JPH0578528B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to 3',4'-dichloropropionanilide and general formula ():

[In the formula, B represents a hydrogen atom, a halogen atom, or a lower alkoxy group. R represents a lower alkyl group. ]
By blending it with more selected compounds, it brings about a synergistic effect that cannot be expected from individual applications.
The present invention relates to a mixed herbicide composition that is capable of killing many types of problem weeds with a low application rate. Many herbicides for paddy fields have been proposed and put into practical use, but most of them are so-called germination inhibitors. However, in actual gardens, even after treatment with germination inhibitors, the activity of the chemicals decreases and various weeds continue to germinate and grow, making it extremely difficult to effectively control weeds with germination inhibitors alone. be. The best form of control is to exterminate almost all paddy weeds at once after they have emerged. Several control methods have been considered as growth treatment agents for such weeds, but 3',4'-dichloropropionanilide (hereinafter referred to as compound A) is widely used worldwide and is extremely effective. It is valid. The reason for this is that this agent does not selectively harm rice plants through its foliage treatment, and has the property of killing all young broad-leaved weeds, including field weeds. Compound A
When applying this method, complete water removal is an absolute condition for the herbicidal effect to be achieved, and water entry must be avoided for at least 2 to 5 days after direct spraying on weed stems and leaves. Compound A is widely used worldwide due to the usage method described above, but in order to develop sufficient effects,
It is necessary to apply a large amount of active ingredient per unit area. Furthermore, Compound A does not have the so-called germination inhibitory effect and is used primarily as a foliar contact herbicide, and when treated in water while water is still standing on the rice field, the active ingredient is diluted and diffused, resulting in an even larger amount of the active ingredient. It requires a drop, and has characteristics that are extremely disadvantageous in practical terms. As a result of various studies to compensate for the above-mentioned drawbacks, the present inventors have found that the mixed composition of the present invention significantly improves the effect of foliage treatment, and furthermore, it has been found that the mixed composition of the present invention significantly improves the effect on foliage treatment, and that it can be used even when the rice field is subsequently flooded with water. Furthermore, they discovered that the efficacy against various weeds was significantly increased and completed the present invention. That is, the mixture of the present invention contains compound A
By mixing the compound represented by the above general formula (), a synergistic effect on various plants is exhibited that far exceeds the effect expected when the two are mixed. When applying the compound of the present invention, it can be applied to any of the following: flooding treatment, foliage treatment after submergence, direct sowing in dry fields, and foliage treatment during direct sowing cultivation in flooded fields, and a practically effective effect can be expected. Examples of compounds having the general formula () used as one of the active ingredients in the herbicide of the present invention are shown in Table 1 (compound numbers are referred to in the following description). The compound represented by the general formula () has an excellent herbicidal effect at a lower dose than conventional herbicides, and is highly safe for rice. In addition, it is highly effective not only against annual grass weeds and annual broad-leaved weeds, but also against perennial weeds, making it highly useful. On the other hand, Compound A is used in higher dosages than the compound represented by the general formula () against weeds and annual weeds, but as a result, the number of perennial weeds that are difficult to control with these agents has increased, and improvement is desired. There is. The present inventor conducted research to increase the herbicidal effect of the compound represented by the general formula (), and found that when compound A is added to the compound represented by the general formula (), the respective herbicidal effects are simply reduced. The present invention was completed by discovering that not only an additive effect but also a synergistic step grass effect appears. This synergistic effect is great, and the composition of the present invention can completely control all types of weeds, from annual weeds to perennial weeds, with a low dosage without causing any phytotoxicity to rice, making the present invention very useful. In particular, the synergistic herbicidal effect on barnyard grass is extremely useful. In addition, the herbicide composition of the present invention is effective even when treated before and after weed germination, and is effective in soil treatment,
High effects can be obtained by treating the leaves and soil as well. It is also useful for various grains other than rice, and can also be used to control various weeds in agricultural and horticultural fields such as fields and orchards, as well as in non-agricultural areas such as playgrounds, vacant lots, forest areas, tank yards, and railway edges. It can be applied and shows great economic effects in weed control. The composition according to the present invention generally contains 0.001 to 50 parts by weight of the compound represented by the general formula () per 1 part by weight of compound A, although it depends on the relative activity of each component.
It is preferably contained in an amount of 0.001 to 10 parts by weight. The amount of mixture to be applied will depend on a number of factors, such as the particular species of target plant to be inhibited, but in general amounts of 0.01 to 10 Kg/ha are usually adequate. Those skilled in the art can readily determine appropriate usage rates by routine, standardized tests without the need for extensive experimentation. Next, Table 1 shows representative examples of compounds represented by the general formula () in the present invention. The following compounds are included in the compounds represented by the general formula (), but the compounds represented by the general formula () are not limited to these.

