Weeding composition suitable for sugarcane field and corn field before and after germination and application thereof

文档序号：590990 发布日期：2021-05-28 浏览：10次中文

阅读说明：本技术 甘蔗田和玉米地芽前芽后均适用的除草组合物及其应用 (Weeding composition suitable for sugarcane field and corn field before and after germination and application thereof ) 是由易芬远卓民权韦茂春王超余青云杨淑兰覃沛卢秋影方冬林于 2021-01-29 设计创作，主要内容包括：本发明的目的是提供一种甘蔗田和玉米地芽前芽后均适用的除草组合物,由以下重量份的活性成分组成：噻酮磺隆1～40份、烯草胺1～60份、吡氯黄隆1～50份。本发明的除草组合物可以有效防除一年生禾本科杂草、莎草科杂草和阔叶杂草,对玉米、甘蔗生长安全,且该组合物性能稳定、高效。(The invention aims to provide a weeding composition suitable for sugarcane fields and corn fields before and after sprouting, which comprises the following active ingredients in parts by weight: 1-40 parts of thiencarbazone-methyl, 1-60 parts of pethoxamid and 1-50 parts of pyrrochlor-methyl. The weeding composition can effectively prevent and remove annual gramineous weeds, cyperaceae weeds and broadleaf weeds, is safe for the growth of corns and sugarcanes, and has stable and efficient performance.)

1. A weeding composition suitable for sugarcane fields and corn fields before and after sprouting is characterized by comprising the following active ingredients in parts by weight: 1-40 parts of thiencarbazone-methyl, 1-60 parts of pethoxamid and 1-50 parts of pyrrochlor-methyl.

2. A herbicidal composition according to claim 1, characterized by consisting of the following active ingredients in parts by weight: 1.5-4 parts of thiencarbazone-methyl, 40-60 parts of pethoxamid and 2-6 parts of pyrrochlor-methyl.

3. A herbicide prepared from the herbicidal composition of claim 1 or 2, which comprises the herbicidal composition and an agriculturally pharmaceutically acceptable adjuvant.

4. A herbicide formulation as claimed in claim 3, characterized in that:

the herbicide is a liquid preparation and is prepared by the weeding composition, a solvent and auxiliary materials;

the auxiliary materials are one or more of emulsifier, dispersant, thickener, stabilizer, defoamer, antifreeze and pH regulator.

5. A herbicide formulation, as claimed in claim 4, characterized in that:

the solvent is one or more of xylene, toluene, biodiesel, diesel oil, methanol, ethanol, n-butanol, isopropanol, acetone, rosin-based vegetable oil, solvent oil, dimethylformamide, dimethyl sulfoxide, water, etc.;

the emulsifier is one or more of calcium dodecyl benzene sulfonate, fatty acid polyoxyethylene ether, alkylphenol polyoxyethylene sulfosuccinate, styrylphenol polyoxyethylene ether, nonylphenol polyoxyethylene ether, castor oil polyoxyethylene ether, fatty acid polyoxyethylene ester and polyoxyethylene fatty alcohol ether;

the dispersing agent is one or more of methyl cellulose, polycarboxylate, methylene dinaphthalene sodium sulfonate, lignosulfonate, polyoxyethylene ether carboxylate, alkylphenol polyoxyethylene, naphthalene sulfonic formaldehyde condensate sodium salt, polyoxyethylene ether sulfonate, fatty acid ester sulfate and glycerol fatty acid polyoxyethylene ether;

the thickening agent is one or more of polyvinyl alcohol, xanthan gum, carboxyethyl cellulose, polyvinyl acetate, carboxymethyl cellulose, methyl cellulose, magnesium aluminum silicate and polyvinyl alcohol;

the stabilizer is one of sodium citrate and resorcinol;

the defoaming agent is one of polyglycerol, organic silicon, polyoxypropylene glycerol ether and phenethyl alcohol oleate;

the antifreezing agent is one or more of ethylene glycol, polyethylene glycol, glycerol or sorbitol;

the pH regulator is one of triethanolamine, citric acid, sodium acetate, sodium hydroxide, potassium hydroxide and ammonia water.

