Methods for controlling potato-lesion nematodes and for disinfecting seeds for garlic cultivation

Abstract

To provide a control method of potato rot nematodes for controlling potato rot nematodes that are parasitic on skinned scaly seeds for planting, a seed disinfection method of garlic cultivation and a seed disinfection device of garlic cultivation.SOLUTION: There is provided a control method of potato rot nematodes for immersing skinned scaly seeds 12 in water 16 and transmitting ultrasonic vibration 24 to potato rot nematodes 22 that are parasitic on the skinned scaly seeds 12 for implanting with the water 16 as a medium to kill the nematodes. By performing an ultrasonic vibration treatment by means of the control method of the potato rot nematodes to the seeds 12 on which the potato rot nematodes 22 may be parasitic, density (a survival rate) of the potato rot nematodes that are parasitic on the scaly seeds 12 for implanting can be reduced. With this, a yield increase can be expected since rotten bulbs of garlic are reduced. Also, extension of a nematode-contaminated farm field can be prevented.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for controlling potato-lesion nematodes that parasitize garlic and the like, a method for disinfecting seeds for garlic cultivation, and an apparatus for disinfecting seeds for garlic cultivation. [Background technology]

[0002] In garlic-producing regions, damage (yield loss) caused by garlic lesion nematodes (pests) is increasing through soil and seed transmission. The principle for controlling lesion nematodes is to not use the scales harvested from contaminated fields as seeds, but to cultivate them in uncontaminated fields. When seeds parasitized by the potato-lesion nematode are planted, the nematodes multiply significantly within the seeds, resulting in the seeds not sprouting after planting, or many of the sprouts dying even if they do. Garlic plants infested with potato-lesion nematodes appear to grow healthily until harvest, but develop severe symptoms such as rotting during storage after harvest. This damage often occurs when the seeds are used as seeds without realizing that they are parasitized by potato-lesion nematodes. Currently, a method for exterminating C. elegans is known in which an attractant for C. elegans is used to attract, capture and dispose of C. elegans in the soil (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2010-100568 Summary of the Invention [Problem to be solved by the invention]

[0004] The attractant for and method for eradicating C. gracilis described in Patent Document 1 are methods for controlling C. gracilis by disinfecting the soil. However, once C. gracilis remains in the soil, it is extremely difficult to completely eradicate it, and it is therefore important to prevent soil contamination by C. gracilis.

[0005] The present invention aims to solve the above problems and to provide a method for controlling potato-lesion nematodes, a method for disinfecting garlic seeds, and an apparatus for disinfecting garlic seeds, all of which parasitize potato-lesion nematodes that parasitize skin-on scale seeds for planting. [Means for solving the problem]

[0006] The method for controlling potato-lesion nematodes of the present invention involves immersing crops in water and transmitting ultrasonic vibrations through the water to potato-lesion nematodes parasitizing the crops, thereby killing the nematodes.

[0007] The method for disinfecting seeds for garlic cultivation of the present invention involves soaking skinned scale seeds in water and transmitting ultrasonic vibrations to potato-lesion nematodes parasitizing the skinned scale seeds through the water, thereby killing the nematodes. [Effects of the Invention]

[0009] The method for controlling potato-lesion nematodes, the method for disinfecting garlic seeds, and the device for disinfecting garlic seeds of the present invention transmit ultrasonic vibrations to seeds that may be infested with potato-lesion nematodes, thereby reducing the density (survival rate) of potato-lesion nematodes that infest scale seeds for planting. This reduces the number of rotting garlic bulbs, which is expected to increase yields. It also prevents the spread of nematode-infested fields. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing a seed disinfection device for garlic cultivation according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention realizes increased yields of garlic and the like and prevents the spread of nematode-infested fields. [Example]

[0012] The method for controlling potato-lesion nematodes, the method for disinfecting seeds for garlic cultivation, and the device for disinfecting seeds for garlic cultivation of the present invention will be described below. Figure 1 is a diagram showing the device for disinfecting seeds for garlic cultivation of the present invention. After much trial and error to find a means of controlling potato-lesion nematodes, the inventors discovered that subjecting free potato-lesion nematodes in water (potassium-lesion nematodes that have escaped into the water from garlic soaked in water) to an ultrasonic cleaner has a nematicidal effect.

