JPS58192805A - Repellent against noxious nematode in soil - Google Patents

Abstract

PURPOSE:The titled inexpensive repellent showing high nematocidal effect on southern root-knot nematode damaging crops seriously, having no phytotoxicity to cucumbers, etc., containing S-methyl-N, N-tetra-methylene dithiocarbamate as an active ingredient. CONSTITUTION:The titled repellent containing S-methyl-N, N-tetramethylene dithiocarbamate as an active ingredient. In the form for use, it is blended with various kinds of carriers depending upon uses, and used in the form of emulsion, wettable powder, granule, dust, etc. The carrier may be liquid or solid, and blended with a surface active agent, etc. The amount of the active ingredient is properly 5-30wt% in the case of granule and 5-90wt% in case of oil and emulsion. The active ingredient can be easily and inexpensively synthesized by reacting pyrrolidine with carbon disulfide, followed by reacting the prepared salt of dithiocarbamate with methyl chloride or dimethyl sulfate.

Description

[Detailed description of the invention] The present invention relates to a soil harmful nematode control agent.

Conventionally, controlling soil pests and diseases in perennial crops such as fruit trees and tea plants has been an important issue, but in recent years, as Japan has seen more intensive use of fields, greenhouse cultivation, and special production of vegetables, Continuous crop failure caused by harmful soil nematodes and pathogenic bacteria has become a problem.

In addition, it is known that harmful soil nematodes are largely responsible for fields that are unsuitable for crop cultivation, known as "dead land."

Damage caused by soil harmful nematodes manifests itself in various ways.

Suppression of early growth or death, and associated yield loss are common. In addition, root vegetables may have abnormal shapes or I! The value of the product is extremely reduced by adding an I mark.

Historically, once a field has been damaged by nematodes, it is impossible to continue cropping it, and especially in intensive fields like Japan, there is no room for a crop rotation system. Therefore, there is a strong demand for a reasonable, safe and inexpensive nematicide for 1@ use.

In general, nematocides come in the following forms: emulsions, oil-based formulations, and granules. Powders are rarely used because they have many problems such as scattering of the chemicals. Among them, nematocides in the form of granules can be treated manually in pre-planting treatment for single use, and in large areas, they can also be treated using a commonly used granulator.

It is reasonable and does not require time and hard labor, nor does it require special machinery. In addition, furrow treatment is the usual method for mid-piling treatment, but if it is in the form of granules, chemical treatment is easily possible.

As mentioned above, granule form is the ideal form of soil treatment agent.

Conventionally, the main drugs known as nematocides are halogenated hydrocarbon-based raw materials, such as chloropicrin, methibromide #, DD (L5-dicclcI propene), and BD.
B (ethylene dibromide).

DCIP (Bischlorone Globyl Ether), DBC
P (1,2-dibromo-75-chloropropane) and the like.

These drugs are inconvenient to handle, such as mucous membrane irritation and metal corrosion. Also 1) BCP, D(
, 'IP agents do not cause drug v4 effects on some crops, and most of the drugs cause phytotoxicity to crops. Furthermore, most of these drugs are in liquid form and require special machinery and training to administer, and when applied to soil, soil II! ! It is necessary to seal the surface with water or cover it with polyethylene, etc., and to avoid chemical damage, it is necessary to plow after a certain period of time to dissipate the chemical into the atmosphere (degassing). This is accompanied by great inconvenience. Also, among those that can be made into one tablet,
The production of DBCP agents has been discontinued due to their toxicity to the human body and their long-term persistence in soil and river water.
The P agent has a problem in that its nematicidal effect is low.

In addition, contact-type nematicides are also used in rice. For example, fensu (0,0-diethyl 0-(4-methylsulfinyl) phenylphox
phothioate], @thoprop (o -x chill 1, S-dipropyl phosphorodithioate), phe
In addition to organic phosphorus agents such as namipbos (x-thyl 3-methyl-4-(methylthio)phenyl (1-methylethyl) phosphoroadate), carfofuran
aldica
It is a carbamate agent such as rb (2-methyl-2(methylthio)propionaldehyde 0-(methylcarbamol)oxime). However, these contact-type nematicides are extremely toxic and are only permitted to be used in granule form, and moreover, are only permitted to be applied by a professional.

Therefore, it is desired to develop a soil nematode control agent that is safe, easy to use, and effective. In order to solve these problems, the present inventors conducted extensive research and discovered a unique action of a certain pyrrolidine compound, thereby completing the present invention.

The present invention is a ±1 W nematode control agent containing S-methyl-N,N-tetramethylene dithiocarbamate as an active ingredient.

The compound according to the present invention can be easily and inexpensively synthesized by reacting pyrrolidine with carbon disulfide and reacting the resulting dithiocarbamate with -Kjl thylchlorite or dimethyl sulfate. The boiling point of the target compound is 156°C/9 HP, and the melting point is 85-87
It is ℃.

The compound according to the present invention can be mixed with various carriers and used in any form such as an emulsion, a wettable powder, a single powder, or a powder.
can be used. The carrier used here may be either liquid or solid, or a combination thereof. Examples of solid carriers include bentonite, Merck, kaolin clay, and gauze, and examples of liquid carriers include inert organic solvents such as xylene, orthochlorotoluene, methylnaphthalene, isophorone, and kerosene.

During formulation, surfactants and the like may be added to provide emulsifying and dispersing properties.

The appropriate active ingredient content is 5 to 50% for single granules, and 5 to 90% for oils and emulsions.

-1 The compounds according to the present invention can be used not only alone, but also in combination with other agricultural chemicals, such as herbicides, fungicides, insecticides, etc., as the case may be.