6. A herbicide formulation, as claimed in claim 3,

the herbicide is a solid preparation and is prepared by matching the weeding composition and auxiliary materials;

the auxiliary material is one or the mixture of two of inert filler, wetting agent, dispersant and disintegrant.

7. The herbicide of claim 6,

the preparation method of the solid preparation comprises the following steps:

mixing the components of the weeding composition with inert fillers, crushing into fine powder, adding a wetting agent, a dispersing agent and a disintegrating agent, and uniformly mixing to prepare powder;

or adding binder to the powder to further prepare into granule.

8. The herbicide of claim 6, wherein:

the inert filler is one or more of diatomite, talcum powder, kaolin, clay, bentonite, attapulgite, white carbon black, starch and light calcium carbonate;

the wetting agent is one or more of sodium dodecyl sulfate, sodium lignosulfonate, sodium methylene dinaphthalene sulfonate, sodium lauryl ether sulfate, sodium fatty alcohol polyoxyethylene ether sulfonate, calcium dodecylbenzene sulfonate, calcium lignosulfonate, nekal BX, wetting penetrant F, saponin powder, soapberry powder and polyether ammonium sulfonate;

the disintegrating agent is one or more of sodium bicarbonate, magnesium chloride, aluminum chloride, sodium chloride, ammonium sulfate and urea;

the binder is one of vegetable gum, animal gum, rosin and modified substances thereof, cellulose and modified substances thereof, paraffin and modified substances thereof, starch and modified substances thereof, sulfur, asphalt and gypsum.

9. Use of a herbicidal composition according to claim 1 or 2 or a herbicide according to any one of claims 3 to 7 for combating annual grassy weeds, sedge weeds and broadleaf weeds.

10. The use of claim 9, wherein: the annual grassy weed, Cyperaceae weed and broadleaf weed are herba Clematidis Intricatae, herba Elephantopi scaberis, herba Stachydis Japonicae, herba Setariae viridis, rhizoma Cyperi, herba Clerodendri Japonici, Arachis hypogaea, semen Setariae, herba Portulacae, herba Alternantherae sessilis, semen Celosiae or herba Ageratae.

Technical Field

The invention relates to the technical field of pesticides, and particularly relates to a herbicide composition suitable for sugarcane fields and corn fields before and after germination, and a preparation method and application thereof.

Background

Corn is an important food crop and feed crop and is the crop with the highest overall yield all over the world, and the planting area and the overall yield are next to those of rice and wheat. At present, the seeding area of China is about 3 hundred million mu, and the seeding area is the third place in grain crops, so that the method has important significance on grain safety of China. The main dominant weeds in the corn field in south China include crab grass, eleusine indica, barnyard grass, ageratum conyzoides, cyperus rotundus, cleavers, setaria japonica, purslane, alternanthera philoxeroides and feather cockscomb, wherein the eleusine indica, the ageratum conyzoides and the cyperus rotundus are difficult-to-control weeds.

Sugarcane is a main raw material of the sugar industry of China, ethanol can be extracted to serve as an energy substitute, China is one of the largest sugarcane planting countries in the world, and the planting range is distributed in most regions in the south of the Yangtze river. The weeds in the sugarcane field are hundreds of types, common annual weeds comprise large crabgrass, green bristlegrass, goosegrass herb, ageratum conyzoides, stephania japonica, wild oats, teff grass, barnyard grass, goosegrass herb and the like, and perennial weeds comprise bermudagrass, bromus bifida, cyperus rotundus, sedum spiniferum, erianum herb, reed, cogongrass and the like.