[0013] (How to control potato lesion nematodes) The method for controlling C. rotten nematodes of the present invention involves soaking crops (such as garlic) in water and transmitting ultrasonic vibrations to C. rotten nematodes that parasitize the crops, thereby killing the nematodes. That is, this is a control method in which ultrasonic vibrations are transmitted to C. rotten nematodes using water as a medium, thereby eradicating the C. rotten nematodes. (1) The container for immersing the nematodes in water (the container that transmits ultrasonic vibrations to the nematodes) and the nematicidal effect (survival rate) Several types of containers made of metal, plastic, and glass were selected to have the least attenuation of ultrasonic vibrations, and the survival rates of C. nematodes (hereinafter referred to as "free nematodes in water") that had escaped from garlic cloves soaked in water were compared after ultrasonic vibrations were transmitted to each container (hereinafter referred to as "ultrasonic vibration treatment") (survival rates in (a) to (c) below). The survival rate is the value (%) obtained by dividing the number of surviving nematodes by the total number of free nematodes in water in the container (number of surviving nematodes + number of dead nematodes). In addition, C. nematodes were recovered from the water in the container after ultrasonic vibration treatment using the Bellman method, placed in a Syracuse watch glass (a nematode observation tool), and examined under a stereomicroscope to count the number of nematodes. An ultrasonic vibration treatment test was conducted on free nematodes in water, in which ultrasonic vibrations were transmitted at an ultrasonic frequency of 40 kHz for 30 minutes. The survival rate of free nematodes in the water without treatment was 94.4%. When garlic (scale seeds) infested with C. rottenea is soaked in water, the C. rottenea escapes from the garlic into the water, but a few percent of the escaped nematodes (C. rottenea) die, reducing the number of surviving escaped nematodes. (a) Viability using glass container: 44.8% (b) Survival rate when using a plastic container: 17.0-53.4% (c) Survival rate when using a metal container: 1.0% (stainless steel container), 0% (aluminum container) Since the survival rates in the above containers (a) to (c) were lower than those in the untreated containers, it was found that the free nematodes in water (potassium lesion nematodes in water) could be killed by subjecting them to ultrasonic vibration treatment.

[0014] (2) Nematicidal effect test on ultrasonic frequency and treatment time We tested the nematicidal effect of ultrasonic vibration treatment on free nematodes in water at different ultrasonic frequencies and treatment times. In the container selection test (1), the survival rate was significantly lower when a metal container was used, so a metal container (aluminum container) was used in this test. (d) A nematicidal effect test was conducted on free-floating nematodes in water (survival rate of 98.0% when untreated) for 30 minutes at ultrasonic frequencies of 28 kHz, 40 kHz, 45 kHz, and 100 kHz. The survival rate was 0% at ultrasonic frequencies of 40 kHz and 45 kHz. The survival rate was 1.4% at 28 kHz, and 18.0% at 100 kHz. The test results showed that the nematicidal effect was highest when the ultrasonic vibration frequency was 40kHz and 45kHz, when the treatment time was 30 minutes. (e) A nematicidal effect test was conducted on free nematodes in water (survival rate of 94.2% when untreated) using ultrasonic vibrations at 40 kHz for treatment times of 15 and 20 minutes. The survival rate after 15 minutes of treatment was 0.2%, and after 20 minutes of treatment the survival rate was 0%. Furthermore, when a nematicidal effect test was conducted using an ultrasonic vibration frequency of 45 kHz for a treatment time of 30 minutes, the survival rate was 0% to 0.2%. As a result of the above tests (d) and (e), it was found that ultrasonic vibration treatments with ultrasonic vibration frequencies of 40 kHz and 45 kHz for a treatment time of 30 minutes had the highest nematicidal effect on free nematodes in water.

