KR101764279B1

KR101764279B1 - Composition for controlling nematode comprising mixture of acetic acid and lactic acid as effective component and uses thereof

Info

Publication number: KR101764279B1
Application number: KR1020150170336A
Authority: KR
Inventors: 김영호; 서윤희
Original assignee: 서울대학교산학협력단
Priority date: 2014-12-04
Filing date: 2015-12-02
Publication date: 2017-08-04
Also published as: KR20160067751A

Abstract

The present invention relates to a composition for controlling nematodes containing a mixture of acetic acid and / or lactic acid as an active ingredient and a use thereof, and the organic acid of the present invention is used for food or contained in many fermented foods, It is cheaper than eco-friendly materials and can be used safely in farmers who need to control nematodes. In particular, even if used periodically in a farm, it is possible to carry out control of the pollution safely because there is no fear of being poisoned by poisonous substances or harming health due to pollution in the cultivation house of a crop.

Description

[0001] The present invention relates to a composition for controlling nematodes containing acetic acid and a lactic acid mixture as an active ingredient and a use thereof.

The present invention relates to a composition for controlling nematodes containing a mixture of acetic acid and lactic acid as an active ingredient and a use thereof.

Unlike in the production of agricultural products, in the case of quarantine nematodes, the possibility of detection of even a very low nematode density after the control can not be totally excluded, so full control of the nematodes should be pursued. In order to do this, it is necessary to introduce a control method that can prevent nematodes from entering the medium at the initial stage of cultivation and to prevent the occurrence of nematodes continuously during the growing season (continuous control strategy). If this method is not applied and the quarantine nematode is likely to be infected, it is necessary to establish a control strategy to eliminate the remaining nematode densities immediately before shipment for export and to suppress the occurrence of nematodes until quarantine of the importing country of Cymbidium Rapid control strategy). The sustainable control strategies should be able to protect the environment of growers who are continuously exposed to these substances by using nematode materials which are harmless to man and environment and to use nematode-toxic substances for rapid control strategies something to do.

All inbred nematodes and all predator nematodes (Mononchida) of Rhabditida are excluded from the quarantine. Since the plant parasitic nematode, which directly affects Cymbidium, is not distributed in Korea, it is likely to enter the cymbidium culture medium due to the wide host range of the parasitic nematode of other crops, ( Bursaphelenchus), which is a fungus that grows in the dead wood, xylophilus ), Ditylenchus sp. And Meloidogyne incognita ), as shown in Table 1 (see Table 1). In the case of pine reeves, which are likely to be contaminated with Bark, a raw material of cymbidium in these nematodes, contamination may be caused not only in the first and second year but also in the culture of the flowering seedlings. Ditylenchus sp., Which is a bacterium but is not inhabited by dead birds and has a low possibility of contamination with Bark, seems to be a more efficient control strategy for exports. In addition, it is impossible to propagate the root-knot nematode, which has no bacterial growth, in the medium.

Korean Patent Laid-Open No. 2008-0074809 discloses a 'natural plant extract and a composition for controlling pests including the same,' and Korean Patent No. 0531489 discloses a composition for controlling nematodes. However, in the present invention, , There is no disclosure of a composition for controlling nematodes containing a mixture of acetic acid and lactic acid as an active ingredient and its use.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned needs, and the present inventors have found that a mixture prepared by adding acetic acid or lactic acid at a specific concentration or acetic acid and lactic acid at the same concentration is added to a pine bug xylophilus ) or the root nematode ( Meloidogyne incognita ), the present invention has been completed.

In order to solve the above problems, the present invention provides a composition for controlling nematodes containing acetic acid, lactic acid or a mixture of acetic acid and lactic acid as an active ingredient.

The present invention also provides a method for preventing or controlling nematode infection by treating the composition with a plant part, soil or seed.

Since the organic acid of the present invention is used for food or contained in many fermented foods, its safety is relatively high and its price is relatively lower than other eco-friendly materials, it can be used safely in farmers needing nematode control. In particular, even if used periodically in a farm, it is possible to carry out control of the pollution safely because there is no fear of being poisoned by poisonous substances or harming health due to pollution in the cultivation house of a crop.

