JPH021802B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to 2,3-dihydro-2,2-dimethyl-7-benzofuranyl [(dibutylamino)thio]
This invention relates to an insecticidal and fungicidal composition characterized by containing methyl carbomate (hereinafter abbreviated as carbosulfan) and diisopropyl 1,3-dithiolane-2-isodenmalonate (hereinafter abbreviated as isoprothiolane) as active ingredients. be. In recent years, mechanical transplantation of young and medium-sized seedlings has been widely used during rice planting in wet rice cultivation. Seedlings for transplantation are generally grown to young or medium-sized seedlings in a 60 x 30 x 3 (cm) nursery box, and then placed in a transplanter and transplanted. The roots of the seedlings are treated with insecticides or fungicides (applied in a seedling box), and the seedlings are transplanted mechanically with the drug attached to the roots, and the paddy rice is infected with early-stage pests in the paddy field, such as leafhopper, brown leafhopper, leafminer fly, rice plant beetle, and rice weevil. , rice weevil, etc., or rice blast disease. This kind of cultivation method is also used in areas where insecticide-resistant leafhoppers are common in the warm southwestern regions, but recently the development of resistance has been observed even with the conventionally used chemicals applied in nursery boxes. In general, mixed powder agents that utilize the mutual effect of organic phosphorus agents and N-methyl carbamate agents are used when applied to rice fields to control black leafhopper, which has developed resistance to organic phosphorus agents and carbamate agents. . Similar organic phosphorus agents and N-
An application method that takes advantage of the synergistic effect of a mixture with a methyl carbamate agent is considered, but conventional N-methyl carbamate causes significant chemical damage to young and medium-sized paddy rice seedlings when applied in a nursery box, so it is difficult to use the conventional N-methyl carbamate when applied in a nursery box. making it impossible. On the other hand, systemic fungicides have also been applied to seedlings before mechanical transplantation and have shown effectiveness in controlling rice blast disease in rice fields.
However, in reality, the insecticide and fungicide used in the seedling box are applied separately and simultaneously, which requires a great deal of labor during the busy farming season for rice transplanting.Furthermore, since large amounts of chemicals are applied to the seedling box, mechanical transplantation is required. Sometimes, the chemicals fall down, resulting in uneven pest control and blast control effects. The present inventors have discovered that chemical damage to young and medium rice seedlings of paddy rice is almost non-existent when applied in a regular nursery box, and that by mixing the chemical, it has a remarkable mutual effect against resistant leafhopper, and furthermore, it is a labor-saving method that can control rice blast disease. As a result of repeated research on insecticidal and bactericidal compositions for treating paddy rice seedling boxes, it was discovered that a mixture of the carbosulfan and isoprothiolane can be used for seedling box treatment, and the present invention was completed. Carbosulfan is a compound described in Japanese Patent Publication No. 53-39487, and exhibits excellent insecticidal activity against Diptera pests, Lepidoptera pests, Coleoptera pests, Hemiptera pests, spider mites, etc. In addition, isoprothiolane is a dithiolane compound described in Japanese Patent Publication No. 47-34126 and exhibits a control effect against rice blast, and also exhibits an effect of inhibiting the growth of brown planthopper. As a result of extensive research, the present inventors have demonstrated that by applying a mixture of carbosulfan and isobutyrothiolane, an excellent synergistic insecticidal effect that could not be expected from the insecticidal properties of each single agent, and a residual effect. It was also found that the properties were significantly superior. Furthermore, the composition of the present invention was as effective against rice blast disease as isobutyrothiolane alone. Furthermore, since it does not cause any chemical damage to useful crops, it can be said to be a suitable insecticide and fungicide from the viewpoint of safety. The insecticidal and fungicidal composition of the present invention is mainly applied to paddy field early-stage pests such as leafhopper, brown leafhopper, leafminer fly, rice plant beetle, rice weevil, and rice water weevil, and to rice blast disease, but it is also used against pests that attack other agricultural and forestry crops. is also useful. When applying the composition of the present invention as an insecticidal fungicide, it can generally be mixed with a suitable carrier and, if desired, emulsifiers, dispersants, suspending agents, penetrating agents, spreading agents, etc. Emulsion by adding stabilizers etc.
It can be put to practical use in any form such as wettable powders, powders, granules, and oils. In this case, the mixing ratio of carbosulfin and isoprothiolane, which are active ingredients, can be freely determined within the range of 1:9 to 9:1, but is preferably within the range of 1:3 to 3:1. . In addition, other types of acaricides, various insecticides, fungicides, plant growth regulators, synergists, attractants,
It is also possible to add repellents, fragrances, etc. Next, some formulation examples of the insecticidal and fungicidal composition of the present invention will be shown, but the present invention is not limited to these ("parts" in the following formulation examples indicate parts by weight). Formulation Example 1 Granule Carbosulfan 5 parts Isoprothiolane 12 parts Crushed clay 83 parts After uniformly mixing carbosulfan and isoprothiolane, this mixture is uniformly mixed with crushed clay to prepare granules. The obtained granules are applied in an amount of 50 to 100 g per seedling box, or 3 to 6 kg per 10 acres. Formulation Example 2 Emulsion Carbosulfan 10 parts Isoprothiolane 20 parts Xylol 60 parts Solpol 2680 (Toho Chemical brand name) 10 parts Mix the above ingredients uniformly to make an emulsion. In use, the emulsion having the above composition is diluted 500 to 2000 times with water and then sprayed at 100 to 1000/10a. Formulation example 3 Wettable powder Carbosulfan 20 parts Isoprothiolane 40 parts Siegrite 35 parts Solpol 8048 (Toho Chemical brand name) 3 parts Lunox 1000 (Toho Chemical brand name) 2 parts Mix and grind the above uniformly to form a wettable powder. do. When using, mix the hydrating agent with the above composition with water at a concentration of 500 to 2000.
Dilute it twice and spray 50-500/10a. Formulation Example 4 Emulsion Carbosulfan 2.0 parts Isoprothiolane 2.5 parts Talc 95.5 parts Mix and grind the above ingredients uniformly to make a powder. When using, powder of the above composition is mixed with a duster for 3 to 4 minutes.
Spray Kg/10a. Next, the usefulness of the composition of the present invention will be specifically explained using test examples. Test example 1 Insecticidal test against resistant leafhopper A chemical solution of a specified concentration was placed in a glass bottle (diameter 5.5 cm, height
Pour 50 ml into a 6.5 cm) container, cover with a cork stopper, put rice seedlings through the hole in the cork, soak the rice roots in the chemical solution, plug the hole with cotton, and put a glass tube into the cork stopper. Ten resistant leafhopper adults (Nakagawara strain) were released and stored in a constant temperature room at 25°C with a lid on.The number of dead insects was counted 4 days after release, and the killing rate was calculated. Furthermore, the median lethal concentration (LC ₅₀ ) was determined using Finny's simple calculation formula. Furthermore,
The Sun method (J.Econ.
Entomol., Vol.53.5p.887-892.1960), the combined toxicity coefficient was determined and the mixed effect was evaluated. The results are shown in Table 1.

