CN114868761B - Bactericide for preventing and treating citrus yellow dragon disease and application thereof - Google Patents

Abstract

The scheme discloses a bactericide for preventing and treating citrus yellow dragon disease and application thereof. The bactericide containing the tetrakis (hydroxymethyl) phosphonium cations is prepared into a bactericide solution, and the mass percentage concentration of the tetrakis (hydroxymethyl) phosphonium cations in the bactericide solution is 1-85%. The bactericide containing the tetrakis hydroxymethyl phosphonium cations disclosed by the application has low phytotoxicity and high compatibility.

Description

A fungicide for preventing and treating citrus huanglongbing and its application

technical field

The invention relates to the technical field of fungicides, in particular to a fungicide for preventing and treating citrus huanglongbing and its application.

Background technique

Citrus Huanglongbing (citrus Huanglongbing) or citrus greening disease (citrus greening disease) is a devastating disease in the citrus industry, which will cause huge losses to the citrus industry. The pathogens of the disease are Gram-negative bacteria, α-proteobacteria, and Candidatus liberibacter, a citrus phloem-restricted bacterium. Candidatus liberibacter can only survive in the phloem of citrus, so far it cannot be cultured in vitro, and it is transmitted through diseased seedlings, scions and vector insects, psyllids.

The existing citrus varieties are all susceptible to citrus Huanglongbing. Symptoms at the citrus seedling stage include short plants, difficulty in taking out shoots, and mottled and yellowed leaves; at the mature stage, the symptoms are slightly yellow and the peel is green. It is commonly known as "red-nosed fruit", and the pulp is bitter, which seriously affects the commercial value. Usually, the infected citrus will turn yellow and wither within a few years after the onset of the disease, which will bring huge economic losses to the fruit growers.

Because Candidatus liberibacter, the pathogenic bacterium of Huanglongbing, can only grow in the phloem and cannot be cultured in vitro, it has greatly hindered the development of drugs for the prevention and treatment of Huanglongbing. The Journal of Huazhong Agricultural University, 2021, Vol. 40, No. 1, pp. 49-57, published "Drug Control Strategies for Citrus Huanglongbing", which reviewed the currently screened drugs for the prevention and control of Huanglongbing. Including β-lactam antibiotics, such as penicillin, ampicillin, cephalexin, penicillin G potassium salt, carbenicillin disodium salt, ampicillin, amoxicillin, etc.; tetracycline, oxytetracycline, sulfadimethoxine sodium wait. But it is worth pointing out that some broad-spectrum antibiotics or bactericidal substances are completely ineffective against Candidatus liberibacter, the pathogen of Huanglongbing. For example, cinoxacin, streptomycin sulfate, polymyxin sulfate, tobramycin, neomycin sulfate, amikacin sulfate, gentamicin sulfate, etc. are completely ineffective against Candidatus liberibacter, the pathogen of Huanglongbing disease. Other broad-spectrum antibiotics such as Jinggangmycin, Zhongshengmycin, hygromycin, kanamycin sulfate, spectinomycin hydrochloride, vancomycin, cycloserine, rifamycin, sulfamethoxazole, sulfathiazole Sodium, chloramphenicol, etc. have only partial effects on Candidatus liberibacter, the pathogen of Huanglongbing, and their activity is low, so they cannot be used as therapeutic agents.

Therefore, Candidatus liberibacter, the pathogen of citrus huanglongbing, is a special bacterium, the presence or absence and magnitude of the effect of bactericidal substances on it need to be tested and verified through experiments, and cannot be simply inferred. The more obvious example is that sulfadimethoxine sodium, sulfamethoxazole, and sulfathiazole sodium belong to the broad-spectrum sulfonamide antibiotics, but only sulfadimethoxine sodium shows high activity, while sulfamethoxazole, sulfamethoxazole, The activity of sulfathiazole sodium is relatively weak and cannot be used as a therapeutic agent.

In addition, according to the reference "Evidence that'Candidatus liberibacter asiaticus' moves predominantly toward new tissue growth in citrus plants" Plant Disease, 2021, Volume 105, Issue 1, pages 34-42. Candidatus liberibacter, the pathogen of citrus huanglongbing, moves to various parts of citrus in the citrus tree with the flow of nutrient solution in the phloem of citrus, and preferentially transfers to new tissues. This indicated that once Candidatus liberibacter, the pathogen of citrus greening disease, infects the citrus tree, it will distribute throughout the citrus tree, which further makes it difficult to control the disease.

Although some patents have disclosed that antibiotics are used for the prevention and treatment of citrus huanglongbing. For example, ZL202011433185.7 discloses a method for preventing and controlling Huanglongbing with avibactam and β-lactam antibiotics; L201610459019.1 discloses the use of trunk injection of ampicillin and cyclopentylpiperazine rifamycin for the prevention and control of Huanglongbing Disease method; ZL201610215621.0 discloses the method of using Zhongshengmycin, oxytetracycline hydrochloride, α-naphthaleneacetic acid, and salicylic acid to treat Huanglongbing by tree trunk injection. These methods often require the use of antibiotic-like substances and require trunk injections. However, the use of antibiotics is likely to cause the residue of citrus antibiotics in citrus fruits, as well as the problem of drug resistance caused by the abuse of antibiotics, and the trunk injection method is inconvenient for farmers to operate, which greatly limits the application of the method.

In addition, some patents disclose methods for the prevention and treatment of citrus huanglongbing by non-antibiotic substances. For example, ZL201811052695.2 discloses that a mixture containing water extract of maple poplar leaves and 3-hydroxyphenylmethylene-1,5-dimethylpyrrolidine-2,4-dione is used for the prevention and treatment of citrus Huanglongbing. ZL202010087340.8 discloses a method for preventing and treating citrus Huanglongbing with thiazoline and copper ammonia. ZL201180055088.1 discloses the use of menadione sodium bisulfite MSB (vitamin K3) for the prevention and treatment of citrus Huanglongbing. ZL20150868515.8 discloses that copper pyrithione, zinc pyrithione or sodium pyrithione is used for the prevention and control of citrus Huanglongbing. These methods use spraying or root irrigation.

Although there have been these research progresses, a cheap and efficient component for the prevention and treatment of citrus greening disease still needs to be discovered urgently.

Contents of the invention

One purpose of this program is to provide a fungicide for preventing and treating citrus huanglongbing.

Another purpose of this program is to provide how to use the above fungicides to prevent and treat citrus huanglongbing.