Fig. 1 is a graph showing the results of an experiment using an organic acid mixture (MX), fosthiazate and microbial strains ( Paenibacillus polymyxa GBR-1), and the pH change (three replicate averages and standard deviations) of the two-year-old cymbidium media.
Fig. 2 shows the growth state of 2-year-old Cymbidium after 21 days of treatment with various substances. A: no treatment, B: 0.5% organic acid mixture, C: microbial strain ( Paenibacillus culture medium (10 ⁷ CFU / mL) of polymyxa GBR-1), D: the nematocide (fosthiazate-fold amount of processing) could not be found the growth or more symptoms (weakened in the control group and all treatment groups).
Figure 3 shows the molecular structure and safety of acetic acid and lactic acid. It is contained in vinegar, yogurt and kimchi, diluted in 4 ~ 8% acetic acid, and approved as a food additive in Europe, America and Oceania.
Fig. 4 is a graph showing the results of the measurement of the root-knot nematode ( Meloidogyne incognita ) of the 2nd instar larva. AD: front of nematode, EH: central part, IL: rear part; A, E, I: No treatment, B, F, J: Acetic acid treatment, C, G, K: Lactic acid treatment, D, H, L: The large and small vacuoles (arrows) formed at the center and back of nematode exposed to organic acids are the result of rapid destruction of nematode tissue. Bar = 10 μm.
FIG. 5 shows the results of comparison of the root formation rate (root-knot nematode effect) of pepper roots after 4 weeks of inoculation with organic acid mixture and fosthiazate treatment. A: non-inoculated untreated, B: rootless nematode inoculated, C: root necrosis inoculated, organic acid treated. D: Root-knot nematode, fosthiazate treatment. A large amount of nodules are formed in the untreated (B) (almost no nodules are formed in the treatment of organic acids (C) and nematocides (D) in the yellow circles).
FIG. 6 shows the results of comparison of the root formation rate (root-knot nematode control effect) of pepper root after 4 weeks of inoculation with organic acid mixture and fosthiazate treatment. Gall index: 0; Lump ratio 0-10%, 1; 11-20%, 2; 21-50%, 3; 51-80%, 4; 81-90%, 5; 91-100%. Treatment content: Con: non-inoculated + no treatment; MI: inoculation + no treatment: Fosth-1: inoculation + carnitine preparation; Fosth-2: inoculation + live nematode treatment; MX (0.5): inoculation + 0.5% organic acid mixture treatment; MX (0.2): inoculation + 0.2% organic acid mixture treatment; MX (0.1): inoculation + 0.1% organic acid mixture treatment, * bar and vertical line represent the mean and standard deviation of five replicate experiments.
FIG. 7 shows the growth of red pepper after 4 weeks of inoculation with an organic acid mixture and fosthiazate treatment. {A: shoot height, B: fresh shoot weight, C: fresh root weight}. Treatment content: Con: non-inoculated + no treatment; MI: inoculation + no treatment: Fosth-1: inoculation + carnitine preparation; Fosth-2: inoculation + live nematode treatment; MX (0.5): inoculation + 0.5% organic acid mixture treatment; MX (0.2): inoculation + 0.2% organic acid mixture treatment; MX (0.1): inoculation + 0.1% organic acid mixture treatment, * bar and vertical line represent the mean and standard deviation of five replicate experiments.
Figure 8 shows the price, dilution rate (application concentration), and the amount of treatment per kg (1000 m ² ) and control cost of the pesticide and organic acid per kg.

In order to achieve the above object, the present invention provides a composition for controlling nematodes containing acetic acid, lactic acid or a mixture of acetic acid and lactic acid as an active ingredient.

In the composition according to an embodiment of the present invention, the mixture of acetic acid and lactic acid may be a mixture of acetic acid and lactic acid prepared by mixing at the same concentration, but is not limited thereto.

In the composition according to an embodiment of the present invention, the nematode may be a plant nematode , preferably a bursaphelenchus xylophilus ), the root nematode ( Meloidogyne incognita ) or plant parasitic nematides other than said nematode, most preferably Bursaphelenchus xylophilus , or Meloidogyne incognita .

