WO2023197675A1 - Bactericide for preventing and controlling citrus huanglongbing and use thereof - Google Patents

Abstract

Disclosed in the present solution are a bactericide for preventing and controlling citrus huanglongbing and the use thereof. The bactericide contains tetrakis(hydroxymethyl)phosphonium. The bactericide containing tetrakis(hydroxymethyl)phosphonium is formulated as a bactericide solution, and the mass percentage concentration of tetrakis(hydroxymethyl)phosphonium in the bactericide solution is 1%-85%. The bactericide containing tetrakis(hydroxymethyl)phosphonium disclosed in the present application has low phytotoxicity and high compatibility.

Description

A fungicide used to prevent and control citrus Huanglongbing and its application Technical field

The present invention relates to the technical field of fungicides, in particular to a fungicide used to prevent and treat citrus Huanglongbing and its application.

Background technique

Citrus Huanglongbing or citrus greening disease is a devastating disease in the citrus industry, which can cause huge losses to the citrus industry. The causative agent of this disease is a Gram-negative bacterium, α-Proteobacteria, and the citrus phloem-restricted bacterium Candidatus liberibacter. Candidatus liberibacter can only survive in the phloem of citrus and is still unable to be cultured in vitro. It is spread through diseased seedlings, scions and the vector insect psyllid.

The existing citrus varieties grown are all susceptible to citrus Huanglongbing fungus. In the citrus seedling stage, the disease manifests itself as short plants, difficulty in sprouting, and mottled yellowing of the leaves; in the mature stage, the disease manifests as yellowing, green skin, commonly known as "red-nosed fruit", and bitter pulp, which seriously affects the commercial value. Usually infected citrus will turn yellow and wither within a few years after the disease occurs, causing huge economic losses to fruit farmers.

Since the pathogenic bacteria of Huanglongbing, Candidatus liberibacter, can only grow in the phloem and cannot be cultured in vitro, the development of prevention and treatment drugs for Huanglongbing has been greatly hindered. "Citrus Huanglongbing Drug Prevention and Control Strategies" published in Journal of Huazhong Agricultural University, 2021, Volume 40, Issue 1, Pages 49-57, reviews the currently selected prevention and treatment drugs for Huanglongbing. These include β-lactam antibiotics, such as penicillin, ampicillin, cephalexin, penicillin G potassium salt, carbenicillin disodium salt, ampicillin, amoxicillin, etc.; tetracycline, oxytetracycline, sulfamethoxine sodium wait. However, it is worth pointing out that some broad-spectrum antibiotics or bactericidal substances are completely ineffective against Candidatus liberibacter, the causative agent of Huanglongbing. For example, cinofloxacin, streptomycin sulfate, polymyxin sulfate, tobramycin, neomycin sulfate, amikacin sulfate, gentamicin sulfate, etc. are completely ineffective against Candidatus liberibacter, the pathogenic bacteria of Huanglongbing. 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 pathogenic bacteria of Huanglongbing, and their activity is low, so they cannot be used as therapeutic agents.

Therefore, Candidatus liberibacter, the pathogen of citrus greening disease, is a special bacterium. The presence and size of the effect of bactericidal substances on it needs to be tested and verified experimentally, and cannot be known simply through inference. One of the more obvious examples is that sulfamethoxazole sodium, sulfamethoxazole, and sulfathiazole sodium all belong to the sulfonamide broad-spectrum antibiotics, but only sulfamethoxazole sodium shows high activity, while sulfamethoxazole, sulfamethoxazole, Sulfathiazole sodium has weak activity and cannot be used as a therapeutic agent.

In addition, according to the reference "Evidence that 'Candidatus liberibacter asiaticus' moves predominantly towards new tissue growth in citrus plants" Plant Disease, 2021, Volume 105, Issue 1, Pages 34-42. The pathogenic bacteria of citrus greening disease, Candidatus liberibacter, follows the flow of nutrient fluid from the phloem of citrus in the citrus tree and moves to various parts of the citrus, preferentially transferring to new tissues. This shows that once Candidatus liberibacter, the pathogen of citrus greening disease, infects a citrus tree, it will be distributed throughout the citrus tree, which further makes it difficult to control the disease.

Although some patents have disclosed the use of antibiotics for the prevention and treatment of citrus greening disease. For example, ZL202011433185.7 discloses a method of preventing and treating Huanglongbing with avibactam and β-lactam antibiotics; L201610459019.1 discloses using tree trunks to inject ampicillin and cyclopentylpiperazine rifamycin to prevent and control Huanglongbing. Methods for treating Huanglongbing disease; ZL201610215621.0 discloses a method of treating Huanglongbing disease using tree trunk injection using Zhongshengmycin, Oxytetracycline Hydrochloride, α-naphthylacetic acid, and salicylic acid. These methods usually require the use of antibiotics and involve injections into the tree trunk. However, the use of antibiotics can easily lead to residues of citrus antibiotics in citrus fruits, as well as drug resistance problems caused by the abuse of antibiotics. The trunk injection method is inconvenient for farmers to operate, which greatly limits the application of the method.

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

Despite these research advances, a cheap and efficient ingredient for preventing and treating citrus greening disease still needs to be discovered.

Contents of the invention

One purpose of this solution is to provide a fungicide for controlling citrus greening disease.

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

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

A fungicide used to prevent and treat citrus greening disease, the fungicide contains tetrahydroxymethylphosphorus cation.

Preferably, the bactericidal agent is formulated as a bactericidal solution, and the mass percentage concentration of tetrahydroxymethylphosphonium cations in the bactericidal solution is 1% to 85%.

In a second aspect, this application provides an application of a fungicide in the prevention and treatment of citrus greening disease. The fungicide as described above is formulated into a fungicide solution. The mass percentage concentration of tetrahydroxymethylphosphonium cations 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 an organic solvent miscible with water; the organic solvent miscible with water includes methanol, ethanol, and glycerin, One or more of ethylene glycol, acetonitrile, dimethylformamide and dimethyl sulfoxide.

Preferably, the bactericide 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 ^- , one or more of F ^- and citrate ions; when the fungicide solution is a tetrakis hydroxymethyl phosphorus sulfate aqueous solution; The mass percentage concentration of hydroxymethylphosphorus sulfate is 1% to 75%; when the bactericide solution is an aqueous solution of tetrahydroxymethylphosphorus chloride, the mass percentage concentration of tetrahydroxymethylphosphorus chloride in the bactericide solution 1% to 80%.

