Application method of nematicide

Abstract

The present invention relates to a method for controlling or preventing infestation of plants by phytopathogenic nematodes, comprising applying a nematicide to the plant or its locus 3 days after transplantation of plant seedlings. The nematicide is preferably a four-membered ring carboxamide nematicide, such as trifluoropyridinamine, for example. When a nematicide is applied to the plant or its locus on the day of transplantation, the methods of the present invention can provide "zero-day protection" to plant seedlings. The method is safe and effective, can efficiently prevent and treat various crop root knot nematode diseases, protects crops, and improves the yield and quality of the crops.

Description

Technical Field

[0001] The present invention relates to a method for controlling or preventing plants from being infected by plant pathogenic nematodes, which comprises applying a nematicide to the plants or a locus thereof within 3 days after transplanting plant seedlings (preferably on the day of transplanting). Background Art

[0002] Plant parasitic nematodes parasitize various tissues of plants, most of which parasitize on plant roots, and a few parasitize on young shoots, stems, leaves, flowers, fruits and seeds of plants. They not only absorb nutrients from plants and directly harm plants, but also the wounds they cause are easy to become infection points for other pathogens. Some virus-transmitting nematodes can also spread a variety of plant viruses. Therefore, in agricultural production, it is necessary to prevent and control the infection of plant pathogenic nematodes.

[0003] Currently, there are many nematicides that can be used to control or prevent plants from being infected by plant pathogenic nematodes. However, in order to avoid the toxic effects of the nematicides themselves on plants, nematicides are usually applied at a later stage (for example, after the plants are transplanted and planted). For example, fluopyram sold by Bayer It is usually applied 7-15 days after transplanting plant (eg cucumber) seedlings to reduce its toxic effects on the plant seedlings. Summary of the invention

[0004] WO2013143811 and WO2015003951 generally disclose a class of novel four-membered ring carboxamide compounds characterized by having a cis-substituted four-membered ring, wherein the four-membered ring carboxamide has nematicidal activity.

[0005] The inventors of the present application explored the application time of this type of compound and unexpectedly found that the four-membered ring carboxamide compound can be applied after the plant seedlings are transplanted (for example, within 3 days after the plant seedlings are transplanted, within 2 days after the plant seedlings are transplanted, within 1 day after the plant seedlings are transplanted, or on the day of the plant seedlings being transplanted), and the compound has no obvious toxic effect on the plant seedlings and can achieve a better nematicidal effect.

[0006] Since the plant seedlings are at their most vulnerable during the transplanting period, those skilled in the art usually allow the plant seedlings to recover for a period of time (e.g., 7-15 days) after transplanting before applying a nematicide (e.g., fluopyram or thiabendazim) to minimize the toxic effects of the nematicide on the plant seedlings.

[0007] On the contrary, the inventors of the present application have found that the four-membered ring carboxamide compound of the present invention can be applied in a short period of time after plant transplanting (e.g., the day of transplanting) without going through a recovery period. Without wishing to be bound by any theory, the inventors of the present application believe that the reason why the nematicide application method of the present invention can achieve better results is that (1) plant pathogenic nematodes (especially root-knot nematodes) infect plants very quickly and cause irreversible damage to the plant root system, so applying the nematicide as early as possible can avoid nematode infection and root damage to the greatest extent; (2) the amount of water required for rooting water in the short period of time after plant seedlings are transplanted (e.g., the day of transplanting plant seedlings) is higher, and the soil is looser, so applying the nematicide at this time is more conducive to the soil distribution of the nematicide, thereby achieving a better nematicidal effect.

[0008] Therefore, the present invention provides a method for controlling or preventing plants from being infested by plant pathogenic nematodes, which comprises applying a nematicide to the plants or a locus thereof within 3 days after transplanting plant seedlings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 The effect of different nematicides on the root length of cucumber plants in the pot test of Example 1 is shown.

[0010] Figure 2 The phytotoxicity of different nematicides on the leaves of cucumber plants in the pot test of Example 1 is shown.

[0011] Figure 3 The phytotoxicity of different nematicides on the leaves of cucumber plants in the field trial of Example 2 is shown.

[0012] Figure 4 The phytotoxicity of different nematicides on the leaves of tomato plants in the pot test of Example 3 is shown.

[0013] Figure 5 The pot test in Example 3 shows the effects of nematicides on tomato root-knot nematodes after application at different times.

[0014] Figure 6 The control effect of different nematicides on tomato root-knot nematodes in a field trial (Test No. 1 in Example 4) is shown.

[0015] Figure 7 The control effect of different nematicides on cucumber root-knot nematodes in a field trial (Test No. 4 in Example 5) is shown.

[0016] Figure 8 The root-knot nematode control efficacy of different nematicides in Example 6 is shown.

[0017] Fig. 9The growth conditions of each group of crops in Example 6 are shown.

[0018] Fig.10 The effects of different nematicides on crop vigor and yield in Example 7 are shown. DETAILED DESCRIPTION

[0019] In some embodiments, the present application provides a method for controlling or preventing a plant from being infested by a plant pathogenic nematode, comprising applying one or more compounds selected from the following or their agriculturally acceptable salts to the plant or its locus within 3 days after the plant seedlings are transplanted:

[0020]

[0021]

[0022]

[0023]

[0024]

[0025] The plant is a plant of the genus Cucumis or a plant of the genus Lycopersicon.