The nematode controlling composition of the present invention may further contain, in addition to the above acetic acid, lactic acid or a mixture of acetic acid and lactic acid, a pesticidally acceptable solid carrier, a liquid carrier, a liquid diluent, a liquefied gas diluent, Solid diluents, or other suitable adjuvants such as emulsifiers, dispersing agents or foaming agents. A composition for controlling a nematode mixed with a mixture of acetic acid, lactic acid or a mixture of acetic acid and lactic acid and the excipient may be formulated into various formulations known in the field of agrochemicals. For formulation, Any of the formulation methods used can be used.

The composition for controlling nematode of the present invention can be formulated into a wettable powder, a granule, a powder, an oil, a spray, a film, a capsule, and a gel, but is not limited thereto.

In order to prevent or control the infection of the nematode, the composition of the present invention may be immersed in the seed or the plant, or may be carried out by spraying or spraying. In the case of soaking, the composition may be poured into the soil around the plant or the seed may be soaked in the composition.

Hereinafter, the present invention will be described in detail with reference to examples. However, the following examples are illustrative of the present invention, and the present invention is not limited to the following examples.

Experimental Methods and Materials

1. Development of sustainable control methods during cultivation (sustainable control strategy)

In the experiment for developing the control method during the cultivation period until the cymbidium emerged, it was found that the organic acid contained in the compost organic material used for the nutrient management of the soil or the compost of the organic material used in the soil, ) Acetic acid, lactic acid and a mixture of these two organic acids were used as the lysosomal material. Bursaphelenchus xylophilus , a Chinese quarantine nematode capable of colonizing fungus in bark and wood sculptures, is widely used as a nematode to be controlled. It is susceptible to contamination of plant areas of cymbidium by infection with plants around Cymbidium Experiments were conducted on the Chinese quail nematode ( Meloidogyne incognita ), which is widely prevalent in Korea.

Pollution characteristics of Cymbidium culture medium and application control strategy of quarantine nematodes Taxa (tree) Nematode to be controlled Contamination Characteristics of Cymbidium Medium Applied Control Strategy Sustainable control strategy Rapid Control Strategy Aphelenchida Bursaphelenchus xylophilus Food-borne O O Tylenchida Ditylenchus sp. Food-borne
Wide host range X O Tylenchida Meloidogyne incognita Wide host range O X

(end) Cymbidium Badge infection Quarantine nematode Pine tree Bursaphelenchus xylophilus ) Control

It is sold by the National Forestry Academy and Botrytis ( Bursaphelenchus xylophilus ) cultivated in the cinerea medium was extracted by the method and Baermann funnel method (Southey, JF 1986. Laboratory methods for work with plant and soil nematodes. The nematocysts diluted with sterilized distilled water (SDW) were used. Diluted acetic acid and lactic acid were dissolved in 0.1 M phosphate buffer (pH 7.0) to give 10.0%, 4.0%, 2.0% Dilutions of 1.0%, 0.5%, 0.2% and 0.1% (w / v) were prepared and mixed with equal amounts of acetic acid and lactic acid at the same concentration. The effect of these organic acids on the nematode effect was evaluated by repeating three times in each well of a 96-well Microtest ^™ Tissue Culture Plate (Becton Dickinson Labware, Franklin Lakes, NJ, USA) in an amount equivalent to 100 μL of an organic acid dilution After 24 hours from the start of the experiment, the nematode was examined under a dissecting microscope under the condition of being stiff, rigid and immobile nematode as a dead nematode and flexible and motile nematode as an acid nematode (Cayrol, JC , Djian, C. and Pijarowski, L. 1989. Rev. Nematol. 12: 331-336). In order to investigate the relationship between the nematode mortality and acidity, organic acids of each concentration were mixed with the same amount of SDW and the acidity of the solution was measured with a pH meter. In order to investigate the effect of these organic acids on the control of pine reeves in the cultivation of Cymbidium, a mixture of acetic acid and lactic acid, which are expected to be synergistic in laboratory experiments, was used. In addition, 0.5% and 0.25% Was used.