Preferably, 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 mixture; preferably mixed with zinc ions.

Preferably, the bactericidal solution also contains a surfactant and a penetrating agent; the surfactant includes alkyl glycosides, azones or silicones; the mass percentage concentration of the surfactant in the bactericidal solution is 2 % to 20%; the preferred mass percentage concentration of surfactant in the bactericide solution is 3% to 10%.

Preferably, the fungicide solution also contains a first plant growth regulator, and the first plant growth regulator includes naphthyl acetic acid, naphthyl acetamide, indole acetic acid, indole butyric acid, ethanol, and nitrophenol. One or more of sodium, gibberellins, brassinosteroids and brassinosteroids.

Preferably, the fungicide solution is used in combination with fertilizer, and the fertilizer is a liquid fertilizer. The liquid fertilizer includes a liquid amino acid fertilizer, a liquid humic acid fertilizer, a liquid medium element fertilizer, a liquid trace element fertilizer, and a liquid macroelement fertilizer. One or more of fertilizers and seaweed extract liquid fertilizers.

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

Preferably, the fungicide solution is diluted with water and used for spraying on citrus leaves and citrus treetops, used for root irrigation on citrus tree roots, and used for injection on citrus trunks; preferably, the fungicide solution is diluted with water and used for citrus leaves and treetops. Use spray on citrus treetops and root irrigation on citrus trees.

Preferably, the insecticides include mineral oil, imidacloprid, thiamethoxam, thiacloprid, clothianidin, chlorothiazide, nitenpyram, acetamiprid, piperamiprid, fipronil, and Daofengsan , dichlorvos, chlorpyrifos, fenitrothion, chlorpyrifos, phoxim, acephate, profenofos, dimethoate, omethoate, triazophos, beta-cyhalothrin, Cyhalothrin, bifenthrin, permethrin, cypermethrin, fenthrin, fenvalerate, deltamethrin, fenpropathrin, isoprocarb, carbofuran, carbofuran, pirimicarb, methomyl, isoprocarb, diflubenzuron, fluflubenzuron, diflubenzuron, fluflubenzuron, fluflubenzuron, methoxyfenozide, cyromazine, fenflubenzuron, fluflubenzuron, Flufenamid, pymetrozine, flufenoxil, fenfentrile, fenpyramid, indoxacarb, didifenthiuron, monocarbamate, bicarbamate, bromofenacet, thifenacetate, fenamifen, Tetramethoxam, propargite, dicofol, chlorantraniliprole, cyantraniliprole, flubendiamide, spirodiclofen, etoxazole, emamectin, abamectin, dinotefuran , spirotetramat, biphenylhydrazine, sodium rosinate, sulfoxaflor, trichlorfon, lufenuron, trichlorfon, propiconazole, beta-cypermethrin, lime sulfide Mixture, one or more of pyrethrin, matrine, nicotine, veratrine, eucalyptol and eucalyptol.

Preferably, the bactericide includes copper hydroxide, calcium copper sulfate, copper hydroxide, copper quinoline, cuprous oxide, copper king, basic copper carbonate, chlorothalonil, tetrachlorophthalide, pentachloronitrobenzene , Dipyridin, carbendazim, benomyl, thiophanate-methyl, thiabendazole, pyrimidine, cyprodinil, fluazinam, clofenacil, trimorpholine, trifluconazole, Prochloraz, prochloraz manganese salt, imazalil, difenoconazole, propiconazole, fluconazole, flusilazole, hexaconazole, epoconazole, nitrileconazole, mefenazole, triazole Alcohol, biphenyltriadienol, triadimefon, tebuconazole, penconazole, myclobutanil, picoconazole, tetrafluorotriazole, tricloconazole, iminoconazole, penconazole, metalaxyl, Metalaxyl, cymoxanil, pyridine, dimethomorph, flumorphaline, propylostrobin, propamocarb, propamocarb hydrochloride, oxazofen, oxamyperm, cartilage Fluopicostrobin, Fluopicostrobin, Fluopicostrobin, Boscalid, Flufenamide, Thifuramide, Pyraclostrobin, Azoxystrobin, Tristrostrobin, Trifloxystrobin, Trifloxystrobin, pyraclostrobin , difendistrobin, picoxystrobin, syringobactin, triclostrobin, procycyclide, vinclozolin, sclerotin, iprodione, fludioxonil, cyanostrobin, tricyclazole, Zinc thiazole, pyroconazole, silothiazolin, allylthiazole, copper thiacetin, thiothiazolin, bromomycin, kasugamycin, polymycin, Jinggangmycin, Ningnanmycin, Shenzimycin antibiotics, pyrimidine nucleoside antibiotics, zhongshengmycin, aminooligosaccharides, lentinan, morpholin hydrochloride, octostrobin, pyridine, cyanazole, ethosaccharin, mancozeb, methane One or more of zinc, thiram, acetate, lime sulfur, dicyanoanthraquinone and captan.

Preferably, the second plant growth regulator includes naphthyl acetic acid, sodium nitrophenate, gibberellin, ethephon, brassinoids, brassinolides, propionylbrassinolides, methylpiperium, dwarf Metastatin, trinexapac-ethyl, paclobutrazol, uniconazole, chlorfenuron, benzylaminopurine, ene adenine, hydroxyene adenine, 2-(acetoxy) benzoic acid, triacontanol, ethylamine, nucleoside or Several kinds.

Preferably, the nematicide includes one or more of difenfos, thiazophos, difenfos, chloropicrin and dithiophos.

The beneficial effects of this program are as follows:

The fungicide containing tetrahydroxymethylphosphonium cation disclosed by the present invention has the following beneficial effects: (1) the fungicide containing tetrahydroxymethylphosphonium cation disclosed by the present invention has excellent control effect on citrus greening disease; (2) the fungicide containing tetrahydroxymethylphosphonium cation disclosed by the present invention has the following beneficial effects: Fungicides containing methylphosphonium cations are cheap and low-cost, and are suitable for large-scale use in the citrus industry; (3) Fungicides containing tetrahydroxymethylphosphonium cations can be degraded after use, leaving no residue, and will not cause drug residue problems in citrus fruits. , avoids the use of antibiotics, and will not cause excessive antibiotic residues and resistance problems caused by large-scale use of antibiotics; (4) Fungicides containing tetrahydroxymethylphosphonium cations are low-toxic substances and do not have teratogenicity or carcinogenicity; (5) ) Fungicides containing tetrakis hydroxymethyl phosphorus cations have good compatibility with plants and do not cause any harm to plants at high concentrations; (6) Fungicides containing tetrakis hydroxymethyl phosphorus cations can be fully soluble in water and can be mixed with Pesticides, fungicides, herbicides, plant growth regulators, fertilizers, etc. commonly used on citrus are mixed and used together. It is easy to use and does not require separate medication, which reduces labor costs.