The labor amount of people is reduced to a certain extent by the herbicide, in recent years, the herbicide is used in large areas in sugarcane fields and corn fields in China, however, the phenomenon of poisoning of the herbicide to different degrees appears every year, and safe, environment-friendly and efficient herbicide products for sugarcane and corn are urgently needed at present.

Thiazolone sulforon belongs to sulfonylaminocarbonyl triazolinone (SCT) herbicides, is an acetolactate synthase (ALS) inhibitor, has systemic property, can be absorbed by plant roots and leaves, and can provide stable weeding effect through a triple weeding mechanism of soil closure, early stem and leaf after seedling and water activation. The thiencarbazone-methyl can be developed into herbicide before sowing, after sowing and before or after seedling in corn field. Thiencarbazone-methyl, common english name, CA accession number: 317815-83-1, chemical name: methyl 4- [ (4, 5-dihydro-3-methoxy-4-methyl-5-oxo-1H-1, 2, 4-triazol-1-yl) carbonyl sulfonamide]-5-methylthiophene-3-carboxylate of formula: c₁₂H₁₄N₄O₇S₂Molecular weight: 390.4, having the formula:

the dimethenamid belongs to a chloroacetamide systemic herbicide, inhibits cell division by inhibiting synthesis of long-chain fatty acid, and finally kills weeds. The herbicide is used for preventing and killing gramineous weeds such as barnyard grass, crabgrass and green bristlegrass and broadleaf weeds such as amaranthus retroflexus and chenopodium album in corn and soybean fields in the early stage before or after germination. Pethoxamid, common english name, CA accession number: 106700-29-2, chemical name: 2-chloro-N- (2-ethoxyethyl) -N- (2-methyl-1-phenylprop-1-enyl) acetamide of formula: c₁₆H₂₂ClNO₂Molecular weight: 295.8, having the formula:

pyrochlorosulfuron, also known as halosulfuron-methyl, acts on acetolactate synthase (ALS) to inhibit desmosine and leucine of branched-chain amino acidBiosynthesis of acid, isoleucine, and thereby inhibiting cell division and plant growth. The herbicide is mainly used for controlling broadleaf weeds and cyperaceae weeds, such as: caulis et folium Gaultheriae Yunnanensis, herba Xanthii, herba Daturae, herba Ambrosia artemisii, herba Amaranthi Tricoloris, seedling of Citrullus lanatus, herba Polygoni Hydropiperis, herba Portulacae, herba Solani Nigri, semen Cassiae, and morning glory. Common name of pyranesulfone and chlorsulfuron in English: halosulfuron-methyl, CA accession number: 100784-20-1, chemical name: 3- (4, 6-dimethoxypyrimidin-2-yl) -1- (1-methyl-3-chloro-4-methoxyformylpyrazol-5-yl) sulfonylurea of formula: c₁₃H₁₅ClN₆O₇S, molecular weight: 434.81, having the formula:

at present, three herbicides with different action mechanisms and weed control spectra are not reported to be used together.

Disclosure of Invention

The invention aims to provide a weeding composition suitable for sugarcane fields and corn pre-emergence and post-emergence, which can effectively prevent and remove annual gramineous weeds, cyperaceae weeds and broadleaf weeds, is safe to corn and sugarcane growth, and has stable and efficient performance.

A weeding composition suitable for sugarcane fields and corn fields before and after sprouting comprises the following active ingredients in parts by weight: 1-40 parts of thiencarbazone-methyl, 1-60 parts of pethoxamid and 1-50 parts of pyrrochlor-methyl.

Preferably, the weeding composition consists of the following active ingredients in parts by weight: 1.5-4 parts of thiencarbazone-methyl, 40-60 parts of pethoxamid and 2-6 parts of pyrrochlor-methyl.

The invention provides a herbicide prepared from the weeding composition, which consists of the weeding composition and an agriculturally and pharmaceutically acceptable auxiliary.

