JP3213112B2 - White root rot control agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an agent for controlling white root rot caused by Trichoderma spp. More specifically, by using Trichoderma spp., Which has an antagonistic effect on white root rot, in combination with an organic acid and an organic fertilizer, the Trichoderma sp. Is stabilized in the soil, and the growth is facilitated. The present invention relates to a pesticidal agent characterized by controlling pests and protecting and growing crop roots.

[0002]

2. Description of the Related Art White root rot is a disease parasitic on the roots of more than 80 species of crops, mainly fruit trees such as apples, pears, grapes, and plums. It invades the roots and causes them to rot and die. I'm sick. It is a disease of roots in soil, especially when permanent crops such as fruit trees are affected, and there is not much effective control method because strong soil fungicides that control bacteria are not available. At present, isobrothion agents (trade name: Fujiwan), thiophanate methyl agents (trade name: Topodine), benomyl agents (trade name: benlate), and the like are recognized as pesticides, but at present there are no effective ones. In addition, since it causes harm to human health and causes environmental pollution, which is a social problem, a biological control method that uses harmless organisms that are useful and harmless to plants without pesticides is a safe and effective alternative to pesticides. It is desired as a law.

On the other hand, it is already widely known that Trichoderma sp., Which is a kind of soil microorganism, itself has a strong antagonistic action against various pathogens of plants.
A bactericide containing it as a main component is registered as an agricultural chemical (Ministry of Agriculture, Forestry and Fisheries Registration No. 7023). Further, a method for growing Trichoderma sp. (Japanese Patent Publication No. 60-22911,
37986) and a turfgrass disease controlling agent (JP-A-3-23
6304) has been developed.

[0004] However, few trichoderma preparations are practically used, and their efficacy has not been evaluated. This suggests that even if an effective antagonistic microorganism such as Trichoderma is introduced to a farm, it will not survive in the competition of various microorganisms in the soil and will not have the expected disease-suppressing effect. It is generally said that this is not the case.

[0005]

In soil, even if a large amount of the same microorganism is administered, it is suppressed by indigenous microorganisms, and it is difficult to change a wide range of microflora. However, it is difficult to maintain the same microorganism for a long time due to the bacteriostatic action of the soil. For this reason, a method for rapidly and permanently fixing useful antagonistic microorganisms to soil is required.

Therefore, a method of immobilizing microbial cells with a polymer substance (Japanese Patent Application Laid-Open No. 234005/1987) and a method of coating cells with a hydrophobic substance (Japanese Patent Application Laid-Open No. 2-212406) have been proposed. There have been reports of stabilization of bacterial cells. In addition, a method of mixing and applying nutrients (rice bran, bran, etc.) together with the bacterial cells (the method of using Agricultural Chemical Registration No. 7023), or a method of suspending a nutrient or a proliferating agent with Trichoderma sp. A method for enhancing the effect, such as the method (Japanese Patent Application Laid-Open No. 4-29905), has been developed.

[0007] However, none of these known methods is satisfactory, and even if applied to actual fields, the intended purpose cannot be achieved. When Trichoderma cells or preparations are applied to a field, no matter how much they are added, they are very small in a large field and spread to the soil, resulting in differences in the methods of use and technical skills of farmers.
Further, it is easily affected by weather conditions, and it is difficult to grow only the cells in competition with the microorganisms in the soil, and it is presumed that the effect lacks stability.

[0008]

DISCLOSURE OF THE INVENTION The present invention has been made for the purpose of newly developing a control system for white root rot, and firstly, prevention of pesticide pollution, prevention of environmental destruction, and the like.
From the viewpoint of safety, conventional synthetic pesticides are not used, and attention has been paid to a biological pesticide, particularly a control system using microorganisms using Trichoderma spp.

Further, the present inventors have solved the above-mentioned many problems in the application of microorganisms such as Trichoderma spp. To soil, and have succeeded in stably growing Trichoderma spp. Without diluting and disappearing in soil. Not only was it possible, but also for the first time to see the need to simultaneously develop systems that could maintain the crops themselves, especially the crop roots.

[0010] Therefore, the present inventors, as a method of controlling white root rot, maintain the roots healthy, so that not only the suppression of white root rot of roots caused by Trichoderma fungi, but at the same time, the roots should be energized. To simultaneously solve the two independent problems of promoting rooting and preventing the invasion and growth of white root rot fungi, and as a result of earnest research, it has been possible to achieve this for the first time by newly adopting the means described below. Success,
The present invention has been completed.

