JPH02258704A - Herbicide for paddy rice reduced in phytotoxicity - Google Patents

Abstract

PURPOSE:To obtain the title herbicide containing 3-(4,6-dimethoxy-1,3,5-triazin-2- yl)-1-[2-(2-methoxyethoxy)-phenylsulfonyl]urea and 1-(alpha,alpha-dimethylbenzyl)-3-p- tolylurea. CONSTITUTION:The title herbicide containing 3-(4,6-dimethoxy-1,3,5triazin-2- yl)-1-[2-(2-methoxyethoxy)phenylsulfonyl]urea (A) and 1-(alpha,alpha-dimethylbenzyl)-3-p- tolylurea (B) as active ingredients. Although the compound A exhibits high weeding effect on weed in paddy field at low chemical amount and sometimes gives phytotoxicity to paddy rice on other hand, a herbicide remarkably reduced in phytotoxicity to transplanted and directly seeded paddy rice and capable of exhibiting high effect on annual weed and perennial weed can be obtained by using the compound A together with the compound B. Amounts of the compound A and compound B used are each 1-10g and 30-100g per 10a.

Description

Detailed Description of the Invention (1) Industrial Field of Application The present invention is directed to 3-(4J-dimethoxy-1,3,5-h riazin-2-yl)-1-C2-(2-methoxyethoxy)- phenylsulfonyl]urea (hereinafter referred to as compound A) and 1-(α,α-dimethylbenzyl)-3-p
- Tolylurea (hereinafter referred to as Compound B) as an active ingredient, the herbicide for paddy rice has significantly reduced phytotoxicity of Compound A to paddy rice.

(2) Problems to be solved by the conventional technology and the invention Compound A is used in a low dosage of 1/100 to 1/200 of conventional herbicides, and is effective against annual weeds other than weeds, such as cyperus japonica, japonica japonica, and japonica japonica, etc. It is also known as a herbicide that exhibits a high herbicidal effect on perennial weeds such as paddy field weeds, such as Japanese grasshopper, paddy field weeds, and paddy field weeds.

However, Compound A sometimes causes phytotoxicity to paddy rice. Particularly, under poor environmental conditions such as high temperatures, sandy soil, and leaky rice fields, and in shallowly planted seedlings, seedlings immediately after transplanting, or seedlings, it causes even stronger phytotoxicity.

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 practically very useful herbicide for paddy fields that is free from chemical damage to transplanted and 1α-seeded rice, and exhibits high efficacy against young and perennial weeds in general.

(3) Means for Solving the Problems The present inventors have found that by adding Compound B to Compound A, the phytotoxicity of Compound A to paddy rice can be significantly reduced, and the efficacy against field weeds and Cyperaceae weeds can be enhanced. I discovered surprising new knowledge.

The effective mixing range of the herbicide for paddy fields of the present invention is that the amount of compound A used is 0.5 to 2 Of/IO.
Compound B is 15-500 g/10 a for a
More preferably, the amount of compound A is 1 to 10 g/10a
(2) Compound B is 30-300 g/10 a.

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

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

(4) Examples Next, examples of typical dosage forms will be given, but 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 3 parts of wettable powder compound A, 880 parts of compound, 10 parts of diatomaceous powder, 20 parts of clay, 2 parts of white carbon, 2 parts of sodium ligninsulfonate, and 3 parts of sodium alkylnaphthalenesulfonate were mixed and ground to obtain active ingredient 6326. A hydrating agent containing the following is obtained.

Example 2 Granule Compound A 0.15 parts, Compound 83 parts, Bentonite 25
Department, talc 8'! , 85 parts of sodium dodecylbenzenesulfonate, 2 parts of sodium dodecylbenzenesulfonate, and 2 parts of sodium ligninsulfonate were mixed together, about 20 parts of water was added, and the mixture was kneaded in a kneader, then granulated through a granulator, and then dried and sized. Active ingredient 3.1
Granules containing 5% are obtained.

(5) Effects of the invention and test examples As shown in the test results described below, the herbicide for paddy fields of the present invention is effective against compound A and weeds of the Cyperaceae family by adding and using compound B in combination with compound A. :
In addition to increasing the potency of compound A, the chemical damage to paddy rice grown by compound A can be significantly reduced.

Test Example 1 A 1Hc plastic pot was filled with paddy soil, and 10 rice plants (variety, first production) at the two-leaf stage were placed in each pot.
It was transplanted to the planting depth of individual 1 mark. The next day after transplantation, the hydrating powder prepared according to Example 1 was submerged with water to a depth of 3 cm, diluted with water to a predetermined dose, and dropped into rice field water. After that, the pot is 0 at noon.
It was grown in an artificial climate room at 5° C./8 hours at night (1 mouth, 0001 ux) for 16 hours at 5°C. Six days after the treatment, the height of the third leaf of rice was measured, 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 115,000a Wagnerbot, and the flooding method was set to 4 cm. Seeds of Novie, Konagi, Hyememisohagi, and Hotarui were sown, and tubers of Omodaka, Urikawa, Mizugayatsu, and Kurogwai were sown, and two-leaf stage rice (variety, first production) were planted, 6 individuals per pot (1cm?
1\3 individuals, 3c+n 3 individuals) were transplanted. After transplant 1
The granules prepared in Example 2 were applied to the water surface for one day. On the day after the treatment and the day after that, water leakage operations were performed at 3 to 7 ports. Observation and investigation were conducted 32 days after treatment according to the following criteria. In addition, regarding rice chemical damage, observational evaluation, plant height, and number of differences were measured, and plant height was expressed as the value of the ratio to the untreated plot. The results are shown in Table 2.

0: No effect, no drug damage ~ 10: Completely dead

Claims (1)

[Claims] 1,3-(4,6-dimethoxy-1,3,5-triazin-2-yl)-1-[2-(2-methoxyethoxy)
-Phenylsulfonyl]urea and 1-(α,α-dimethylbenzyl)-3-p-tolylurea as active ingredients.A herbicide for paddy rice with reduced phytotoxicity.