In addition, a standard amount of fosthiazate (30% of liquid) (5 mL per 20 L of water) and a microbial strain ( Paenibacillus polymyxa GBR-1 ) (Khan et al 2008 Bioresour Technol 99:... 3016-3023) a brain heart infusion 2 days with shaking to 28 ℃ (200 rpm) after the culture was diluted in SDW the bacterial density in the ^{10 broth 7 CFU (colony-forming} unit ) / mL. < / RTI > Among 2 - year - old cymbidiums purchased from cymbidium cultivation farms located in Incheon, 2,000 cymbidium infestants were inoculated to the plants grown on average in the above laboratory experiments. Inoculation and incubation with organic acid mixture, nematicide and bacterial suspension Cymbidium was injected into the plant rhizosphere in 10 mL per pot. After watering, the plants were placed in a greenhouse with a randomized block design at a temperature of 25 ± 2 ° C, and cultivated with a minimum amount of water once a day. Inoculation of the nematode and treatment of the control agent After 7 days, the mixture of the potting soil and the root of the plant was collected and 100 g of the mixture was extracted with Baermann funnel for 5 days (Southey, JF 1986. Laboratory methods for work with plant and soil Nematodes, Ministry of Agriculture Fisheries and Food, HMSO, London, UK). Extracted nematodes were classified into two groups according to the morphology of nematodes and esophagus according to the morphology of the nematode and Aphelenchida, Tylenchida, Longidoridae and Trichodoridae and other saprobes (Hooper, DJ 1982. Structure . and classification of nematodes in: investigated as a Plant nematology, ed by JF Southey, pp 3-45 Her Majesty's Stationary Office, London, UK) roots and three replications for each density of the mixture of the medium.... The plants not inoculated with nematode were pulverized 7 days, 14 days and 21 days after treatment, and the pH was measured by pH meter after 1: 1 mixing with SDW. After 21 days, the growth condition of the plants was examined.

(B) by organic acids Root-knot nematodes Meloidogyne incognita )of Investigation of control effect

The nematode used in this study is a nematode that is continuously cultivated in the red pepper of this laboratory. The eggmass formed in the roots of the pepper is separated by Baermann funnel method (Southey, JF 1986. Laboratory methods for work and plant nematodes. The second nematode larvae were diluted with SDW, and acetic acid and lactic acid were dissolved in 0.1 M phosphate buffer (pH 7.0) as the nematode, Diluted acetic acid and lactic acid diluted solution, acetic acid and lactic acid diluted solution were mixed in the same amount, and the same concentration of organic acid mixed diluent was used. My (In vitro vitro ) were examined in the same manner as in the case of the pine reeves. The changes in the detailed structure of the larvae were examined by observing the larvae of the second instar larvae with high magnification under the microscope. In the pot experiment, the organic acid mixture was used as in the case of pine reeves. The plant used for the effective control effect was not the cymbidium of the root-knot nematode but the host plant, red pepper. After 4 weeks, the lump formation rate was calculated as the ratio of the roots with the hump (lump ratio) to the index of gall index (GI>0; lupine ratio 010%, 1; 1120%, 2; 2150% %, 4; 8190%, 5; 91100%), and the stem and root growth of each treatment were investigated.

Example 1. Development of sustainable control methods during cultivation (sustainable control strategy)

As shown in Table 2, acetic acid and mixed liquor showed almost 100% live nematode up to 1.0%, whereas lactic acid showed 100% live nematode only at 5.0%, which is the highest concentration of acetic acid and lactic acid and mixed liquor. At lower concentrations, the mortality rate decreased rapidly, but the rate of decrease was significantly greater in acetic acid and mixed solution. The results of the statistical analysis were as follows: 1. The average concentration of live nematode and organic acid mixture was significantly higher than that of 5.0% and 0.5%. When the mixture of organic acid and acetic acid was compared with that of acetic acid and lactic acid alone, the nematode activity of root nodule was increased and the nematode mechanism was also changed. Especially, Lactic acid was 4 times bigger than that of the control (Table 2). As shown in Table 2, the high mixing effect of acetic acid at a rapid decline in the drug efficacy indicates that the effective duration of the mixed solution can be prolonged due to the mixing effect when the active ingredient is naturally reduced after acetic acid alone treatment, Since the molecular weight of lactic acid (MW = 90) is larger than that of acetic acid (MW = 60), the residual effect of lactic acid-containing mixed solution becomes longer due to its physicochemical properties. The duration of the control effect was further increased.

