filter paper, and the recovered filtrate was freeze-dried to obtain a chitin oligosaccharide powder.

(2) Cellooligosaccharide

271g (water content: 1.8%, dry mass 266g) of cotton linter pulp (97% cellulose content, manufactured by imperial workers コーセン) was mixed with 38g of 85% by mass phosphoric acid (fuji フイルム and kogaku koku) using a food mixer (model: HBF500S, manufactured by ハミルトンビーチ) to obtain 309g of a reaction raw material (water content: 3.4%, phosphoric acid content: 10.4%).

Next, 309g of the reaction raw material was charged into a vibration mill (model MB-1, manufactured by CENTRAL CHEMICAL ENGINEER CO., LTD., pot size 5L) together with 13kg of a carbon steel ball of phi 3/4 inches, and subjected to hydrolysis reaction for 24 hours by dry pulverization under conditions of a total amplitude of 8mm, a frequency of 16.2Hz, and a jacket circulating water temperature of 75 ℃ to recover a reaction powder.

10g of the reaction powder and 90g of ion-exchanged water were put into a 200L beaker, and stirred at 25 ℃ for 1 hour using an electromagnetic stirrer, to obtain an extract solution of a cellulose hydrolysate.

Subsequently, 1.3g of a 40 mass% aqueous calcium hydroxide solution was added to the extract, and the mixture was stirred at 25 ℃ for 1 hour by using a magnetic stirrer to prepare a neutralized solution, and the supernatant was collected by a centrifugal separator and then freeze-dried to obtain cellooligosaccharide powder.

(3) Xylo-oligosaccharide

A strain of Acremonium Cellulolyticus TN (FERM P-18508) was added to a liquid medium (アビセル 50g/L, KH)₂O₄24g/L, 5g/L ammonium sulfate, 1/2H potassium tartrate₂O4.7 g/L, urea 4g/L, Tween 801 g/L, MgSO₄·7H₂O 1.2g/L、ZnSO₄·7H₂O 10mg/L、MnSO₄·5H₂O 10mg/L、CuSO₄·5H₂O10mg/L)100mL of 500mL flask was cultured with shaking at 30 ℃ for 6 days. 5g of corn cob powder was suspended in 50mL of the supernatant of the resulting culture medium by centrifugation, and the reaction was carried out at 50 ℃ for 72 hours with stirring. The supernatant of the obtained reaction solution was subjected to centrifugal separation and freeze-dried to obtain a xylooligosaccharide raw material powder.

[2. cultivation of strawberry ]

(1) Preparation of plant vigor agent

The oligosaccharides prepared in [1. preparation of oligosaccharides ] were dissolved in water with a mixer so that the concentration (mass ppm) of the active ingredient in the plant-energizing agent was 1000 times as high as that in examples 1 to 12 and comparative examples 1 to 5 shown in table 1, and then sterilized with a 0.45 μm filter, and the obtained product was used as a plant-energizing agent stock solution. This stock solution was diluted 1000 times with water and used in the following cultivation test. Hereinafter, the plant activator obtained by diluting the stock solution 1000 times may be referred to as "plant activator diluent". The composition ratio of each oligosaccharide in the table represents mass%.

(2) Cultivation test 1 (examples 1 to 12, comparative examples 1 to 5)

(parent plant cultivation-seedling cultivation)

In the field fertilized 2 weeks before field planting, parent plants (one-season variety: Chazhu Ji) were field-planted with a ridge width of 200cm and an inter-plant interval of 80cm, and were watered thoroughly. Parent plants were divided into 4 plants/area in 20 areas, and seedlings germinated from the growing fibrous runners were guided to pots for raising seedlings and rooted by being supported by wooden columns. The 1 st to 3 rd sub-plants of each of the fibrous branches growing from the parent plant survived, and the fibrous branches were cut off at the moment when the true leaves were spread into 2 to 4 pieces, and 28 seedlings were collected for each individual area (7 plants/parent 1 plant). The seedlings harvested to the pots were watered sufficiently to promote rooting, and were cultivated for 1.5 months while picking the leaves in such a manner that the number of true leaves became 3 to 5.

(field planting-harvesting)

The field cultivation uses a total of 80m²The field in the plastic greenhouse. Ridges with the ridge width of 60cm and the ridge height of 10cm are made in the deeply ploughed field, and 2 planting lines with the inter-plant distance of 30cm are carried out. Among the strawberry seedlings obtained by seedling culture, well-grown seedlings were selected, and 20 plants/field were planted in 20 fields. After 2 weeks after planting, the plants were watered thoroughly, and then new leaves were developed and adjusted to the extent that they were watered as soon as the soil surface was dry. The soil management and plant management (leaf picking, core picking, fruit picking, etc.) during the period from planting to harvesting are performed according to conventional cultivation methods.

(use of plant-activating agent)

The parent plants, seedlings, and plant bodies after the seedling stage were sprayed with the diluted solution of the plant vigor agent under the conditions described in table 1 to wet the leaf surface and the soil.

An aqueous solution (plant vigor agent diluent) prepared for each condition and having an active ingredient concentration of the plant vigor agent was prepared at 1.0 kg/area, and leaf surface spreading using a watering can and spreading operation of the soil portion near the roots were performed.

