A herbicidal composition containing pretilachlor and clomazone, emulsifiable concentrate preparation and application thereof

Abstract

The present invention belongs to the field of pesticides, and specifically relates to a herbicidal composition comprising pretilachlor and clomazone and an application thereof, wherein the mass ratio of pretilachlor and clomazone is (2-3):1; wherein the mass ratio of pretilachlor and clomazone is 3:1, and the composition has a synergistic effect on Dactylopius vaginalis and Leptochloa chinensis. The emulsifiable concentrate prepared by the present invention has a small average particle size and a minimum surface tension, which is conducive to the exertion of drug efficacy and can effectively prevent and kill broad-leaved weeds and grass weeds in rice fields.

Description

Technical Field

[0001] The invention belongs to the field of pesticide preparations, and particularly relates to a herbicidal composition comprising pretilachlor and clomazone, an emulsifiable concentrate preparation and applications thereof. Background Art

[0002] Pretilachlor is a selective pre-emergence treatment agent that can be absorbed by the plant hypocotyl, mesocotyl and coleoptile, and slightly absorbed by the roots. It directly interferes with protein synthesis in weeds and has an indirect effect on photosynthesis and respiration. The young weeds of the affected weeds are twisted, the primary leaves are difficult to extend, the leaves turn dark green, and growth stops until they die.

[0003] Clomazone is a selective pre-emergence herbicide that can be absorbed by roots and young shoots and transmitted upward to various parts of weeds through transpiration, thereby controlling the biosynthesis of chlorophyll in weeds. Although they can sprout and emerge from the soil, they have no pigment, causing them to die in a short period of time. It can effectively prevent and control annual grass and broad-leaved weeds, such as barnyard grass, foxtail grass, crabgrass, goosegrass, nightshade, Xanthium sibiricum, Elsholtzia ciliata, water spinach needle, wild watermelon seedling, quinoa, Polygonum, Amaranth, Purslane, Bidens pilosa, wolf grass, Commelina communis and other weeds.

[0004] In the existing patent document CN201210499174.8, a lotus root field herbicide composition containing pretilachlor and clomazone is disclosed. The composition contains two active ingredients, and is prepared into a preparation with the addition of pesticide adjuvants and carriers. The two active ingredients are pretilachlor and clomazone, and the ratio of pretilachlor to clomazone in the whole preparation is 1 to 50:1; however, the document does not record whether the herbicide composition has a synergistic effect. No research has been conducted on the combined effect of pretilachlor and clomazone in the prior art.

[0005] Emulsifiable concentrates have the characteristics of high content of active ingredients, good stability, easy use, good control effect, simple processing technology, and low equipment requirements. These advantages make emulsifiable concentrates occupy a place in pesticide formulations. Developing emulsifiable concentrate preparations with excellent control effects is also one of the paths for green development of agriculture. Summary of the invention

[0006] The object of the present invention is to provide a herbicidal composition comprising pretilachlor and clomazone with excellent control effect, an emulsifiable concentrate formulation and its application. The specific technical scheme is: A herbicidal composition comprising pretilachlor and clomazone, wherein the mass ratio of pretilachlor to clomazone is (2-3):1. Preferably, the mass ratio of pretilachlor to clomazone is 3:1.

[0007] The herbicidal composition is in the form of an emulsifiable concentrate, comprising the following ingredients in percentage by weight: 30% pretilachlor, 10% isothiocarb, 5-10% emulsifier, 0.2-0.8% azone, and 100% solvent; the emulsifier is composed of Nongru 500#, Atlox 4912 and Ethylan 1008; and the solvent is soybean oil.

[0008] The preferred emulsifiable concentrate formulation contains the following ingredients in percentage by weight: 30% pretilachlor, 10% isothiocyanate, 3% Nongru 500#, 2% Atlox 4912, 2% Ethylan 1008, 0.5% Azone, and the solvent soybean oil makes up 100%.

[0009] The herbicidal composition is used for preventing and controlling weeds in crop fields, wherein the weeds are gramineous weeds and broadleaf weeds; and the crop is rice.

[0010] By adopting the above technical solution, the present invention has the following beneficial effects: The present invention screens out a mass ratio of pretilachlor and clomazone of 3:1 to achieve a synergistic effect on Daffodil and Leptochloa chinensis. The emulsifiable concentrate prepared by the present invention has a small average particle size and minimal surface tension, which is conducive to the exertion of drug efficacy and can effectively prevent broad-leaved weeds and grass weeds in rice fields. DETAILED DESCRIPTION

[0011] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present invention.

[0012] The present invention is further explained below in conjunction with specific implementation modes.

[0013] Example 1 Indoor joint action test of pretilachlor and clomazone against weeds Experimental materials and methods Weeds: Duck tongue grass, Leptochloa chinensis. The above weed seeds were collected from the field and stored indoors for future use.

[0014] Tested drugs: Pretilachlor technical, Isopropylamine technical Test method: The test soil was quantitatively filled to 4 / 5 of the pot, and the soil moisture was maintained by bottom seepage. The pretreated weed seeds were planted in the pots, and the soil was sprayed 24 hours after sowing. Each treatment was repeated 4 times. After 21 days of treatment, the aboveground part of the plant was weighed and the fresh weight inhibition rate was calculated.

[0015] Fresh weight inhibition rate / %=[(fresh weight of surviving weeds in the control area - fresh weight of surviving weeds in the treatment area) / fresh weight of surviving weeds in the control area]×100.

[0016] Combined action: The theoretical fresh weight inhibition rate of each treatment combination was calculated by Gowing method (E0=X+YX*Y / 100), and then compared with the measured inhibition rate (E) to evaluate the type of combined action of the two on weeds. When the E-E0 value is greater than 10%, it is a synergistic effect; when it is less than -10%, it is an antagonistic effect; and between -10% and 10%, it is an additive effect.