The pH of acetic acid, lactic acid, and mixed solution showed a high acidity to 1.0%, but it was changed to pH 5 or more at 0.5% concentration, which seems to be the result of neutral phosphate buffer solution. One of the basic soil properties is the buffering function of pH (Kissel, DE, Sonon, LS and Cabrera, ML 2012. Rapid measurement of soil pH buffering capacity. Soil Sci . Soc . Am . J. 76: 694- 699), the culture soil used for the cultivation of cymbidium is also mixed with various nutrient sources and has a buffering function similar to that of the soil. Therefore, even if some of these organic acids are injected into the culture soil, the pH of the culture soil I do not think it will be big.

In each organic acid, the higher the pH, the lower the live nematode rate, and the higher the acidity, the higher the live nematode power. However, at the same concentration (0.1-0.5%), lactic acid with lower pH is lower in nitrate percentage than acetic acid with higher pH. This is due to the selective permeability of the body wall of the nematode, (Lambert, K. and Bekal, S. 2002. Introduction to plant-parasitic nematodes. The Plant Health Instructor DOI: 10.1094 / PHI-I-2002-1218-01.) The permeability of acetic acid with low molecular weight is higher than that of lactic acid Therefore, it is thought that the nematocidal power is increased. Therefore, in the port test for controlling the pine tree reef disease of organic acids, an organic acid mixture solution is used.

Lactic Acid, Lactic Acid, and Acetic Acid - Lactic Acid Mixture Dilution. density Acetic acid Lactic acid Mixed liquid Mixed effect ^b Rate of live nematodes (%) ^a pH Rate of live nematodes (%) pH Rate of live nematodes (%) pH 0.00% 5.9 ± 2.2 × ^c 7.0 5.9 ± 2.2X 7.0 5.9 ± 2.2X 7.0 1.00 NS ^d 5.00% 100.0 + 0.0Z 2.6 100.0 + 0.0Z 3.5 100.0 + 0.0Z 3.0 1.00NS 2.00% 100.0 + 0.0Z 3.2 15.2 ± 2.2Y 3.9 100.0 + 0.0Z 3.5 1.74 * 1.00% 100.0 + 0.0Z 3.9 5.4 ± 1.3X 4.4 95.4 ± 6.2Z 4.2 1.81 * 0.50% 54.0 8.0 Y 6.0 2.2 ± 2.1 WX 5.1 15.4 + 4.8 Y 5.5 0.55 * 0.25% 4.4 ± 1.2X 6.6 1.1 ± 1.0W 6.3 11.1 + 2.4XY 6.6 4.04 * 0.10% 6.0 ± 2.1X 6.9 4.5 ± 1.4X 6.7 8.5 ± 1.4X 6.8 1.62 *

^a Rate of insecticide (%) = number of dead nematodes / total number of appendages x 100

^b. Mixture effect = live nematode of mixture at the same concentration / live nematode of acetic acid and lactic acid

The mean of letters such as ^c is indicated by the least significant difference test (LSD), with no significant difference at P ≤ 0.05.

^d Orthogonal contrast between the mean of mixture and acetic acid and lactic acid: not significant at NS, P ≤ 0.05; *, P ≤ 0.05.

In the port test for the control of pine tree reptile, the densities of the nematode species belonging to Rhabditida were the highest in the untreated control at 7 days after treatment. Aphelenchida nematodes, (2,000), and no plant parasitic nematodes belonging to Tylenchida, Longidoridae and Trichodoridae were found at all (Table 3). This is consistent with the previous results of the nematode survey of cymbidium and the growth of the pine tree rehabilitate.

