JPH09143013A - Plant-vitalizing agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plant-vitalizing agent having a control effect against plant pathogenic fungi and a plant growth-stimulating activity, not polluting environments and high in the safety. SOLUTION: This plant-vitalizing agent contains chitosan oligosaccharide and at least one kind of substance selected from chitosan, chitosan oligosaccharide and their salts. At least one kind of substance selected from Montmorillonite, vermiculite, zeolite, diatomaceous earth, activated carbon and charcoal is preferably added as an excipient and a release-sustaining agent. The phytoalexin-inducing activity (elicitor activity) of the chitin oligosaccharide and the antifurigal activity of at least one kind of the substance selected from the chitosan, the chitosan oligosaccharide and their salts against plant pathogenic fungi synergistically act on the plant to give a remarkably more excellent disease resistance-imparting effect and a growth-stimulating effect than cases wherein the chitin oligosaccharide, etc., are independently used, respectively.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a plant vitalizing agent having an effect of enhancing disease resistance of a plant and promoting healthy growth by applying it to a plant or soil.

[0002]

2. Description of the Related Art Increasing the yield per unit area is an important issue in agricultural production, and various fertilizers, pesticides, etc. are used to improve disease resistance of plants and promote their growth. There is. However, chemical agents such as pesticides produced by chemical synthesis often remain in the soil for a long period of time once sprayed, which leads to environmental pollution and pollution. Therefore, there is a need for a substance that has no problems such as environmental pollution and pollution, and that improves the disease resistance of plants and promotes growth.

Under these circumstances, in recent years, chitosan prepared from chitin, which is a natural polysaccharide contained in shells of crustaceans such as crab and shrimp, or a partially decomposed product thereof has antibacterial properties. However, various plant disease control agents, soil conditioners, plant growth promoters and the like have been proposed which utilize chitin, chitosan or partial decomposition products thereof.

For example, a soil conditioner containing chitosan as a main component (Japanese Patent Laid-Open No. 63-146982), chitin, a chitin-containing organic substance or chitosan, zeolite and / or shell,
Soil disease control material containing Streptomyces cyanogenus or Streptomyces olibaceus
2614), EDT on chitosan or low-viscosity chitosan
A liquid fertilizer containing A for inhibiting the occurrence of plant diseases (Japanese Patent Laid-Open No. 1-239077), a chitosan organic acid salt and an alkylphenoxypolyalkoxyalcohol dissolved in water, and a plant disease controlling liquid for gardening (Japanese Patent Laid-Open No. 4-3200). -253901), a growth activator for turfgrass containing chitosan degradation product and acetic acid as active ingredients (Japanese Patent Laid-Open No. 6-181636), chitin, and a plant growth containing at least one selected from chitosans as active ingredients. Accelerators (JP-A-63-33310) and the like have been proposed.

On the other hand, in recent years, a plant body recognizes an oligosaccharide, which is a polysaccharide fragment derived from the cell surface of the plant pathogenic fungus or the plant itself, as an infection signal (elicitor) and produces a phytoalexin derivative or the like to produce a plant pathogenic fungus. It has been elucidated to activate the defense mechanism against (AGDarvill and P.Albershaim; Ann.Rev.Plant.Phys
iol., 35, 243, 1984).

Chitin oligosaccharides have an elicitor effect on rice plant cells (Naoto Shibuya, Journal of Japan Society of Pesticides, 19,67-71,1994) and an elicitor effect on tomato (G. Felix, M. Regenass, T. Bol
ler. The Plant Journal, 4 (2), 307-316, 1993) has been reported. Furthermore, it has been revealed that chitin oligosaccharides can also be an inducer of chitinase, which is a cell wall-degrading enzyme of pathogenic bacteria produced by plants.

[0007]

The above-mentioned conventional plant disease controlling agents, soil improving agents, and plant growth promoting agents were mostly focused on the antibacterial activity against chitosan and chitosan oligosaccharides against plant pathogenic fungi. However, the antibacterial properties of chitosan and chitosan oligosaccharides are bacteriostatic action, and they do not have sufficient bactericidal action at normal use concentrations, and they are compatible with a wide variety of plant pathogens existing in nature. Not something you can do. For this reason,
It was hard to say that a sufficient controlling effect against various plant pathogens can be obtained.

According to the experiments conducted by the present inventors, chitin oligosaccharides, which are said to have an elicitor effect, cannot be said to be sufficiently effective in controlling phytopathogenic fungi when used alone. Met.

