CN114868761A

CN114868761A - Bactericide for preventing and treating citrus greening disease and application thereof

Info

Publication number: CN114868761A
Application number: CN202210372756.3A
Authority: CN
Inventors: 邓方坤; 蔡德珍; 邓正安; 胡秀筠
Original assignee: Jiangxi New Dragon Biotechnology Co ltd; Institute of Applied Chemistry Jiangxi Academy of Sciences
Current assignee: Jiangxi New Dragon Biotechnology Co ltd; Institute of Applied Chemistry Jiangxi Academy of Sciences
Priority date: 2022-04-11
Filing date: 2022-04-11
Publication date: 2022-08-09
Anticipated expiration: 2042-04-11
Also published as: WO2023197675A1; CN114868761B

Abstract

The scheme discloses a bactericide for preventing and treating citrus huanglongbing and application thereof, wherein the bactericide contains tetrakis hydroxymethyl phosphonium cation. The bactericide containing the tetrakis (hydroxymethyl) phosphonium cation is prepared into a bactericide solution, and the mass percentage concentration of the tetrakis (hydroxymethyl) phosphonium cation in the bactericide solution is 1-85%. The bactericide containing the tetrakis (hydroxymethyl) phosphonium cation disclosed by the application has low toxicity to plants and high compatibility.

Description

Bactericide for preventing and treating citrus greening disease and application thereof

Technical Field

The invention relates to the technical field of bactericides, and particularly relates to a bactericide for preventing and treating citrus greening disease and application thereof.

Background

Citrus greening disease (citrus huanganglingbin) or citrus greening disease (citrus greening disease) is a devastating disease in the citrus industry, causing huge losses to the citrus industry. The pathogen of the disease is gram-negative bacteria, alpha-Proteobacteria, citrus phloem-restricted bacteria Candidatus liberibacter. Candidatus liberibacter can only survive in the phloem of citrus, and cannot be cultured in vitro at present, and is spread by diseased seedlings, scions and vector insect psyllids.

The existing citrus varieties are susceptible varieties of citrus yellow dragon germs. The disease symptoms are characterized in that the plants are short and small, the shoots are difficult to extract, and the leaves are mottled and yellowed in the seedling stage of the oranges; the mature period is yellow, the peel is green, commonly called as "red naseberry", the pulp is bitter and astringent, and the commercial value is seriously influenced. Generally, the susceptible citrus is yellowed and withered within a few years after the onset of disease, and huge economic loss is brought to fruit growers.

The development of the drug for preventing and treating the huanglongbing is greatly hindered because the pathogenic bacteria Candidatus liberibacter of the huanglongbing can only grow on phloem and can not be cultured in vitro. The Mandarin orange Huanglongbing prevention and treatment strategy published in the university of agriculture, Vol.40, No.1, pages 49-57 of Huazhong university of agriculture, in 2021, reviews the prevention and treatment drugs for Huanglongbing currently screened. Wherein the antibiotics comprise beta-lactam antibiotics, such as penicillin, ampicillin, cephalexin, penicillin G potassium salt, carbenicillin disodium salt, ampicillin, amoxicillin and the like; tetracycline, oxytetracycline, sulfadimethoxine sodium, and the like. However, it is worth noting that some broad-spectrum antibiotics or bactericidal substances are completely ineffective against the pathogen Candidatus liberibacter. Such as cinoxacin, streptomycin sulfate, polymyxin sulfate, tobramycin, neomycin sulfate, amikacin sulfate, gentamicin sulfate and the like, are completely ineffective against the pathogenic bacteria Candidatus liberibacter of huanglongbing. Other broad-spectrum antibiotics such as validamycin, zhongshengmycin, hygromycin, kanamycin sulfate, spectinomycin hydrochloride, vancomycin, cycloserine, rifamycin, sulfamethoxazole, sodium sulfathiazole, chloramphenicol and the like have only partial effects on the pathogenic bacteria Candidatus liberibacter of the huanglongbing disease, have low activity and cannot be used as a therapeutic agent.

Therefore, the pathogenic bacteria Candidatus liberibacter of citrus flavedo is a special bacterium, and the existence and the size of the effect of the bactericidal substance on the pathogenic bacteria Candidatus liberibacter need to be tested and verified through experiments, and cannot be known through simple inference. The obvious examples are that the sulfadimethoxine sodium, the sulfamethoxazole and the sulfamethoxazole sodium belong to the broad-spectrum antibiotics of the sulfonamides, but only the sulfadimethoxine sodium shows high activity, but the sulfamethoxazole and the sulfamethoxazole sodium have weak activity and cannot be used as therapeutic agents.

Furthermore, according to the reference "Evidence that the expression of bacteria is affected by the expression of new tissue growth in citrus plants", Plant Disease,2021, volume 105, stage 1, pages 34-42. The pathogenic bacteria Candidatus liberibacter moves to each part of the citrus along with the nutrient flow of the phloem of the citrus in the citrus tree and preferentially transfers to new tissues. This indicates that the pathogenic bacteria Candidatus liberibacter of citrus flavedo, once infecting the citrus tree, will distribute throughout the citrus tree, further making control of the disease difficult.

Although there have been several patents disclosing antibiotics for the control of citrus greening disease. For example ZL202011433185.7 discloses a method for preventing and treating huanglongbing by abamectin and beta-lactam antibiotics; l201610459019.1 discloses a method for preventing and controlling huanglongbing using trunk injection of ampicillin and cyclopentylpiperazine rifamycin; ZL201610215621.0 discloses a method for treating huanglongbing disease by using zhongshengmycin, oxytetracycline hydrochloride, alpha-naphthylacetic acid and salicylic acid through trunk injection. These methods typically require the use of antibiotic substances and require the use of trunk injections. However, the use of antibiotics is easy to cause the residue of citrus antibiotics in citrus fruits and the drug resistance problem caused by the abuse of antibiotics, and the trunk injection mode is inconvenient for farmers to operate, thus greatly limiting the application of the method.

Other patents disclose methods for controlling citrus greening disease using non-antibiotic substances. For example, ZL201811052695.2 discloses a mixture containing extract of Chinese wingnut leaf and 3-hydroxyphenylmethylene-1, 5-dimethylpyrrolidine-2, 4-dione for preventing and treating citrus greening disease. ZL202010087340.8 discloses a method for preventing and treating citrus greening disease by thiazoline and cuaminosulfate. ZL201180055088.1 discloses the use of menadione sodium bisulfite MSB (vitamin K3) for the control of citrus greening disease. ZL20150868515.8 discloses the use of copper, zinc or sodium pyrithione in the prevention and control of citrus greening disease. These methods use spraying or root irrigation.

Despite the research progress, an inexpensive and efficient component for preventing and treating citrus greening disease still needs to be found.

Disclosure of Invention

One object of the scheme is to provide a bactericide for preventing and treating citrus greening disease.

Another object of the present invention is to provide a method for controlling citrus greening disease using the above fungicide.

In order to achieve the purpose, the scheme is as follows:

a bactericide for preventing and treating citrus huanglongbing, which contains tetrakis hydroxymethyl phosphonium cation.

Preferably, the bactericide is prepared into a bactericide solution, and the mass percentage concentration of the tetrakis hydroxymethyl phosphonium cation in the bactericide solution is 1-85%.

In a second aspect, the application provides an application of a bactericide in preventing and treating citrus greening disease, wherein the bactericide is prepared into a bactericide solution, and the mass percentage concentration of tetrakis hydroxymethyl phosphonium cation in the bactericide solution is 1-85%; the solvent of the bactericide solution is water or water and an organic solvent, and the organic solvent is an organic solvent miscible with water; the water-miscible organic solvent comprises one or more of methanol, ethanol, glycerol, ethylene glycol, acetonitrile, dimethylformamide and dimethyl sulfoxide.