In order to achieve the above purpose, the program is as follows:

A fungicide for preventing and treating citrus huanglongbing, the fungicide contains tetrakis hydroxymethyl phosphonium cation.

Preferably, the fungicide is prepared as a fungicide solution, and the mass percent concentration of tetrakishydroxymethylphosphonium cations in the fungicide solution is 1%-85%.

In the second aspect, the application provides a kind of fungicide in the prevention and treatment of citrus huanglongbing. The above-mentioned fungicide is formulated as a fungicide solution, and the mass percent concentration of tetrahydroxymethylphosphorus cation in the fungicide solution is: 1% to 85%; the solvent of the bactericide solution is water or water and an organic solvent, and the organic solvent is a water-miscible organic solvent; the water-miscible organic solvent includes methanol, ethanol, glycerin, One or more of ethylene glycol, acetonitrile, dimethylformamide and dimethyl sulfoxide.

Preferably, the fungicide 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 one or more of citrate ions; when the fungicide solution is tetrakis hydroxymethyl phosphorus sulfate aqueous solution; four The mass percentage concentration of hydroxymethyl phosphorus sulfate is 1%～75%; 1% to 80%.

Preferably, the bactericide solution is mixed with amino acids, polypeptides, potassium ions, phosphate ions, magnesium ions, calcium ions, zinc ions, iron ions, boric acid, borax, manganese ions, molybdate ions and humic acid, seaweed polysaccharide One or more of them are used in combination; preferably mixed with zinc ions.

Preferably, the bactericide solution also includes surfactants and penetrants; the surfactants include alkyl glycosides, azone or organosilicon; the bactericide solution contains a mass percent concentration of surfactants of 2 % to 20%; preferably, the mass percent concentration of the surfactant contained in the fungicide solution is 3% to 10%.

Preferably, the first plant growth regulator is also included in the bactericide solution, and the first plant growth regulator comprises naphthaleneacetic acid, naphthaleneacetamide, indole acetic acid, indole butyric acid, diethyl diethyl ethyl, double nitrophenol One or more of sodium, gibberellin, brassinolide and brassinolide.

Preferably, the bactericide solution is used in combination with fertilizers, the fertilizers are liquid fertilizers, and the liquid fertilizers include liquid amino acid fertilizers, liquid humic acid fertilizers, liquid middle element fertilizers, liquid trace element fertilizers, and liquid macroelement fertilizers. One or more of manure and seaweed extract liquid fertilizer.

Preferably, the bactericide solution is used in combination with pesticides or herbicides, and the pesticides are insecticides used on citrus, bactericides, second plant growth regulators and nematicides; Herbicides, one or more of glyphosate, glufosinate, diquat, paraquat, 2,4-dichlorophenoxyacetic acid, 2,4 drops of butyl ester, nonanoic acid and ammonium nonanoate; preferred The pesticide is a fungicide used on citrus; preferably the herbicide is a citrus orchard herbicide.

Preferably, after the bactericide solution is diluted with water, it is used for spraying on citrus leaves and citrus treetops, for citrus tree root irrigation, and for citrus trunk injection; It is used as a spray on citrus treetops and as a root irrigation for citrus trees.

Preferably, the insecticides include mineral oil, imidacloprid, thiamethoxam, thiacloprid, clothianidin, clothiaprid, nitenpyram, acetamiprid, piperid, fipronil, Daofengsan , Dichlorvos, Chlorpyrifos, Fenitrothion, Phthion, Isocarbophos, Phoxim, Acephate, Profenofos, Dimethoate, Omethoate, Triazophos, Lambda-Cyhalothrin, Cyhalothrin, Bifenthrin, Permethrin, Cypermethrin, Etoprofen, Fenvalerate, Deltamethrin, Fenpropathrin, Isoprocarb, Carbofuran, Carbosulfan, Pirimicarb, methomyl, isoprocarb, tebufenozide, triflubenzuron, diflubenzuron, hexaflumuron, hexazuron, methoxyfenozide, cyromazine, diflubenzuron, flubenzuron, Flunicamid, pymetrozine, metaflumizone, chlorfenapyr, tofenpyramid, indoxacarb, diafenthiuron, monoformamidine, amitraz, bromofen, hexythiazox, fenazafen, Tetrafenazin, propargite, dicofol, chlorantraniliprole, cyantraniliprole, flubendiamide, spirodiclofen, etoxazole, emamectin, abamectin, dinotefuran , spirotetramat, bifenazine, sodium rosinate, sulfoxaflor, monosultap, dimehypo, trichlorfon, lufenuron, buprofezin, propiconazole, beta-cypermethrin, lime sulfur Mixture, one or more of pyrethrins, matrine, nicotine, veratrine, eucalyptol and picroderm.

Preferably, the fungicides include copper hydroxide, copper calcium sulfate, copper cyanoline, copper quinoline, cuprous oxide, copper king, basic copper carbonate, chlorothalonil, tetrachlorophthalide, pentachloronitrobenzene , Sodium sulfonate, carbendazim, benomyl, thiophanate-methyl, thiabendazole, pyrimethanil, cyprodinil, fluazinam, chlorpyrimidol, tridemorpholine, fluconazole, Prochloraz, prochloraz manganese salt, imazalil, difenoconazole, propiconazole, fuconazole, flusilazole, hexaconazole, epoconazole, fenconazole, fenconazole, triazole Alcohol, bifentriazole, triadimefon, tebuconazole, diniconazole, mycloconazole, pyridoxazole, tetrafluconazole, penconazole, imidazole, penconazole, metalaxyl, Metalaxyl, cymoxan, rice blastamide, dimethomorph, flumorph, mandiprodil, propamocarb, propamocarb hydrochloride, oxafefenone, hymexazol, rust Ling, Fluopyram, Fluopyram, Boscalid, Fluoramide, Thiofuramide, Pyraclostrobin, Azoxystrobin, Kresstrobin, Trifloxystrobin, Enoxastrobin, Pyrastrostrobin , phenoxystrobin, picoxystrobin, syringstrobin, enotristrobin, procymidone, vinclozolin, sclerotin, iprodione, fludioxonil, cyclostrobin, tricyclazole, Zinc thiazole, eclozole, silthiazil, allylbenthiazole, thiabyl copper, thiamethoxazole, bromthalonil, kasugamycin, polyoxin, Jinggangmycin, Ningnanmycin, Shenzimycin Antibiotics, pyrimidine nucleoside antibiotics, Zhongshengmycin, amino oligosaccharins, lentinan, morpholine hydrochloride, octoprodil, rice blastin, cyazofamid, acetic allicin, mancozeb, dyson One or more of zinc, thiram, propineb, lime sulfur, dicyanoanthraquinone and captan.