Detailed ways

The implementation of this solution is described in further detail below. Obviously, the described embodiments are only some of the embodiments of this solution and are not exhaustive of all embodiments. It should be noted that, as long as there is 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 objects and are not necessarily used to describe a specific order or sequence. It should be understood that data so used are interchangeable where appropriate. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, such as processes, methods, systems, products or devices that include a series of steps or units, and are not necessarily limited to those explicitly listed may include other steps or elements not expressly listed or inherent to the process, method, product or apparatus.

The effectiveness of antibacterial substances in inhibiting Huanglongbing essentially depends on the efficiency of the drugs being absorbed by citrus and transported to the site of bacterial growth. Once the citrus greening disease pathogen Candidatus liberibacter infects the citrus tree, it will be distributed throughout the citrus tree. The inventor of the present application found that effective antibacterial substances should be absorbed by the citrus tree and conducted in the phloem of the citrus tree. . The composition of citrus phloem is mainly aqueous solution. Therefore, the conduction of antibacterial substances in them requires that the substance has a certain degree of water solubility, and that the antibacterial substance cannot cause toxicity to plant tissues at an effective bactericidal concentration. Therefore, it is very challenging to screen out pharmaceutical ingredients that are effective in preventing and treating Huanglongbing.

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

The inventor of this application chose to use Candidatus liberibacter, the pathogen of citrus greening disease, in view of the fact that it is difficult to culture in vitro, but it belongs to the family Rhizobiaceae.

Candidatus liberibacter, a strain closely related to the crop model strain Sinorhizobium meliloti, is used to simulate the citrus greening disease pathogen Candidatus liberibacter.

Therefore, this application discloses a fungicide containing tetrakis (hydroxymethyl) phosphonium as an active ingredient, which is screened out by Sinorhizobium meliloti and used for the prevention and control of citrus greening disease. The fungicide provided by this application contains a tetrahydroxymethylphosphonium cation with a structure shown in formula (1),

In one embodiment, the bactericide is formulated as a bactericide solution, and the mass percentage concentration of tetrahydroxymethylphosphonium cations in the bactericide solution is 1 to 85 wt%.

When the fungicide containing the above-mentioned tetrahydroxymethylphosphorus cation is used to prevent and control citrus greening disease, the fungicide is formulated into a fungicide solution, and the mass percentage concentration of the tetrahydroxymethylphosphonium cation in the fungicide solution is 1wt% to 85wt%. ; The solvent of the bactericide solution is water or water and an organic solvent. The organic solvent here is preferably an organic solvent miscible with water.

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

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

Tetrakis hydroxymethyl phosphorus sulfate (THPS) and tetrakis hydroxymethyl phosphorus chloride (THPC) containing tetrakis hydroxymethyl phosphorus cations are widely used as biocides in water treatment, oil fields, papermaking and other industries, and can also be used Permanent flame retardant for pure cotton and polyester fabrics.

The advantages of tetrahydroxymethylphosphonium cation are:

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

2. After use, it quickly degrades into completely harmless substances, with no residual pollution and is safe for the environment;

3. Tetrakis (THPS) and tetrakis (THPC) are low-toxic compounds that are not carcinogenic or teratogenic; regarding tetrakis (THPS) and tetrakis The test report of tetrakis(hydroxymethyl)phosphonium sulfate(THPS)(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 tetrakis hydroxymethyl phosphorus sulfate solution and tetrakis hydroxymethyl phosphorus chloride solution with a mass percentage concentration of 70wt% to 85wt% are aqueous solutions, the commercially available tetrakis hydroxymethylphosphorus sulfate solution or tetrahydroxymethylphosphonium chloride solution Phosphorus chloride solution can be mixed with a variety of plant nutritional 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, glycerin, ethylene glycol, acetonitrile, dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). .

In one embodiment, in addition to tetrahydroxymethylphosphonium cations, the bactericide solution also contains a variety of 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 Cl- ^.

In one embodiment, the biocide solution is combined 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 mixture; preferably mixed with zinc ions.

In one embodiment, the bactericidal solution also contains a surfactant and a penetrant; wherein the surfactant is such as alkyl glycoside, azone or silicone; in the bactericidal solution, the mass percentage concentration of the surfactant is 2wt% ~20wt%; preferably, the mass percentage concentration of surfactant in the bactericide solution is 3wt% ~ 10wt%.

In one embodiment, the fungicide solution also contains a first plant growth regulator, wherein the first plant growth regulator is such as naphthyl acetic acid, naphthyl acetamide, indole acetic acid, indole butyric acid, acetate, and nitrophenol. One or more of sodium, gibberellins, brassinosteroids and brassinosteroids. The first plant growth regulator in the fungicide solution is commonly added to liquid fertilizers and has a growth-promoting effect on plants.

In one embodiment, the fungicide solution is used in combination with a fertilizer, wherein the fertilizer is a liquid fertilizer, and the liquid fertilizer includes 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 One or more of the seaweed extract liquid fertilizers.

In one embodiment, the fungicide solution is diluted with water and then sprayed on citrus leaves and citrus treetops, used for root irrigation on citrus tree roots, and used for injection on citrus trunks; preferably, the fungicide solution is diluted with water and then used on citrus leaves and treetops. Use it as spray on citrus treetops and as root irrigation on citrus trees.