Preferably, the disinfectant solution further contains SO ₄ ^2- ，HSO ₄ ^- ，SO ₃ ^2- ，HSO ₃ ^- ，H ₂ PO ₄ ^- ，HPO ₄ ^2- ，PO ₄ ^3- ，Cl ^- ，Br ^- ，I ^- ，NO ₃ ^- ，CH ₃ COO ^- ，F ^- And citrate ions; when the bactericide solution is a tetrakis hydroxymethyl phosphonium sulfate aqueous solution; the mass percentage concentration of the tetrakis (hydroxymethyl) phosphonium sulfate in the bactericide solution is 1-75%; when the bactericide solution is fourWhen the hydroxymethyl phosphorus chloride is in the water solution, the mass percentage concentration of the tetrakis hydroxymethyl phosphorus chloride in the bactericide solution is 1-80%.

Preferably, the bactericide solution is mixed with one or more of amino acid, polypeptide, potassium ion, phosphate radical ion, magnesium ion, calcium ion, zinc ion, iron ion, boric acid, borax, manganese ion, molybdate radical ion, humic acid and algal polysaccharide for use; preferably in combination with zinc ions.

Preferably, the bactericide solution also comprises a surfactant and a penetrant; the surfactant comprises an alkyl glycoside, azone or silicone; the disinfectant solution contains 2-20% of surfactant by mass percent; preferably, the disinfectant solution contains 3 to 10 mass percent of surfactant.

Preferably, the bactericide solution further comprises a first plant growth regulator, and the first plant growth regulator comprises one or more of naphthylacetic acid, naphthylacetamide, indoleacetic acid, indolebutyric acid, diethyl aminoethyl hexanoate, compound sodium nitrophenolate, gibberellin, brassinolide and brassinolide.

Preferably, the bactericide solution is used in combination with a fertilizer, the fertilizer is a liquid fertilizer, and the liquid fertilizer comprises one or more of a liquid amino acid fertilizer, a liquid humic acid fertilizer, a liquid medium element fertilizer, a liquid trace element fertilizer, a liquid macroelement fertilizer and a seaweed extract liquid fertilizer.

Preferably, the fungicide solution is used in combination with a pesticide or herbicide, the pesticide being an insecticide for use on citrus, a fungicide, a second plant growth regulator and a nematicide; the herbicide comprises one or more of citrus orchard herbicide, glyphosate, glufosinate, diquat, paraquat, 2, 4-dichlorophenoxyacetic acid, 2, 4-d butyl ester, pelargonic acid and ammonium nonanoate; preferably, the pesticide is a bactericide used on citrus; preferably, the herbicide is a citrus orchard herbicide.

Preferably, the bactericide solution is diluted by adding water and then is sprayed on citrus leaves and citrus treetops, and is used for irrigating roots of citrus trees and is injected into citrus trees; preferably, the bactericide solution is diluted by adding water and then is sprayed to citrus leaves and citrus treetops for use, and the citrus roots are irrigated with roots for use.

Preferably, the insecticide comprises mineral oil, imidacloprid, thiamethoxam, thiacloprid, clothianidin, imidacloprid, nitenpyram, acetamiprid, meperidine, fipronil, phenthoate, dichlorvos, chlorpyrifos, fenitrothion, chlorfenafos, isocrotophos, phoxim, acephate, profenofos, dimethoate, omethoate, triazophos, lambda-cyhalothrin, bifenthrin, permethrin, cypermethrin, ethofenprox, deltamethrin, fenpropathrin, isoprocarb, carbofuran, carbosulfan, pirimicarb, methomyl, isoprocarb, tebufenozide, triflumuron, hexaflumuron, methoxyfenozide, cyromazine, chlorbenzuron, flufenoxuron, flonicamid, pymetrozine, metaflumizone, fenpyrazox, fenpyraclofen, indoxacarb, diafenthiuron, amiuron, amicarb, amitraz, hexythiazox, fenazaquin, clofentezine, propargite, dicofol, chlorantraniliprole, cyanobenzamide, flubendiamide, spirodiclofen, etoxazole, emamectin benzoate, abamectin, dinotefuran, spirotetramat, diphenoxylate, sodium rosinate, flonicamid, monosultap, dimehypo, trichlorfon, lufenuron, buprofezin, propiconazole, high-efficiency cypermethrin, ethiofenprox, pyrethrin, matrine, nicotine, veratrine, eucalyptol and piceatin.

Preferably, the bactericide comprises copper hydroxide, copper calcium sulfate, cuaminosulfate, oxine-copper, cuprous oxide, copper oxychloride, basic copper carbonate, chlorothalonil, tetrachlorophthalide, pentachloronitrobenzene, sodium disulfate, carbendazim, benomyl, thiophanate-methyl, thiabendazole, pyrimethanil, cyprodinil, fluazinam, fenamipraminol, tridemorph, triflumizole, prochloraz manganese salt, imazalil, difenoconazole, propiconazole, flutriafol, hexaconazole, epoxiconazole, fenbuconazole, triticonazole, triadimenol, bitertanol, triadimenol, tebuconazole, diniconazole, myclobutanil, pyridil, tetraconazole, ipconazole, imibenconazole, penconazole, metalaxyl, mefenoxam, cymoxanil, fenoxanil, dimethomorph, flumorphine, propamocarb hydrochloride, hymexazol hydrochloride, one or more of carboxin, fluopicolide, fluopyram, boscalid, flutolanil, thifluzamide, pyraclostrobin, azoxystrobin, kresoxim-methyl, trifloxystrobin, enestroburin, pyraclostrobin, difenoconazole, pyribenzoxad, coumoxystrobin, enestroburin, procymidone, vinclozolin, iprodione, fludioxonil, cyanocinum, tricyclazole, thiazole zinc, metconazole, silthiopham, probenazole, thiencone, benzil, bromacil, kasugamycin, polyoxin, validamycin, nanmycin, shenqinmycin, pyrimidine antibiotic, zhongshengmycin, amino-oligosaccharide, lentinan, moroxydine hydrochloride, xinjuniper, isoprothiolane, cyazofamid, ethylicin, mancozeb, zineb, thiram, propineb, lime-sulphur, dithianon and captan.

Preferably, the second plant growth regulator comprises one or more of naphthylacetic acid, sodium nitrophenolate, gibberellin, ethephon, brassinolide, propionyl brassinolide, mepiquat chloride, chlormequat chloride, trinexapac-ethyl, paclobutrazol, uniconazole, forchlorfenuron, benzylaminopurine, adenine, enadenine, 2- (acetoxy) benzoic acid, triacontanol, diethyl aminoethyl hexanoate, nucleotides, cyanamide, silatran, butyrhydrazide, S-abscisic acid, chlorpropham, captan, flumetralin, thidiazuron, pendimethalin and butralin.

Preferably, the nematicide comprises one or more of fenamiphos, fosthiazate, fenamiphos, chloropicrin and cadusafos.