[0015] (3) Testing the nematicidal effect of the garlic root nematode that parasitizes the garlic skin (protective leaves and outer skin) (f) A test was conducted to test the nematicidal effect of ultrasonic vibration treatment on potato-lesion nematodes (hereinafter referred to as "intradermal nematodes") that parasitize the protective leaves and outer skin of garlic. In this test, the protective leaves, the first outer skin (the outer skin covering the protective leaves), the second outer skin (the outer skin covering the first outer skin), and the third outer skin (the outermost outer skin covering the second outer skin) of garlic (scale seeds for planting) were immersed in water, and the intradermal nematodes that parasitize the skin were treated with ultrasonic vibration as described in (a) and (b) below, and the survival rate of the intradermal nematodes was confirmed. The number of nematodes parasitizing the garlic skin was counted by examining each part of the skin with an optical microscope. In this test, a stainless steel container was used as the metal container to store the garlic skins, in order to perform a long-term ultrasonic vibration treatment (ultrasonic vibration treatment for a continuous treatment time of 60 minutes as described in (b) below). (i) After ultrasonic vibration treatment at an ultrasonic frequency of 40 kHz for 30 minutes, the survival rate of nematodes in the protected leaves was 64.0%, the survival rate of nematodes in the first outer skin was 13.5%, the survival rate of nematodes in the second outer skin was 15.0%, and the survival rate of nematodes in the third outer skin was 15.4%. (b) After ultrasonic vibration treatment at an ultrasonic frequency of 45 kHz for 60 minutes, the survival rate of nematodes in the protected leaves was 48.5%, that of nematodes in the first outer skin was 47.5%, that of nematodes in the second outer skin was 13.4%, and that of nematodes in the third outer skin was 12.0%. According to the above tests (a) and (b), it was found that ultrasonic vibration treatment also had a certain degree of nematicidal effect on intradermal nematodes, but the nematicidal effect was low. (g) In order to improve the nematicidal effect on the garlic skin, an intermittent ultrasonic vibration treatment was performed, in which the treatment was interrupted for a certain period of time and then repeated, to test the nematicidal effect on intradermal nematodes. In this test, the intermittent treatments described in (c) and (ii) below were performed on intradermal nematodes that parasitize the skin (protective leaves, outer skin) of garlic (scale seeds for planting), and the survival rate of the intradermal nematodes was confirmed. In this test, a stainless steel container was used as the metal container to store the garlic skin, as ultrasonic vibration treatment was performed for a long period of time (ultrasonic vibration treatment for a continuous treatment time of 60 minutes). (c) Intermittent treatment in which ultrasonic vibration treatment is performed for 30 minutes at an ultrasonic frequency of 45 kHz, followed by ultrasonic vibration treatment for 30 minutes at an ultrasonic frequency of 40 kHz, then the treatment is stopped for 60 minutes, and ultrasonic vibration treatment is again performed for 30 minutes at an ultrasonic frequency of 45 kHz, followed by ultrasonic vibration treatment for 30 minutes at an ultrasonic frequency of 40 kHz. (2) Intermittent treatment in which ultrasonic vibration treatment is performed for 60 minutes at an ultrasonic frequency of 45 kHz, the treatment is stopped for 60 minutes, and then ultrasonic vibration treatment is performed again for 60 minutes at an ultrasonic frequency of 45 kHz. In the intermittent treatments (c) and (ii) above, the survival rate of nematodes in the garlic skin was 0%, indicating that intermittent treatment provides a high nematicidal effect. Dry garlic skins contain large numbers of highly durable dormant potato-lesion nematodes (nematodes that lie dormant in a coiled state). When garlic skins are soaked in water, dormant potato-lesion nematodes wake up from dormancy and begin to move. Non-dormant potato-lesion nematodes can be killed by the first ultrasonic vibration treatment (treatment before interruption). Furthermore, by performing ultrasonic vibration treatment again after an interruption (interruption), dormant potato-lesion nematodes can also be killed. In this way, a high nematicidal effect can be achieved by intermittently performing ultrasonic vibration treatment on potato-lesion nematodes that parasitize the skin.

[0016] (h) Control of edible parts of garlic Large (advanced) and small (young) potato-lesion nematodes lurk in the scales, which are the edible parts of garlic cloves. However, because the edible parts of garlic scales are thick, ultrasonic vibrations do not reach the interior. Furthermore, the medium (water) that transmits ultrasonic vibrations does not penetrate the edible parts. Therefore, ultrasonic vibration treatment does not have a nematicidal effect on potato-lesion nematodes that parasitize the edible parts of the scales. To control potato-lesion nematodes that parasitize the edible parts of the scales, dry heat treatment is used, as described below in the seed disinfection method for garlic cultivation.

[0017] (i) Garlic cultivation test using scale seeds treated with ultrasonic vibration Healthy scale seeds (seeds not infested with potato-lesion nematodes) were treated with ultrasonic vibrations and a garlic cultivation test was conducted. This test was conducted to demonstrate that planting seeds that had been treated with ultrasonic vibrations would not have a negative effect on garlic cultivation. Two types of scales were used in the test cultivation: large (scale weight 11g) and small (scale weight 7g). It was confirmed that planting seeds that had been treated with ultrasonic vibrations would not have a negative effect on garlic cultivation, regardless of whether they were large or small seeds. In this cultivation test, the growth of above ground parts (garlic plant height and stem diameter) and harvested products (harvested garlic bulb diameter and bulb weight) were compared between garlic cultivation in which ultrasonically vibration-treated seeds were planted (treated cultivation) and garlic cultivation in which seeds not treated with ultrasonic vibration were planted (untreated cultivation). There was no difference in the growth of above ground parts or the harvested product between the treated and untreated cultivations. This cultivation test demonstrated that planting seeds treated with ultrasonic vibration according to the present invention does not have any adverse effects on garlic cultivation.