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

In one embodiment, the insecticide includes mineral oil, imidacloprid, thiamethoxam, thiacloprid, clothianidin, chlorothiazide, nitenpyram, acetamiprid, piperamiprid, fipronil, rice Powder, dichlorvos, chlorpyrifos, fenitrothion, chlorpyrifos, hydrofenthion, phoxim, acephate, profenofos, dimethoate, omethoate, triazophos, beta-cyhalothrin , cyhalothrin, bifenthrin, permethrin, cypermethrin, fenthrin, fenvalerate, deltamethrin, fenpropathrin, isoprocarb, carbofuran, carbofuran , pirimicarb, methomyl, isoprocarb, difenflurazide, diflubenzuron, diflubenzuron, fluflubenzuron, fluflubenzuron, methoxyfenozide, cyromazine, fenflubenzuron, fluflubenzuron , flufenamid, pymetrozine, flufenoxazone, fenfentrile, fenpyramid, indoxacarb, didifenthiuron, monocarbamate, bicarbamate, bromofenacet, thifenacet, quinfenfendifen , tetraphenicol, proparmectin, dicofol, chlorantraniliprole, cyantraniliprole, flubendiamide, spirodiclofen, etoxazole, emamectin, abamectin, dimethonate Amine, spirotetramat, biphenyl hydrazine, sodium rosinate, sulfoxaflor, trichlorfon, lufenuron, trichlorfon, propiconazole, beta-cypermethrin, stone One or more of sulfur compounds, pyrethrins, matrine, nicotine, veratrine, eucalyptol and cypressin.

In one embodiment, the bactericide includes copper hydroxide, copper calcium sulfate, copper hydroxide, copper quinoline, cuprous oxide, copper king, basic copper carbonate, chlorothalonil, tetrachlorophthalide, pentachloronitro Benzene, sodium sulfonate, carbendazim, benomyl, thiophanate methyl, thiabendazole, pyrimidine, cyprodinil, fluazinam, clofenacil, trimorpholine, trifluconazole , prochloraz, prochloraz manganese salt, imazalil, difenoconazole, propiconazole, fluconazole, flusilazole, hexaconazole, epoconazole, nitrileconazole, fenconazole, triconazole Triadimefon, diphenyltriadienol, triadimefon, tebuconazole, penconazole, mycloconazole, picoconazole, tetrafluorotriazole, triconazole, iminoconazole, penconazole, metalaxyl , metalaxyl, cymoxanil, blastamide, dimethomorph, flumorpholine, diphenylcarb, propamocarb, propamocarb hydrochloride, oxazofen, oxamyperm, Fluopyram, Fluopicostrobin, Fluopicostrobin, Boscalid, Fluopyram, Thifuramide, Pyraclostrobin, Azoxystrobin, Tristrostrobin, Trifloxystrobin, Trifloxystrobin, Triclostrobin Lipid, diphenoxystrobin, picoxystrobin, syringobactin, triclostrobin, procyperide, vinclozolin, sclerotin, iprodione, fludioxonil, cyanostrobin, tricyclazole , Zinc thiazole, phylloxazole, silothiazole, allylbenthiazole, copper thiacetin, thiothiazolinone, bromomycin, kasugamycin, polymycin, Jinggangmycin, Ningnanmycin, Shenzin Mycomycins, pyrimidine nucleoside antibiotics, zhongshengmycin, aminooligosaccharides, lentinan, morpholin hydrochloride, octostrobin, rice blastin, cyanazole, ethosaccharin, mancozeb, One or more of the following: Senzin, Thiram, Prosin, lime sulfur mixture, dicyanoanthraquinone and Captan.

In one embodiment, the second plant growth regulator includes naphthyl acetic acid, sodium nitrophenate, gibberellin, ethephon, brassinoids, brassinolides, propionylbrassinolides, mepifenidium, Chlormequat, trinexapac-ethyl, paclobutrazol, uniconazole, chlorfenuron, benzylaminopurine, ethylene adenine, hydroxyene adenine, 2-(acetoxy) benzoic acid, triacontanol, chlorethylamine, Nucleotide, cyanamide, sulfonium ring, butyrohydrazide, S-entitonin, chlorpheniramine, fentanyl, flumetrazine, thidiazuron, pendimethalin and sulfamethoxazole. Or several; the second plant growth regulator in this embodiment includes various types of plant growth regulators.

In one embodiment, the nematicide includes one or more of difenfos, thiazophos, difenfos, chloropicrin and dithiophos.

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

Since Candidatus liberibacter, the pathogen of citrus greening disease, is difficult to culture in vitro, but it belongs to the family Rhizobiaceae, see the document "structure of lipopolysaccharide from Liberibacter crescens is low molecular weight and offers insights into Candidatus Liberibacter biology" International Journal of Molecular Science, 2021,22 ,11240 . Therefore, the strain Sinorhizobium meliloti, which is closely related to the pathogen Candidatus liberibacter of citrus greening disease, was used for screening. The Sinorhizobium meliloti used in the experiment was purchased from the China Agricultural Microbial Culture Collection Center with 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, 1 150 μl of % Na ₂ MoO ₄ solution, 150 μl of 1% MnSO ₄ solution, 150 μl of 1% B(OH) ₃ solution, and 1500 ml of tap water, mix evenly. Dispense into 250ml Erlenmeyer flasks, add 100ml culture 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 following preparation: A pharmaceutical solution.

Because the commercially available tetrakis hydroxymethyl phosphorus sulfate (THPS) is an aqueous solution of tetrakis hydroxymethyl phosphorus sulfate (THPS) with a content of 75 wt%, 100 μl of commercially available tetrakis hydroxymethyl phosphorus sulfate (THPS) with a mass percentage concentration of 75 wt% ( THPS) aqueous solution was added to 1000 μl of DMSO to prepare a tetrahydroxymethylphosphorus sulfate DMSO solution.

Add the above-mentioned first agent solution and the prepared tetrahydroxymethylphosphorus sulfate DMSO solution to the above-mentioned Sinorhizobium alfalfa liquid culture medium that has been cooled to room temperature and is ready for use. Add two bottles of each solution, adding 25 μl and 50 μl respectively; the control (CK) is to add DMSO solvent to the above-mentioned Sinorhizobium alfalfa liquid culture medium that has been cooled to room temperature for use, and add two bottles similarly, add 25 μl and 50 μl DMSO respectively; Add 100 μl of Sinorhizobium meliloti bacterial solution to all the culture media added to the solution, and measure the absorbance Abs595nm after culturing on a shaking table at 28°C for 32 hours. (The above-mentioned Sinorhizobium meliloti bacterial solution is a plate of Sinorhizobium meliloti colonies picked the day before and inoculated into a liquid medium, and cultured in a shake flask at 28°C for use.) The results of the shake flask screening experiment are 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 alfalfa ACCC17528. Menadione sodium bisulfite MSB disclosed in ZL201180055088.1 has only moderate activity against Sinorhizobium alfalfa ACCC17528. 4-Isopropyl-3-methylphenol (common name, thymol) is weakly active. Tetrahydroxymethylphosphorus sulfate (THPS) has a weak inhibitory activity against Sinorhizobium alfalfa ACCC17528 at a concentration of 18.75 ppm, and a strong inhibitory activity against Sinorhizobium alfalfa ACCC17528 at a concentration of 37.5 ppm, which is close to complete inhibition.

