JPS6141486B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a nematicide, and more particularly to a nematicide that has a strong control effect against plant parasitic nematodes and is free from the risk of phytotoxicity to target cultivated crops. Conventionally, there are liquid agents such as DBCP (nemagon) and DCIP (nemamol) to exterminate plant-parasitic nematodes, but liquid scents such as DD, chloropicrin, methyl bromide, ethylene dibromide, etc. Vaporizing agents have been widely used. However, since these fumigants aim to produce effects using toxic gases, their usage is complicated.
Moreover, it cannot be used during crop growth because it causes serious chemical damage to crops, and it is necessary to leave the cultivated land fallow for a long period of time after treating the soil, which has the disadvantage that the cultivated land cannot be used efficiently. In view of the above-mentioned drawbacks, the present inventors have conducted extensive research with the aim of obtaining a nematicide that has a strong nematicidal effect and is free from the risk of phytotoxicity to cultivated crops. As a result, the inventors discovered that 2-(2-chloroacetamino)pyridine and its salts met the above objectives, and completed the present invention. That is, the present invention relates to a nematicide containing at least one kind of 2-(2-chloroacetamino)pyridine and its salt as an active ingredient. The 2-(2-chloroacetamino)pyridine of the present invention has the following formula: It can be produced by various methods. For example, it can be produced by adding an ethyl ether solution of chloroacetyl chloride to a mixture of 2-aminopyridine, pyridine and ethyl ether at a temperature of about 5°C or less, and adding cold water to the formed crystals. can. Then, it can be made into a salt using a suitable acid according to a conventional method. Representative examples of the salt of 2-(2-chloroacetamino)pyridine include mineral acid salts such as hydrochloride and sulfate. The nematocides of the present invention are particularly suitable for Meloidgyne species, Heterodera
It is effective against parasitic nematodes such as Pratylenchus species and Pratylenchus species. A typical example of the Meloidogyne species mentioned above is the sweet potato nematode that parasitizes tomatoes, cucumbers, and spinach; a representative example of the Heterodera species is the Dipotato nematode that parasitizes potatoes; and a typical example of the Platylenchus species is burdock and Japanese yam. For example, there are plants that parasitize the plant. The nematicide of the present invention exhibits nematicidal action even in a relatively small amount, and usually has an active ingredient per 10 ares.
A usage amount of about 100g to 10Kg, preferably about 200g to 5Kg is sufficient. The 2-(2-chloroacetamino)pyridine of the present invention can be used as a composition in various forms. For example, in the form of an organic solvent solution such as xylene, cyclohexanone, azetone, methanol, or ethanol, or in the form of an aqueous emulsion using a conventionally known emulsifier, or with a solid carrier such as soil, sand, or ordinary adsorbent. They can be mixed and used in the form of granules, powders, etc. Furthermore, seeds in advance,
It can also be used by applying it to cereals and the like. The nematicide of the present invention has no risk of phytotoxicity to crops, and therefore, unlike the conventional fumigants and liquid agents described above, it can be used even during crop growth. Furthermore, since the insecticidal effect continues for a required period of time even after being sprayed on the soil, by treating the soil with the chemical of the present invention prior to planting or sowing plants, the preventive effect against plant damage caused by nematodes can be exerted. can. The nematicide of the present invention can also be used in combination with conventionally known fungicides, insecticides, herbicides, and other chemicals or various fertilizers. As described above, the nematocide of the present invention can be easily applied to plants and soil in any form, and there is no fear of phytotoxicity to plants, and there is no need to leave the cultivated land fallow. Therefore, it has great advantages in terms of labor saving and efficient use of cultivated land. Hereinafter, the features of the present invention will be further clarified through Examples and Test Examples, where all "%" indicates "% by weight". Example 1 Emulsion % 2-(2-chloroacetamino)pyridine
20.0 Xylene 40.0 Cyclohexanone 20.0 Tween80 (trademark, manufactured by Wako Pure Chemical Industries, Ltd.) 15.6 Span80 (trademark, manufactured by Wako Pure Chemical Industries, Ltd.) 4.4 Mix and stir the above components to prepare an emulsion that can be emulsified in water for use. Example 2 Wettable powder % 2-(2-chloroacetomino)pyridine 20.0 Kaolin 40.0 Diatomaceous earth 20.0 Bentonite 10.0 Emar 40 Powder 5.5 Demol EP powder 3.5 Alkyl phosphate 1.0 Mix and stir the above ingredients to make a wettable powder . Example 3 Granules % Wettable powder of Example 2 10 Dolomite 90 The above components were mixed and stirred, and 15 parts of a 2% carboxymethyl cellulose aqueous solution was added to 100 parts of this mixture. After thorough stirring and mixing, the mixture was placed in a granulator. Take the form of granules. Test example 1 (immersion test) 2-(2-chloroacetamino)pyridine,
Dissolve in 0.5 ml of 98% methanol and add deionized water to make a total volume of 10 ml. Take 1 ml of this solution into a test tube, and in this 1 ml contains about 100 second-stage larvae (larvae that hatched within 24 hours) of the sweet potato beetle, Meloidogyne incognita acrita.
Add the nematode solution and leave at 25°C for 24 hours. Thereafter, the number of sample nematodes is counted, and then the sample is placed in a Bellman separator, and after being left for 24 hours, the number of live nematodes separated is counted, and the mortality rate is calculated according to the following formula. Mortality rate (%) = (1-b/ac) x 100 a: Number of test nematodes (Measure the actual number with a stereomicroscope (30x magnification) and express the average value of two times.) b: Number of nematodes in the test area Number of live nematodes separated by Bellman (When passed through special paper, live nematodes remain in the liquid and dead nematodes remain in the residue. Count the number of nematodes in the liquid.) c: Bellman separation rate in control plot 2- (2- Table 1 shows the insect mortality rates calculated as described above by varying the concentration of chloroacetamino)pyridine.

Table 1 shows that the 2-(2-chloroacetamino)pyridine of the present invention has a strong nematicidal effect even at low concentrations. Test example 2 (field test) Nematode contaminated soil (approximately 50 centipedes of sweet potato
head/soil 10g) of the emulsion of Example 1 500 times, 1000
Dilute it 2000 times, 4000 times and spray it on the soil surface at a rate of 2l/ ^m2 . One week later, tomato seedlings are planted, and one month later, the degree of root nodule growth is observed. The test area is 2 x 2 m ² .
Repeat 3 times. As a comparative drug, 20 l/10a of DD emulsion, a conventional nematocide, was injected and the degree of root nodule attachment was observed in the same manner. The degree of root nodule attachment is measured by the percentage of the root nodule covered part to the entire root according to the following evaluation criteria. 0...0% 1...25% or less 2...50% or less 3...75% or less 4...100% The results are shown in Table 2.

[Table] Test Example 3 (Field Test) Nematode-contaminated soil (approximately 50 centipedes
40 kg/10 g of the granules of Example 3 per head/10 g of soil.
Spray at the rate of 10a, 20Kg/10a, 10Kg/10a, 5Kg/10a and mix gently. One week later, tomato seedlings were planted, and one month later, the degree of root nodule attachment was measured in the same manner as in Test Example 2. The results are shown in Table 3. Additionally, Table 3 also shows the results obtained when DD emulsion, a conventional nematocide, was injected at 20 liters/10 a as a comparative drug.

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Claims (1)

[Claims] 1. A nematicide containing at least one of 2-(2-chloroacetamino)pyridine and its salt as an active ingredient.