JPS6345365B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a granular harmful nematode control agent. Traditionally, in perennial crops such as fruit trees and tea plants,
Controlling soil pests and diseases has always been an important issue, but in recent years, as fields have become more intensively used, cultivated in facilities, and vegetables have become specialties, problems with continuous cropping caused by soil harmful nematodes and pathogens have become a problem. There is. In particular, it is known that in fields that are unsuitable for crop cultivation, which are known as inhospitable areas, in addition to soil pathogenic bacteria, harmful soil nematodes are largely involved. Damage caused by soil harmful nematodes can occur in a variety of ways, but the most common ones are delayed initial growth or death, and an associated decrease in yield.In addition, root vegetables may be deformed or have their surfaces damaged. and extremely reduce the product value. On top of that,
It also plays a major role as a vector for various soil pathogens. Furthermore, once a field has been damaged by nematodes, continuous cropping is impossible, especially in intensive agriculture like Japan, where there is no room for a crop rotation system. There is a strong demand for nematicides. Conventional drugs known as nematicides are mainly halogenated hydrocarbon fumigants, such as chloropicrin, methyl bromide, DD (1,3-dichloropropene), EDB (ethylene dibromide),
DCIP (bischloroisopropyl ether),
DBCP (1,2-dibromo-3-chloropropane)
etc. Among these drugs, chloropicrin and methyl bromide are commercially available in cylinder form due to their physical properties.
It is mainly used for soil disinfection. EDB, D-D
is the most commonly used nematicide worldwide,
Due to its physical properties, it is commercially available in oil or emulsion form. In addition, DBCP and DCIP have high boiling points of 187°C and 196°C, respectively, so they are used as emulsions like other fumigants, but they are mainly commercially available in granule form. On the other hand, these halogeno-hydrocarbon compounds have problems in handling, such as mucous membrane irritation and metal corrosiveness. Furthermore, most drugs cause phytotoxicity to crops, except for DBCP and DCIP, which do not cause phytotoxicity to some crops. Additionally, most of these chemicals are in liquid form, and require special equipment and machinery when applied to soil. Furthermore, the boiling points of these compounds are e.g.
CH ₃ Br: 4℃, DD: 119℃, EDB: 131℃, which are low, so in order to develop the effect, the soil surface is sealed with water for a certain period of time or covered with polyethylene, etc., and in addition, to avoid chemical damage. Therefore, it is necessary to plow after a certain period of time to dissipate the chemicals into the atmosphere (degassing). As described above, it is very inconvenient to use. Furthermore, production of DBCP and DCIP, which can be made into granules, has been discontinued due to the problems that the DBCP agent is toxic to the human body and remains in soil and river water for a long time. DCIP agents have a problem of low nematicidal activity. In addition, contact nematicides are also used in the United States. For example, Fensulfothion [o, o-
Diethyl o-(4-methylsulfinyl) phenyl phosphorothioate], Ethoprop (o-ethyl s,s-dipropyl phosphorodithioate),
Organic phosphorus agents such as Phenamiphos [ethyl 3-methyl-4-(methylthio)phenyl(1-methylethyl)phosphoramidate], and
Carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuranyl methyl carbamate),
It is a carbamate agent such as Aldicarb [2-methyl-2(methylthio)propylaldehyde o-(methylcarbamoyl)oxime]. however,
Although these contact-type nematicides have high nematicidal activity, they are extremely toxic and are only permitted in granule form, and moreover, only for application by a professional. In order to solve these problems, the present inventors completed the present invention as a result of various studies. The present invention is a granular harmful nematode control agent containing S-methyl-N,N-dimethylthiol carbamate. The term "granular" as used in the present invention includes not only so-called granules but also so-called fine granules. Furthermore, when granulating S-methyl-N,N-dimethylthiol carbamate according to the present invention,
Granules and fine granules can be prepared by impregnating or adhering it to a highly oil-absorbing granular carrier such as diatomaceous earth. The present invention is not limited to this, but it is also possible to mix it with various carriers depending on the use, mix it with water, etc., and granulate it by a commonly used agricultural chemical production technique. Examples of carriers used include bentonite, talc, kaolin clay, and clay. Furthermore, surfactants and the like may be added to impart emulsifying and dispersing properties during formulation. The amount of active ingredient in the granules can be increased or decreased by approximately 5-40%. Furthermore, the agent according to the present invention can be used not only alone, but also in combination with other agricultural chemicals, such as selective herbicides, fungicides, insecticides, or fertilizers. The compound according to the present invention can be easily synthesized by reacting dimethylamine with carbonyl sulfide and reacting the resulting carbamate salt with methyl chloride or dimethyl sulfate. Its boiling point is 117°C/90mmHg. The excellent effects of the harmful nematode control agent according to the present invention will be explained below with reference to test examples. Test Example 1 Test against sweet potato knot nematode using tomatoes as an indicator Sweet potato knot nematode (meloidogyne incognita) contaminated soil grown using sweet potatoes as a host was packed in a 1/10000a pot with a height of 14 cm, and Example 1
A predetermined amount of granules that acted according to the method was mixed. DBCP, a commercially available nematicide, was used for comparison purposes.
Granules and DCIP granules were also treated in the same way. The powder (control) was mixed with 25 parts of the active ingredient, 50 parts of Fubasami Clay (trademark of Onuki Mining Co., Ltd.), and 25 parts of Carplex (trademark of Shionogi & Co., Ltd.), and mixed into the soil in the same manner as the granules. . Emulsion (control) is the active ingredient
10 parts, xylene 85 parts, Solpol 800A (Toho Chemical
Co., Ltd. Trademark) Mix at 5 parts and apply 1000/ml on the surface of the pot.
It was diluted with water to a concentration of 10a and then irrigated. After each chemical treatment, the pots were left for 7 days, and 10 tomato seeds were sown per pot. The test was conducted in a glass greenhouse (25-30℃)
One month after sowing, the degree of parasitic root galls, chemical damage, and stem and leaf weight were investigated. The test was repeated three times, and the average values of the results are shown in Table 1. The degree of parasitic root galls and chemical damage were expressed by the following values.