Further, the invention provides a technical scheme when the herbicide is a liquid preparation, and the herbicide is prepared by matching the weeding composition, a solvent and auxiliary materials;

the auxiliary materials are one or more of emulsifier, dispersant, thickener, stabilizer, defoamer, antifreeze and pH regulator.

Furthermore, the solvent is one or more of xylene, toluene, biodiesel, diesel oil, methanol, ethanol, n-butanol, isopropanol, acetone, rosin-based vegetable oil, solvent oil, dimethylformamide, dimethyl sulfoxide, water and the like;

the stabilizer is one of sodium citrate and resorcinol;

the defoaming agent is one of polyglycerol, organic silicon, polyoxypropylene glycerol ether and phenethyl alcohol oleate;

the antifreezing agent is one or more of ethylene glycol, polyethylene glycol, glycerol or sorbitol;

the pH regulator is one of triethanolamine, citric acid, sodium acetate, sodium hydroxide, potassium hydroxide and ammonia water.

Furthermore, the invention provides a technical scheme that the herbicide is a solid preparation, and the herbicide is prepared by matching the weeding composition and auxiliary materials;

the auxiliary material is one or the mixture of two of inert filler, wetting agent, dispersant and disintegrant.

Further, the preparation method of the solid preparation comprises the following steps:

or adding binder to the powder to further prepare into granule.

Furthermore, the inert filler is one or a mixture of more than one of diatomite, talcum powder, kaolin, clay, bentonite, attapulgite, white carbon black, starch and light calcium carbonate;

the disintegrating agent is one or more of sodium bicarbonate, magnesium chloride, aluminum chloride, sodium chloride, ammonium sulfate and urea;

The invention further provides the application of the weeding composition or the herbicide in preventing and killing annual gramineous weeds, cyperaceae weeds and broadleaf weeds.

Further, the annual grassy weed, cyperaceae weed, and broadleaf weed are Tephrosia purpurea, crab grass, barnyard grass, green bristlegrass, cyperus rotundus, cleomiasis versicolor, Arachis hypogaea, setaria italica, purslane, alternanthera philoxeroides, feather cockscomb, or ageratum.

With the growing area of the sugarcane high-sugar variety being larger and larger, the herbicide safe to the sugarcane high-sugar variety and the corn is less, the occurrence amount of weeds such as bermuda grass, cyperus rotundus, aged digitaria sanguinalis, eleusine indica, ageratum conyzoides and erigeron breviscapus in the sugarcane field and the corn field is gradually increased, and aiming at the problems, the invention has the following characteristic effects:

(1) the composition of the thiencarbazone-methyl, the dimethenamid and the pyrrochlor has high efficiency on conventional weeds, and particularly has outstanding effect on weeds which are difficult to remove in corn fields and sugarcane fields, such as bermuda grass, cyperus rotundus, aged large crabgrass, eleusine indica, ageratum, horseweed herb and the like.

(2) The composition of the thiencarbazone-methyl, the dimethenamid and the pyrrochlorsulfuron is safe to sugarcane high-sugar varieties and corn sensitive varieties, has low residue and low toxicity to people and livestock, has less dosage compared with other sugarcane field herbicides and corn herbicides, can be used as a pre-emergence herbicide and a post-emergence herbicide, and has great economic and social benefits when being popularized and applied.

(3) The herbicide composition has the advantages of obvious synergistic effect in a certain proportioning range, obviously improved control effect compared with a single agent, enlarged weed control spectrum, reduced dosage, avoidance of increase of agricultural cost and waste of the herbicide caused by blind increase of the dosage of the herbicide, and environmental protection.

(4) The action mechanisms of the thiencarbazone-methyl, the pethoxamid and the pyrrochlor are different, the defect that resistance is easy to generate after long-term single use can be overcome, and the weeds in the sugarcane field and the corn field do not generate resistance to the thiencarbazone-methyl and the pethoxamid at present, so that the service life of the herbicide is prolonged, and the herbicide has important significance for comprehensive treatment of the resistance of the weeds.