Preferably, the second plant growth regulator comprises naphthaleneacetic acid, sodium nitrophenolate, gibberellin, ethephon, brassinolide, brassinolide, propionyl brassinolide, mepiperium, dwarf Metrapine, trinexapac-ethyl, paclobutrazol, uniconazole, forchlorfenuron, benzylaminopurine, adenine adenine, hydroxyadenine adenine, 2-(acetoxy)benzoic acid, triacontanol, diethyl hexanoate, nucleus One of glucosinolate, cyanamide, silicone, butyrhydrazide, S-inducer, chlorphenamine, yiyadan, flubenzamine, thiadizuron, pendimethalin and secbutaline, or Several kinds.

Preferably, the nematicides include one or more of fenamiphos, thiazophos, fenamiphos, chloropicrin and thiamephos.

The beneficial effects of this program are as follows:

The bactericide containing tetrahydroxymethylphosphonium cation disclosed by the present invention has the following beneficial effects: (1) the bactericide containing tetrahydroxymethylphosphonium cation disclosed by the present invention has an excellent control effect on citrus Huanglongbing; Methylphosphonium cation fungicides are cheap and low in cost, and are suitable for large-scale use in the citrus industry; (3) fungicides containing tetrahydroxymethylphosphonium cations can be degraded after use without residue, and will not cause drug residue problems in citrus fruits , avoiding the use of antibiotics, and will not cause antibiotic residues exceeding the standard and the resistance problem of antibiotics being used in large quantities; (4) fungicides containing tetrakis hydroxymethyl phosphonium cations are low-toxic substances, and do not have mutagenicity and carcinogenicity; (5) ) Fungicides containing tetrahydroxymethylphosphorus cations have good compatibility with plants, and do not cause phytotoxicity to plants at high concentrations; (6) Fungicides containing tetrahydroxymethylphosphorus cations are fully soluble in water and can Insecticides, fungicides, herbicides, plant growth regulators, fertilizers, etc. commonly used on citrus are mixed and prepared, and used in combination. It is easy to use, does not need to be used separately, and reduces labor costs.

Detailed ways

The implementation manner of this solution will be further described in detail below. Apparently, the described embodiments are only part of the embodiments of the solution, rather than exhaustive of all the embodiments. It should be noted that, in the case of no conflict, the embodiments in this solution and the features in the embodiments can be combined with each other.

The terms "first", "second", etc., if present, in the description and claims are used to distinguish similar items and not necessarily to describe a specific order or sequence. It should be understood that the data so used are interchangeable under appropriate circumstances. Furthermore, the terms "comprising" and "having", as well as any variations thereof, are intended to cover a non-exclusive inclusion, for example, of a process, method, system, product or device comprising a series of steps or elements, not necessarily limited to the expressly listed Instead, other steps or elements not explicitly listed or inherent to the process, method, product or apparatus may be included.

The effect of antibacterial substances on inhibiting Huanglongbing essentially depends on the efficiency of the drugs absorbed by citrus and transported to the growth site of bacteria. Once the citrus huanglongbing pathogen Candidatus liberibacter infects the citrus tree, it will be distributed throughout the citrus tree. The inventors of the present application have found that effective antibacterial substances should be able to be absorbed by the citrus tree and conduct in the phloem of the citrus tree. . The composition of the phloem of citrus is mainly aqueous solution. Therefore, the conduction of the antibacterial substance in it must require that the substance has a certain water solubility, and the antibacterial substance cannot cause toxicity to plant tissues at an effective bactericidal concentration. Therefore, it is very challenging to screen out medicinal ingredients that can effectively prevent and treat Huanglongbing.

If antibiotics are used to prevent and control citrus Huanglongbing, it is necessary to find a suitable method for drug use because of the poor permeability and conductivity of antibiotics.

The inventors of the present application consider that Candidatus liberibacter, the pathogen of citrus greening disease, is difficult to cultivate in vitro, but belongs to the family Rhizobiumaceae Rhizobiaceae, so they choose to use the strain Sinorhizobium meliloti, which has a close affinity with Candidatus liberibacter, the pathogen of citrus greening disease, to simulate the crop model bacteria of citrus Huanglongbing pathogen Candidatus liberibacter.

Therefore, the present application discloses a fungicide containing tetrakis(hydroxymethyl)phosphonium as an active ingredient screened by Sinorhizobium meliloti, which is used for the prevention and control of citrus huanglongbing. The bactericide provided by the application comprises tetrakis hydroxymethyl phosphorus cations having a structure shown in formula (1),

In one embodiment, the bactericide is prepared as a bactericide solution, and the mass percent concentration of tetrakishydroxymethylphosphonium cations in the bactericide solution is 1 wt % to 85 wt %.

When the fungicide containing the above-mentioned tetrahydroxymethylphosphonium cation is applied to prevent and treat citrus huanglongbing, the fungicide is prepared as a fungicide solution, and the mass percentage concentration of the tetrakishydroxymethylphosphonium cation in the fungicide solution is 1 wt% to 85 wt%. The solvent of the bactericide solution is water or water and an organic solvent, and the organic solvent here is preferably a water-miscible organic solvent.

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

In one embodiment, when the bactericide solution is an aqueous solution of tetrakis hydroxymethyl phosphorus sulfate; the mass percent concentration of tetrakis hydroxymethyl phosphorus sulfate in the bactericide solution is 1wt%～75wt%; When the phosphorous aqueous solution is used, the mass percent concentration of tetrakishydroxymethyl phosphorus chloride in the fungicide solution is 1 wt% to 80 wt%.

Tetrahydroxymethylphosphorus sulfate (THPS) and tetrahydroxymethylphosphorus chloride (THPC) containing tetrahydroxymethylphosphorus cations are widely used as biocides in water treatment, oil field, papermaking and other industries, and can also be used in Permanent flame retardant for pure cotton and polyester-cotton fabrics.