The density and control value of the pine tree worms were significantly lower in each treatments regardless of the type and concentration of treatments, and there was no significant difference between treatments. In addition, low nematode concentrations were observed in all the treatments in the same manner as in the case of the pine reeves, but the control was lower than that of the pine reemergens in GBR-1 and 0.5% of the organic acid mixture. As a result, the organic acid mixture solution was used as an antagonistic bacterium Paenibacillus polymyxa GBR-1 and it is considered to be equivalent to the nematode.

In the 2-year old cymbidium culture medium, the organic acid mixture (MX), the nematicide (Fosthiazate SL 30) and the microbial strain ( Paenibacillus polymyxa GBR-1) after 7 days of treatment. Treatment (concentration) Aphelenchida ^a Saprobes ^b Plant-parasitic nematodes ^c density Control (%) ^d density Control (%) density Control (%) Control 26.0 ± 19.3 × ^e - 162.0 + - 94.3X - 0.0 - MX (0.5%) 4.0 ± 3.5Y 84.6 72.0 + - 75.2XY 55.6 0.0 - MX (0.25%) 2.0 ± 3.5Y 92.3 40.0 ± 33.0 Y 75.3 0.0 - Fosthiazate (1x) 0.0 ± 0.0Y 100.0 30.0 ± 31.2Y 81.5 0.0 - Fosthiazate (2x) 0.0 ± 0.0Y 100.0 16.0 6.9 Y 90.1 0.0 - GBR-1 8.0 ± 6.9Y 69.2 90.0 ± 64.9XY 44.4 0.0 -

^a Most of the pines ( Bursaphelenchus xylophilus

^b is a nematode belonging to Rhabditida, the most common bacterial nematode

^c Investigate nematodes belonging to Tylenchida, Longidoridae or Trichodoridae

^d Control = (nematode density of control - nematode density of control) / control nematode density x 100

^f GBR-1 = culture dilution (10 ⁷ CFU / ml) of Paenibacillus polymyxa GBR-1

The acidity of the cultivated soil was varied within the range of variation within the pH range from 1.0 to 1.0, and there was no significant difference between the treatments. No significant pH change was observed after treatment (Fig. 1). The pH of the cultured soil before treatment was slightly higher than that of control. However, after treatment, the variation was smaller and the variation of treatment was decreased to pH 4.0 at 21 days after treatment. This is probably due to the homogenization of the physico - chemical properties of soil by continuous exposure to the same irrigation and growth conditions.

As a result of investigation of the growth of plants after 21 days of treatment, no symptoms of weakness were observed in high concentration of organic acid mixture, nematicide and GBR-1 treatment (Fig. 2), and plant weight, leaf height, shoot, There was no significant difference in growth characteristics between treatments (Table 4). However, root length (stem length) and stem diameter were significantly or slightly higher in GBR-1 and 0.5% organic acid mixture than in nematicide supplementation treatment, suggesting that the effect of promoting plant growth is somewhat high.

As a result, it was found that the mixture of acetic acid and lactic acid decreased the density of Chinese quarantine nematodes such as pine reeves in case of accidental pollution through the cultivation soil such as bark, have. However, in the case of cultivated cymbidium, the disappearance of organic acids from the culture soil to the outside is prevented to some extent by the pollen, and the production period of the initial culture soil, And the cultivation of cymbidium such as cultivation in the summer season immediately before export, it is possible to carry out the continuous and effective quarantine nematode control by periodically treating the organic acid mixture solution. In the case of microbials, the control effect of pine reeves was significantly higher than that of the control, but the effect was somewhat lower than that of the organic acid mixture and the anticipated effect of promoting growth of cymbidium was not observed. Most of all, considering the cost of additional research for formulation of microorganisms and the cost of controlling the application of these agents, it is difficult to use in the farmhouse, and thus it is considered to be less effective in controlling quarantine nematodes.

