JPH05246816A - Nematocide and method for destroying nematode - Google Patents

Abstract

PURPOSE:To obtain a nematocide showing no bad influence on plants, not destroying an ecosystem, safely usable, having no harm on crops, comprising seed coat of peanut or its extract with water, hot water or a hydrophilic organic solvent as an active ingredient. CONSTITUTION:A nematocide comprises seed coat of peanut which has been treated as waste and readily and inexpensively obtainable or its extract with water, hot water or a hydrophilic organic solvent (e.g. methanol, ethyl acetate or acetone) as an active ingredient and is applied to plants causing damages by nematodes. The seed coat of peanut is preferably ground. Advantageously, the seed coat of peanut waste is effectively utilized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nematicide and a nematicidal method applied to a plant which is damaged by nematodes.

[0002]

2. Description of the Related Art Conventional techniques for nematicides can be roughly classified into the following two. That is, one is a method using a pesticide, which is a fumigation method using chloropicrin, EDB or the like. The other is a method of reducing damage by rotating crops of a counter-plant (Agricultural Technology Series, Soil Fertilizers, p. 222). Other than the above two methods, not only targeting nematodes, but aiming at effects on various organisms in soil and effects of improving physical properties, for example, use of compost and poultry manure (Chikioka , Takezawa: "Kanto Higashiyama Pest Research Group Annual Report" Vol. 25, p. 127, 1978
"Plant Protection", Vol. 44, p. 535, 1990). Although not practiced, a method of utilizing a microorganism that parasitizes and kills nematodes has been proposed (JP-A-62-1953).
15, JP-A-62-29506).

[0003]

However, the conventional techniques using pesticides exert toxicity almost indiscriminately on organisms in the soil and have a strong effect, but they have a great adverse effect on the ecosystem and cause a great deal of damage to workers. It is also a dangerous method for humans, and has the drawback that it will eventually lead to the destruction of the global environment. On the other hand, the rotation method is an excellent method considering the ecology of plants such as nematodes and agricultural crops, but the type of rotation crops is limited, and the effect is indirect, so the effectiveness is questioned. There are many things with. In addition, many plants used for the method of rotating repellent plants are not edible. In this way, none of them is satisfactory.

An object of the present invention is to provide a nematicide which has no adverse effects on plants, does not destroy the ecosystem in soil, can be used safely, and is safe for feeding crops. is there.

[0005]

[Means for Solving the Problems] From the current situation as described above,
In order to develop a satisfactory nematicide, a search for safe crops having nematicidal power was conducted, and it was found that peanut could be a suitable nematicide. In particular, they found that the seed coat had a nematicidal component.

That is, when the outer shell (pericarp) of peanut, seed coat, seeds from which seed coat was peeled off and their aqueous extracts were respectively brought into contact with soil nematodes, strong killing action not found in the outer shell and seeds was observed. Insect worm was found to be present in the seed coat and its water extract.

Further investigation further revealed that the hot water extract of seed coat also has nematicidal activity, and that this extract is a heat-stable component. When extracted with a non-water-soluble solvent such as n-hexane, the extract showed almost no nematicidal activity, but with hydrophilic solvents such as methanol, ethyl acetate, or acetone, nematicidal activity appeared. , And found that an extract of a hydrophilic solvent is also possible.

The present invention is a nematicide containing peanut seed coat as an active ingredient. Further, it is a nematicide which contains at least one of a water extract, a hot water extract and a hydrophilic organic solvent extract of the seed coat of peanut as an active ingredient.

Arachis used in the present invention
Plants belonging to the genus include all peanut cultivated species that grow in various parts of the world. The peanut seed coat refers to an extremely thin film-like tissue that covers the surface of peanut seeds, and generally exhibits a brown color when matured. In order to obtain this seed coat, the seed coat and seed must be separated because they are in close contact.

The seed coat may be a raw seed coat, but it can be collected by roasting, roasting, or immersing in water or hot water, and is not particularly limited. However, the seed coat can be easily removed from the seed coat by immersion in water, hot water, roasting or roasting, and can be easily separated by slightly applying force or twisting the seed coat. It is preferable in terms. The roasting or roasting method does not deactivate the active ingredient by heating. In the method of dipping in water or hot water, the active ingredient is transferred also to water or hot water. The active ingredient is present without inactivation even in the immersion liquid as it is or after being concentrated and dried.