That is, the present invention newly addresses a previously unknown new technical problem of developing a new system capable of simultaneously achieving both direct control of white root rot caused by Trichoderma spp. And healthy growth of crops, especially roots. It has been successfully set up and solved by the new means described below. In other words, in the present invention, the technical problem, that is, the object of the invention itself is already novel, and the means for solving the problem, that is, the structure of the invention, is novel.

[0012] In the present invention, as described above, first, a method for stably growing Trichoderma spp., Which has an antagonistic effect on white root rot, in soil is found.

A solution having a certain concentration of an organic acid, for example, 0.1 to 5% for citric acid, and most preferably 0.3 to 1%, shows an inhibitory effect on white rot fungus, but Trichoderma. It does not adversely affect the growth of the genus Bacteria, and on the contrary, it becomes a growth nutrient and promotes the growth. On the other hand, organic acids have a root-promoting action and give vitality to the growth of crops.

Further, the organic fertilizer not only contains amino acids and nucleic acids as a main component but also serves as a growth nutrient for Trichoderma spp., And the contained amino acids and nucleic acids have the effect of promoting rooting and elongation of crops.

As described above, as a system for effectively controlling white root rot of growing crops, not only the control of white root rot but also the growth of Trichoderma spp. As a result of investigations to achieve the newly set object of the present invention, which promotes rooting promotion of the present invention, as described above, adopting a new configuration using Trichoderma spp., An organic acid, and an organic fertilizer in combination. Has confirmed that the roots of crops can be healthy at the same time as controlling white rot, and here we have completed a system to permanently and securely control white rot and without causing pollution. It is a thing. That is, the object of the present invention was successfully achieved.

Hereinafter, the white root rot control system according to the present invention will be described in more detail.

The Trichoderma genus used in the present invention comprises:
It is only necessary to screen for a white rot fungus, which is a pathogen of soil disease, by a counter-culture method, and select and use a substance having an antagonistic effect against the pathogen. For example, Trichoderma viride
IFO9066, polysporum (T. polyspo)
rum) IFO9322, Longibra gear Tsum (T.
Longibrachiatum IFO4847, T. koningii IFO9085, and other Trichoderma spp. can be cultured to screen for strains having antagonistic activity against the pathogen, and these strains can be used alone or in combination of two or more strains. As the Trichoderma genus used in the present invention, a microorganism having an antagonistic effect on white rot fungus is used. It is of course possible to select a microorganism having a wide range of antagonistic powers and use it.

In the present invention, the Trichoderma spp. Selected in this manner is cultured in large quantities, only the cells are separated from the culture, and the obtained cells, spores and hyphae are used. Can also be used. For example, spores, viable bacteria that obtained hyphae, of course, were obtained by culturing Trichoderma spp. Selected in the above in a large amount in a grain medium such as barley or rye or in a solid medium such as sawdust, rice bran, and bran. Formulations such as concentrated, paste-like, freeze-dried, and dried simple and stable media can be used.

In addition, a starch, a sugar such as lactose, and an inorganic salt may be mixed as a nutrient with the mixture of these cells, and a base for facilitating colonization and growth in soil may be added. Furthermore, base materials (organic materials, mineral materials, etc.) that can be molded into granules are blended and molded.
Granules that are easy to handle can also be used as the microbial preparation of the present invention.

The organic acid used in the present invention is citric acid,
One or more of malic acid and itaconic acid are preferable, but other organic acids can be used as long as they do not affect Trichoderma sp. it can. The organic acid may be used as a solid, but it is dissolved in water at the time of use to make a 0.1 to 5% solution, and the above-mentioned preparation of Trichoderma sp. It is suitable to apply directly by application or irrigation into soil.

Examples of the organic fertilizer used in the present invention include fish solubles or those obtained by decomposing the same with proteolytic enzymes, gelatin, gelatin-containing substances, and hoof horn solution obtained by proteolysis of animal fertilizer such as hoof horn. A liquid amino acid / protein solution is used. This is Trichoderma,
A mixed solution is prepared by mixing with an organic acid solution to have a concentration of 0.1 to 0.5% (in terms of dry matter), and directly applied to the root of the crop as described above.

Although the details of the mechanism for controlling white root rot in the present invention must be studied in the future, it is presumed as follows. That is, as described above, by simultaneously applying not only Trichoderma spp. But also an organic acid and an organic fertilizer, the white root rot fungi attached to the roots are killed, and the remaining fungi and white spots that invade from the surroundings are killed. By preventing the growth and invasion of Trichoderma fungi that grow around the roots, it is possible to surely control white root rot. In other words, first, the white rot fungus is killed by the organic acid. The organic acid concentration is 0.1 to 5% in terms of citric acidity, and the optimum concentration is 0.3 to 1% without any damage to roots and no influence on Trichoderma spp. This removes the fungus on the surface of the root, and at the same time, the Trichoderma and nutrients adhere to the roots with the organic acids or are present in large amounts around the roots, and the Trichoderma sp. This will prevent the growth and invasion of the fungus and protect the roots.

