JPH04154705A - Herbicide for paddy rice plant having reduced phytotoxicity - Google Patents

Abstract

PURPOSE:To obtain a herbicide for paddy field having a little phytotoxicity and high effects by adding 1-(alpha,alpha-dimethylbenzyl)-3-p-tolylurea to S-benzyl-N-(1,2- dimethylpropyl)-N-ethylthiocarbamate. CONSTITUTION:1-(alpha,alpha-Dimethylbenzyl)-3-p-tolylurea is added to S-benzyl-N-(1,2- dimethylpropyl)-N-ethylthiocarbamate to give an extremely useful herbicide which enormously reduces phytotoxicity of the above-mentioned thiocarbamate to paddy rice plant and has enhanced effects on cockspur-grass and cyperaceous weeds.

Description

Detailed description of the invention (1) Industrial application field S-benzyl-N-(1,2-dimethylpropyl)-
N-ethylthiocarbamate (hereinafter referred to as compound A).

) and 1- (α,α-dimethylbenzyl)-3-p-)
The present invention relates to a herbicide for paddy rice that contains rillurea (hereinafter referred to as compound B) as an active ingredient and has significantly reduced chemical damage to paddy rice caused by compound A.

(2) Prior Art and Problems to be Solved by the Invention Compound A is known as a herbicide that exhibits high efficacy against young weeds in paddy fields, such as field weeds, Japanese cypress, and grasshopper, at a dosage of around 200 g per IOa. .

However, Compound A is insufficiently effective against perennial weeds, such as Cyperaceae, Cyperaceae, Cyperaceae, and Cyperaceae, and Omodakaceae, Urikawa, Omodaka, etc., and may sometimes cause phytotoxicity to paddy rice.

Particularly, under poor environmental conditions such as high temperatures, sandy soil, and leaky rice paddies, seedlings planted shallowly or immediately after transplanting are more susceptible to chemical damage.

On the other hand, Compound B is known as a herbicide, and is used to control rice field weeds and Cyperaceae weeds such as Cyperus and Firefly.
It is widely used as a herbicide for weeds such as Japanese grasshopper, Japanese cypress, and black croaker, as it shows excellent herbicidal effects on these weeds.

Until now, there is no literature describing the combination of Compound A and Compound B.

The present invention provides a water herbicide which is extremely useful in practice, without worrying about chemical damage to transplanted paddy rice, and which is highly effective against young and perennial weeds.

(3) Means for solving the problem By adding compound B to compound A, the present inventor has solved the problem.
Surprising new findings have been discovered that the compound significantly reduces the chemical damage caused to paddy rice, and also enhances its efficacy against Cyperaceae weeds.

The effective mixing range of the herbicide for paddy fields of the present invention is whether the amount used is 50 to 80 [1 g/
1. Compound B is 15-500g/l with respect to Da, 0a
More preferably, 150 to 400 g of compound A/
Compound B is 30-300g/1.10a. It is OA.

The herbicide for paddy fields of the present invention can be formulated into various dosage forms such as emulsions, wettable powders, granules, flowables, granular irrigation agents, and microcapsules in polymeric substances by applying conventional formulation methods for agricultural chemical formulations. I can do something.

In addition, in order to enhance the effect on broad-leaved weeds such as Kikashigusa, Azena, Helaomodaka, etc. and perennial difficult-to-control weeds such as Urikawa, Omodaka, and Kurogwai, hensulfuron-methyl, virazosulfuron-ethyl, nnosulfuron, N-(2-chloro imidazo[1,2~a]pirin-
3-ylsulfonyl)-N'-(4,6-shiftkin-
It is also possible to add urea (2-pyrimidinyl), virazolate, virazoquinfen, henzofenasop, etc.

Furthermore, in order to expand the range of action, other herbicides, insecticides, fungicides, plant growth regulators, fertilizers, etc. may be mixed.

(4) Examples Next, examples of typical dosage forms will be given.It goes without saying that the mixing ratio of the active ingredients can be varied within the above-mentioned range. "Parts" in the description indicate parts by weight.

Example 1 Hydration containing 5696 active ingredients was prepared by mixing and pulverizing 2 parts of wettable powder compound A2B, 28 parts of compound B, 37 parts of clay, 2 parts of white carbon, 2 parts of sodium lignin sulfonate, and 3 parts of sodium alkylnaphthalene sulfonate. get the agent.

Example 2 7 parts of granule compound A, 87 parts of compound, 30 parts of bentonite, 52 parts of talc, 2 parts of sodium dodecylbenzenesulfonate and 2 parts of sodium ligninsulfonate were mixed, approximately 20 parts of water was added, and the mixture was mixed in a kneader. After kneading, the mixture is granulated through a granulator, and then dried and sized to obtain granules containing 14% of the active ingredient.

(5) Effects of the invention and test examples As shown in the test results described later, the herbicide for rice fields of the present invention is capable of increasing the herbicidal efficacy of compound A against weeds and weeds of the Cyperaceae family by adding and using compound B in combination with compound A. In addition, it becomes possible to significantly reduce the phytotoxicity of Compound A to paddy rice.

Test Example 1 In a 100 ml Erlenmeyer flask, Nisprocarb was added as an active ingredient at 1.3.2.6.5.2.10.41) pm,
Daimron 0.18.0.37.0.75.1.5.
100 ml of Mr. Kasugai's hydroponic solution prepared by mixing 3 ppm and each drug to a predetermined concentration was dispensed, and 10 paddy rice plants (variety: Koshihikari) at the two-leaf stage were subjected to root immersion treatment.

After that, cover the Erlenmeyer flask with aluminum foil and
It was grown in an artificial climate room at 5° C./8 hours at night at 16 hours (10,0001 ux). On the 10th day after the treatment, the height of the third leaf and the height of the fourth leaf of rice were determined as n1, and the ratio to the untreated plot was determined. The experiment was repeated twice, and the results are shown in Table 1.

Test Example 2 Paddy soil was plowed into a 1/5000 a Wagner pot and the flooding method was set to 4 cm. After burying the tubers of Urikawa and Kurogwai to a depth of 3 cm, mixed sowing of Nobie and Hotarui in the soil 1 (towards the bottom), Tamaga yatsuri, Konagi,
Cyperus tubers were sown on the soil surface, and on the next day, 6 individuals of two-leaf stage rice (variety: Koshihikari) were transplanted per pot (3 individuals per pound, 3 individuals planted in 3cITl). Seven days after transplantation, the water surface was treated with the granules prepared according to Example 2, and water leakage was performed at a rate of 3 cm/day the day after the treatment and the day after. On the 20th day after the treatment, observation and investigation were conducted according to the following criteria. In addition, regarding rice chemical damage, observational evaluation and plant height measurements were made, and plant height was expressed as a ratio to untreated plots. The results are shown in Table 2.
two.

0 Effect No chemical damage~jO: Complete withering Table 1 Table　　　　　　　(Continued)

Claims (1)

[Claims] S-benzyl-N-(1,2-dimethylpropyl)-N
- A herbicide for paddy rice with reduced phytotoxicity, characterized by containing ethylthiocarbamate and 1-(α,α-dimethylbenzyl)-3-p-tolylurea as active ingredients.