The advantages of Tetrahydroxymethylphosphonium cation are:

1. The preparation and synthesis process is simple, the cost is low, and the sources are extensive;

2. After use, it will be rapidly degraded into completely harmless substances, with no residual pollution at all, and safe for the environment;

3. Tetrahydroxymethylphosphorus sulfate (THPS) and tetrahydroxymethylphosphorus chloride (THPC) are low-toxic compounds, not carcinogenic and teratogenic; For the test report of tetrakis (hydroxymethyl) phosphonium sulfate (THPS) (CAS No. 55566-30-8) AND tetrakis (hydroxymethyl)phosphonium chloride(THPC)(CAS No.124-64-1)in F334/N rats and B6C3F1 mice.";

4. Since the commercialized mass percentage concentration is 70wt%～85wt% tetrakis hydroxymethyl phosphorus sulfate solution and tetrakis hydroxymethyl phosphorus chloride solution are aqueous solution, so commercially available tetrakis hydroxymethyl phosphorus sulfate solution or tetrakis methylol phosphorus Phosphorous chloride solution can be mixed with a variety of plant nutrient fertilizer factors or elements, such as amino acids, polypeptides, potassium, phosphorus, magnesium, calcium, zinc, iron, boron, manganese, molybdenum, humic acid, seaweed polysaccharides, etc.

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

In one embodiment, in addition to tetrakishydroxymethylphosphonium cations, the fungicide solution also contains various ions, such as SO ₄ ^2- , HSO ₄ ^- , SO ₃ ^2- , HSO ₃ ^- , H ₂ PO ₄ ^- , One or more of HPO ₄ ^2- , PO ₄ ^3- , Cl ^- , Br ^- , I ^- , NO ₃ ^- , CH ₃ COO ^- , F ^- and citrate ions, preferably containing SO ₄ ^2- and/or or Cl ⁻ .

In one embodiment, the fungicide solution is mixed with amino acids, polypeptides, potassium ions, phosphate ions, magnesium ions, calcium ions, zinc ions, iron ions, boric acid, borax, manganese ions, molybdate ions and humic acid, seaweed polysaccharide One or more of them are used in combination; preferably mixed with zinc ions.

In one embodiment, surfactant and penetrating agent are also included in the bactericide solution; Wherein surfactant is such as alkyl glycoside, azone or organic silicon; In bactericide solution, the mass percent concentration of surfactant is 2wt% ～20wt%; preferably in the fungicide solution, the mass percentage concentration of the surfactant is 3wt%～10wt%.

In one embodiment, the fungicide solution also includes the first plant growth regulator, wherein the first plant growth regulator such as naphthyl acetic acid, naphthaleneacetamide, indole acetic acid, indole butyric acid, diethyl diethyl ethyl, compound nitrophenol One or more of sodium, gibberellin, brassinolide and brassinolide. The first plant growth regulator in the fungicide solution is usually added in liquid fertilizers and has a growth promoting effect on plants.

In one embodiment, the fungicide solution is used in combination with fertilizers, wherein the fertilizers are liquid fertilizers, and the liquid fertilizers include liquid amino acid fertilizers, liquid humic acid fertilizers, liquid medium-nutrient fertilizers, liquid trace-element fertilizers, liquid macronutrient fertilizers and One or more of seaweed extract liquid fertilizers.

In one embodiment, after the bactericide solution is diluted with water, it is used for spraying on citrus leaves and citrus treetops, for citrus root irrigation, and for citrus trunk injection; Use with citrus treetop spray and as a root scrub for citrus trees.

In one embodiment, the fungicide solution is used in combination with a pesticide or herbicide, wherein the pesticide is an insecticide used on citrus, a fungicide, a second plant growth regulator and a nematicide; the herbicide includes citrus orchard weed control Glyphosate, glufosinate, diquat, paraquat, 2,4-dichlorophenoxyacetic acid (2,4-D), 2,4-D butyl ester, nonanoic acid and ammonium nonanoate One or several kinds; the preferred pesticide is a fungicide used on citrus; the preferred herbicide is a citrus orchard herbicide.

In one embodiment, the insecticides include mineral oil, imidacloprid, thiamethoxam, thiacloprid, clothianidin, clothiaprid, nitenpyram, acetamiprid, piperid, fipronil, San, dichlorvos, chlorpyrifos, fenitrothion, thionon, isocarbophos, phoxim, acephate, profenofos, dimethoate, omethoate, triazophos, lambda-cyhalothrin , cyhalothrin, bifenthrin, permethrin, cypermethrin, etofenproxil, fenvalerate, deltamethrin, fenprovir, isoprocarb, carbofuran, carbosulfan , Anti-pirimicarb, methomyl, isoprocarb, tebufenozide, triflubenzuron, diflubenzuron, hexaflumuron, hexazuron, methoxyfenozide, cyromazine, chlorflubenzuron, fluflubenzuron , flonicamid, pymetrozine, metaflumizone, chlorfenapyr, tofenpyrad, indoxacarb, diafenthiuron, monoformamidine, amitraz, bromofen, hexythiazox, fenazaquin , tetrafenazine, propargite, dicofol, chlorantraniliprole, cyantraniliprole, flubendiamide, spirodiclofen, etoxazole, emamectin, abamectin, dinotefuran Amine, spirotetramat, bifenazine, sodium rosinate, sulfoxaflor, monosultap, dimehypo, trichlorfon, lufenuron, buprofezin, propiconazole, beta-cypermethrin, stone One or more of sulfur compounds, pyrethrins, matrine, nicotine, veratrine, eucalyptol and picroderm.

In one embodiment, the bactericide includes copper hydroxide, copper calcium sulfate, copper cyanoline, copper quinoline, cuprous oxide, copper king, basic copper carbonate, chlorothalonil, tetrachlorophthalide, pentachloronitro Benzene, sodium sulfonate, carbendazim, benomyl, thiophanate-methyl, thiabendazole, pyrimethanil, cyprodinil, fluazinam, chlorpyrimidol, tridemorpholine, fluconazole , prochloraz, prochloraz manganese salt, imazalil, difenoconazole, propiconazole, fuconazole, flusilazole, hexaconazole, flueconazole, cyanobenazole, fenconazole, three Triconazole, Bifenazole, Triadimefon, Tebuconazole, Diniconazole, Myclobutanil, Pyridoxazole, Tetrafluconazole, Buconazole, Imidazole, Penconazole, Metalaxyl , mefenaxyl, cymoxan, rice blastamide, dimethomorph, flumorph, mandipropamid, propamocarb, propamocarb hydrochloride, oxaflucone, hymexazol, wilt Ruoxin, Fluopyram, Fluopyram, Boscalid, Fluoxamide, Thiofuramide, Pyraclostrobin, Azoxystrobin, Kresstrobin, Trifloxystrobin, Enoxastrobin, Azostrobin Lipid, phenoxystrobin, picoxystrobin, syringagactin, enotristrobin, procymidone, vinclozolin, sclerotin, iprodione, fludioxonil, cyclostrobin, tricyclazole , Zinc thiazole, Yekuzol, silthiazil, allyl benzothiazole, thiabyl copper, thiamethoxamyl, bromthalonil, kasugamycin, polyoxin, Jinggangmycin, Ningnanmycin, Shenzine Mycin, pyrimidine nucleoside antibiotics, Zhongshengmycin, amino oligosaccharins, lentinan, morpholine hydrochloride, octoprodil, rice blastin, cyazazole, acetic allicin, mancozeb, substitutes One or more of zinc, thiram, propineb, lime sulfur, dicyanoanthraquinone and captan.