Example 2

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

1. The Sinorhizobium alfalfa ACCC17528 in this example is cultured using the sterilized medium of Sinorhizobium alfalfa in Example 1. The culture temperature is 28°C in a shake flask at 180 rpm until the OD ₆₀₀ value is about 1.0. Use a sterile medium to Dilute 50 times with water to prepare the diluted Sinorhizobium alfalfa ACCC17528 for later use.

The medium formula of Sinorhizobium alfalfa is:

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

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

Add 200 μl of a THPS medium solution containing 375 ppm to A2 (obtained by diluting a commercially available THPS aqueous solution with a mass percentage concentration of 75 wt% with the liquid medium of Sinorhizobium meliloti that has been sterilized and cooled to room temperature). Add to A3 200 μl of medium solution containing 375 ppm THPS. At this time, the liquid volume in A3 is 400 μl. Take 200 μl of the solution from A3 and add it to A4 to mix. Then take 200 μl of the solution from A4 and add it to A5 to mix. Follow this method to perform two-fold gradient dilution. to A11. Then take 200μl from A11 and add it to A12.

Well A1 is a negative control, in which no THPS-containing medium solution is added. Add 50 μl of the diluted Sinorhizobium meliloti ACCC17528 from step 1 to A1 to A11. A12 undiluted alfalfa Sinorhizobium sinensis ACCC17528.

After incubating the 96-well plate in a 28°C incubator for 48 hours, use a microplate reader to measure the absorbance value of each well at 595 nm. The holes where Sinorhizobium alfalfa grows will have large absorbance values, while the holes where Sinorhizobium alfalfa does not grow will have very small absorbance values or close to 0. The minimum concentration of tetrahydroxymethylphosphorus sulfate (THPS) that can inhibit the growth of Sinorhizobium alfalfa ACCC17528 is the MIC value. At this concentration, the absorbance is very small, or close to 0. However, Sinorhizobium alfalfa grows in the adjacent wells of this concentration and has a larger absorbance value in the well diluted 2 times the concentration.

The measured minimum inhibitory concentration MIC of tetrahydroxymethylphosphorus sulfate (THPS) against Sinorhizobium alfalfa ACCC17528 is 9.4 ppm (calculated as tetrahydroxymethylphosphorus sulfate (THPS)). The results of the 96-well plate assay 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 fungicide to plants.

Dilute the commercially available tetrakis hydroxymethyl phosphorus sulfate aqueous solution with a mass percentage concentration of 75% with tap water, and dilute it into tetrakis hydroxymethyl phosphorus sulfate aqueous solutions with concentrations of 1350 ppm, 675 ppm, 450 ppm, 150 ppm, 135 ppm and 15 ppm respectively. Use tap water as the Contrast with CK.

Soak corn seeds in these solutions respectively. Soak 10 seeds in each concentration of solution overnight. Then take it out; put a piece of filter paper on the petri dish, take 4ml of the above 1350ppm, 675ppm, 450ppm, 150ppm, 135ppm, 15ppm tetrakis hydroxymethylphosphorus sulfate aqueous solution, use 4ml of tap water as a negative control, and add it to each petri dish respectively. Then place the above-mentioned soaked corn seeds on the filter paper, and put the petri dish into a 28°C incubator for germination. Remove after three days. Measure the shoot length and root length of germinated corn seeds. The measured data are shown in Table 2.

Calculate the mean and variance of the root length and shoot length data of corn germination in each treatment group, and conduct a t test with the control clear water treatment group to calculate the significant difference between the treatment group and the control clear water group. If there is no significant difference between the treatment and control groups, this indicates no inhibition. If there is a significant difference between the treatment group and the control group, it indicates inhibition.

The data in Table 2 shows that when corn germination is treated with solutions with THPS concentrations of 15ppm, 135ppm, 150ppm, and 450ppm, there is no significant difference in the root length and shoot length of corn compared with the control group. At a THPS concentration of 1350 ppm, the corn sprout length of the treatment group was significantly different from that of the control group, indicating that THPS strongly inhibited corn germination. At a THPS concentration of 675 ppm, there was no significant difference in corn sprout length between the treatment group and the control group, indicating no inhibitory effect. However, at this concentration, the corn root length of the treatment group was significantly different from that of the control group. When the THPS concentration is 675ppm, the average root length of the corn in the treatment group is 34mm, and the average root length of the corn in the control group is 94mm. The inhibition rate is (94-34)/94=64%. According to the corn seed germination test, it was determined that the safe concentration of THPS for plants is between 450-675ppm.

Table 2

Example 4

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

Formula 1: 50 grams of zinc sulfate heptahydrate, 53 grams of commercially available tetrahydroxymethylphosphorus sulfate (THPS) (75%wt) aqueous solution, 48g of water, 0.5g of commercially available mixed amino acid powder (80%wt), 6 Gram alkyl glycoside APG0810, mix evenly to form a homogeneous clear solution. The mass percentage of THPS in the prepared solution is 25%; it is recorded as Zn-THPS.

Formula 2: 35 grams of ferrous sulfate heptahydrate, 54.4 grams of commercially available tetrahydroxymethylphosphorus sulfate (THPS) (75%wt) aqueous solution, 56g of water, 0.6g of commercially available mixed amino acid powder (80%wt), 6 grams of alkyl glycoside APG0810, mix evenly to form a homogeneous clear solution. The mass percentage of THPS in the prepared solution 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 tetrahydroxymethylphosphorus sulfate (THPS) (mass content 75% wt) aqueous solution, 125 grams of water, commercially available mixed amino acids 1.4 grams of powder (80%wt) and 10 grams of alkyl glycoside APG0810, mix evenly to form a uniform clear solution. The mass percentage of THPS in the prepared solution is 18%; it is recorded as Fe-Zn-THPS.