【table】

【table】

【table】

[Table] Test Example 2 Control test against Pratylenchus penetrans using burdock as an indicator. Soil contaminated with Pratylenchus penetrans, which was grown using kidney beans as a host, was packed in a 1/10000a pot with a height of 14 cm, and the same method as in Example 1 was carried out. A predetermined amount of granules prepared in the same manner were mixed. In addition
DBCP granules and powders prepared in the same manner as in Test Example 1 were also treated in the same manner. After standing for 7 days, 5 burdock seeds were sown per pot. The test was conducted in a glass greenhouse (25-30°C), and the degree of root damage, chemical damage, and total weight were investigated 50 days after sowing. The test was repeated three times, and the average value of the results is shown in Table 2. The degree of damage to the roots was determined by the number of browned parts of the roots (not specified). The labeling of drug damage was carried out in accordance with Test Example 1.

【table】

[Table] Test Example 3 Control test of sweet potato knot nematode in the field targeting cucumbers Granule prepared according to Example 2 and test in a field contaminated with sweet potato knot nematode where sweet potatoes had been planted in the previous crop. A powder prepared in the same manner as in Example 1 was spread over the entire surface of the field, and the field was immediately mixed with plowing. In addition
DBCP granules were treated in the same way. After being left for 5 days, 8 cucumber seedlings with 5 true leaves developed were planted per 2 m ² of each plot. The test was repeated three times from mid-June to early August, during which irrigation and pest control practices were followed. Plant height including lateral branches and test example 1
Table 3 shows the average values of the root gall level and chemical damage survey results.

[Table] As described above, the granules of the present invention exhibit a high control effect against sweet potato knot nematodes and northern red cabbage nematodes that cause great damage to crops. And tomatoes,
It is an excellent nematocide that is highly safe and has no chemical harm to cucumbers and burdock. Examples of formulations are shown below. In addition, all parts in the text indicate parts by weight. Example 1 S-methyl-N,N-dimethylthiol carbamate 25 parts Granular diatomaceous earth 75 parts The above active ingredients were impregnated into granular diatomaceous earth to prepare granules. Example 2 S-methyl-N,N-dimethylthiol carbamate 25 parts Newcol 565 (dispersant, Nippon Nyukazai Co., Ltd. trademark)
5 parts granular diatomaceous earth 70 parts A mixture of the above active ingredient and activator was impregnated into granular diatomaceous earth to form a granule. Example 3 S-methyl-N,N-dimethylthiol carbamate 25 parts Carplex (silica, trademark of Shionogi & Co., Ltd.)
15 parts bentonite 55 parts Surfinol TGE (nonionic surfactant,
Air Products and Chemicals, Inc. Trademark)
2 parts Rapizole B-80 (dispersant, NOF Corporation trademark)
Three parts or more were mixed and ground to form granules by mixing with water.

Claims (1)

[Claims] 1. A granular harmful nematode control agent containing S-methyl-N,N-dimethylthiol carbamate.