[Table] As shown in Table 1, the composition of the present invention exhibited superior systemic insecticidal activity to each agent alone, and also exhibited a strong synergistic effect. Test example 2 Residual efficacy against resistant black leafhopper and chemical damage test on rice by applying chemicals in a nursery box Paddy rice seedlings were cultivated in a nursery box as usual, and (variety:
Nipponbare), 21 days after sowing (on the day of transplanting), 70g of test granules were applied to each seedling box, and then thoroughly watered with water. Two hours after application, a 1/10,000-are pot (filled with soil and water was added to create a paddy field condition). The seedlings (with soil still attached) that had been scraped out of the seedling box were transplanted into the pot (with the soil still attached), with 5 plants per pot. Every designated day, the pot was covered with a wire mesh cylinder and 10 adult resistant leafhoppers (Nakagawara strain) were released per pot.The number of dead insects was counted after 48 hours to determine the mortality rate. Furthermore, a sample for chemical damage investigation was prepared in the same manner, and the properties of the pod leaves and plant height were investigated according to the number of days that had passed since transplantation. Both races were held in three consecutive races in one ward. The results are shown in the table.

[Table] As shown in Table 2, the composition of the present invention exhibited excellent residual efficacy against resistant leafhopper and did not cause any chemical damage to rice. Test Example 3 Test of the control effect of rice blast disease using seedling box application Rice grown in pots as in Test Example 2 was stored in a glass room, and rice blast fungus spores were sprayed and inoculated according to the number of days that had passed since transplantation. Seven days after inoculation, the number of rice blast lesions per pot was investigated, and the control value was determined using the following criteria. The results are shown in Table 3. Control value = (Number of lesions in untreated area - Number of lesions in treated area / Number of lesions in untreated area) × 100

[Table] As shown in Table 3, the composition of the present invention exhibited an excellent control effect against rice blast.

Claims (1)

[Claims] 1 2,3-dihydro-2,2-dimethyl-7-
An insecticidal and fungicidal composition comprising benzofuranyl[(dibutylamino)thio]methyl carbamate and diisopropyl 1,3-dithiolane-2-isodenmalonate as active ingredients.