The present invention has been made in view of the above problems, and an object thereof is to have a controlling effect against phytopathogenic fungi and a promoting effect on plant growth and to undergo biodegradation even when sprayed on plants or soil, An object of the present invention is to provide an environmentally friendly and highly safe plant vitalizing agent without the problem of remaining for a long period of time.

[0010]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that chitin oligosaccharides having an elicitor effect, chitosan having an antibacterial activity, chitosan oligosaccharides and their By using in combination with at least one selected from salt, these effects act synergistically, the effect of enhancing the disease resistance of the plant and promoting the growth is significantly obtained as compared with the case where these are used alone. Therefore, the present invention has been completed.

That is, the plant vitalizing agent of the present invention is characterized by containing chitin oligosaccharides and at least one selected from chitosan, chitosan oligosaccharides and salts thereof.

The phytoalexin-inducing activity possessed by chitin oligosaccharides is obtained by using the plant vitalizing agent of the present invention in combination with chitin oligosaccharides and at least one selected from chitosan, chitosan oligosaccharides and salts thereof. Elicitor activity) and the antibacterial activity against plant pathogens possessed by at least one selected from chitosan, chitosan oligosaccharides and salts thereof synergistically exert an excellent disease resistance imparting effect and growth promoting effect. You can

Further, chitin oligosaccharides, chitosan, chitosan oligosaccharides and salts thereof are all obtained from chitin, which is a natural product that is present in large amounts in the natural world, and even when sprayed on plants or soil. Since it is decomposed, there is no problem of remaining for a long time, it is environmentally friendly and highly safe.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, chitin oligosaccharides, chitosan, chitosan oligosaccharides and salts thereof are chitins prepared by a conventional method from shells of crustaceans such as crabs and shrimps, chemically or enzymatically. It is obtained by subjecting it to a selective treatment.

That is, chitin oligosaccharide
It is obtained by partial hydrolysis with an acid or an enzyme. As the chitin oligosaccharide, one or more selected from N-acetylchitobiose, N-acetylchitotriose, N-acetylchitotetraose, N-acetylchitopentaose and N-acetylchitohexaose. A mixture of is preferably used. In addition, chitin oligosaccharides or a mixture thereof are commercially available from each company, for example, "NA
-COS-Y "(trade name, manufactured by Yaizu Suisan Chemical Co., Ltd.) and the like can be used.

Chitosan can be obtained by heat-treating chitin in concentrated alkali to deacetylate it.
Since chitosan naturally exists as a cell wall component of zygomycetes such as Mucor rouxii, which is a kind of mold, it may be used.

Chitosan oligosaccharide is obtained by partially hydrolyzing chitosan. The partial hydrolysis of chitosan is carried out by heating chitosan with an acid such as hydrochloric acid, acetic acid, formic acid or the like, or removing the acid, or neutralizing and desalting chitosan, crystallizing, and further drying powder, Alternatively, it can be carried out by a method of dissolving chitosan in a dilute acid and then allowing a chitosan degrading enzyme such as chitosanase or D-glucosaminidase to act. The chitosan oligosaccharide obtained by these methods is usually a mixture of chitobiose, chitotriose, chitotetraose, chitopentaose, chitohexaose, chitoheptaose, chitooctaose and the like. In the present invention, it is possible to use in the state of a mixture of chitosan oligosaccharides, column chromatography, by a method such as solvent fractionation method,
It may be fractionated and purified to a desired degree of polymerization before use. In addition, chitosan oligosaccharide or a mixture thereof is also commercially available from each company, and for example, “COS-Y” (trade name, manufactured by Yaizu Suisan Chemical Co., Ltd.) can be used.

In the present invention, as salts of chitosan or chitosan oligosaccharides, inorganic salts such as hydrochlorides and sulfates, organic acid salts such as acetates, lactates and formates are preferably used.

In the plant vitalizing agent of the present invention, the compounding ratio of chitin oligosaccharide and at least one selected from chitosan, chitosan oligosaccharide and salts thereof is 1: 1 by weight.
It is preferably 1 to 50. When the compounding ratio of chitin oligosaccharide and at least one selected from chitosan, chitosan oligosaccharide and salts thereof is out of the above range,
The effect is the same as when either one is used alone, and the synergistic effect of the above two kinds of components cannot be sufficiently obtained.