The scheme has the following beneficial effects:

the bactericide containing tetrakis (hydroxymethyl) phosphonium cation disclosed by the invention has the following beneficial effects: (1) the bactericide containing tetrakis hydroxymethyl phosphonium cation disclosed by the invention has excellent effect of preventing and treating citrus yellow shoot; (2) the bactericide containing the tetrakis hydroxymethyl phosphonium cation is low in price and cost, and is suitable for large-scale use in citrus industry; (3) the bactericide containing the tetrakis hydroxymethyl phosphonium cation can be degraded after being used, has no residue, cannot cause the problem of drug residue in citrus fruits, and avoids the problems of use of antibiotics, overproof antibiotic residue and resistance caused by large-scale use of antibiotics; (4) the bactericide containing the tetrakis (hydroxymethyl) phosphonium cation belongs to low-toxicity substances and has no teratogenicity and carcinogenicity; (5) the bactericide containing the tetrakis (hydroxymethyl) phosphonium cation has good biocompatibility to plants, and does not cause phytotoxicity to the plants at high concentration; (6) the bactericide containing the tetrakis (hydroxymethyl) phosphonium cation can be completely dissolved in water, can be mixed and prepared with a pesticide bactericide herbicide, a plant growth regulator, a fertilizer and the like commonly used on citrus, and can be used in combination, so that the use is simple and convenient, independent application is not needed, and the labor cost is reduced.

Detailed Description

Embodiments of the present solution are described in further detail below. It is clear that the described embodiments are only a part of the embodiments of the present solution, and not an exhaustive list of all embodiments. It should be noted that, in the present embodiment, the features of the embodiment may be combined with each other without conflict.

The terms first, second and the like in the description and in the claims, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It will be appreciated that the data so used may be interchanged where appropriate. Moreover, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The effectiveness of an antimicrobial substance to inhibit huanglongbing depends essentially on the efficiency with which the drug is absorbed by the citrus and transported to the site of bacterial growth. While the pathogenic bacteria Candidatus liberibacter will distribute throughout the citrus once infecting the citrus tree, the inventors of the present application have found that effective antimicrobial substances should be absorbed by the citrus tree and conducted through the phloem of the citrus tree. The phloem of citrus is mainly composed of an aqueous solution. Thus, the need for the antimicrobial substance to be conductive within the device requires that the substance be water soluble to some extent and that the antimicrobial substance not be toxic to plant tissue at effective germicidal concentrations. Therefore, screening out the medicinal components for effectively preventing and treating the yellow dragon disease is very challenging.

If antibiotics are used for preventing and treating citrus greening disease, a mode suitable for using the medicine needs to be found due to poor permeability and conductivity of the antibiotics.

In view of the difficulty of in vitro culture of the citrus flavedo pathogen Candidatus liberibacter, but belonging to the family Rhizobiaceae, the inventors of the present application selected to use a species Sinorhizobium meliloti crop model bacterium, Sinorhizobium meliloti, closely related to the citrus flavedo pathogen Candidatus liberibacter, to mimic the citrus flavedo pathogen Candidatus liberibacter.

Therefore, the application discloses a bactericide which is screened by using Sinorhizobium meliloti and contains tetrakis (hydroxymethyl) phosphonium cation as an effective component, and is used for preventing and controlling citrus yellow shoot. The bactericide provided by the application comprises tetrakis hydroxymethyl phosphonium cation with the structure shown in formula (1),

in one embodiment, the germicide is formulated as a germicide solution in which the concentration of tetrakis hydroxymethyl phosphonium cation is 1 wt% to 85 wt%.

When the bactericide containing the tetramethylolphosphonium cation is applied to preventing and treating citrus yellow shoot, the bactericide is prepared into a bactericide solution, and the mass percentage concentration of the tetramethylolphosphonium cation in the bactericide solution is 1-85 wt%; the solvent of the germicide solution is water or water and an organic solvent, and the organic solvent is preferably an organic solvent miscible with water.

When the solvent of the germicide solution is water, the compound containing a tetramethylolphosphonium cation is preferably tetramethylolphosphonium sulfate (THPS), or tetramethylolphosphonium chloride (THPC).

In one embodiment, when the germicide solution is an aqueous solution of tetrakis hydroxymethyl phosphonium sulfate; the mass percentage concentration of the tetrakis (hydroxymethyl) phosphonium sulfate in the bactericide solution is 1-75 wt%; when the bactericide solution is a tetramethylolphosphonium chloride aqueous solution, the mass percent concentration of tetramethylolphosphonium chloride in the bactericide solution is 1-80 wt%.

Tetrakis (hydroxymethyl) phosphonium sulfate (THPS) and tetrakis (hydroxymethyl) phosphonium chloride (THPC) containing tetrakis (hydroxymethyl) phosphonium cations are widely used as biocides in water treatment, oil field, paper making and other industries, and can also be used as permanent flame retardants for pure cotton and polyester-cotton fabrics.

The advantages of the tetrakis hydroxymethyl phosphonium cation are:

1. the preparation and synthesis process is simple, the cost is low, and the source is wide;

2. after being used, the material is quickly degraded into completely harmless substances, has no residual pollution and is safe to the environment;

3. tetrakis (hydroxymethyl) phosphonium sulfate (THPS) and tetrakis (hydroxymethyl) phosphonium chloride (THPC) are low-toxicity compounds, and do not have carcinogenicity and teratogenicity; for testing of tetrakis (hydroxymethyl) phosphonium sulfate (THPS) AND tetrakis (hydroxymethyl) phosphonium chloride (THPC), the U.S. NIH Report National Toxicology Program Technical Report Series No.296, "Toxicology AND carcinogenesis students of the physicians (hydroxymethyl) phosphonium sulfate (THPS) (CAS No.55566-30-8) AND physicians (hydroxymethyl) phosphonium chloride (THPC) (CAS No.124-64-1) in F334/N rates AND B6C3F1 micro.";

4. since commercial tetrakis (hydroxymethyl) phosphonium sulfate solution and tetrakis (hydroxymethyl) phosphonium chloride solution with the mass percentage concentration of 70-85 wt% are aqueous solutions, the commercial tetrakis (hydroxymethyl) phosphonium sulfate solution or tetrakis (hydroxymethyl) phosphonium chloride solution can be mixed with various plant nutrient fertilizer factors or elements, such as amino acids, polypeptides, potassium, phosphorus, magnesium, calcium, zinc, iron, boron, manganese, molybdenum, humic acid, algal polysaccharides, and the like.

In one embodiment, the water-miscible organic solvent comprises one or more of methanol, ethanol, glycerol, ethylene glycol, acetonitrile, Dimethylformamide (DMF) and Dimethylsulfoxide (DMSO).

In one embodiment, the germicide solution contains multiple ions, such as SO, in addition to the tetrakis hydroxymethyl phosphonium cation ₄ ^2- ，HSO ₄ ^- ，SO ₃ ^2- ，HSO ₃ ^- ，H ₂ PO ₄ ^- ，HPO ₄ ^2- ，PO ₄ ^3- ，Cl ^- ，Br ^- ，I ^- ，NO ₃ ^- ，CH ₃ COO ^- ，F ^- And citrate ion, preferably containing SO ₄ ^2- And/or Cl ^- 。

In one embodiment, the bactericide solution is mixed with one or more of amino acids, polypeptides, potassium ions, phosphate ions, magnesium ions, calcium ions, zinc ions, iron ions, boric acid, borax, manganese ions, molybdate ions, humic acid and algal polysaccharides; preferably in combination with zinc ions.

In one embodiment, the germicide solution also contains a surfactant and a penetrant; wherein surfactants such as alkyl glycosides, azones or silicones; in the bactericide solution, the mass percent concentration of the surfactant is 2-20 wt%; preferably, the mass percent concentration of the surfactant in the bactericide solution is 3-10 wt%.