Formula 4: 42 grams of anhydrous copper sulfate, 111 grams of commercially available tetrahydroxymethylphosphorus sulfate (THPS) (75% wt) aqueous solution, 86 grams of water, 1.4 grams of commercially available mixed amino acid powder (80% wt), 10 Gram alkyl glycoside APG0810 and mix evenly to form a uniform clear solution. After preparation, the mass percentage of THPS in the solution is 33%; it is recorded as Cu-THPS.

Formula 5: 6.7 grams of boric acid, 55 grams of water, 60.6 grams of commercially available tetrahydroxymethylphosphorus 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 evenly to form a homogeneous clear solution. The mass percentage of THPS in the prepared solution 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 tetrahydroxymethylphosphorus 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 evenly to form a uniform clear solution. The mass percentage of THPS in the prepared solution is 32%; it is recorded as AM-THPS.

Use a 96-well plate to determine the minimum inhibitory concentration MIC value of each formula, copper sulfate pentahydrate, and commercially available THPS (75%) aqueous solution against Sinorhizobium meliloti. The MIC value was measured twice in parallel. The test procedures were the same as in Example 2. The measured minimum inhibitory concentration MIC values of each formula are shown in Table 3.

The MIC value based on the concentration of each formula is defined as the solution content of each formula being 100% of the concentration of the formula. For example, dilute the solution of formula (1) 1000 times to obtain a solution with a concentration of 1000 ppm based on formula (1). The formula concentration of this solution (calculated as formula (1)) is 1000 ppm, but the content in THPS is 1000× 25%=250ppm.

table 3

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

Example 5

Example of mixing and preparation of THPS aqueous solution and fungicide

Combine 10 grams of zinc thiazole (97.5%), 2 grams of NP-10 (nonylphenol polyoxyethylene ether), 2 grams of 1602 (tristyrylphenol polyoxypropylene polyoxyethylene ether), 0.2 grams of xanthan gum, 4 g of sodium lignosulfonate, 0.2 g of sodium carboxymethylcellulose, 3 g of ethylene glycol, add 10 g of commercially available tetrahydroxymethylphosphorus sulfate (THPS) (75% wt) aqueous solution, and add 68.6 g of water to 100 g, and sanded to obtain a suspension mixture of 9.75% thiazole zinc and 7.5% THPS thiazole zinc THPS.

Example 6

Example of mixed formulation of THPS and pesticides

Combine 3g of chlorantraniliprole (95%), 1g of NP-10 (nonylphenol polyoxyethylene ether), 4g of 1602 (tristyrylphenol polyoxypropylene polyoxyethylene ether), and 0.2 xanthan gum g, 5 g sodium lignosulfonate, 0.2 g sodium carboxymethyl cellulose, 3 g glycerol, add 10 g of commercially available tetrahydroxymethylphosphorus sulfate (THPS) (75% wt) aqueous solution, add 73.6 g of water Make up to 100 grams, and perform sand grinding to obtain a chlorantraniliprole THPS suspension mixture of 2.85% chlorantraniliprole and 7.5% THPS.

Example 7

Example of mixed formulation of THPS and herbicide

Add 10 grams of commercially available tetrahydroxymethylphosphorus sulfate (THPS) (75% wt) aqueous solution to 80 grams of 20% glufosinate ammonium solution, add 6 grams of alkyl glycoside APG0810, and 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 mixed preparation of THPS and plant growth regulators

Mix 0.1 g of brassinolide, 0.1 g of gibberellin, 0.1 g of benzylaminopurine, 0.1 g of naphthylacetic acid, 20 g of commercially available tetrahydroxymethylphosphorus sulfate (THPS) (75% wt) aqueous solution, and 6 g Alkyl glycoside APG0810, add 73.7 grams of water to prepare an aqueous solution containing THPS 15%, brassinosteroid 0.1%, gibberellin 0.1%, benzylaminopurine 0.1%, and naphthylacetic acid 0.1%.

Example 9

From 2020 to 2021, pharmaceutical experiments will be conducted in the navel orange garden of Dongshan Village, Dayu County, Ganzhou City. The navel orange variety is Newhall. The test trees were all adult fruit-bearing trees infected with Huanglongbing. Each treatment was replicated with 3 plants, and a total of 12 diseased trees were tested. The experimental area is supplemented by normal water, fertilizer and pesticide management (mainly to control citrus psyllid). The application of water, fertilizer and pesticides in each treatment group was consistent. The experimental design is shown in Table 4.

Among them, treatment group 1 is a spray diluted with 500 times of the agent mixed with water on November 21, 2020, and a spray diluted with 500 times of the agent mixed with water on May 27, 2021. The whole tree leaves should be sprayed with water and dripping water. The final concentration of the spray liquid is 416ppm based on THPS.

Treatment group 2 is a spray diluted with 1,000 times of the agent mixed with water on November 21, 2020, and a spray diluted with 1,000 times of the agent mixed with water on May 27, 2021. The whole tree leaves should be sprayed with water and dripping water. The final concentration of the spray liquid is 208ppm based on THPS.

Treatment group 3 is the treatment agent diluted 1000 times with water and sprayed on November 21, 2020, and the roots were irrigated at the same time. Each tree was irrigated with 1 kg of roots and diluted 1000 times with water. 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 roots of each tree were irrigated with 1kg of treatment agent diluted 1000 times with water. Foliar spray should be based on spraying water dripping on the entire tree leaf surface. The final concentration of the spray liquid is 208ppm based on THPS.

Treatment group 4 (control group CK) was sprayed with the control agent diluted 500 times with water on November 21, 2020, and sprayed with 500 times dilution of the control agent mixed with water on May 27, 2021. The final concentration of spray liquid is 0ppm based on THPS.

Among them (1) Processing pharmaceutical formula:

Commercially available tetrahydroxymethylphosphorus sulfate (THPS) (75%wt) aqueous solution 139 grams, alkyl glycoside (APG0810) 30 grams, water 331 grams, total weight 500 grams. The concentration based on THPS is 20.8%.

(2) Control drug formula:

Alkyl glycoside (APG0810) 30g, water 470g, total weight 500g.

Table 4.