The plant-activating agent of the present invention may be commercialized in the form of powder, granules, liquid or the like. In addition, upon spraying, the above product may be sprayed directly or diluted with water or the like to an appropriate concentration and sprayed. When diluted in water, it is preferable to dilute the chitin oligosaccharide to 0.0001 to 0.1%, chitosan, chitosan oligosaccharide and its salt to 0.01 to 1% before use. Further, the spraying method is not particularly limited, for example, a method of directly spraying the leaves, stems, etc. of the plant, a method of spraying in the culture medium or soil for cultivating the plant, and a method of spraying in the culture medium or soil mixed with a fertilizer etc. Any method may be used. When compounded in fertilizers, as fertilizers, chemical fertilizers containing nitrogen, phosphoric acid, and potassium, oil dregs, fish dregs, bone meal, seaweed meal, amino acids,
The types of organic fertilizers such as sugars and vitamins are not limited.

When formulating the plant-activating agent of the present invention, commonly used excipients such as dextrin may be used, but clay minerals such as montmorillonite and vermiculite, zeolite, diatomaceous earth, It is more preferable to use those having an action as a sustained release agent (those that retain the active ingredient and gradually release it over a long period of time) such as activated carbon or charcoal. When these are used, 0.01 to 1 part by weight of chitin oligosaccharide, chitosan, chitosan oligosaccharide and 100 parts by weight of at least one selected from montmorillonite, vermiculite, zeolite, diatomaceous earth, activated carbon and charcoal are used. It is preferable to add at least one selected from those salts in an amount of 0.1 to 10 parts by weight.

If desired, the plant vitalizing agent of the present invention may be mixed with a preservative such as potassium sorbate, a pigment or the like.

[0023]

[Examples] In the following examples, as the chitin oligosaccharide, a chitin oligosaccharide mixture "NA-COS-Y" (trade name, manufactured by Yaizu Suisan Chemical Co., Ltd.) having the composition shown in Table 1 below was used. . As the chitosan oligosaccharide acetate and chitosan oligosaccharide lactate, "COS-Y" (trade name, Yaizu), which is a mixture of chitosan oligosaccharides having the composition shown in Table 2 below, which is prepared by an enzymatic method using chitosanase. Suisan Kagaku Co., Ltd.) was used as an acetate salt and a lactate salt, respectively.

[0024]

[Table 1]

[0025]

[Table 2]

Example 1 100 g of chitin oligosaccharide "NA-COS-Y" and 100 g of chitosan oligosaccharide "COS-Y" acetate, 800 g of dextrin
Was added and mixed well, and granulated using a fluidized granulator to obtain 980 g of a granular plant-activating agent.

Comparative Example 1 In Example 1, 100 g of chitin oligosaccharide "NA-COS-Y"
Without the addition of chitosan oligosaccharide "COS-Y" acetate,
Granules were obtained in the same manner as in Example 1, except that dextrin was mixed.

Example 2 10 g of chitin oligosaccharide "NA-COS-Y" and 100 g of chitosan were mixed with 10 kg of sodium montmorillonite and wet granulated to obtain 10 kg of a granular plant active agent.

Comparative Example 2 In Example 2, chitin oligosaccharide “NA-COS-Y” was not blended, but only chitosan and sodium montmorillonite were mixed, and the same procedure as in Example 2 was followed to obtain granules. It was

Comparative Example 3 In Example 2, chitosan was not blended, but only chitin oligosaccharide “NA-COS-Y” and sodium montmorillonite were mixed, and the same procedure as in Example 2 was followed to obtain granules. It was

Example 3 0.1 g of chitin oligosaccharide "NA-COS-Y", 1 g of lactate of chitosan oligosaccharide "COS-Y", 0.5 g of potassium sorbate as a preservative, and 0.01 g of yellow dye , Dissolved in 10 L of water (liter, the same below), 10 L of liquid plant vitalizing agent
I got

Test Example 1 1% by weight of the granular plant-activating agent obtained in Example 1 was
Test solutions were prepared by dissolving in tap water so that the concentrations were 0.1% by weight, 0.01% by weight, 0.001% by weight, 0.0001% by weight and 0.00001% by weight. For comparison, a solution in which glucose was dissolved at the same concentration was also prepared.

Twenty-five grains of radish radish seeds were sown on each of 13 plastic petri dishes covered with absorbent cotton, and one petri dish was filled with tap water as a control and the other 6 petri dishes.
40 ml of the test solution in which the plant-activating agent was dissolved at each concentration was injected into each petri dish, and 40 ml of the solution in which glucose was dissolved at each concentration was injected into the remaining 6 petri dishes.