In one embodiment, the fungicide solution further comprises a first plant growth regulator, wherein the first plant growth regulator is one or more of naphthylacetic acid, naphthylacetamide, indoleacetic acid, indolebutyric acid, diethyl aminoethyl hexanoate, sodium nitrophenolate, gibberellin, brassinolide and brassinolide. The first plant growth regulator in the fungicide solution is typically added to liquid fertilizers and has a growth promoting effect on plants.

In one embodiment, the antimicrobial solution is used in combination with a fertilizer, wherein the fertilizer is a liquid fertilizer comprising one or more of a liquid amino acid fertilizer, a liquid humic acid fertilizer, a liquid medium element fertilizer, a liquid trace element fertilizer, a liquid macroelement fertilizer and a seaweed extract liquid fertilizer.

In one embodiment, the bactericide solution is diluted by adding water and then is sprayed on citrus leaves and citrus treetops, and is used for irrigating roots of citrus trees and is used for injecting citrus trees; preferably, the bactericide solution is diluted by adding water and then sprayed to citrus leaves and citrus treetops for root irrigation.

In one embodiment, the fungicide solution is used in combination with a pesticide or herbicide, wherein the pesticide is an insecticide for use on citrus, a fungicide, a second plant growth regulator, and a nematicide; the herbicide comprises one or more of citrus orchard herbicide, glyphosate, glufosinate, diquat, paraquat, 2, 4-dichlorophenoxyacetic acid (2, 4-D), 2, 4-D butyl ester, pelargonic acid and ammonium nonanoate; the pesticide is preferably a bactericide used on citrus; preferably the herbicide is a citrus orchard herbicide.

In one embodiment, the insecticide comprises mineral oil, imidacloprid, thiamethoxam, thiacloprid, clothianidin, imidacloprid, nitenpyram, acetamiprid, meperidine, fipronil, phenthoate, dichlorvos, chlorpyrifos, fenitrothion, chlorfenafos, isocrotophos, phoxim, acephate, profenofos, dimethoate, omethoate, triazophos, lambda-cyhalothrin, bifenthrin, permethrin, cypermethrin, ethofenprox, fenpropathrin, isoprocarb, carbofuran, carbosulfan, pirimicarb, methomyl, isoprocarb, tebufenozide, triflumuron, hexaflumuron, methoxyfenozide, cyromazine, chlorbenzuron, flufenoxuron, flonicamid, pymetrozine, metaflumizone, fenpyrazox, fenpyraclofen, indoxacarb, diafenthiuron, amiuron, amicarb, amitraz, hexythiazox, fenazaquin, clofentezine, propargite, dicofol, chlorantraniliprole, cyanobenzamide, flubendiamide, spirodiclofen, etoxazole, emamectin benzoate, abamectin, dinotefuran, spirotetramat, diphenoxylate, sodium rosinate, flonicamid, monosultap, dimehypo, trichlorfon, lufenuron, buprofezin, propiconazole, high-efficiency cypermethrin, ethiofenprox, pyrethrin, matrine, nicotine, veratrine, eucalyptol and piceatin.

In one embodiment, the bactericide includes copper hydroxide, copper calcium sulfate, cuaminosulfate, oxine-copper, cuprous oxide, copper oxychloride, basic copper carbonate, chlorothalonil, tetrachlorophthalide, pentachloronitrobenzene, sodium diuron, carbendazim, benomyl, thiophanate-methyl, thiabendazole, pyrimethanil, cyprodinil, fluazinam, fenamipraminol, tridemorph, triflumizole, prochloraz-manganese salt, imazalil, difenoconazole, propiconazole, flutriafol, hexaconazole, epoxiconazole, fenbuconazole, triticonazole, triadimenol, bitertanol, triadimenol, tebuconazole, diniconazole, myclobutanil, pyridil, tetraconazole, ipconazole, imibenconazole, penconazole, metalaxyl, mefenoxam, cymoxanil, fenoxanil, dimethomorph, flumorphine, propamocarb hydrochloride, hymexazol hydrochloride, the pesticide composition comprises carboxin, fluopicolide, fluopyram, boscalid, flutolanil, thifluzamide, pyraclostrobin, azoxystrobin, kresoxim-methyl, trifloxystrobin, enestroburin, pyraclostrobin, difenoconazole, pyribenzoxad, coumoxystrobin, enestroburin, procymidone, vinclozolin, iprodione, fludioxonil, cyanocinum, tricyclazole, thiazole zinc, metconazole, silthiopham, probenazole, thiencone, benzil, bromacil, kasugamycin, polyoxin, validamycin, nanmycin, shenqinmycin, pyrimidine antibiotic, zhongshengmycin, amino-oligosaccharide, lentinan, moroxydine hydrochloride, xinjuniper, isoprothiolane, cyazofamid, ethylicin, mancozeb, zineb, thiram, propineb, thionazole, dithianon and captan.

In one embodiment, the second plant growth regulator comprises one or more of naphthylacetic acid, sodium nitrophenolate, gibberellin, ethephon, brassinolide, propionyl brassinolide, mepiquat chloride, chlormequat chloride, trinexapac-ethyl, paclobutrazol, uniconazole, forchlorfenuron, benayl aminopurine, enadenine, 2- (acetoxy) benzoic acid, triacontanol, diethyl aminoethyl hexanoate, nucleotides, cyanamide, silatran, butyrhydrazide, S-abscisic acid, chlorpropham, captan, flumetralin, thidiazuron, pendimethalin and butralin; the second plant growth regulator in this embodiment includes various types of plant growth regulators.

In one embodiment, the nematicide comprises one or more of fenamiphos, fosthiazate, fenamiphos, chloropicrin, and cadusafos.

The present application is further illustrated by the following specific examples.

Since the citrus yellow shoot pathogen Candidatus Liberibacter is difficult to culture in vitro, but belongs to Rhizobiaceae, see the literature "Structure of lipid from Liberibacter crescents is low Molecular weight and of bacteria infection in International Journal of Molecular Science,2021,22, 11240. Therefore, the selection was carried out using Sinorhizobium meliloti, a strain having a close affinity to the causative bacterium Candidatus liberibacter. The experimental Sinorhizobium meliloti strain is purchased from China agricultural microorganism strain collection center with the strain number ACCC 17528.

Example 1

Shaking flask screening experiment of tetrakis hydroxymethyl phosphonium (tetrakis (hydroxymethyl) phosphonium) fungicide.

The formula of the culture medium of the Sinorhizobium meliloti is as follows: sucrose 30 g, K ₂ HPO ₄ 0.375 g KH ₂ PO ₄ 0.375 g, MgSO ₄ .7H ₂ 0.3 g of O, 0.21 g of NaCl, 4.2 g of yeast extract powder and 1% of Na ₂ MoO ₄ 150 μ l of solution, 1% MnSO ₄ Solution 150. mu.l, 1% B (OH) ₃ The solution was mixed well with 150. mu.l of tap water (1500 ml). The medium was dispensed into 250ml Erlenmeyer flasks, 100ml of the medium was added to each Erlenmeyer flask, and sterilized at 121 ℃ for 25 minutes. Cooling to room temperature for use.

0.05 g of metronidazole, 0.05 g of 4-isopropyl-3-methylphenol, 0.10 g of menadione sodium bisulfite and 0.05 g of dihydromyricetin are respectively added into 1000 mul of DMSO solvent to prepare a first medicament solution.

Since the commercial tetrakis (hydroxymethyl) phosphonium sulfate (THPS) is an aqueous solution of tetrakis (hydroxymethyl) phosphonium sulfate (THPS) having a concentration of 75 wt%, 100. mu.l of a commercial aqueous solution of tetrakis (hydroxymethyl) phosphonium sulfate (THPS) having a concentration of 75 wt% was added to 1000. mu.l of DMSO to prepare a tetrakis (hydroxymethyl) phosphonium sulfate DMSO solution.