In conclusion, the invention mixes three herbicides of thiencarbazone-methyl, alachlor and pyrrochlor with different action mechanisms and herbicide controlling spectra according to a certain proportion to achieve the purposes of increasing action target sites and expanding the herbicide controlling spectra, and the final composition can well prevent and treat annual and perennial weeds such as large crabgrass, goosegrass, barnyard grass, ageratum, cyperus rotundus, stinky weed, wild peanuts, setaria italica, purslane, allium sativum, celosia, green bristlegrass, moleplant, wild oats, teff, barnyard grass, pigweed, bermudagrass, bromus bisporus, spiny sedge, horseweed, reed, cogongrass and the like. The herbicide composition is safe to common varieties and high-sugar varieties of sugarcane and corn, is applied to weeding in sugarcane fields and corn fields, and has the characteristics of good weeding effect, high efficiency, convenience in use, low toxicity to people and livestock and environmental friendliness.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more concise and clear, the present invention is described with reference to the following specific examples, but the present invention is by no means limited to these examples. The following are only preferred embodiments of the present invention, which are intended to illustrate the present invention and should not be construed as limiting the scope of the present invention. It should be understood that any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Example 1 (indoor toxicity test of compounding Thifensulfuron-methyl, alachlor and sulfonylurea herbicides on Sphallerocarpus gracilis)

Indoor bioassay is carried out to determine the synergistic condition of the compound of the thiencarbazone-methyl, the alachlor and the sulfonylurea herbicide, wherein the sulfonylurea herbicide is pyrrochlor-methyl; chlorimuron-ethyl; ③ bensulfuron-methyl; nicosulfuron (Nicosulfuron); rimsulfuron (Rimsulfuron). The method comprises the steps of selecting soil without herbicide application and having a pH value of 6.5 by taking alligator Alternanthera (Mart.) as a raw test object, drying and sieving the soil, and then filling the soil into a plastic flowerpot (with a tray) with a diameter of 25cm and a depth of 30 cm. Adopting stem leaf spraying method, referring to NY/T1155.4-2006 indoor bioassay test criteria herbicide part 4: activity assay test the stem leaf spray method was used for the experiments, which were repeated 4 times for each treatment, and 15 plants were repeated for each repetition, with no agent treatment being used as a blank control. Statistical data analysis methods herbicide part 7 of the indoor bioassay test criteria for pesticides referenced NY/T1155.7-2006: the Colby method in the combined action determination of mixing is used for calculating each mixingCombined theoretical survival rate of weeds E₀Value, actual weed survival E value and difference between theoretical and actual (E-E)₀)。

Theoretical weed survival rate of the mixture E₀Calculating according to the formula (1):

in the formula:

survival rate of a-thiencarbazone-methyl on target weeds at a dose of single use;

survival rate of B-pethoxamid against target weeds when used alone at a certain dose;

survival rate of C-sulfonylurea herbicide to target weed when used alone at a certain dose;

n-survival of weeds with herbicide N;

n-is the variety number of the mixed herbicide;

E₀the theoretical value of the survival rate of the target weeds when the three agents of the thiencarbazone-methyl, the pethoxamid and the sulfonylurea herbicide are mixed;

e is a measured value of the control on the survival rate of the target weeds when three medicaments of the thiencarbazone-methyl, the pethoxamid and the sulfonylurea herbicide are mixed.

Three judgment standards of effect shown after the herbicide is mixed: e₀-E>10% of the composition is synergistic effect; e₀-E<-10% is antagonism; e₀An E value of. + -. 10% is additive effect.

The results are shown in Table 1.