Further, by applying these, new roots are generated in the crop, and the crop which has been weakened by the invasion of the fungus of white root rot becomes vegetative and becomes resistant to white root rot. This is thought to be due to the root-promoting action of amino acids and proteins and the same root-promoting action of organic acids.

Thus, the present invention relates to Trichoderma spp.
By simply applying organic acids, organic fertilizers, or nutrients, it is possible to simultaneously kill the white root rot fungus itself and grow healthy crop roots at the same time. It provides a new type of control agent that is completely separate from the agent category. Such a type of control agent is particularly effective for crops that take a long time to grow, such as fruit trees, and cannot be easily cut or extracted even if a disease occurs.

Next, the present invention will be described in more detail based on examples.

[0026]

Example 1 Trichoderma viride (Trichode)
rmavide) IFO9066, and a bacterium having an antagonistic activity against white root rot was screened.

The Trichoderma bacterium thus obtained was cultured in a rye medium for 10 days.
C. and dried with a crusher to prepare a Trichoderma preparation. This Trichoderma fungus spores 10 ⁸ / g
Was included above.

Citric acid 10% (W / V), itaconic acid 5
The dried fish solubles were added to and dissolved in a solution of 20% (W / V) to obtain a mixed solution of 20% (W / V). The thus obtained Trichoderma preparation and the organic acid / nutrient solution were separately packaged and mixed at the time of use.

[0029]

Example 2 An actual control test was conducted in a field against white root rot of pear. Location: Imari City, Saga Prefecture Crop / Cultivar: Pear “Kosui” Tree age 7 to 8 years (white scab attacked tree)

The organic acid and nutrient solution prepared in Example 1
Trichoderma preparation 50 in 500 cc of 0-fold diluted solution
0 g was added to make a suspension-like mixture, which was applied to the excavated pear root. Further, a solution obtained by diluting 2 liters of the organic acid solution with 100 liters of water was poured around the root. Then, 1.5 kg of the Trichoderma preparation was mixed with the excavated soil and back-filled around the root. In addition, the test was similarly performed about the following control 1 and 2 as a control.

"Control 1" pesticide Fujiwan granules (trade name) 3
Kilograms were applied to the digged pear roots to backfill the soil.
300 g of pesticide Top Gin M (trade name) was dissolved in 150 liters of water and poured into the same pear planting hole.

"Control 2" A tree that had developed white rot was managed as it was.

One year later, when the roots were dug up and examined again, the results shown in Table 1 below were obtained.

[0034]

[Table 1]

As is evident from the above results, in Example 2, the amount of spoiled roots caused by white root rot was reduced. In addition, the amount of fine roots generated was large.

In contrast, the amount of spoiled roots did not increase in the control 1 pesticide treatment. In addition, fine roots can be seen,
Diseased roots still remained. In Control 2, the disease of white root rot was enlarged and no new roots were found. It was about to die.

[0037]

Industrial Applicability According to the present invention, it is possible to directly kill white leaf rot itself, and at the same time grow healthy crops, especially crop roots. For the first time, it is now possible to safely control pesticides for a long time without causing pesticide pollution.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) A01N 63/00 C05G 3/02 C12N 1/14

Claims (4)

(57) [Claims] [1] Trichoderma viride (Thichoderma vi)
ride), Trichoderma polysporum
lysporum), Trichoderma longifragitam (Tric)
a microorganism belonging to the genus Trichoderma selected from the group consisting of hoderma longibrachiatum and Trichoderma koningii, and an organic fertilizer comprising an organic acid (excluding oxalic acid) and an amino acid / protein solution. Control agent for white root rot. 2. The control agent according to claim 1, wherein the organic acid is selected from the group consisting of citric acid, malic acid and itaconic acid. 3. The control agent according to claim 1, wherein the organic fertilizer is a fish solible, an animal proteolytic extract, gelatin or the like which is easily liquefied. 4. Trichoderma viride (Thichoderma vi)
ride), Trichoderma polysporum
lysporum), Trichoderma longifragitam (Tric)
a microorganism belonging to the genus Trichoderma selected from the group consisting of hoderma longibrachiatum and Trichoderma koningii, and an organic fertilizer comprising an organic acid (excluding oxalic acid) and an amino acid / protein solution.
A method for controlling white root rot, wherein the components are simultaneously applied and / or the first to third components are applied at staggered times.