Sampling was carried out on November 20, 2020 before spraying. 4-5 mature leaves were collected from each of the five directions of the Huanglongbing diseased trees in the southeast, northwest, and middle directions. A total of 20-25 leaves were collected from each tree. Avoid crossing between samples during the collection process. 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 Fluorescence PCR Detection Method for Citrus Huanglongbing" was adopted. The veins in the leaf samples were cut out and ground into powder using liquid nitrogen. About 200 mg of leaf vein powder was taken to extract vein DNA from leaf samples using the CTAB-Triton method. Use SYBR Green I fluorescent dye PCR method 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, which causes citrus greening disease. It is 87 bp in size and is a single-copy fragment.

SYBR Green I fluorescent dye PCR reaction system 25ul, containing final concentration 1×SYBR Green I Quantitative IQ SYBR Green Supermix (Bio-Rad USA), 0.75μmol/L primer pair CQULA04F/CQULA04R and 2μl template. Fluorescence quantitative PCR detection was performed on a fluorescence quantitative PCR instrument, with pre-amplification at 95°C for 1 min; denaturation at 95°C for 15 s; annealing at 59°C for 15 s; extension at 72°C for 20 s; 41 cycles. Set up multiple simultaneous fluorescence acquisitions during the extension phase of each cycle. In order to verify the specificity of amplification, melting curve analysis was performed immediately after the amplification was completed. The reaction program was: 95°C, 30s; 55°C, 30s; starting from 55°C, hold for 1s for every 0.5°C increase, and continue to increase. 80 times (until 95℃). Record the measured Ct value.

According to the document "Preliminary Report on the Screening Test of Agents for the Prevention and Control of Citrus Huanglongbing" Plant Protection 2014, Volume 40 (2), Pages 166-170.

Use formula

CN=75×10 ^{11.61-0.288Ct} Calculate the bacterial load of Huanglongbing tree tissue.

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

CN is the bacterial load per gram of tissue of Huanglongbing diseased trees. (Unit is pathogen DNA copy number, copy number/g, CN/g)

After spraying, the sample will be taken once on February 21, 2021, 2 months after the first dose. Sampling will be conducted once on April 13, 2021. After the second spray application, sampling will be done once on July 10, 2021, and once on August 28, 2021. The test results are shown in Table 5.

table 5

It can be seen from Table 5 that the Huanglongbing pathogen reduction rate % = (CN value of bacteria in the treatment area before application of pesticides - CN value of bacteria in treatment area after application of pesticides)/CN value of bacteria in treatment area before application of pesticides × 100%. For convenience, August 28, 2021 is used.

Among them, in treatment 1, the reduction rate of Huanglongbing pathogens was 100%; in treatment 2, the reduction rate of Huanglongbing pathogens was 99.7%; in treatment 3, the reduction rate of Huanglongbing pathogens was 99.9%. However, the number of Huanglongbing pathogens in the control group increased by 14%. It can be seen that the therapeutic effect of tetrahydroxymethylphosphorus sulfate (THPS) is related to the concentration of the agent. The therapeutic effect is better when diluted 500 times than when diluted 1000 times. At the same time, root irrigation treatment has a synergistic effect on the treatment effect of pesticides.

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 very few red-nosed fruits, and a few fruits have some green skin that does not completely turn orange (not included in the good fruit). When the fruit is tasted artificially, the sweetness of the fruit is high, which is equivalent to normal fruits without Huanglongbing. Among them, the good fruit rate of treatment 2 is about 75%. There are some red-nosed fruits. The fruits taste normal in appearance. The sweetness is not as good as that of treatment 1, and there is a slight sour taste. The good fruit rate of treatment 3 is about 85%. There are a small number of red-nosed fruits on the lower branches. When you taste the fruits with normal appearance, the sweetness is not as good as that of treatment 1, but the sweetness is acceptable. In treatment 4 (control treatment), basically all fruits were red nose fruits and had no commercial value.

It can be seen from the above examples that tetrakis hydroxymethyl phosphorus sulfate (THPS) and tetrakis hydroxymethyl phosphorus chloride (THPC) containing tetrakis hydroxymethyl phosphorus cations have low toxicity to plants and have high compatibility.

Obviously, the above-mentioned embodiments of the present invention are only examples to clearly illustrate the present invention, and are not intended to limit the implementation of the present invention. For those of ordinary skill in the art, based on the above description, they can also make There are other different forms of changes or modifications, and it is impossible to exhaustively enumerate all the embodiments here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims (14)