And respectively adding the first medicament solution and the prepared tetramethylolphosphate DMSO solution into the liquid culture medium of the Sinorhizobium meliloti which is cooled to room temperature for later use. Adding two bottles into each solution, and adding 25 mul and 50 mul respectively; control (CK) is prepared by adding DMSO solvent to the liquid culture medium of Sinorhizobium meliloti cooled to room temperature, adding two bottles, and adding 25 μ l DMSO and 50 μ l DMSO, respectively; to all the media to which the solution was added, 100. mu.l of Sinorhizobium meliloti solution was added, and the absorbance was measured after shake cultivation at 28 ℃ for 32 hours at Abs595 nm. (wherein the Sinorhizobium meliloti bacterial liquid is obtained by picking a plate Sinorhizobium meliloti bacterial colony of Sinorhizobium meliloti on the previous day, inoculating the plate Sinorhizobium meliloti bacterial colony into a liquid culture medium, and performing shake flask culture on the plate to obtain a standby bacterial liquid at 28 ℃), and the shake flask screening experiment results are shown in Table 1.

TABLE 1

As can be seen from the results in Table 1, the fungicides metronidazole and dihydromyricetin were inactive against Sinorhizobium meliloti ACCC 17528. The menadione sodium bisulfite MSB disclosed in ZL201180055088.1 inhibited sinorhizobium meliloti ACCC17528 only moderately active. 4-isopropyl-3-methylphenol (trivial name, thymol) is less active. At a concentration of 18.75ppm, tetrakis (hydroxymethyl) phosphonium sulfate (THPS) has weak inhibitory activity on Sinorhizobium meliloti ACCC17528, and at a concentration of 37.5ppm, has strong inhibitory activity on Sinorhizobium meliloti ACCC17528, and is nearly completely inhibited.

Example 2

Determination of bactericidal activity of tetrakis (hydroxymethyl) phosphonium (tetrakis) phosphonium) bactericide by the 96-well plate method.

1. The Sinorhizobium meliloti ACCC17528 of this example was cultured in the medium of the sterilized Sinorhizobium meliloti of example 1 at 28 ℃ and shaking at 180rpm to OD ₆₀₀ The value is about 1.0, and the diluted sinorhizobium meliloti ACCC17528 is diluted by 50 times with sterile water for later use.

The formula of the culture medium of the sinorhizobium meliloti comprises the following components:

sucrose 30 g, K ₂ HPO ₄ 0.375 g, KH ₂ PO ₄ 0.375 g, MgSO ₄ .7H ₂ 0.3 g of O, 0.21 g of NaCl, 4.2 g of yeast extract powder and 1% of Na ₂ MoO ₄ 150 μ l of solution, 1% MnSO ₄ Solution 150. mu.l, 1% B (OH) ₃ The solution is 150 mul, 1500ml tap water, mixed evenly, autoclaved at 121 ℃ for 25 minutes and cooled to room temperature for standby.

2. The minimum inhibitory concentration MIC values of tetrakis (hydroxymethyl) phosphonium sulfate (THPS) were tested in one row of 96-well plates. In row A, the wells are A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12. 200. mu.l of sterilized liquid medium of Sinorhizobium meliloti was added to each of A2 and A12.

200. mu.l of a 375ppm TMHPS medium solution (obtained by diluting a commercially available 75 wt.% aqueous solution of THPS with sterilized liquid medium of Sinorhizobium meliloti after cooling to room temperature) was added to A2. mu.l of a 375ppm TMHPS medium solution was added to A3, the volume of the liquid in A3 was 400. mu.l, 200. mu.l of the solution was taken from A3 and mixed with A4, 200. mu.l of the solution was taken from A4 and mixed with A5, and two-fold gradient dilution was performed in this manner to A11. mu.l was taken from A11 and added to A12.

Wells a1 were negative controls in which no THPS-containing medium solution was added. To A1 to A11 was added 50. mu.l of the diluted Sinorhizobium meliloti ACCC17528 of step 1. A12 Dilute Sinorhizobium meliloti ACCC17528 was not added.

After culturing the 96-well plate in an incubator at 28 ℃ for 48 hours, the absorbance of each well was measured at 595nm using a microplate reader. The rhizobium meliloti has a large absorbance value in the pores where it grows, whereas the rhizobium meliloti has no pores where it grows, and the absorbance value is small or close to 0. The MIC value was determined as the minimum concentration of tetrakis (hydroxymethyl) phosphonium sulfate (THPS) that inhibited the growth of Sinorhizobium meliloti ACCC 17528. At this concentration, the absorbance was small, or close to 0. And the Sinorhizobium meliloti in the hole with the concentration diluted by 2 times grows in the hole adjacent to the hole with the concentration, and has larger absorbance value.

The minimum inhibitory concentration MIC of tetrakis (hydroxymethyl) phosphonium sulfate (THPS) to Sinorhizobium meliloti ACCC17528 was determined to be 9.4ppm (calculated as tetrakis (hydroxymethyl) phosphonium sulfate (THPS)). The 96-well plate assay results were smaller than the shake flask assay, probably due to the difference between the culture environment of shake flask shaking and the stationary culture environment of 96-well plate.

Example 3

Toxicity of tetrakis (hydroxymethyl) phosphonium (tetrakis) (hydroxymethy) phosphoniums) fungicide to plants was determined.

The commercial 75% tetrakis (hydroxymethyl) phosphonium sulfate aqueous solution is diluted by tap water to 1350ppm, 675ppm, 450ppm, 150ppm, 135ppm and 15ppm tetrakis (hydroxymethyl) phosphonium sulfate aqueous solution respectively, and tap water is used as a reference CK.

Corn seeds were soaked in these solutions separately, 10 seeds were soaked in each concentration of solution, and soaked overnight. Then taking out; a piece of filter paper was placed on the petri dish, and 4ml of the above aqueous solution of 1350ppm, 675ppm, 450ppm, 150ppm, 135ppm, 15ppm of tetrakis hydroxymethyl phosphonium sulfate was taken and added to each petri dish separately using 4ml of tap water as a negative control. Then, the soaked corn seeds are placed on a filter paper sheet, and the culture dish is placed in an incubator at 28 ℃ for germination acceleration. Removed after three days. The shoot length and root length of the maize seed germination were measured. The measured data are shown in Table 2.

And (3) calculating the mean and variance of the data of the root length and the bud length of the corn germination of each treatment group, carrying out t detection on the data and the control clear water treatment group, and calculating the significant difference between the treatment group and the control clear water group. No inhibition is indicated if there is no significant difference between the treated and control groups. Inhibition is indicated if there is a significant difference between the treated and control groups.

The data in Table 2 show that the root length and shoot length of the corn are not significantly different from those of the control group when the corn is germinated by treating the corn with the solution with the THPS concentration of 15ppm, 135ppm, 150ppm and 450 ppm. At a THPS concentration of 1350ppm, the corn sprout length of the treated group was significantly different from that of the control group, which is shown by strong inhibition of the THPS on the corn sprout. At a THPS concentration of 675ppm, there was no significant difference in corn sprout length in the treated group from the control group, indicating no inhibition. However, at this concentration, the corn root length of the treated group was significantly different from that of the control group. At a THPS concentration of 675ppm, the average root length of the treated corn was 34mm, the average root length of the control corn was 94mm, and the inhibition rate was (94-34)/94-64%. According to the corn seed germination test, the safe concentration of the THPS to the plants is determined to be between 450 and 675 ppm.