TABLE 1 indoor toxicity assay of Alternanthera philoxeroides compounded by thiencarbazone (A), dimethenamid (B) and sulfonylurea herbicide (C)

From the table 1, the combination of the thioncarbazone-methyl, the pethoxamid and the sulfonylurea herbicide shows that the cotoxicity coefficient of the mixed herbicide is more than-10 percent compared with that of the alligator alternanthera, and no antagonism occurs, which indicates that the combination of the thioncarbazone-methyl, the pethoxamid and the sulfonylurea herbicide is feasible. The survival rate of the individual combinations of thiencarbazone-methyl, pethoxamid and pyrrochloruron in comparison with the other combinations is different (E)₀-E) is higher than other treatments, which shows that the synergistic effect of the combination of thiencarbazone-methyl, pethoxamid and pyrrochlor-methyl is obviously higher than that of other combinations.

Example 2 (indoor toxicity test of compounding Thidiazuron, pyraclonuron and chloroacetamide herbicides on Spanish crassifolium)

On the basis of the example 1, the synergistic condition of the compound of the thiencarbazone-methyl, the pyrrochlor-methyl and the chloracetamide herbicides is determined through indoor bioassay, wherein the variety of the chloracetamide herbicides is (I) diniconazole; ② Metazachlor (Metazachlor); ③ Dimethenamid; benomyl (Carbetamide); diflufenican (Diflufenican). Likewise, the test method and the synergistic effect evaluation were the same as in example 1 with alternanthera philoxeroides as the bioassay target, and the results are shown in table 2.

TABLE 2 indoor toxicity assay of Alternanthera philoxeroides compounded by Thiazosulfuron (A), chloroacetamide herbicide (B) and picolyl (C)

The table shows that the co-toxicity coefficient of the mixture is more than-10% compared with that of the alligator alternanthera, and no antagonism occurs, which indicates that the compounding of the thiencarbazone-methyl, the pyrrochlor-methyl and the chloracetamide herbicides is feasible. Compared with other combinations, the compound mixture of the thiencarbazone-methyl, the pyrrochlor-methyl and the dimethomorph-sodium is prepared from the following raw materials of the crassipes latifoliaSurvival rate difference of Zicao (E)₀-E) is significantly higher than other treatments, indicating that the synergistic effect of the combination of thiencarbazone-methyl, pyrrochlor and pethoxamid is significantly higher than that of other combinations.

Example 3 (indoor toxicity assay of Triazolinone herbicides, Enalachlor and Biclosulfuron for Alternanthera philoxeroides)

On the basis of the examples 1 and 2, the synergistic condition of the compounded triazolinone herbicide, the dimethenamid and the pyrrochlorsulfuron is determined through indoor bioassay, wherein the triazolinone herbicide is named as the thiencarbazone-methyl; (ii) Amicarbazone (amicabazone); ③ Sulfentrazone (Sulfenpyrazone); carfentrazone-ethyl ester (Carfentrazone-ethyl). Likewise, alternanthera philoxeroides was used as a raw material, and the test method and the synergistic effect evaluation were performed as in example 1, and the results are shown in table 3.

TABLE 3 indoor toxicity assay of Echinacea by compounding triazolinone herbicide (A), pethoxamid (B) and picosulfuron (C)

The difference of the survival rate of the mixed preparation when the pyrrochlor, the dimethenamid and the thiencarbazone are compounded to the alternanthera philoxeroides (E)₀the-E) is higher than other treatments, which shows that the synergistic effect of the combination of the pyrrochlor, the dimethenamid and the thiencarbazone-methyl is most obvious.