It can also be used in combination with fertilizers.

Next, the effect of controlling soil harmful nematodes of the present invention will be explained using test examples.

Trial 11 Test against sweet potato necropsy nematode as a tomato indicator Sweet potato necropsy nematode (meloidogyne incognita) grown using sweet potatoes as a host
Contaminated soil was packed in a 1/10000 m pot with a height of 14 eM, and a predetermined amount of granules prepared according to Example IVc were mixed therein. For comparison, commercially available nematocidal granules and other control chemicals were treated in the same manner. After each chemical treatment S was left for 7 days, 10 tomato plants were sown per pot.

The test was conducted in a glass greenhouse (25 to 30°C), and one month after sowing, the degree of root gall parasitism, chemical damage, and grave electricity were investigated. The test was repeated five times. The average values of the results are shown in Table 1, and the degree of root gall parasitism and chemical damage were expressed according to the following criteria.

Degree of root gall parasitism Corresponding disease index Number of root galls 0・・・・−・ 0
None 1... 1-25%
1~82・--- 26−
50% 9-203...
51-75% 21-304...
76 to 100% 50 or more Shiba Harm -...No drug damage observed±...Minor drug damage observed+...-...Apricot slight... Remarkable signs of harm are observed... No germination or withering Table 1 Test Example 2 Predetermined amount of oil prepared according to Test Example 5 against sweet potato nematodes using tomatoes as an indicator and Example 4 An emulsion prepared according to 1. The mixture was diluted 4 times, 8 times, and 16 times with water, and prepared at a concentration of 15 and 20 tons per 10 a, and was placed in the center of the pot at a depth of 8 cI4 [1 point]. Further, the pot was sealed with 50 μl of water per pot.

For comparison purposes, commercially available nematicides DD,
EDB was treated in the same manner as before, and plowed on the 5th day for degassing. On the 8th day after each chemical treatment, tomatoes were sown according to Test Example 1. We conducted an investigation into the degree of drug damage. The test was repeated three times.

The average values of the results are shown in Table 2.

Table 2 Test Example 6 Test against the Red-bellied nematode as a burdock indicator
pratylencbus penetrmnm) contaminated soil was packed into a 1/10000 m bot with a height of 141, and a predetermined amount of the granules prepared according to Example 2 were mixed therein.

Note that a comparative drug was also treated in the same manner.

78 days after treatment, 5 grains of burdock per pot were sown. The test was conducted in a glass greenhouse (25-50℃), and after sowing,
On day 0, the degree of root damage, chemical damage, and total weight were investigated. The test was repeated five times. The average values of the results are shown in Table 3.

The degree of root damage was determined according to the number of browned parts of the roots. In addition, regarding chemical damage, #L experimental reference example 1 was conducted.

Degree of damage Corresponding morbidity index Number of browning parts 0...
...0 None 1...
... 1-25% 1-52...
...26~450% 6~103・
・・・・・・ 51~75% 11~154
...... 76-100% 16 or more Table 5 Test Example 4 Concerning cucumbers in the field tS test against sweet potato Nekop nematodes Sweet potato f:411 was added to the bait crop in a field contaminated with Sweet Potato Nekop nematodes A predetermined amount of granules prepared according to Example 1 was spread over the entire surface of the field, and the field was immediately plowed into a mixed layer. Comparative control drugs were treated in the same manner.

On the 5th day after the chemical treatment, 10 cucumber seedlings, each with 5 leaves developed, were planted per 4 plots. The test was repeated twice. After that, water treatment and pest control were carried out in accordance with customary practices in the village. The test was conducted from July 26th to September 8th, and cucumbers were harvested every 5 days, and the number and weight of each cucumber was measured. On September 8th, each plant was excavated and the extent of parasitic root cavities and stem and leaf types were investigated.

The average value of the results is shown in the fourth view.

[1 As mentioned above, S-methyl-N,N-tetramethylene dithiocarbamate according to the present invention has a tremendous amount of t! l
It shows a high control effect against the sweetpotato Nekop nematode and the Kitane' Dasare nematode. - Moreover, it has the excellent feature of not causing any damage to tomatoes, cucumbers, burdock, etc.

Examples of formulations are shown below. Parts in the text are parts by weight.

Example 1 Granule S-Methyl-N,N-tetramethylene dithiocarbamate 0s Granular diatomaceous earth (10-16 mesh) 90s Impregnated with the above active ingredient granular diatomaceous earth.

The granules of the present invention were prepared.

Example 2 Granule Guinou ± 70 parts Bentonite 25 parts Lausol B
-80 (dispersant, Nippon Oil & Fats ■ trademark) 5 parts or more and water were added and mixed, and the mixture was granulated and dried using a conventional granulation method.

For this granular carrier 85s, S-methyl-N, N
- The granules of the present invention were impregnated with 15 parts of tetramethylene dithiocarbamate.

Example 6 Oil agent 10 parts of S-methyl-N,N-tetramethylene dithiocarbamate and 90 parts or more of 0-chlorotoluene were mixed and dissolved to prepare an oil agent of the present invention.

Example 4 Emulsion S-methyl-N,N-tetramethylene dithiocarbamate 80 parts xylene 10
Partsuru Ball 800A (emulsifier, Toho Chemical Trademark)
At least 10 parts were mixed and dissolved to prepare an emulsion of the present invention.

Hodogaya Chemical Industry Co., Ltd.

Claims (1)

[Claims] A soil harmful nematode control agent characterized by containing S-methyl=N,N-tetramethylene dithiocarbamate as an active ingredient.