TABLE 2

Example 4

Tetrakis (hydroxymethyl) phosphonium germicides are complexed with different metal ions, amino acids.

Formula 1: zinc sulfate heptahydrate 50 g, commercial THPS (75% wt) aqueous solution 53 g, water 48 g, commercial mixed amino acid powder (80% wt)0.5 g, 6 g alkyl glycoside APG0810, mixed uniformly to a homogeneous clear solution. The mass percentage of the THPS in the prepared solution is 25 percent; denoted as Zn-THPS.

And (2) formula: 35 g of ferrous sulfate heptahydrate, 54.4 g of commercial tetrakis (hydroxymethyl) phosphonium sulfate (THPS) (75% wt) aqueous solution, 56 g of water, 0.6 g of commercial mixed amino acid powder (80% wt), 6 g of alkyl glycoside APG0810, and the mixture is uniformly mixed to form a uniform clear solution. The mass percentage of the THPS in the prepared solution is 27 percent; denoted as Fe-THPS.

And (3) formula: 45 g of ferrous sulfate heptahydrate, 55.7 g of zinc sulfate heptahydrate, 77 g of commercial THPS (75 wt% in mass) aqueous solution, 125 g of water, 1.4 g of commercial mixed amino acid powder (80 wt%), and 10 g of alkyl glycoside APG0810, and the raw materials are uniformly mixed to obtain a uniform clear solution. The mass percentage of the THPS in the prepared solution is 18 percent; denoted as Fe-Zn-THPS.

And (4) formula: 42 g of anhydrous copper sulfate, 111 g of commercial THPS (75% wt) aqueous solution, 86 g of water, 1.4 g of commercial mixed amino acid powder (80% wt) and 10 g of APG0810, which are uniformly mixed to form a uniform clear solution, wherein the THPS content in the prepared solution is 33% by mass; denoted as Cu-THPS.

And (5) formula: boric acid 6.7 g, water 55 g, commercial tetrakis (hydroxymethyl) phosphonium sulfate (THPS) (75% wt) water solution 60.6 g, commercial mixed amino acid powder (80% wt)0.6 g, alkyl glycoside APG0810 g, mixed well to a homogeneous clear solution. The mass percentage of the THPS in the prepared solution is 35 percent; denoted B-THPS.

And (6) formula: 3.3 g of ferrous sulfate heptahydrate, 17.2 g of zinc sulfate heptahydrate, 2.2 g of boric acid, 99.8 g of commercial tetrakis (hydroxymethyl) phosphonium sulfate (THPS) (75% wt) aqueous solution, 80 g of water, 26.4 g of commercial mixed amino acid powder (80% wt), 6 g of alkyl glycoside APG0810, and the mixture is uniformly mixed to form uniform clear solution. The mass percentage of the THPS in the prepared solution is 32 percent; denoted as AM-THPS.

The MIC values for the minimum inhibitory concentration of each formulation and copper sulfate pentahydrate, a commercially available aqueous solution of THPS (75%) were determined in parallel 2 times using 96-well plates, and the procedure was as in example 2. The MIC values of the minimum inhibitory concentrations of the formulations are shown in Table 3.

Wherein the MIC value of each formulation concentration is defined as the concentration of each formulation at 100% of the formulation concentration. For example, the solution of the formulation (1) is diluted 1000 times to obtain a concentration solution of 1000ppm in the formulation (1), the formulation concentration of the solution (in the formulation (1)) being 1000ppm, but the content thereof in terms of THPS being 1000 × 25% ═ 250 ppm.

TABLE 3

Table 3 shows that the MIC value of Zn-THPS in THPS is 1.6ppm, and the MIC value of commercial THPS (75% wt) aqueous solution in THPS is 17% of the MIC value of 9.4ppm, which indicates that the THPS and Zn are combined to have synergistic effect. MIC values of B-THPS and AM-THPS in THPS are 8.8ppm and 6ppm respectively, and the MIC values are not much different from MIC values of 9.4ppm in THPS of commercial THPS (75% wt) aqueous solution, which shows that B or amino acid has small interaction with THPS and does not influence the bactericidal activity of the THPS. In addition, MIC values of Cu-THPS and Fe-THPS in THPS are respectively 24.8ppm and 20.2ppm, which are both larger than MIC value of 9.4ppm in THPS of a commercial THPS (75% wt) aqueous solution, and the fact that Cu or Fe interacts with THPS is proved to reduce the sterilization effect of THPS.

Example 5

Example of mixing and formulating THPS aqueous solution and bactericide

10 g of zinc thiazole (97.5%), 2 g of NP-10 (nonylphenol polyoxyethylene ether), 2 g of 1602 (tristyrylphenol polyoxypropylene polyoxyethylene ether), 0.2 g of xanthan gum, 4 g of sodium lignosulfonate, 0.2 g of sodium carboxymethylcellulose and 3 g of ethylene glycol are added into 10 g of commercial aqueous solution of tetrakis (hydroxymethyl) phosphonium sulfate (THPS) (75 wt%), and 68.6 g of water is added to 100 g for sand grinding, so that suspension mixture of the zinc thiazole and the THPS with 9.75% of zinc thiazole and 7.5% of THPS is obtained.

Example 6

Examples of mixed formulations of THPS and insecticides

3 g of chlorantraniliprole (95%), 1 g of NP-10 (nonylphenol polyoxyethylene ether), 4 g of 1602 (tristyrylphenol polyoxypropylene polyoxyethylene ether), 0.2 g of xanthan gum, 5 g of sodium lignosulfonate, 0.2 g of sodium carboxymethylcellulose and 3 g of glycerol are added into 10 g of a commercial aqueous solution of tetrakis (hydroxymethyl) phosphonium sulfate (THPS) (75 wt%), 73.6 g of water is added to make up to 100 g, and sanding is carried out to obtain a chlorantraniliprole THPS suspending agent mixed solution of 2.85% of chlorantraniliprole and 7.5% of THPS.

Example 7

Examples of mixed formulations of THPS and herbicides

Commercially available aqueous solution of tetrakis (hydroxymethyl) phosphonium sulfate (THPS) (75% wt) 10 g was added to 80 g of 20% glufosinate solution, 6 g of the alkyl glycoside APG0810 was added, and 4 g of water was added to make up to 100 g, to give an aqueous solution of 16% glufosinate, 7.5% THPS.

Example 8

Example of Mixed formulation of THPS with plant growth regulator

0.1 g of brassinolide, 0.1 g of gibberellin, 0.1 g of benzylaminopurine and 0.1 g of naphthylacetic acid, 20 g of commercial Tetramethylolthiophosphate (THPS) (75% wt) aqueous solution, 6 g of alkyl glycoside APG0810 and 73.7 g of water are added to prepare aqueous solution containing THPS 15%, brassinolide 0.1%, gibberellin 0.1%, benzylaminopurine 0.1% and naphthylacetic acid 0.1%.

Example 9

The experiment of the medicament is carried out in the navel orange garden of the Dongshan village in Dayun county of Ganzhou city in 2020 to 2021. The navel orange variety is Newhall. The test trees are all adult bearing trees infected with yellow dragon disease. 3 replicates per treatment were tested for a total of 12 trees of diseased trees. The test area is supplemented with normal water and fertilizer management and pesticide management (mainly for controlling diaphorina citri). The water and fertilizer application of each treatment group is kept consistent. The experimental design is shown in table 4.