Growth characteristics of 2-year-old Cymbidium after 21 days of treatment with organic acid mixture (MX), fosthiazate microbial strain ( Paenibacillus polymyxa GBR-1) Treatment No. of leaves Plant height (cm) Root length (cm) Stem diameter (cm) Fresh weight (g) Shoot Root Control 23.0 ± 2.6 × ^a 16.7 ± 3.2X 39.5 + - 6.6XY 17.9 + 1.4XY 13.6 ± 2.1X 56.2 ± 24.2X MX (0.5%) 24.0 占 .9X 18.7 ± 2.3X 45.1 ± 5.4XY 20.7 + 4.6X 14.4 + 1.7X 63.2 ± 32.7X MX (0.25%) 21.3 ± 1.2X 18.7 ± 2.5X 37.5 + 7.4XY 18.1 ± 0.8XY 12.6 + 1.4X 47.4 + - 11.7X Fosthiazate (1x) 15.7 + - 6.8X 18.7 ± 2.5X 27.4 + 24.0 Y 13.7 ± 4.4Y 11.0 + 1.9X 35.1 + - 34.6X Fosthiazate (2x) 23.7 ± 1.2X 20.0 ± 3.0X 52.2 ± 0.4X 19.4 ± 0.2XY 13.1 ± 0.3X 63.6 ± 6.3X GBR-1 18.3 ± 5.7X 19.3 + 4.2X 45.5 ± 7.8XY 20.9 ± 3.6X 12.7 ± 2.7X 63.3 ± 36.4X

^a mean of such letters was no significant difference at P ≤0.05 display by the least significant difference test (LSD).

Above all, these organic acids are used for food or are contained in many fermented foods, so they are safe and can be safely used in Cymbidium cultivation farms (FIG. 3). Therefore, even if Cymbidium farmers use it periodically, they will be able to carry out control management with confidence, because they are not poisoned by poisonous substances or harm the health due to pollution in Cymbidium cultivation house.

(B) by organic acids Root-knot nematodes Meloidogyne incognita )of Control effect

My (In vitro In vitro , the nematode larvae were exposed to organic acids for 24 hrs. The larvae of the nematode were observed by the stereomicroscope. Most of the living nematodes were in a smooth form with no movement, There was no dead nematode. Compared with the average of live organisms in the organic acid mixture, 0.1% and 0.2%, respectively. When the dead nematodes (larvae) were observed closely in the live nematode (control), acetic acid, lactic acid and mixed solution treatment of the untreated control, the outline of the front part of the nematode was clear and there was no structure However, the structure of the anterior part of the larvae was slightly blurred, especially large and small vacuoles were formed at the center and back of the body, and the level of vacuole formation of the organic acid mixture was greater than that of each organic acid. (Fig. 4).

Meloidogyne incognita by concentration of acetic acid, lactic acid and acetic acid-lactic acid mixture Treatment concentration Live nematode rate (%) ^a Acetic acid Lactic acid Mixed liquid 1.0% 100.0 0.0A ^b X ^c 100.0 + 0.0AX 100.0 + 0.0AX 0.5% 100.0 + 0.0AX 100.0 + 0.0AX 100.0 + 0.0AX 0.2% 100.0 + 0.0AX 93.5 ± 3.3BX 100.0 + 0.0AX 0.1% 100.0 + 0.0AX 5.3 ± 1.3CY 100.0 + 0.0AX 0.0% 1.6 ± 1.4BX 1.6 + 1.4CX 1.6 ± 1.4BX

* 3 Repeat average

^a Percentage of total number of dead 2nd instar larvae to total number of second instar larvae exposed to organic acids for 24 hours

The mean of the same letter in the ^b column indicates that there is no significance at P ≤ 0.05 by Duncan's multiple range test.

The mean of the same letter in row ^c indicates no significance at P ≤ 0.05 by Duncan's multiple range test.

In the pot experiment using red pepper, the roots formation rate was about 50% in the roots of unprocessed pepper after 4 weeks of inoculation with root nodule. However, by the treatment of fosthiazate and organic acid except 0.1% The degree of root formation was significant and showed almost complete control, and there was no significant difference in the mortality between the nematicide and the organic acid mixture (FIGS. 5 and 6).