In one embodiment, the second plant growth regulator comprises naphthaleneacetic acid, sodium nitrophenolate, gibberellin, ethephon, brassinolide, brassinolide, propionylbrassinolide, mepiperium, Chlormequat, trinexapac-ethyl, paclobutrazol, uniconazole, forchlorfenuron, benzylaminopurine, adenine adenine, hydroxyadenine adenine, 2-(acetoxy) benzoic acid, triacontanol, diethyl hexanoate, One of nucleotides, cyanamide, silicone, butyrhydrazide, S-reversin, chlorphenamine, yibadan, flumetriamine, thiadizuron, pendimethalin and secbutaline Or several; the second plant growth regulator in this embodiment includes various types of plant growth regulators.

In one embodiment, the nematicides include one or more of fenamiphos, thiazophos, fenamiphos, chloropicrin and thiamephos.

The present application will be further described through specific examples below.

Candidatus liberibacter, the causative agent of citrus greening disease, is difficult to culture in vitro, but it belongs to the family Rhizobiaceae. 0. Therefore, Sinorhizobium meliloti, a strain closely related to Candidatus liberibacter, the pathogen of citrus greening disease, was used for screening. The Sinorhizobium meliloti used in the experiment was purchased from the China Agricultural Microorganism Culture Collection Center with the strain number ACCC17528.

Example 1

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

The medium formula of Sinorhizobium meliloti is: 30 grams of sucrose, 0.375 grams of K ₂ HPO ₄ , 0.375 grams of KH ₂ PO ₄ , 0.3 grams of MgSO ₄ .7H ₂ O, 0.21 grams of NaCl, 4.2 grams of yeast extract powder, 1 %Na ₂ MoO ₄ solution 150 μl, 1% MnSO ₄ solution 150 μl, 1% B(OH) ₃ solution 150 μl, 1500ml tap water, mix well. Divide into 250ml Erlenmeyer flasks, add 100ml medium to each Erlenmeyer flask, and sterilize at 121°C for 25 minutes. Cool to room temperature and set aside.

Take 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, respectively, and add them to 1000 μl of DMSO solvent to prepare the first A drug solution.

Because commercially available tetrakis hydroxymethyl phosphorus sulfate (THPS) is the tetrakishydroxymethyl phosphorus sulfate (THPS) aqueous solution that content is 75wt%, so 100 μ l commercially available mass percent concentration is the tetrakishydroxymethyl phosphorus sulfate (THPS) of 75wt%. THPS) aqueous solution was added to 1000 μl of DMSO to prepare tetrakishydroxymethylphosphine sulfate DMSO solution.

Add the above-mentioned first drug solution and the prepared DMSO solution to the above-mentioned Sinorhizobium meliloti liquid culture medium cooled to room temperature for use. Add two bottles of each solution, add 25 μl and 50 μl respectively; control (CK) is to add DMSO solvent to the above-mentioned S. Add 100 μl of Sinorhizobium meliloti bacterium solution to all the medium added to the solution, and measure the absorbance Abs595nm after culturing on a shaker at 28° C. for 32 hours. (Wherein the aforementioned Sinorhizobium meliloti bacterium liquid is picked the plate Sinorhizobium meliloti bacterium colony to inoculate in the liquid culture medium the day before, 28 ℃ shakes the flask to culture and prepares the bacterium liquid for use), the shaking flask screening test result is shown in Table 1 .

Table 1

From the results in Table 1, it can be seen that the fungicides metronidazole and dihydromyricetin have no activity against Sinorhizobium meliloti ACCC17528. The menadione sodium bisulfite MSB disclosed in ZL201180055088.1 has only moderate activity against S. meliloti ACCC17528. 4-isopropyl-3-methylphenol (common name, thymol) is less active. Tetrahydroxymethylphosphorus sulfate (THPS) has a weak inhibitory activity against S. meliloti ACCC17528 at a concentration of 18.75ppm, and a strong inhibitory activity against S. meliloti ACCC17528 at a concentration of 37.5ppm, which is close to complete inhibition.

Example 2

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

1. The Sinorhizobium meliloti ACCC17528 in the present embodiment is cultured using the culture medium of the Sinorhizobium meliloti sterilized in Example 1, and the culture temperature is 180 rpm at 28 ° C in a shaker flask, until the _OD600 value is about 1.0, using sterile The diluted S. meliloti ACCC17528 was diluted 50 times with water for use.

The medium formula of Sinorhizobium meliloti is:

Sucrose 30 g, K ₂ HPO ₄ 0.375 g, KH ₂ PO ₄ 0.375 g, MgSO ₄ .7H ₂ O 0.3 g, NaCl 0.21 g, yeast extract powder 4.2 g, 1% Na ₂ MoO ₄ solution 150 μl, 1% MnSO ₄ 150 μl of solution, 150 μl of 1% B(OH) ₃ solution, and 1500 ml of tap water were mixed evenly, autoclaved at 121° C. for 25 minutes, and cooled to room temperature for use.

2. Test the minimum inhibitory concentration MIC value of tetrahydroxymethylphosphorus sulfate (THPS) in a row of wells of a 96-well plate. Such as row A, the holes are A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12. Except for A2 and A12, 200 μl of sterilized liquid medium of Sinorhizobium meliloti was added.

In A2, add 200 μl of 375ppm THPS medium solution (dilute the commercially available THPS aqueous solution with a mass percentage concentration of 75wt% with the liquid medium of Sinorhizobium meliloti sterilized and cooled to room temperature to obtain. In A3, add 200μl medium solution containing 375ppm THPS. At this time, the liquid volume in A3 is 400μl, take 200μl solution from A3 and add it to A4 and mix it, then take 200μl solution from A4 and add it to A5 and mix it, and perform two-fold gradient dilution in this way to A11. Then take 200μl from A11 and add to A12.