[0018] (4) Effect of ultrasonic vibration treatment on the control of potato-lesion nematodes Since the survival rate of C. elegans in the ultrasonic vibration treatments (a) to (g) above was lower than that in the untreated case, it was found that C. elegans parasitizing crops can be killed by treating the C. elegans with ultrasonic vibrations using water as a medium. This C. elegans control method (nematicidal effect) can be used to control C. elegans parasitizing other crops (for example, bulbous plants such as tulips, irises, and onions) in addition to C. elegans parasitizing garlic. The method for controlling C. gracilis of the present invention can kill C. gracilis that infest crops, thereby reducing the density (survival rate) of C. gracilis that infest scale seeds for planting. This reduces the rate of garlic rot, which is expected to increase yields. It can also prevent the spread of nematode-infested fields.

[0019] (Methods for disinfecting garlic seeds) The seed disinfection method for garlic cultivation of the present invention involves soaking skin-on scale seeds in water and transmitting (irradiating) ultrasonic vibrations to (irradiate) the potato-lesion nematodes that parasitize the skin-on scale seeds using the water as a medium to kill the nematodes.The seed disinfection method for garlic cultivation of the present invention uses the potato-lesion nematode control method of the present invention as one step in seed disinfection for garlic cultivation. The steps (A) to (B) of the method for disinfecting garlic seeds for planting according to the present invention are as follows: All the seed disinfection treatments except for step (B) are known treatments used to combat potato-lesion nematodes. (a) Immediately after harvesting, garlic is dry-heat treated at 50°C for 6 hours. This kills the potato-lesion nematodes that parasitize the edible parts of the scales. (b) Before planting, the scale seeds for planting are subjected to ultrasonic vibration treatment (the method for controlling potato-lesion nematodes of the present invention), thereby killing potato-lesion nematodes that parasitize the skin of the scales. (c) After treatment in (b), disinfect the seeds with a rust mite treatment before planting. (2) After the treatment of (3), disinfect the seeds with Benlate (registered trademark) T wettable powder 20 before planting. The seed disinfection method for garlic cultivation of the present invention can further strengthen the prevention of the spread of contamination in the field compared to conventional seed disinfection (seed disinfection using procedures other than (b)).

[0020] (Seed disinfection equipment for garlic cultivation) The seed disinfection device 10 for garlic cultivation of the present invention shown in Figure 1 comprises a seed disinfection tank 14 for storing skin-on scale seeds 12, water 16 for storing in the seed disinfection tank 14, an ultrasonic vibrator 18 for seed disinfection attached to the bottom surface 14a or side surface 14b (vibration surfaces 14a, 14b) of the seed disinfection tank 14, and an ultrasonic oscillator 20 for supplying power to the ultrasonic vibrator 18 for seed disinfection.The device kills the potato-lesion nematodes 22 by transmitting (irradiating) ultrasonic vibrations 24 to the potato-lesion nematodes 22 immersed in the water 16 using the water 16 as a medium. The seed disinfection device 10 for garlic cultivation of the present invention uses the method for controlling potato-lesion nematodes of the present invention, and is a device for killing potato-lesion nematodes that parasitize the skin of scale seeds 12 for planting and potato-lesion nematodes 22 (escaped nematodes) that have escaped into the water 16 of the seed disinfection tank 14. In Fig. 1, the bottom surface 14a of the seed disinfection tank 14 is the vibrating surface, but the side surface 14b may also be the vibrating surface. In addition, the seed disinfection ultrasonic vibrator 18 is directly attached to the bottom surface 14a of the seed disinfection tank 14. Although the escaped potato-lesion nematode 22 (escaped nematode) shown in Figure 1 cannot be seen with the naked eye, it is depicted in the figure as if it were visible in order to clarify its presence.

[0021] (About seeds for planting) Currently, garlic is commonly cultivated using seeds containing scales with the skin attached as seeds for planting. The method for controlling C. gracilis of the present invention has a high nematicidal effect on seeds for planting, is classified as a physical control method among methods that do not use pesticides, and can be a groundbreaking preventive measure for preventing the spread of C. gracilis-infected fields. [Explanation of symbols]

[0022] 10 Seed disinfection device 12 scale seeds 14 Seed disinfection tank 16 Medium (water) 18 Ultrasonic vibrator for seed disinfection 20 Ultrasonic oscillator 22 Potato Lesion Nematode 24 Ultrasonic vibration

Claims

1. This method for controlling potato-lesion nematodes comprises immersing a crop in water and transmitting ultrasonic vibrations to the potato-lesion nematodes parasitizing the crop through the water, thereby killing the nematodes.

2. This method for disinfecting seeds for garlic cultivation comprises soaking the skinned scale seeds in water and transmitting ultrasonic vibrations to potato-lesion nematodes parasitizing the skinned scale seeds through the water as a medium to kill the nematodes.

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