Each petri dish was placed at 25 ± 2 ° C. in the dark for 5 days and in the light for 2 days to grow radish radish. 20 ml of each solution was replenished on the third day of cultivation.

From each petri dish, radish radish was harvested, the foliage length was measured, and the average value was obtained. The results are shown in Table 3 after converting the stem and leaf length of the control kaiware radish cultivated only with tap water to 100.

[0036]

[Table 3]

From the results shown in Table 3, 0.01 to 0.00 of the cultivated radish radish was cultivated using the solution in which the plant vitalizing agent was dissolved.
It can be seen that at a concentration of 01% by weight, it grows better than those cultivated with tap water and those cultivated with glucose.

Test Example 2 5 L of culture soil containing 30% by weight of commercially available compost was added to N:
After mixing 5g of chemical fertilizer with P: K of 4: 3: 2,
The granular plant vitalizing agent obtained in Example 2, the granules obtained in Comparative Example 2, and the granules obtained in Comparative Example 3 were each added to 0.
2% by weight, 0.1% by weight, and 0.02% by weight were mixed to obtain soil for radish radish cultivation. As a control, a soil was prepared by mixing the same culture soil with the same chemical fertilizer as above.

Each of the soils was placed in a No. 8 chrysanthemum pot having an outer diameter of 24 cm, a height of 22 cm, and an inner volume of 5.4 L, which is a pot for cultivation, and 8 seeds of 20 days radish seeds were sown. Cultivated outdoors from July 1st to July 29th. In addition, except in rainy weather,
Water was sprinkled once a day, and no fertilizer or pesticide was applied.

After harvesting, it was air-dried and divided into an above-ground portion (stems and leaves) and an underground portion (root), and the weight of each was measured to obtain an average value. The results are shown in Table 4. In Table 4, what was cultivated using the soil mixed with the granular plant vitalizing agent obtained in Example 2 was cultivated using the soil mixed with the granular agent obtained in Example 2 and Comparative Example 2. What was cultivated using the soil mixed with the granules obtained in Comparative Example 2 and Comparative Example 3 is referred to as Comparative Example 3. This also applies to Tables 5 and 6 below.

[0041]

[Table 4]

From the results shown in Table 4, the 20 days radish cultivated in the soil containing the granular plant vitalizing agent of Example 2, the granules of Comparative Example 2 and the granules of Comparative Example 3 were the grains of Comparative Example 2. Roots cultivated using soil mixed with the agents at concentrations of 0.2% by weight and 0.1% by weight, Roots cultivated with soil mixed with the granules of Comparative Example 3 at concentrations of 0.2% by weight and 0.1% by weight, Comparative Example 3 Except for the foliage part cultivated using the soil in which the granules were mixed at a concentration of 0.2% by weight, all grow larger than the control, but the granular plant vitality of Example 2 in which chitin oligosaccharide and chitosan were used in combination What was cultivated in the soil mixed with the agent, compared with those cultivated using the soil mixed with the granules of Comparative Example 2 containing only chitosan, the granules of Comparative Example 3 containing only chitin oligosaccharide, It can be seen that the roots also clearly grow well.

Test Example 3 Cucumber seeds were germinated in a pot for raising seedlings, and the granular plant-activating agent obtained in Example 1 was added to water at a double leaf stage.
Cucumber seedlings were obtained by spraying a solution dissolved at a concentration of 1% by weight and 0.01% by weight and raising the seedlings.

N: P: K is 4: 3: 2 as a fertilizer component.
A granular plant-activating agent obtained by using the chitin oligosaccharide and the chitosan oligosaccharide acetate obtained in Example 1 in combination in the soil to which an appropriate amount of the compound fertilizer and beef manure was applied, Comparative Example 1
The ridges were formed in the greenhouse while plowing the granules containing only the chitosan oligosaccharide acetic acid salt obtained in the above step to the soil so as to be 0.1% by weight and 0.01% by weight, respectively. Also,
As a control, a ridge was created in which neither the plant vitalizing agent nor the granules were plowed.

Next, three of the above-mentioned cucumber seedlings having an average length of 7 cm were planted in each ridge, and cultivation was carried out from March 10, 1994 to May 25, 1994. As a general rule, watering was performed once a day, and topdressing with liquid fertilizer was performed twice during the period. The general management work was performed as usual, but pest control with pesticides was not performed.