Although there are some varieties of peanuts that can be edible with the seed coat attached, they are mostly edible only for seeds. The seed coat is currently treated as waste and is not treated as useful. Therefore, it can be easily obtained as a starting material for producing the nematicide of the present invention.

The extract containing peanut seed coat and the active ingredient may be directly applied to a field or the like, but it is preferable to process it by shaping it into a form such as solid or liquid which is easy to apply. The seed coat of peanut may be the seed coat itself, but in this case, it is desirable to pulverize the seed coat. Also, any one or more of the seed coat itself, the water extract of the seed coat, the hot water extract, and the hydrophilic organic solvent extract of the seed coat may be used as the active ingredient, and they may be used alone or in combination. These nematicides can also be mixed with other agents and can also be hydrated, adsorbed, mixed, liquid, solid,
It is also possible to formulate the powder by any one or more methods and use it as a material for agricultural and horticultural products such as for upland field, paddy rice, horticulture, golf course, ranch and forestry.

As a nematicidal method, the nematicidal method performed by using this material for agricultural and horticultural products is suitable in practice, but is not particularly limited. However, in reality, it is desirable to bury it in the soil or sprinkle or spray it on the soil.

Even if this component was used, it had no effect of killing bacteria, fungi, yeast, actinomycetes, etc., and also had no effect of killing microorganisms such as Paramecium. A killing effect was observed only for certain species of nematodes.

[0015]

The present invention is a nematicidal agent containing peanut seed coat or its water, hot water, or an extract of a hydrophilic organic solvent as an active ingredient, so that it has no adverse effect on plants and destroys the ecosystem in soil. It is safe to use and safe to eat harvested crops. Also, because the seed coat is treated as waste,
It is also preferable in terms of effective utilization of waste.

[0016]

【Example】

[Example 1] Harvested peanuts from Chiba are dried in the sun,
A nematicide containing the seed coat and the roasted seed coat as active ingredients was obtained. For comparison, outer shells and seeds were prepared from the same peanut. These were tested for nematicidal effect against nematodes collected by the Balemann method from the soil of a soybean field in Maruoka, Fukui Prefecture.

First, when 80 nematodes and living seed coats (1/2 seeds) were added to 2 ml of water, death started from 1 hour later and they all died 16 hours later. A similar attempt using roasted seed coats yielded the same results. Next, put 60 dogs in 1 ml of water and make the seed coat smaller than the above, 5 × 5 mm.
One piece of the above was put in and tested on both raw and roasted samples. Thirty
After a minute, nematodes near the samples died in both samples. After 4 days, all of the roasted samples died, and the raw samples died, although some were still alive. No nematicidal effect was observed on the raw outer shell (pericarp) and seeds of peanuts. Moreover, in many of the tests, many Paramecium mixed in the nematode suspension did not die.

[Example 2] Peanut seeds were roasted and allowed to cool, and then the seed coat was peeled off from the seed to collect 5 g of the seed coat. 100 ml of water
After dipping in, the seed coat was removed to obtain a liquid.

The test nematodes were collected as follows. That is, in a tomato field in Shizuoka prefecture, we went to a field with particularly severe root-knot nematode damage and collected the soil around the roots of root-knotted tomatoes to obtain a test soil with a high root-knot nematode density.

3 ml of the above peanut water extract was added to 20 g of test soil, mixed and allowed to stand for 1 month at room temperature. As a control, the above extract was replaced with 3 ml of water, and the same procedure was performed.

To determine the effect, nematodes in the soil of the test plot and the control plot were collected by the Balemann method, diluted with water, and a certain amount was taken and observed with a stereomicroscope. Only the root-knot nematodes were calculated and the numbers of root-knot nematodes in the two wards were compared. The number of nematodes showed the average value and standard deviation.

As a result, the number of nematodes in 20 g of soil was 19 in the control group.
75 ± 370, the test section was 538 ± 199. That is, the number of root-knot nematodes in the test group to which the water extract of peanut was added was reduced to about 27% of that in the control group.

[Example 3] A test solution was prepared as follows. That is, peanut roasted seed coat 5 used in Example 2
After immersing g in 100 ml of water and leaving it at room temperature all day and night,
The water extract from which the seed coat was removed by filtering with filter paper was used as a stock solution.

The nematodes were washed with water on the stems and roots of the radish, and then chopped and soaked in distilled water for a whole day and night, and the nematodes parasitizing the radish were collected and used for the test.