Well A1 is a negative control, in which no medium solution containing THPS is added. Add 50 μl of the diluted S. meliloti ACCC17528 from step 1 to A1 to A11. A12 without the diluted Sinorhizobium meliloti ACCC17528.

After the 96-well plate was placed in an incubator at 28°C for 48 hours, the absorbance value of each well was measured at 595 nm with a microplate reader. The wells where S. meliloti grows have a large absorbance value, while the wells where S. meliloti does not grow have a small or close to zero absorbance value. The minimum concentration of THPS that can inhibit the growth of S. meliloti ACCC17528 was taken as the MIC value. At this concentration, the absorbance is very small, or close to zero. However, the S. meliloti grows in the adjacent wells of this concentration and the wells with a 2-fold dilution concentration have a larger absorbance value.

The measured minimum inhibitory concentration MIC of tetrahydroxymethylphosphorus sulfate (THPS) against Sinorhizobium meliloti ACCC17528 was 9.4ppm (calculated as tetrahydroxymethylphosphorus sulfate (THPS)). The results of the 96-well plate test were smaller than those of the shake flask test, which may be due to the difference between the shaking culture environment of the shake flask and the static culture environment of the 96-well plate.

Example 3

Determination of the toxicity of tetrakis (hydroxymethyl) phosphonium fungicides to plants.

The commercially available mass percent concentration is 75% tetrakis hydroxymethyl phosphorus sulfate aqueous solution and dilutes with tap water, is diluted to concentration respectively and is 1350ppm, 675ppm, 450ppm, 150ppm, 135ppm, the tetrakis hydroxymethyl phosphorus sulfate aqueous solution of 15ppm, uses tap water clear water as Control CK.

The corn seeds were respectively soaked in these solutions, 10 seeds were soaked in each concentration solution, and soaked overnight. Take out then; Put a piece of filter paper on the petri dish, get 4ml above-mentioned 1350ppm, 675ppm, 450ppm, 150ppm, 135ppm, 15ppm tetrakis hydroxymethyl phosphorus sulfate aqueous solution, add in each petri dish respectively with 4ml tap water clear water as negative control. Then put the above-mentioned soaked corn seeds on the filter paper sheet, and put the petri dish into a 28° C. incubator for germination. Take it out after three days. Measure shoot length and root length for germinated corn seeds. The measured data can be seen in Table 2.

Calculate the average and variance of the root length and bud length data of corn germination in each treatment group, and perform t-test with the control clean water treatment group, and calculate the significant difference between the treatment group and the control clean water group. No inhibition was indicated if there was no significant difference between the treated and control groups. Inhibition is indicated if there is a significant difference between the treatment group and the control group.

The data in Table 2 shows that when the corn is germinated with THPS concentrations of 15ppm, 135ppm, 150ppm, and 450ppm, the root length and shoot length of the corn are not significantly different from those of the control group. When the concentration of THPS was 1350ppm, there was a significant difference in the corn germination length of the treatment group and the control group, which showed that THPS strongly inhibited the corn germination. When the concentration of THPS was 675ppm, there was no significant difference in the corn bud length between the treatment group and the control group, indicating that there was no inhibitory effect. However, at this concentration, the corn root length of the treatment group was significantly different from that of the control group. Under the THPS concentration of 675ppm, the average root length of corn in the treatment group was 34mm, and that in the control group was 94mm, and the inhibition rate was (94-34)/94=64%. According to the germination test of corn seeds, it is determined that the safe concentration of THPS to plants is between 450-675ppm.

Table 2

Example 4

Tetrakis (hydroxymethyl) phosphonium fungicide is coordinated with different metal ions and amino acids.

Formula 1: 50 grams of zinc sulfate heptahydrate, 53 grams of commercially available tetrakis hydroxymethyl phosphorus sulfate (THPS) (75%wt) aqueous solution, 48 grams of water, 0.5 grams of commercially available mixed amino acid powder (80%wt), 6 gram of alkyl glycoside APG0810, mix well to form a homogeneous clear solution. The mass percent content of THPS in the solution after preparation is 25%; it is recorded as Zn-THPS.

Prescription 2: 35 grams of ferrous sulfate heptahydrate, 54.4 grams of commercially available tetrakis hydroxymethyl phosphorus sulfate (THPS) (75%wt) aqueous solution, 56 grams of water, 0.6 grams of commercially available mixed amino acid powder (80%wt), 6 grams of alkyl glycoside APG0810, mixed well to form a homogeneous clear solution. The mass percent content of THPS in the solution after preparation is 27%; it is recorded as Fe-THPS.

Formula 3: 45 grams of ferrous sulfate heptahydrate, 55.7 grams of zinc sulfate heptahydrate, 77 grams of commercially available tetrakis hydroxymethyl phosphorus sulfate (THPS) (mass content 75%wt) aqueous solution, 125 grams of water, commercially available mixed amino acids Powder (80%wt) 1.4 grams, 10 grams of alkyl glycoside APG0810, mix well to form a homogeneous clear solution. The mass percent content of THPS in the solution after preparation is 18%; it is recorded as Fe-Zn-THPS.

Formula 4: 42 grams of anhydrous copper sulfate, 111 grams of commercially available tetrakis hydroxymethyl phosphorus sulfate (THPS) (75%wt) aqueous solution, 86 grams of water, 1.4 grams of commercially available mixed amino acid powder (80%wt), 10 gram of alkyl glycoside APG0810, mixed evenly to form a homogeneous clear solution, the mass percentage of THPS in the solution after preparation is 33%; recorded as Cu-THPS.

Formula 5: 6.7 grams of boric acid, 55 grams of water, 60.6 grams of commercially available tetrakis hydroxymethyl phosphorus sulfate (THPS) (75%wt) aqueous solution, 0.6 grams of commercially available mixed amino acid powder (80%wt), 6 grams of alkyl Glycoside APG0810, mix well to form a homogeneous clear solution. The mass percent content of THPS in the solution after preparation is 35%; it is recorded as B-THPS.

Formula 6: 3.3 grams of ferrous sulfate heptahydrate, 17.2 grams of zinc sulfate heptahydrate, 2.2 grams of boric acid, 99.8 grams of commercially available tetrakisphosphonium sulfate (THPS) (75%wt) aqueous solution, 80 grams of water, commercially available Mix 26.4 grams of amino acid powder (80% wt) and 6 grams of alkyl glycoside APG0810, and mix well to form a homogeneous clear solution. The mass percent content of THPS in the solution after preparation is 32%; it is recorded as AM-THPS.