Cucumbers were harvested three times in total for one month from April 26th to May 25th. The number and weight of the harvested cucumbers were measured, and the average weight per individual was calculated.
In addition, the occurrence of diseases during the cultivation period and the damage caused by pests were observed. Table 5 shows the results.

[0047]

[Table 5]

From the results in Table 5, the cucumber cultivated in the soil sprayed with the granular plant-activating agent obtained in Example 1 and the soil sprayed with the granule obtained in Comparative Example 1 was cultivated in the control soil. The total weight of the cucumbers was higher than that of the cucumbers, and the average individual weight was also higher.
The granules containing only the chitosan oligosaccharide acetate obtained in Comparative Example 1 are more cultivated in the soil sprayed with the granular plant-activating agent containing the chitin oligosaccharide and the chitosan oligosaccharide acetate obtained in It can be seen that the number of harvested plants, the total weight, and the average individual weight are clearly superior to those cultivated in the soil sprayed with. In addition, both the occurrence of powdery mildew, the damage caused by leaf mites and aphids were obtained in the control soil and Comparative Example 1 when cultivated in the soil sprayed with the granular plant-activating agent obtained in Example 1. Less than when cultivated on soil with sprinkled granules.

Test Example 4 Three places of 20th century pear garden in Tottori prefecture (1st to 3rd test zones)
In 1/3 of each pear garden, a liquid obtained by diluting the granular plant-activating agent obtained in Example 1 with water to a concentration of 0.05% by weight into 1/3, and 1/3 the granule obtained in Comparative Example 1 Pear was cultivated by spraying a solution diluted with water to a concentration of 0.05% by weight with water without addition (control) in the remaining 1/3 every 20 days.
The test period is from April 15th to September 4th, 1995. Each of the 1000 fruits is wrapped in a bag marked by coloring, and the number of fruits that have decayed or fallen due to black spot disease is measured. did. The management operations such as fertilization, chemical control, fruit picking, and bag hanging were performed under exactly the same conditions. Table 6 shows the number of illnesses falling in each test section.

[0050]

[Table 6]

From the results shown in Table 6, both the granular plant-activating agent obtained in Example 1 and the granular agent obtained in Comparative Example 1 have the effect of suppressing the drop of pear due to black spot disease. The plant revitalizing agent obtained by using the chitin oligosaccharide and the chitosan oligosaccharide acetate obtained in Example 1 together has less drop due to black spot than the granules containing only the chitosan oligosaccharide acetate obtained in Comparative Example 1. It can be seen that the effect of doing so is remarkable.

[0052]

As described above, according to the present invention,
By combining chitin oligosaccharides with at least one selected from chitosan, chitosan oligosaccharides and salts thereof, phytoalexin-inducing activity (elicitor activity) of chitin oligosaccharides, chitosan, chitosan oligosaccharides and them Synergistically with the antibacterial activity against the pathogenic fungus of the plant having at least one selected from the salts of the above, it is possible to obtain a significantly superior disease resistance imparting effect and growth promoting effect than when they are used alone I understand.
Further, the component to be added to the plant vitalizing agent of the present invention is a natural product and is biodegraded even when sprayed on plants or soil,
There is no problem of remaining for a long time, it is environmentally friendly and highly safe.

Claims (4)

[Claims] 1. A plant vitalizing agent comprising chitin oligosaccharides and at least one selected from chitosan, chitosan oligosaccharides and salts thereof. 2. The chitin oligosaccharide and the chitosan,
The plant vitalizing agent according to claim 1, wherein the compounding ratio with at least one selected from chitosan oligosaccharides and salts thereof is 1: 1 to 50 by weight. 3. A chitin oligosaccharide and at least one selected from chitosan, chitosan oligosaccharide and salts thereof, and at least one selected from montmorillonite, vermiculite, zeolite, diatomaceous earth, activated carbon and charcoal. The plant vitalizing agent according to claim 1 or 2, which is contained. 4. Chitin oligosaccharide based on 100 parts by weight of at least one selected from montmorillonite, vermiculite, zeolite, diatomaceous earth, activated carbon and charcoal.
4. The plant vitalizing agent according to claim 3, containing 0.01 to 1 part by weight, and 0.1 to 10 parts by weight of at least one kind selected from chitosan, chitosan oligosaccharide and salts thereof.