1. A fungicide for preventing and treating citrus greening disease, characterized in that the fungicide contains tetrahydroxymethylphosphorus cation.
2. The fungicide for preventing and treating citrus greening disease according to claim 1, wherein the fungicide is formulated as a fungicide solution, and the mass percentage concentration of tetrahydroxymethylphosphonium cations in the fungicide solution is 1 %~85%.
3. An application of a fungicide in the prevention and treatment of citrus greening disease, characterized in that the fungicide as claimed in claim 1 is formulated as a fungicide solution, and the mass percentage concentration of tetrahydroxymethylphosphonium cations 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 an organic solvent miscible with water; the organic solvent miscible with water includes methanol, ethanol, and glycerin, One or more of ethylene glycol, acetonitrile, dimethylformamide and dimethyl sulfoxide.
4. The application according to claim 3, characterized in that the bactericide 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 tetrahydroxymethylphosphorus sulfate When it is an aqueous solution; the mass percentage concentration of tetrakis hydroxymethyl phosphorus sulfate in the bactericide solution is 1% to 75%; when the bactericide solution is an aqueous solution of tetrakis hydroxymethyl phosphorus chloride, the tetrakis hydroxymethyl phosphorus sulfate in the bactericide solution is The mass percentage concentration of hydroxymethylphosphorus chloride is 1% to 80%.
5. The application according to claim 3, characterized in that the bactericide solution is mixed with amino acids, polypeptides, potassium ions, phosphate ions, magnesium ions, calcium ions, zinc ions, iron ions, boric acid, borax, and manganese ions, One or more of molybdate ions, humic acid, and trehalose are used in a mixture; preferably, they are mixed with zinc ions.
6. The application according to claim 3, characterized in that the bactericidal solution also contains a surfactant and a penetrating agent; the surfactant contains alkyl glycosides, azones or silicones; the bactericidal solution contains The mass percentage concentration of surfactant contained is 2% to 20%; preferably, the mass percentage concentration of surfactant contained in the bactericide solution is 3% to 10%.
7. The application according to claim 3, characterized in that the fungicide solution also contains a first plant growth regulator, and the first plant growth regulator contains naphthyl acetic acid, naphthyl acetamide, indole acetic acid, indole One or more of butyric acid, ampicillin, sodium nitrophenolate, gibberellins, brassinolides and brassinoids.
8. The application according to claim 3, characterized in that the fungicide solution is used in combination with fertilizer, and the fertilizer is a liquid fertilizer, and the liquid fertilizer includes a liquid amino acid fertilizer, a liquid humic acid fertilizer, and a liquid medium element fertilizer. Fertilizer, one or more of liquid trace element fertilizer, liquid macro element fertilizer and seaweed extract liquid fertilizer.
9. The application according to claim 3, characterized in that the fungicide solution is used in combination with a pesticide or herbicide, and the pesticide is a pesticide used on citrus, a fungicide, a second plant growth regulator and a herbicide. Nematodes; the herbicides include citrus herbicide, glyphosate, glufosinate-ammonium, diquat, paraquat, 2,4-dichlorophenoxyacetic acid, 2,4 drops of butane, nonanoic acid and nonanoic acid One or more ammonium species; preferably, the pesticide is a fungicide used on citrus; preferably, the herbicide is a citrus orchard herbicide.
10. The application according to claim 3, characterized in that the fungicide solution is diluted with water and used for spraying on citrus leaves and citrus treetops, for root irrigation, and for injection on citrus trunks; preferably, the sterilization After diluting the agent solution with water, spray it on citrus leaves and citrus tree tops, and use it on citrus tree roots for root irrigation.
11. The application according to claim 9, characterized in that the pesticides include mineral oil, imidacloprid, thiamethoxam, thiacloprid, clothianidin, chlorothiazide, nitenpyrid, acetamiprid, piperazolin Chloropyron, fipronil, Daofengsan, dichlorvos, chlorpyrifos, fenitrothion, chlorpyrifos, acetonitrile, phoxim, acephate, profenofos, dimethoate, omethoate, trimethoate Zofos, beta-cyhalothrin, cyhalothrin, bifenthrin, permethrin, cypermethrin, fenmethrin, fenvalerate, deltamethrin, fenpromethrin, isoprocarb, Carbofuran, carbofuran, pirimicarb, methomyl, isoprocarb, difenflurazide, diflubenzuron, diflubenzuron, fluflubenzuron, fluflubenzuron, methoxyflufenozide, fly killer Amine, chlorflubenzuron, fluflubenzuron, sulfeniprid, pymetrozine, flufenacet, fenfentrile, fenpyridoxime, indoxacarb, didifenthiuron, monoformamidine, biformamidine, bromide Esters, tetrafenacet, quinfenacet, tetrafenazine, propargite, dicofol, chlorantraniliprole, cyantraniliprole, flubendiamide, spirodiclofen, etoxazole, methaminoavermide Vitamin, abamectin, dinotefuran, spirotetramat, biphenylhydrazine, sodium rosinate, sulfoxaflor, insecticide, insecticide, trichlorfon, lufenuron, buprofen , one or more of propiconazole, beta-cypermethrin, lime sulfur mixture, pyrethrin, matrine, nicotine, veratrine, eucalyptol and cypermethrin.
12. The application according to claim 9, characterized in that the bactericide includes copper hydroxide, copper calcium sulfate, copper hydroxide, copper quinoline, cuprous oxide, copper king, basic copper carbonate, chlorothalonil, Tetrachlorophthalide, pentachloronitrobenzene, sodium diclofenac, carbendazim, benomyl, thiophanate methyl, thiabendazole, pyrimidine, cyprodinil, fluazinam, chlorfenacil , Trimorpholine, Tricloconazole, Prochloraz, Prochloraz manganese salt, Imazalil, Difenoconazole, Proconazole, Fluconazole, Flusilazole, Hexaconazole, Fluconazole, Triadimefonazole, fencloconazole, triadimefonazole, diphenyltriadimefonol, triadimefon, tebuconazole, diconazole, myclobutanil, picoconazole, tetrafluoroethazole, tetraconazole, imine Azole, penconazole, metalaxyl, metalaxyl metalaxyl, cymoxanil, blastamide, dimethomorph, flumorpholine, propylomid, propamocarb, propamocarb hydrochloride, oxamidazole pyraclostrobin, pyraclostrobin, pyraclostrobin, fluopicolin, fluopyram, boscalid, fluopyram, thifuramide, pyraclostrobin, azoxystrobin, mefenoxystrobin, trifloxystrobin Ester, tristrostrobin, pyraclostrobin, ditristrobin, picoxystrobin, syringomycin, tristrostrobin, procyperide, vinclozolin, pyraclostrobin, iprodione, fludioxonil , cyanobistrobin, tricyclazole, zinc thiazole, cyanazole, silicothiazole, allylbenthiazole, copper thiacetin, thiadiazole, bromomycin, kasugamycin, polymycin, Jinggangmycin Ingredients, Ningnanmycin, Shenzimycin, pyrimidine nucleoside antibiotics, Zhongshengmycin, aminooligosaccharides, lentinan, morpholin hydrochloride, octostrobin, rice blast spirit, cyanazole,, B One or more of allicin, mancozeb, mancozeb, thiram, acetate, lime sulfur, dicyanoanthraquinone and captan.
13. The application according to claim 9, characterized in that the second plant growth regulator includes naphthylacetic acid, sodium nitrophenolate, gibberellins, ethephon, brassinoids, brassinosteroids, propionylurethane Tyrosinolide, mepifenidium, chlormequat, trinexapac-ethyl, paclobutrazol, uniconazole, chlorfenuron, benzylaminopurine, ethylene adenine, hydroxyene adenine, 2-(acetoxy)benzoic acid, Triacontanol, ethyl ester, nucleotides, cyanamide, sulfonate, butyric acid hydrazide, S-actin, chlorpheniramine, fentanyl, flumetrazine, thidiazuron, dimethapent One or more of the spirits and Zhongding spirits.
14. The application according to claim 9, characterized in that the nematicide includes one or more of difenfos, thiazophos, difenfos, chloropicrin and dithiophos.