The nematocidal effect of the nematode material administered to the soil is related to the distribution of such materials in the initial soil and redistribution through diffusion and loss (Bromilow, RH 1973. Ann. Appl. Biol 75: 473-479). Fungicidal nematodes with molecular weight of 283 such as Fosthiazate (C ₉ H ₁₈ NO ₃ PS ₂ ) are less fluid than low-molecular organic acids and have high adsorption power with organic matter. So, Mix well, you can fully exercise the effect of control. On the other hand, in case of low molecular organic acid, the fluidity is high and the adsorption power with organic matter is low. Therefore, when the oil is applied to the packaging, the fluidity is high and the spreading power is large. Therefore, the oil component is distributed evenly, . Especially, in the cultivation of cymbidium, the pot is very closely packed with the medium, bark and roots. Therefore, when the pesticide is treated, it is difficult to penetrate the root, so that it is difficult to control the soil pest by pesticide treatment. In this respect, organic acids are not toxic and can be safely used. Moreover, even when nematodes are used, they are more advantageous than nematocides which are highly toxic. Particularly, among the major nematicides, halved nematicides such as MB, EDB, DBCP, Telone, and Temik are classified as ozone depletion and carcinogens and their use is prohibited. It can be used as a countermeasure prevention strategy.

The effect of organic acid mixture and nematode treatment on plant growth was investigated. As a result, there was no significant difference between inoculation-non-inoculation, treatment-free treatment and treatment-treatment in all plant growth including shoot height, fresh shoot weight and fresh root weight 7). However, the maximum growth rate of all plant growth was 0.2% in organic acid mixture and the lowest in 0.5%, and the addition of 0.1% organic acid mixture showed some improvement in fresh weight and fresh weight compared to nematode. This suggests that the low concentration (0.1%, 0.2%) mixture treatment improves the growth of plants slightly by nematode control, while the high concentration (over 0.5%) suggests the possibility of plant weakness. Of course, the control of root - knot nematode of 0.5% mixture was slightly higher than that of 0.2%, but there is no significant difference, so there will be no difference in the control in actual packaging. In practice, the control effect of nematodes is determined by the concentration time product (CTP), which is the product of the concentration of the nematocide (concentration, C) and the time of exposure to the nematocide (time, T) Long-term exposure at lower concentrations than in short-term exposure is more effective in controlling nematodes (Hague et al., 1964 Hort. Res., Edinb. 3: 84-101). Therefore, by increasing the amount of low concentration (0.2%) of organic acid mixture and increasing the soil residue period of the active ingredient, it is possible to obtain a similar or somewhat improved control effect to the high concentration treatment and reduce the weakness due to the high concentration of organic acid have. Especially, it is expected that the possibility of the occurrence of weakness is more reduced than the treatment of organic acid alone because the concentration of the mixed solution is half the concentration of each organic acid.

When the organic acid mixture is applied for the control of the root-knot nematode contaminated with the cymbidium, which is not the host plant, the effect of controlling the nematicide is inevitably different. However, considering the reduction in the natural density of root-knot nematodes in non-dominant plants, and because there is room for nematodes to invade and escape from the plants in the host plants, the control effect of root-knot nematodes exposed to the cymbidium medium always increases The possibility is more likely to be more effective for effective control of the nematode contaminated root-knot nematode.

The biggest problem in the management of control is the economic efficiency due to the control cost. As shown in FIG. 8, when the sales price of the nematicide and organic acid and the standard concentration of the nematocide were 0.2% (500 times) of the organic acid as shown in the study, they were packaged in an area of 10a (1,000 m ² ) ) And $ 3.5-4.5 for the nematicide, and the cost of controlling the mixture is somewhat less than that of the nematocide or the nematocide. Considering that economical problems are one of the major limiting factors in biological control using microorganisms, which is a typical environmentally friendly management method, the use of environmentally friendly control methods using organic acids may reduce the economic burden of growers. Therefore, the use of organic acids for quarantine nematode control in Cymbidium growers may be encouraged.

Claims

( Bursaphelenchus xylophilus ) containing 0.25% (w / v) of a mixture of acetic acid and lactic acid prepared by mixing acetic acid and lactic acid at the same concentration as an active ingredient.

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A method for preventing or controlling infection of pine tree bush ( Bursaphelenchus xylophilus ) by treating the composition of claim 1 to a plant part, soil or seed.