Example 4 (indoor toxicity test of the two-two binary combination of Thidiazuron, dimethenamid and pyrrochlor-p-methyl and the three-element combination of Shenghongji)

To further clarify the pesticide effect of two-two binary compounding and three-way compounding of thiencarbazone-methyl, pethoxamid and pyrrochlorvinphos, Ageratum conyzoides L in 3-leaf stage is used as a bioassay object, the test method and the evaluation method are the same as those in example 1, and the binary compounding data statistical analysis method refers to NY/T1155.7-2006 pesticide indoor bioassay testCriterion herbicides part 7: the survival rate E of each mixed combination is calculated by a Gowing method in the combined action determination of mixing₀Value, actual survival rate E value and difference between theoretical value and actual value (E)₀-E)。

Theoretical weed control effect of mixed agent E₀Calculating according to the formula (2):

in the formula:

x is the survival rate of the weeds when the dosage of the herbicide A is P;

y represents the survival rate of the weeds when the dosage of the herbicide B is Q;

E₀theoretical survival when herbicide a is used at P + theoretical survival when herbicide B is used at Q;

e, the actual survival rate of the herbicide A and the herbicide B after being mixed according to the proportion;

three judgment standards of effect shown after the herbicide is mixed: e₀-E>10% of the composition is synergistic effect; e₀-E<-10% is antagonism; e₀An E value of. + -. 10% is additive effect.

The results are shown in tables 4 and 5.

TABLE 4 indoor toxicity test results of pairwise binary pairwise recombination of thiencarbazone-sodium, dimethenamid-and pyrrochlor for ageratum

TABLE 5 indoor toxicity assay results for the ternary complex pairing of thiencarbazone-methyl, pethoxamid and pyrrochlor-methyl for ageratum

As can be seen from Table 4, the survival rate difference of the ageratum in the binary compound pairing of the thiencarbazone-methyl, the dimethoate and the pyrrochlor is 10.2-12.8, and the synergistic effect is shown. As can be seen from Table 5, the survival rate difference of the triathlons, the setron, the dimethenamid and the pyrroside is 14.0-17.5, and the synergistic effect is shown. Thifensulfuron-methyl, alachlor and pyrrochlor ternary combination E₀The E value is all two-by-two binary combination of the Thione sulforon, the dimethenamid and the pyrrochlor₀The E value is high, which indicates that the control effect of the ternary combination of the thiencarbazone-methyl, the alachlor and the pyrrochlor on the ageratum is better than that of the binary combination.

Example 5 (indoor toxicity test of Thifensulfuron methyl, dimethenamid and pyrrochlorsulfuron and their combinations on weeds)

To determine the optimal mixture ratio of thiencarbazone-methyl, dimethenamid-methyl and pyrrochloruron, cyperus rotundus Linn in the 4-leaf stage and Digitaria sanguinalis (L.) chop in the 4-leaf stage were used as bioassay objects, and the test method and the synergistic effect evaluation were the same as those in example 1. The results are shown in tables 6 and 7.

TABLE 6 indoor toxicity test results of thiencarbazone-methyl, dimethenamid and pyrrochloruron and their combination on Cyperus rotundus

The combination mode of the herbicides is evaluated according to a Colby method, and data in Table 6 show that the ternary combination of the thiencarbazone-methyl, the dimethenamid and the pyrrochloruron has obvious synergistic effect on the cyperus rotundus, and E₀-E values are all greater than 13%.

TABLE 7 indoor toxicity test results of thiencarbazone-methyl, dimethenamid and pyrrochloruron and their combination on crab grass

Evaluating the herbicide combination mode according to the Colby method, and the data in Table 7 show that the ternary combination of the thiencarbazone-methyl, the dimethenamid-methyl and the pyrrochloruron has obvious synergy on the crab grass, and E₀-E values are all greater than 12%.

According to the results of tables 5, 6 and 7, thiencarbazone-sodium showed a significant synergistic effect at a low dose (15g a.i./ha), alachlor at a high dose (300g a.i./ha) and a combination of low and high doses (30, 60g a.i./ha) of pyrrochlor-sulfuron, E₀-E > 15. The optimal mixing proportion range is 15: 300: 30-15: 300: 60, namely 1: 20: 2 to 4.

Example 6: 22% of emulsifiable concentrate of thiencarbazone-sodium-metolachlor-pyrrochlor.