[0017] Test results: As can be seen from Table 1, the combination of pretilachlor and clomazone exhibits a synergistic and additive effect on Duckweed; when the mass ratio of pretilachlor to clomazone is 15:5, the combination Duckweed exhibits a synergistic effect. As can be seen from Table 2, pretilachlor and clomazone exhibit a synergistic and additive effect on Leptochloa chinensis; when the mass ratio of pretilachlor to clomazone is 15:5 and 10:5, the combination exhibits a synergistic effect on Leptochloa chinensis. Therefore, the present invention has screened out a ratio of pretilachlor and clomazone that has a synergistic effect on both the weeds Duckweed and Leptochloa chinensis, with a mass ratio of 15:5. Preparation research was carried out based on the above synergistic ratio.

[0018] Table 1 Indoor potted test of the combination of pretilachlor and isothiocyanate with Dalbergia vaginalis

[0019] Table 2 Determination of the effect of pretilachlor and clomazone on the indoor potted plants of Leptochloa chinensis

[0020] Example 2 40% Pretilachlor·Isopropylamine EC Preparation Emulsion formula EC1: contains the following components by weight percentage: 30% pretilachlor, 10% isothiocyanate, 3% agricultural milk 500#, 2% Atlox 4912, 2% Ethylan1008, 0.5% azone, and the solvent soybean oil makes up 100%; EC2: contains the following components by weight percentage: 30% pretilachlor, 10% isothiocyanate, 3% Nongru 500#, 4% Atlox 4912, 0.5% azone, and the solvent soybean oil makes up 100%; EC3: contains the following components in percentage by weight: 30% pretilachlor, 10% isothiocarb, 2% Atlox 4912, 5% Ethylan1008, 0.5% azone, and the solvent soybean oil makes up 100%; EC4: contains the following components in percentage by weight: 30% pretilachlor, 10% isothiocyanate, 3% Nongru 500#, 4% Ethylan 1008, 0.5% azone, and the solvent soybean oil makes up 100%; EC5: contains the following components in percentage by weight: 30% pretilachlor, 10% isothiocyanate, 3% Nongru 500#, 2% Atlox 4912, 2% Ethylan1008, 0.5% azone, and the solvent methyl oleate makes up 100%; Preparation method: Dissolve the original drug in a solvent, add an emulsifier, mix and dissolve under stirring to make a homogeneous transparent liquid. Index test method Emulsion particle size determination: The particle size of 1500 dilutions of chlorpyrifos EC in different solvents was measured by laser particle size analyzer. Each treatment was repeated 4 times.

[0021] Emulsion surface tension measurement: The surface tension of the solution to be tested was measured using a BYZ-1 fully automatic surface tension tester. The instrument was zeroed before use. The platinum sheet was rinsed with deionized water and anhydrous ethanol three times, respectively, and heated with an alcohol lamp until it turned red. When it cooled, the platinum sheet was hung on a hook and then set to zero. 15-20 mL of the solution was added to the plastic dish on the loading table, and each treatment was repeated 4 times.

[0022] Test results: Table 3: Effects of different emulsifiers on the physical and chemical properties of chlorpyrifos EC

[0023] As shown in Table 3, the emulsifier combination and the choice of solvent will have a significant impact on the particle size and surface tension of the EC. EC1 has a small particle size and low surface tension, which helps to exert the efficacy of the drug.

[0024] Example 3: Weed control effect of 40% pretilachlor and clomazone EC on rice fields Test agent: EC1-5 in Example 2; Test method: The plot area is 25m2, repeated three times, and randomly arranged in blocks. Soil spray treatment, 21 days after treatment, the above-ground part of the plant is weighed to calculate the fresh weight inhibition rate.

[0025] Fresh weight inhibition rate / %=[(fresh weight of surviving weeds in the control area - fresh weight of surviving weeds in the treatment area) / fresh weight of surviving weeds in the control area]×100.

[0026] Test results: As shown in Table 4, the emulsifiable concentrates prepared in the present invention have excellent control effects on gramineous weeds and broadleaf weeds in rice fields, among which the EC1 preparation has excellent control effect, which is significantly different from other treatments.

[0027] Table 4: Test on the control effect of 40% pretilachlor·isothiazolin EC on weeds in rice fields

[0028] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit it.

Claims

1. A herbicidal composition comprising pretilachlor and clomazone, characterized in that: The mass ratio of pretilachlor and isothiocarb is (2-3):

1.

2. The herbicidal composition according to claim 1, characterized in that The mass ratio of pretilachlor and isothiocarb is 3:

1.

3. The herbicidal composition according to claim 2, characterized in that The dosage form is emulsifiable concentrate.

4. The herbicidal composition according to claim 3, characterized in that The emulsifiable concentrate preparation contains the following ingredients in percentage by weight: 30% pretilachlor, 10% isothiocarb, 5-10% emulsifier, 0.2-0.8% azone, and 100% solvent; the emulsifier is composed of Nongru 500#, Atlox 4912 and Ethylan 1008; and the solvent is soybean oil.

5. The herbicidal composition according to claim 4, characterized in that The emulsifiable concentrate preparation contains the following ingredients in percentage by weight: 30% pretilachlor, 10% isothiocarb, 3% Nongru 500#, 2% Atlox 4912, 2% Ethylan 1008, 0.5% Azone, and the solvent soybean oil makes up 100%.

6. Use of the herbicidal composition according to any one of claims 1 to 5 for controlling weeds in crop fields.

7. The use according to claim 6, characterized in that The weeds are grass weeds and broadleaf weeds; and the crop is rice.

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