Use a 96-well plate to measure the minimum inhibitory concentration MIC value of each formulation and copper sulfate pentahydrate, commercially available THPS (75%) aqueous solution to Sinorhizobium meliloti, and measure twice in parallel. The test procedure is the same as in Example 2. Table 3 shows the minimum inhibitory concentration MIC value of each formulation.

Wherein, the MIC value in terms of each formula concentration is defined as the content of each formula solution being 100% of the formula concentration. For example, the solution of formula (1) is diluted 1000 times to obtain a concentration solution of 1000 ppm based on formula (1). 25% = 250 ppm.

table 3

It can be seen from Table 3 that the MIC value of Zn-THPS in terms of THPS is 1.6ppm, which is 17% of the MIC value in terms of THPS of commercially available THPS (75%wt) aqueous solution 9.4ppm, indicating that there is a synergistic effect between THPS and Zn . However, the MIC values of B-THPS and AM-THPS calculated in THPS are 8.8ppm and 6ppm respectively, which are not much different from the MIC value calculated in THPS of commercially available THPS (75%wt) aqueous solution of 9.4ppm, indicating that B or amino acid and The THPS interaction is small and does not affect the bactericidal activity of THPS. In addition, the MIC values of Cu-THPS and Fe-THPS in terms of THPS are 24.8ppm and 20.2ppm respectively, both of which are larger than the MIC value of 9.4ppm in terms of THPS of the commercially available THPS (75%wt) aqueous solution, indicating that Cu or Fe Interaction with THPS will reduce the bactericidal effect of THPS.

Example 5

Example of mixing preparation of THPS aqueous solution and fungicide

Zinc thiazole (97.5%) 10 grams, 2 grams NP-10 (nonylphenol polyoxyethylene ether), 2 grams 1602 (tristyrylphenol polyoxypropylene polyoxyethylene ether), xanthan gum 0.2 grams, 4 gram sodium lignosulfonate, 0.2 gram sodium carboxymethyl cellulose, 3 gram ethylene glycols, add commercially available tetrakis hydroxymethyl phosphorous sulfate (THPS) (75%wt) aqueous solution 10 grams, water 68.6 grams make up to 100 Gram, carry out sand grinding, obtain 9.75% thiazole zinc, the suspension concentrate mixed liquor of the thiazole zinc THPS of 7.5% THPS.

Example 6

Example of THPS mixed with insecticide

Chlorantraniliprole (95%) 3 grams, 1 gram NP-10 (nonylphenol polyoxyethylene ether), 4 grams 1602 (tristyrylphenol polyoxypropylene polyoxyethylene ether), xanthan gum 0.2 gram, 5 gram sodium lignosulfonate, 0.2 gram sodium carboxymethyl cellulose, 3 gram glycerin, add commercially available tetrakis hydroxymethyl phosphorus sulfate (THPS) (75%wt) aqueous solution 10 grams, add water 73.6 grams Make up to 100 grams, carry out sand grinding to obtain 2.85% chlorantraniliprole, 7.5% THPS chlorantraniliprole THPS suspension mixture.

Example 7

Example of THPS mixed with herbicide

Add 10 grams of commercially available tetrahydroxymethylphosphorus sulfate (THPS) (75% wt) aqueous solution into 80 grams of 20% glufosinate-ammonium solution, add 6 grams of alkyl glycoside APG0810, add 4 grams of water to make up to 100 grams, An aqueous solution of 16% glufosinate-ammonium and 7.5% THPS was obtained.

Example 8

Example of mixing and preparing THPS with plant growth regulators

0.1 gram of brassinolide, 0.1 gram of gibberellin, 0.1 gram of benzylaminopurine, 0.1 gram of naphthaleneacetic acid, 20 grams of commercially available tetrakis hydroxymethyl phosphorus sulfate (THPS) (75%wt) aqueous solution, 6 grams Alkyl glycoside APG0810 was prepared by adding 73.7 grams of water to an aqueous solution containing 15% THPS, 0.1% brassinolide, 0.1% gibberellin, 0.1% benzylaminopurine, and 0.1% naphthaleneacetic acid.

Example 9

From 2020 to 2021, the drug experiment will be carried out in the navel orange orchard of Dongshan Village, Dayu County, Ganzhou City. The navel orange variety is Newhall. The test trees were all adult fruiting trees infected with Huanglongbing. Three plants were replicated for each treatment, and a total of 12 diseased trees were tested. The test area is supplemented by normal water and fertilizer management and pesticide management (mainly to control citrus psyllids). Each treatment group kept the same water and fertilizer application. The experimental design is shown in Table 4.

Among them, treatment group 1 was sprayed with 500 times of the treatment agent diluted with water on November 21, 2020, and sprayed with 500 times of the treatment agent diluted with water on May 27, 2021. The dripping water sprayed on the leaves of the whole tree shall prevail. The spray liquid has a final concentration of 416ppm in THPS.

Treatment group 2 was sprayed with 1000 times dilution of treatment agent with water on November 21, 2020, and 1000 times dilution spray of treatment agent with water on May 27, 2021. The dripping water sprayed on the leaves of the whole tree shall prevail. The spray liquid has a final concentration of 208ppm in THPS.

Treatment group 3 was sprayed on November 21, 2020 by diluting 1000 times of the treatment agent with water and irrigating the roots at the same time. The treatment agent was diluted 1000 times with 1 kg of water for root irrigation of each tree. On May 27, 2021, the treatment agent was diluted 1000 times with water and sprayed, and the roots were irrigated at the same time. The treatment agent diluted 1000 times with 1kg of water was applied to each tree. The foliar spray is based on the wet dripping of the whole tree foliage. The spray liquid has a final concentration of 208ppm in THPS.

Treatment group 4 (control group CK) was sprayed with a 500-fold dilution of the control drug with water on November 21, 2020, and a 500-fold dilution of the control drug with water on May 27, 2021. The final concentration of the spray liquid is 0ppm in THPS.

Wherein (1) treatment agent formula:

Commercially available tetrakis hydroxymethyl phosphorus sulfate (THPS) (75%wt) aqueous solution 139 grams, alkyl glycoside (APG0810) 30 grams, water 331 grams, total weight 500 grams. Wherein the concentration is 20.8% in THPS.

(2) The formula of the control drug:

Alkyl glucoside (APG0810) 30 grams, water 470 grams, total weight 500 grams.

Table 4.