Wherein, the treatment group 1 comprises that the treatment agent is diluted and sprayed with water 500 times for 11/21/2020, and the treatment agent is diluted and sprayed with water 500 times for 27/5/2021. The spraying of water drops on the whole leaf surface is used as the standard. The final concentration of the sprayed liquid medicine in THPS is 416 ppm.

The treatment group 2 is prepared by diluting and spraying 1000 times of treatment agent with water in 2020 for 11/21 days, and diluting and spraying 1000 times of treatment agent with water in 2021 for 5/27 days. The spraying of water drops on the whole leaf surface is used as the standard. The final concentration of the sprayed liquid medicine is 208ppm in THPS.

The treatment group 3 is a treatment agent which is diluted by 1000 times of water and sprayed on the trees after being diluted by 21 days 11 months 11 years 2020, and roots are irrigated simultaneously, and 1kg of roots of each tree is irrigated with the treatment agent diluted by 1000 times of water. Diluting the treatment agent 1000 times by adding water for spraying in 2021 year, 5 month and 27 day, and irrigating roots simultaneously, wherein 1kg of the treatment agent diluted by adding water for 1000 times is irrigated to the roots of each tree. The leaf surface spraying is based on the spraying of the wet water drops on the whole leaf surface. The final concentration of the sprayed liquid medicine is 208ppm in THPS.

The treatment group 4 (control group CK) was prepared by diluting the control drug 500 times with water and spraying it on 11/21/2020 and diluting the control drug 500 times with water and spraying it on 27/5/2021. The final concentration of the sprayed liquid medicine is 0ppm calculated by THPS.

Wherein (1) the formula of the treatment agent is as follows:

139 g of commercial tetrakis (hydroxymethyl) phosphonium sulfate (THPS) (75% wt) in water, 30 g of alkyl glycoside (APG0810), 331 g of water, and 500 g of total weight. Wherein the concentration is 20.8% based on THPS.

(2) The reference medicament formula comprises:

30 g of alkyl glycoside (APG0810), 470 g of water and 500 g of total weight.

Table 4.

Sampling 20 days 11 months before spraying, collecting 4-5 mature leaves in five directions of the Huanglongbing disease trees in south, east and north, respectively, collecting 20-25 leaves in total for each tree, avoiding cross contamination among samples in the collection process, and sending the collected samples to a laboratory for treatment or temporarily storing the samples at 4 ℃.

The national standard GB/T28062-2011 real-time fluorescence PCR detection method for citrus greening disease is adopted. The veins in the leaf samples were cut and ground to powder using liquid nitrogen. About 200mg of vein powder was used to extract vein DNA from leaf samples by the CTAB-Triton method. Detection was performed using SYBR Green I fluorescent dye PCR.

The primer pair CQULA04F sequence is: 5'-TGGAGGTGTAAAAGTTGCCAAA-3', respectively; the CQULA04R sequence was: 5'-CCAACGAAAAGATCAGATATTCCTCA-3' are provided. The amplified fragment is a specific target sequence of ribosomal protein gene rplJ/rplL of the mycobacterium tuberculosis of liberibacter asiaticus, the size of the specific target sequence is 87bp, and the specific target sequence is a single copy fragment.

SYBR Green I fluorescent dye PCR reaction system 25ul, containing 1 XSSYBR Green I quantitative IQ SYBR Green Supermix (Bio-Rad USA) final concentration, 0.75. mu. mol/L primer pair CQULA04F/CQULA04R and 2. mu.l template. Performing fluorescent quantitative PCR detection on a fluorescent quantitative PCR instrument, and performing pre-amplification at 95 ℃ for 1 min; denaturation at 95 ℃ for 15 s; annealing at 59 ℃ for 15 s; extension at 72 ℃ for 20 s; 41 cycles. The simultaneous multiple acquisition of fluorescence is set at the extension phase of each cycle. To verify the specificity of amplification, the melting curve was analyzed immediately after amplification was completed, and the reaction procedure was: at 95 ℃ for 30 s; 30s at 55 ℃; the temperature was increased by 0.5 ℃ for 1s from 55 ℃ and was continuously increased 80 times (to 95 ℃). The Ct values obtained by the measurement were recorded.

According to the literature, "preliminary report of screening test for prevention and control drug for citrus huanglongbing", 2014,40 vol (2), 166-170 page.

Using the formula

CN＝75×10 ^{11.61-0.288Ct} And calculating the bacterial carrying capacity of the tree body tissue of the huanglongbing.

Ct is a Ct value obtained by SYBR Green I fluorescent dye fluorescent quantitative PCR determination.

CN is the bacterial load of each gram of tissue of the Huanglongbing disease tree. (in units of copy number of pathogen DNA, copy number/g, CN/g)

Samples were taken 2 months 21 days 2021 year after the first dose after spraying. Samples were taken at 13 days 4 months 2021. After the second spray application, samples were taken 10 days 7 and 10 days 2021, and 28 days 8 and 28 days 2021. The test results are shown in Table 5.

TABLE 5

As can be seen from table 5, the percent reduction of huanglongbing disease bacteria is (CN value of bacteria before application to the treatment area-CN value of bacteria after application to the treatment area)/CN value of bacteria before application to the treatment area × 100%. For convenience, it is counted in 2021, 8 months and 28 days.

In the treatment 1, the bacterial reduction rate of the huanglongbing disease is 100 percent; 2, treatment, wherein the bacterial reduction rate of the huanglongbing disease is 99.7 percent; and 3, treatment, wherein the bacterial reduction rate of the huanglongbing is 99.9%. The increase in the level of Huanglongbing in the control group was 14%. It can be seen that the therapeutic effect of the composition containing tetrakis (hydroxymethyl) phosphonium sulfate (THPS) is related to the concentration of the agent. The therapeutic effect is better when the medicine is diluted by 500 times than when the medicine is diluted by 1000 times. Meanwhile, the root irrigation treatment has a synergistic effect on the treatment effect of the medicament.

At 11 months and 30 days 2021, fruits from four treatment groups were harvested. The good fruit rate of the treatment 1 is about 95 percent, the basic fruit type is normal, the red nose fruit is few, and a few fruits have green tangerine peels which are not completely special and turn orange (no good fruit is counted). The fruit is tasted artificially, and has high sweetness, which is equivalent to the normal fruit without Huanglongbing. The good fruit rate of the treatment 2 is about 75%, and the red nose fruit is partially present, so that the fruit with normal appearance is tasted, the sweetness is lower than that of the treatment 1, and the fruit is slightly sour. The good fruit rate of the treatment 3 is about 85%, a small part of the red naseberry tastes the fruit with normal appearance at the lower branch, the sweetness is not as good as that of the treatment 1, but the sweetness is still enough. Treatment 4 (control treatment), which was essentially red naseberry, had no commercial value.

From the above examples, it is clear that Tetrakis Hydroxymethyl Phosphonium Sulfate (THPS) and Tetrakis Hydroxymethyl Phosphonium Chloride (THPC) containing tetrakis hydroxymethyl phosphonium cation have low toxicity to plants and high compatibility.

It should be understood that the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention, and it will be obvious to those skilled in the art that other variations or modifications may be made on the basis of the above description, and all embodiments may not be exhaustive, and all obvious variations or modifications may be included within the scope of the present invention.

Claims

1. The bactericide for preventing and treating citrus huanglongbing is characterized by containing tetrakis hydroxymethyl phosphonium cation.

2. The bactericide for controlling citrus greening disease according to claim 1, wherein the bactericide is formulated as a bactericide solution, and the mass percentage concentration of tetrakis hydroxymethyl phosphonium cation in the bactericide solution is 1-85%.