[Table] The mixture of the present invention may be sprayed as a raw material itself, or may be mixed with a carrier and other adjuvants as necessary to form a formulation commonly used as a herbicide, such as powder, coarse powder, etc. It is prepared and used as fine granules, granules, wettable powders, emulsions, aqueous solutions, aqueous solutions, oil suspensions, etc. Individual active compounds often exhibit drawbacks in their herbicidal activity, but in such cases, the herbicidal activity of a combination of two active compounds is simply the sum of the respective activities of the two compounds ( When the activity is greater than the expected activity, this is called synergism. The expected activity of a particular combination of two herbicides can be calculated as follows. (See Colby SR Calculation of synergistic and antagonistic reactions of herbicide combinations, "Weed," Vol. 15, pp. 20-22, 1967) E = α + β - α · β / 100 α: Amount of herbicide A in a kg/ha Inhibition rate β when treated with herbicide B: Inhibition rate E when treated with herbicide B at an amount of bKg/ha: Herbicide A at AKg/ha, herbicide B at bKg/ha
In other words, if the actual inhibition rate is greater than the above calculation, it can be said that the combined activity exhibits a synergistic effect. When using the mixture of active ingredient compounds of the present invention as a herbicide, it is generally carried out in a suitable carrier, such as a fixed carrier such as clay, talc, bentonite, diatomaceous earth, or water, alcohols (methanol, ethanol, etc.). etc.), aromatic hydrocarbons,
It can be applied in combination with liquid carriers such as ethers, ketones, esters (ethyl acetate, etc.), acid amides (dimethylformamide, etc.), and if desired, emulsifiers, dispersants, suspending agents, penetrants, By adding spreading agents, stabilizers, etc., emulsions, hydrating agents, powders,
It can be put to practical use in any dosage form such as granules. In addition, if necessary, other types of herbicides, various insecticides, fungicides, synergists, etc. may be mixed and applied at the time of formulation or spraying. Next, specific formulation examples of formulations using the compounds of the present invention will be shown. Parts indicate parts by weight. However, the formulation examples of the present invention are not limited to these only. Formulation example 1 Granule compound No. 17 ...0.1 part Compound A ...25 parts Bentonite ...34.9 parts Talc ...40 parts After uniformly mixing and pulverizing the above, add a small amount of water and mix and knead. Then, it is granulated using an extrusion type granulator and dried to form granules. Formulation example 2 Granule compound No. 4 ...0.15 parts Compound A ...10 parts Bentonite ...49.85 parts Talc ...40 parts After uniformly mixing and pulverizing the above, add a small amount of water and mix and knead. The product is granulated using an extrusion granulator and dried to form granules. Formulation example 3 Granule Compound No. 8...0.4 parts Compound A...40 parts Siegrite A (kaolin clay: trade name of Sieglite Industries Co., Ltd.)...55.6 parts Solpol 5039 (nonionic surfactant and Mixture with anionic surfactant: Toho Chemical Co., Ltd. (trade name)
...2 parts Carplex (anti-caking agent) (white carbon: brand name of Shionogi & Co., Ltd.) ...2 parts The above are mixed and ground uniformly to make a wettable powder. Formulation example 4 Wettable powder Compound No. 12...0.8 parts Compound A...25 parts Siegrite A (kaolin clay: trade name of Sieglite Industries Co., Ltd.)...70.2 parts Solpol 5039 (nonionic surfactant) and anionic surfactant: Toho Chemical Co., Ltd. (trade name)
...2 parts Carplex (anti-caking agent) (white carbon: brand name of Shionogi & Co., Ltd.) ...2 parts The above are mixed and ground uniformly to make a wettable powder. Formulation example 5 Emulsion compound No. 8...0.5 parts Compound A...25 parts Xylene...55 parts Dimethylformamide...19.8 parts Solpol 2680 (mixture of nonionic surfactant and anionic surfactant: Toho Chemical) Co., Ltd. product name)
... 5 parts or more are mixed uniformly to form an emulsion. Next, the effects of the herbicide composition of the present invention will be specifically explained by giving test examples. Test Example 1 Weeding effect test under flooded conditions After putting Okizuke soil in a 1/5000 are Wagner pot, water was added and mixed to create a flooded condition with a water depth of 0.5 cm. Seeds of Japanese millet, broad-leaved weeds (Prunus japonica, Azena, and Kikashigusa), and firefly were mixedly sown in the above pots, and furthermore, tubers of Japanese snail, tubers of Cyperus japonica, and tubers of Japanese cypress were placed in the beds. Furthermore, rice seedlings at the 2.5 leaf stage were transplanted, the pots were placed in a greenhouse at 20 to 25℃, and the plants were grown.
At the leaf stage, a diluted drug solution was applied to the foliage and soil surface using a spray gun in a predetermined amount. Three days later, it was flooded to a depth of 2 cm. Three weeks after the chemical solution treatment, the herbicidal effect on various weeds was investigated according to the following criteria. The results are shown in Table 2. Criterion 5...Weed killing rate of 90% or more (almost complete death) 4... 70-90% 3... 40-70% 2... 20-40% 1... 5-20% 0... 〃 5% or less (almost no effect) However, the above weed killing rate was determined by the following formula by measuring the weight of above-ground plants in the chemically treated area and the weight of above-ground plants in the non-treated area. Weed killing rate (%) = (1 - above-ground grass weight in treated area / above-ground grass weight in non-treated area) × 100

【table】

[Table] Test Example 2 A polyethylene pot with an inner diameter of 8 cm was filled with paddy soil, and Japanese millet was grown in the field.
At the leaf stage, a predetermined amount of each drug formulated into a wettable powder was applied to the leaves and soil. The pots were kept at a temperature of 25 to 30°C for controlled growth, and on the third day after treatment, the pots were filled with water to a depth of 2 cm. Thirty days after the treatment, the weight of above-ground grass of the remaining barnyard grass and the weight of above-ground grass in the untreated area were measured, and the herbicidal rate (%) was calculated using the following formula. The results are shown in Table 3. Weed killing rate (%) = (1 - above-ground grass weight in treated area / above-ground grass weight in untreated area) × 100 In Table 3, the E value is the expected suppression rate calculated from Colby's formula in the previous period. Show value.

【table】

【table】

Claims (1)

[Claims] 1 3',4'-dichloropropionanilide and the general formula (): [In the formula, B represents a hydrogen atom, a halogen atom or a lower alkoxy group. R represents a lower alkyl group. ]
A herbicidal composition containing a compound represented by the following as an active ingredient.