20 ml with a lid for rubbing 3 ml of test solution
It was placed in a glass case (diameter 30 × height 30 mm), the above-mentioned radish parasitic nematode suspension was dropped, and about 50 animals were naturally diffused.

The results were summarized in Table 1 by observing the progress of nematode motility reduction, cessation, and rigor due to death with a stereoscopic microscope.

[0027]

[Table 1]

As is apparent from the table, the control had no death, whereas the test solution containing the test solution having a concentration of 50 times or more died athletic slowness or died by 50% to 80% or more.
Therefore, it was confirmed that the peanut seed coat had a nematicidal effect, and that the water extract could be used as a nematicide.

[Example 4] The peanut seeds were immersed in water,
The seed coat and seed were separated, and the seed coat was air-dried and then crushed.
0 g was used. Extracted samples were prepared by selecting ethanol and methanol as representatives of water and hydrophilic organic solvents. That is, for the extraction, first, 20 ml of water was added to 1 g of the sample, and the mixture was sonicated for 0.5 hour and then centrifuged to separate into a supernatant and a residue. The supernatant was used as a water extraction test solution. This was distilled under reduced pressure to dryness. For nematicidal test, dissolve the test solution in water to 0.1
% Aqueous solution, 5 ml was placed in a petri dish, and about 50 Rabditis nematodes were added for observation. C. elegans of the genus Rabditis is a colony of E. coli on nutrient agar plates.
Tests were carried out by growing i) as food.

As a result, most of the water-extracted test solutions died after 160 hours.

Next, 1.0 g of the same seed coat air-dried pulverized product,
20 ml of methanol was added, mixed, stirred and extracted 3 times. The extracts were collected, centrifuged, and the supernatant was taken and distilled under reduced pressure to dryness. This was added to a 1% Tween 20 aqueous solution and emulsified to obtain a methanol extraction test solution. Dissolved in water 0.1%
It was made into an aqueous solution, placed in a petri dish (5 ml), and about 50 nematodes were added for observation.

As a result, about 50% were dead after 16 hours. As a control, no nematodes died when similarly tested with 0.1% and 1% Tween 20 aqueous solutions.

From the above results, it was confirmed that the active ingredient having nematicidal activity is an aqueous solution and can be extracted into a hydrophilic organic solvent. Since it is difficult to accurately calculate the number of nematodes, it is shown as an approximate number.

[Example 5] 100 g of seeds immediately after peeling off the peanut outer shell (pericarp) were placed in a beaker and immersed in 100 ml of water, and after 24 hours, filtered with a filter paper to remove seeds, seed coats and suspended matter. Was used as the test liquid.

The nematodes used were the root-knot nematodes used in Example 2 and the Labytis spp. Nematodes used in Example 4.

In the case of root-knot nematodes, 3 ml of the test solution was placed in the same container as that used in Example 4, 100 test nematode suspensions (2000 / ml) were added, and observed with a stereomicroscope. After 96 hours, the morphology of all nematodes became linear, and the movement was completely stopped.

Test liquid 3 in the case of Labytis spp.
ml, 100 test nematodes were tested. Movement slowed after 4 hours, 50% died 120 hours later, and 90% or more died 164 hours later.

[0038]

Industrial Applicability As described above, the present invention is a nematicide which contains the seed coat of peanut or its water, hot water, or an extract of a hydrophilic organic solvent as an active ingredient, and therefore has no adverse effect on plants. The ecosystem in soil is not destroyed, it can be used safely, and it is safe to eat crops. Further, since the seed coat is treated as a waste, it can be easily obtained at a low cost and is extremely preferable in terms of effective utilization of the waste.

Claims (7)

[Claims] 1. A nematicide containing peanut seed coat as an active ingredient. 2. A nematicide containing as an active ingredient any one or more of a water extract, a hot water extract, and a hydrophilic organic solvent extract of the seed coat of peanut seed coat. 3. The nematicide according to claim 1, wherein the seed coat of peanut belongs to the genus Arachis. 4. The nematicide according to claim 1, 2 or 3, wherein the seed coat of peanut is obtained by immersion in water, hot water, roasting or roasting. 5. The seed coat of peanut is a raw seed coat.
Or the nematicide according to 3. 6. A material for agricultural and horticultural products in which the nematicide according to claim 1, 2, 3, 4 or 5 is formulated in any one or more of water-containing, adsorption, mixing, liquid, solid and powder. .. 7. A nematicidal method using the material for agricultural and horticultural products according to claim 6.