3. The application of the bactericide in preventing and treating citrus greening disease is characterized in that the bactericide according to claim 1 is prepared into a bactericide solution, and the mass percentage concentration of tetrakis hydroxymethyl phosphonium cation in the bactericide solution is 1-85%; the solvent of the bactericide solution is water or water and an organic solvent, and the organic solvent is an organic solvent miscible with water; the water-miscible organic solvent comprises one or more of methanol, ethanol, glycerol, ethylene glycol, acetonitrile, dimethylformamide and dimethyl sulfoxide.

4. Use according to claim 3, wherein the disinfectant solution also contains SO ₄ ^2- ，HSO ₄ ^- ，SO ₃ ^2- ，HSO ₃ ^- ，H ₂ PO ₄ ^- ，HPO ₄ ^2- ，PO ₄ ^3- ，Cl ^- ，Br ^- ，I ^- ，NO ₃ ^- ，CH ₃ COO ^- ，F ^- And citrate ions; when the bactericide solution is a tetrakis (hydroxymethyl) phosphonium sulfate aqueous solution; the mass percentage concentration of the tetrakis (hydroxymethyl) phosphonium sulfate in the bactericide solution is 1-75%; when the bactericide solution is a tetramethylolphosphonium chloride aqueous solution, the mass percentage concentration of tetramethylolphosphonium chloride in the bactericide solution is 1-80%.

5. The use according to claim 3, wherein the disinfectant solution is used in admixture with one or more of amino acids, polypeptides, potassium ions, phosphate ions, magnesium ions, calcium ions, zinc ions, iron ions, boric acid, borax, manganese ions, molybdate ions, humic acid, and trehalose; preferably in combination with zinc ions.

6. The use according to claim 3, wherein the disinfectant solution further comprises a surfactant and a penetrant; the surfactant comprises an alkyl glycoside, azone or silicone; the disinfectant solution contains a surfactant with the mass percentage concentration of 2-20%; preferably, the disinfectant solution contains 3 to 10 mass percent of surfactant.

7. The use of claim 3, wherein the antimicrobial solution further comprises a first plant growth regulator comprising one or more of naphthylacetic acid, naphthylacetamide, indoleacetic acid, indolebutyric acid, diethyl aminoethyl hexanoate, sodium compound nitrophenolate, gibberellin, brassinolide and brassinolide.

8. The use according to claim 3, wherein the disinfectant solution is used in combination with a fertilizer, the fertilizer being a liquid fertilizer comprising one or more of a liquid amino acid fertilizer, a liquid humic acid fertilizer, a liquid medium element fertilizer, a liquid trace element fertilizer, a liquid macroelement fertilizer and a seaweed extract liquid fertilizer.

9. The use according to claim 3, wherein the fungicide solution is used in combination with a pesticide or herbicide, said pesticide being an insecticide for use on citrus, a fungicide, a second plant growth regulator and a nematicide; the herbicide comprises one or more of citrus orchard herbicide, glyphosate, glufosinate, diquat, paraquat, 2, 4-dichlorophenoxyacetic acid, 2, 4-d butyl ester, pelargonic acid and ammonium nonanoate; preferably, the pesticide is a bactericide used on citrus; preferably, the herbicide is a citrus orchard herbicide.

10. The use of claim 3, wherein the disinfectant solution is diluted with water and then sprayed on citrus leaves and citrus tips, applied to citrus roots, and injected into citrus stems; preferably, the bactericide solution is diluted by adding water and then is sprayed to citrus leaves and citrus treetops for use, and the citrus roots are irrigated with roots for use.

11. The use according to claim 9, wherein the insecticide comprises mineral oil, imidacloprid, thiamethoxam, thiacloprid, clothianidin, imidaclothiz, nitenpyram, acetamiprid, meperidine, fipronil, phenthoate, dichlorvos, chlorpyrifos, fenitrothion, chlorfenafos, isocrotophos, isocarbophos, phoxim, acephate, profenofos, dimethoate, omethoate, triazophos, lambda-cyhalothrin, bifenthrin, permethrin, cypermethrin, ethofenprox, fenvalerate, deltamethrin, fenpropathrin, carbofuran, carbosulfan, pirimicarb, methomyl, isoprocarb, triflumuron, diflubenzuron, chlorfluazuron, chlorfenapyr, fluazuron, pymetrozine, metaflumizone, chlorfenapyr, pyraclostrobin, diafenthiuron, amitraz, fenisobromolate, hexythiazox, fenazaquin, propargite, dicofol, chlorantraniliprole, cyantraniliprole, flubendiamide, spirodiclofen, etoxazole, emamectin benzoate, abamectin, dinotefuran, spirotetramat, bizizanol, sodium rosinate, sulfoxaflor, monosultap, dimehypo, trichlorfon, lufenuron, buprofezin, propiconazole, lambda-cyhalothrin, lime sulphur, pyrethrin, matrine, nicotine, veratrine, eucalyptol and celastrus angulatus.

12. The use according to claim 9, wherein the bactericide comprises copper hydroxide, copper calcium sulfate, cuaminosulfate, oxine-copper, cuprous oxide, copper oxychloride, basic copper carbonate, chlorothalonil, tetrachlorophthalide, pentachloronitrobenzene, sodium diuron, carbendazim, benomyl, thiophanate-methyl, thiabendazole, pyrimethanil, cyprodinil, fluazinam, fenarimol, tridemorph, triflumizole, prochloraz manganese, imazalil, difenoconazole, propiconazole, flutriafol, flusilazole, hexaconazole, epoxiconazole, fenbuconazole, triticonazole, triadimenol, bitertanol, triadimenol, triadimefon, tebuconazole, myclobutanil, pyridinozole, tetraconazole, ipconazole, imibenconazole, penconazole, metalaxyl, mefenoxamine, cyazofamid, isoprothiolamide, flumorphine, propamocarb, propamocarb hydrochloride, famoxadone, hymexazol, carboxin, fluopicolide, fluopyram, boscalid, flutolanil, thifluzamide, pyraclostrobin, azoxystrobin, kresoxim-methyl, trifloxystrobin, enestroburin, pyraclostrobin, difenoconazole, pyribenzoxadinocap, coumoxystrobin, procymidone, vinclozolin, dimethachlon, iprodione, fludioxonil, cynanfol, tricyclazole, zinc thiazole, metconazole, silthiopham, probenazole, pyraclostrobin, kasugamycin, polyoxin, validamycin, jinggangmycin, ningnanmycin, shenqinmycin, pyrimidine nucleoside antibiotics, zhongshengmycin, amino-oligosaccharin, lentinan, morpholine hydrochloride, xinafungan, isoprothiolane, cyazofamid, ethylicin, mancozeb, zineb, thiram, propineb, thifensulam, dithianon and pyrazocarb.

13. The use of claim 9, wherein the second plant growth regulator comprises one or more of naphthylacetic acid, sodium nitrophenolate, gibberellin, ethephon, brassinolide, propionyl brassinolide, mepiquat chloride, chlormequat chloride, trinexapac-ethyl, paclobutrazol, uniconazole, forchlorfenuron, benzylaminopurine, adenine, enadenine, 2- (acetoxy) benzoic acid, triacontanol, diethyl aminoethyl hexanoate, nucleotides, cyanamide, silatran, butyryl hydrazine, S-abscisic acid, chlorpropham-chloride, captan, flumetralin, thidiazuron, pendimethalin and butralin.

14. The use according to claim 9, wherein the nematicide comprises one or more of fenamiphos, fosthiazate, fenamiphos, chloropicrin and cadusafos.