Samples were taken on November 20, 2020 before spraying, and 4-5 mature leaves were collected from the southeast, northwest, middle, and five directions of Huanglongbing diseased trees. A total of 20-25 leaves were collected from each tree. During the collection process, crossover between samples was avoided. Contamination, the collected samples are sent to the laboratory for processing, or temporarily stored at 4°C.

The national standard GB/T28062-2011 "Real-time fluorescent PCR detection method for citrus Huanglongbing" was adopted. The veins in the leaf samples were cut out and ground into powder using liquid nitrogen. Take about 200mg of vein powder and use CTAB-Triton method to extract vein DNA from leaf samples. SYBR Green I fluorescent dye PCR method was used for detection.

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

SYBR Green I fluorescent dye PCR reaction system 25ul, containing final concentration 1×SYBR Green I quantitative IQSYBR Green Supermix (Bio-Rad USA), 0.75 μmol/L primer pair CQULA04F/CQULA04R and 2 μl template. Fluorescent quantitative PCR detection was performed on a fluorescent quantitative PCR instrument, pre-amplification at 95°C for 1min; denaturation at 95°C for 15s; annealing at 59°C for 15s; extension at 72°C for 20s; 41 cycles. Set up simultaneous multiple acquisitions of fluorescence during the extension phase of each cycle. In order to verify the specificity of the amplification, immediately after the amplification is completed, the analysis of the melting curve is carried out. The reaction program is: 95°C, 30s; 80 times (up to 95°C). Record the measured Ct value.

According to the literature "Preliminary Report on Screening Tests of Chemicals for Prevention and Control of Citrus Huanglongbing", Plant Protection 2014, Vol. 40 (2), pp. 166-170.

use formula

CN=75×10 ^{11.61-0.288Ct} to calculate the amount of bacteria carried in the tree tissue of Huanglongbing.

Ct is the Ct value determined by SYBR Green I fluorescent dye fluorescence quantitative PCR.

CN is the amount of bacteria carried per gram of tissue of Huanglongbing diseased trees. (The unit is the DNA copy number of pathogenic bacteria, copy number/g, CN/g)

After spraying, take a sample on February 21, 2021, 2 months after the first dose. One sampling on April 13, 2021. After the second spraying of medication, a sample will be taken on July 10, 2021, and a sample will be taken on August 28, 2021. The test results are shown in Table 5.

table 5

It can be known from Table 5 that the decline rate of Huanglongbing pathogenic bacteria = (CN value of the bacteria in the treatment area before the application of the drug - the CN value of the bacteria in the treatment area after the application of the drug) / the CN value of the bacteria in the treatment area before the application of the drug × 100%. For convenience, it is calculated on August 28, 2021.

Among them, in treatment 1, the reduction rate of Huanglongbing bacteria was 100%; in treatment 2, the reduction rate of Huanglongbing bacteria was 99.7%; in treatment 3, the reduction rate of Huanglongbing bacteria was 99.9%. However, the Huanglongbing bacteria in the control treatment group increased by 14%. It can be seen that the therapeutic effect of THPS is related to the concentration of the drug. The therapeutic effect at 500-fold dilution is better than at 1000-fold dilution. At the same time, root irrigation treatment has a synergistic effect on the treatment effect of chemicals.

On November 30, 2021, the fruits of the four treatment groups were harvested. Among them, the good fruit rate of treatment 1 is about 95%, the basic fruit shape is normal, there are few red-nosed fruits, and a few fruits have some green skins that are not completely spot-colored and turn orange (not counted as good fruits). The fruit is artificially tasted, and the sweetness of the fruit is high, which is equivalent to the normal fruit without Huanglongbing. Among them, the good fruit rate of treatment 2 is about 75%, and there are some red-nosed fruits, which taste normal in appearance. The sweetness is not as good as that of treatment 1, and there is a little sour taste. The good fruit rate of treatment 3 is about 85%, and there are a few red-nosed fruits. On the lower branches, the fruits with normal appearance are tasted. The sweetness is not as good as that of treatment 1, but the sweetness is acceptable. Treatment 4 (control treatment) is basically red-nosed fruit and has no commercial value.

It can be known from the foregoing examples that tetrakishydroxymethylphosphorus sulfate (THPS) and tetrakishydroxymethylphosphorus chloride (THPC) containing tetrakishydroxymethylphosphorus cations have low phytotoxicity and high compatibility.

Obviously, the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, rather than limiting the implementation of the present invention. For those of ordinary skill in the art, on the basis of the above description, they can also make It is not possible to exhaustively list all the embodiments here, and any obvious changes or changes derived from the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims (9)

1. The application of the bactericide in preventing and treating citrus yellow dragon disease is characterized in that the bactericide is prepared into a bactericide solution, and the mass percentage concentration of the tetrakis (hydroxymethyl) phosphonium cations 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 which is miscible with water; the water-miscible organic solvent comprises one or more of methanol, ethanol, glycerol, ethylene glycol, acetonitrile, dimethylformamide and dimethyl sulfoxide; the bactericide solution also contains SO ₄ ^2- ，HSO ₄ ^- ，Cl ^- One or more of them.

2. The use according to claim 1, wherein when the bactericide solution is an aqueous solution of phosphorus tetramethylolsulfate, the mass percentage concentration of the phosphorus tetramethylolsulfate in the bactericide solution is 1% -75%.

3. The use according to claim 1, wherein when the bactericide solution is an aqueous solution of tetrakis (hydroxymethyl) phosphonium chloride, the mass percentage concentration of the tetrakis (hydroxymethyl) phosphonium chloride in the bactericide solution is 1% -80%.

4. The use according to claim 1, wherein the bactericide solution is mixed with one or more of amino acids, polypeptides, boric acid and humic acid, trehalose.

5. The use according to claim 1, wherein the biocide solution further comprises a surfactant and a penetrant; the surfactant comprises an alkyl glycoside, azone or silicone; the bactericide solution contains 2-20% of surfactant by mass percent.

6. The use according to claim 1, wherein the fungicide solution further comprises a first plant growth regulator comprising one or more of naphthalene acetic acid, naphthalene acetamide, indole acetic acid, indole butyric acid, diethyl amine, sodium nitrophenolate, gibberellin, brassinolide and brassin.

7. The use according to claim 1, wherein the bactericide 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.

8. Use according to claim 1, wherein the fungicide solution is used in combination with a pesticide, which is a pesticide for citrus use, a second plant growth regulator and a nematicide.

9. The use according to claim 1, wherein the bactericide solution is diluted with water and sprayed onto citrus leaves and citrus tree tips, root-rooted citrus tree roots and injected into citrus trunks.