The fruits ripened into red were harvested in this order, and 20 plants (1 division) were subjected to measurement of the average harvest yield and average sugar degree per 1 plant and compared under each condition. The average sugar degree of 20 grains in each region was measured using a sugar meter. The test results are shown in table 1.

[3. cultivation of Brassicaceae plants (reference examples 1 to 3) ]

Experiments were conducted using pinus koraiensis as a cruciferae family.

Ridging is performed in a field cultivated by turning compost, with a distance of about 15-20 cm between strips, seeds of komatsuna (いなむら species) are sown at intervals of 1-1.5 cm, soil is lightly covered to press the land, and then sufficient watering is performed. The germinated field pine was appropriately thinned, and the diluted solution of the plant-activating agent was spread to wet the leaf surface and soil under the conditions described in table 2. Harvesting is carried out when the height of the crops reaches 20-25 cm, and the harvesting weight of each 1 plant of 20 seedlings is compared. The test results are shown in table 2.

TABLE 2

As is clear from the results in table 1, in the cultivation of strawberries, if a plant vigor agent containing both an exogenous elicitor and an endogenous elicitor is used for seedlings, the yield is significantly improved, and strawberries with high sugar content can be obtained. On the other hand, according to the results of table 2, in the cultivation of pinus koraiensis, which is a crucifer plant, even if a plant-vigor agent including both an exogenous elicitor and an endogenous elicitor is used for seedlings in addition to the growth period before harvesting, a significant increase in weight per 1 plant cannot be confirmed.

Claims

1. A strawberry cultivation method comprises the following steps: a plant vigor agent comprising an exogenous elicitor and an endogenous elicitor is applied to the seedling at least 1 time.

2. A method of cultivating strawberries according to claim 1, comprising the steps of: applying the plant activator to the seedlings 2-15 days after germination for at least 1 time.

3. A method of cultivating strawberries according to claim 1 or 2, comprising the steps of: the plant vigor agent is further applied to the plant body at least 1 time after the seedling stage.

4. A method of cultivating a strawberry according to claim 1, wherein the seedling is a daughter plant germinated from an aerial of a parent plant.

5. A method of cultivating strawberries according to claim 4, comprising the steps of: further applying the plant vigor agent to the parent plant at least 1 time during the period before the 1 st daughter plant sprouts from the growing runners.

6. The method for cultivating strawberries as claimed in claim 1, wherein the exogenous elicitor is chitin oligosaccharide, and the endogenous elicitor is at least 1 oligosaccharide selected from cellooligosaccharide and xylooligosaccharide.

7. A strawberry cultivation method according to claim 6, wherein the mass ratio of the exogenous elicitor to the endogenous elicitor in the plant vigor agent is 0.1-5.

8. A method of cultivating strawberries according to claim 1 or 6, wherein the endogenous elicitor comprises xylooligosaccharide.

9. The method according to claim 8, wherein the endogenous elicitor includes both cellooligosaccharide and xylooligosaccharide.

10. The method for cultivating strawberries according to claim 9, wherein the mass ratio of the cellooligosaccharide to the xylooligosaccharide in the plant activator is 0.2-5.

11. A strawberry cultivation method according to claim 1 or 6, wherein the plant vigor agent is applied to the plant at a concentration at which the total content of the exogenous elicitor and the endogenous elicitor is 0.1 to 500 ppm by mass.

12. A method of cultivating strawberries according to claim 1 or 6, wherein the plant vigor agent is applied to the plants by foliar application.

13. A method of cultivating strawberries according to claim 1 or 6, wherein the strawberries are of the season variety.

14. A plant activator, which is a plant activator comprising an exogenous elicitor and an endogenous elicitor used in the cultivation of strawberries, is applied to seedlings at least 1 time.

15. The plant vigor agent according to claim 14, which is applied at least 1 time to seedlings 2-15 days after germination.

16. The plant vigor agent of claim 14 or 15, which is further applied to the plant body after the seedling stage at least 1 time.

17. The plant vigor agent of claim 14, the seedling is a daughter plant that germinates from a runner of a parent plant.

18. The plant vigor agent of claim 17, which is further applied to the parent plant at least 1 time during the period before the 1 st daughter plant sprouts from the growing runners.

19. The plant activator of claim 14, the exogenous elicitor being a chitin oligosaccharide and the endogenous elicitor being at least 1 oligosaccharide selected from the group consisting of cellooligosaccharides and xylooligosaccharides.

20. The plant activator according to claim 19, wherein the mass ratio of the exogenous exciton to the endogenous exciton in the plant activator is 0.1-5.

21. The plant vigor agent of claim 14 or 19, comprising xylo-oligosaccharides as the endogenous elicitor.

22. The plant vigor agent of claim 21, comprising as the endogenous elicitor both cello-and xylo-oligosaccharides.

23. The plant vigor agent according to claim 22, wherein the mass ratio of the cellooligosaccharides to the xylooligosaccharides in the plant vigor agent is 0.2-5.

24. The plant activator according to claim 14 or 19, which is applied to a plant at a concentration at which the total content of the exogenous exciton and the endogenous exciton becomes 0.1 to 500 ppm by mass.

25. The plant vigor agent of claim 14 or 19, which is applied to a plant by foliar spreading.

26. The plant vigor agent of claim 14 or 19, the strawberry being a seasonal variety.