[0026] The method of the present invention is particularly valuable when applied to plants of the genus Cucumis and Lycopersicon, because as is well known to those skilled in the art, seedlings of plants of the genus Cucumis and Lycopersicon are more fragile and less tolerant to drugs than seedlings of other crops.

[0027] In a preferred embodiment, the compound is selected from:

[0028]

[0029]

[0030] or its agriculturally usable salt.

[0031] In a preferred embodiment, the compound is N-[(1,2 cis)-2-(2,4-dichlorophenyl)cyclobutyl]-2-(trifluoromethyl)pyridine-3-carboxamide (the ISO name of this compound is "cyclobutrifluram", CAS RN [1460292-16-3]) or an agriculturally acceptable salt thereof.

[0032] The presence of one or more possible asymmetric carbon atoms in a compound means that the compound may exist in the form of optical isomers (i.e., enantiomers or diastereoisomers). Due to restricted rotation around a single bond, atropisomers may also be produced. The present invention includes all possible isomeric forms of the compound (e.g., geometric isomers) and mixtures thereof. The present invention includes all possible tautomeric forms of the compound, as well as racemic compounds (i.e., mixtures of at least two enantiomers in a ratio of substantially 50:50).

[0033] The compounds of the present invention comprise (1S,2S) and (1R,2R) enantiomers, and the ratio of (1S,2S) enantiomer to (1R,2R) enantiomer is greater than 1.5:1, greater than 2.5:1, greater than 4:1, greater than 9:1, greater than 20:1 or greater than 35:1.

[0034] In a preferred embodiment, the compound is the pure (1S,2S) enantiomer.

[0035] In a more preferred embodiment, the compound is the (1S, 2S) stereoisomer of Compound 1 having the following structure:

[0036]

[0037] As is well known to those skilled in the art, a wedge-shaped bond in a compound structure represents the absolute stereochemistry in the compound, while a thick straight bond in a compound structure represents the relative stereochemistry in the compound.

[0038] If desired, enantiomerically pure final compounds can be obtained from the racemic material by separation techniques (eg, reverse phase chiral chromatography), or by stereoselective synthetic techniques (eg, using chiral starting materials).

[0039] The compounds administered in the methods of the present invention are commercially available and / or can be prepared using methods known in the art and / or methods reported in the literature (e.g., in WO2013143811 or WO2015003951, the contents of which are incorporated herein by reference in their entirety).

[0040] In each case, the compounds applied in the methods of the invention may be in free form, in oxidized form as an N-oxide or in salt form, for example an agriculturally acceptable salt form.

[0041] N-oxides are oxidized forms of tertiary amines or oxidized forms of nitrogen-containing heteroaromatic compounds. They are described, for example, in "Heterocyclic N-oxides", by A. Albini and S. Pietra, CRC Press, Boca Raton 1991.

[0042] In some embodiments, the compound is applied in an amount of 1-20 mg, preferably 2-15 mg, more preferably 3-10 mg per plant.

[0043] In some embodiments, the compound is applied in an amount of 50-1000 g, preferably 100-500 g, more preferably 250 g per hectare (ha).

[0044] In the method of the present invention, the compound is usually applied as a component of a nematicidal composition. The nematicidal composition can be in the form of a formulation selected from the following: aerosol sprays, capsule suspensions, concentrated cold mists, dustable powders, emulsifiable concentrates, oil-in-water emulsions, water-in-oil emulsions, encapsulated granules, fine granules, gases (under pressure), gas-producing products, granules, concentrated hot mists, large granules, microgranules, oil-dispersible powders, oil-miscible flowable concentrates, oil-miscible liquids, pastes, plant sticks, soluble concentrates, soluble powders, suspension concentrates (flowable concentrates), ultra-low volume (ulv) liquids, ultra-low volume (ulv) suspensions, water-dispersible granules or tablets, water-dispersible powders for slurry treatment, water-soluble granules or tablets, water-soluble powders for seed treatment and wettable powders.

[0045] The nematicidal composition generally comprises a liquid or solid carrier and optionally one or more commonly used formulation adjuvants, which may be solid or liquid adjuvants, for example, unepoxidized or epoxidized vegetable oils (e.g., epoxidized coconut oil, rapeseed oil or soybean oil), defoamers (e.g., silicone oils), preservatives, clays, inorganic compounds, viscosity modifiers, surfactants, adhesives and / or tackifiers. The composition may further comprise fertilizers, micronutrient donors or other preparations that affect plant growth, and may comprise combinations containing the compounds of the invention and one or more other bioactive agents, such as bactericides, fungicides, nematicides, plant activators, acaricides and insecticides.

[0046] The compositions are prepared in a manner known per se, in the absence of auxiliaries, for example by grinding, sieving and / or compressing the solid compound according to the invention, and in the presence of at least one auxiliary, for example by intimately mixing and / or grinding the compound according to the invention with one or more auxiliary agents. In the case of the solid compounds according to the invention, the grinding / milling of the compound is to ensure a specific particle size.

[0047] Examples of compositions for use in agriculture are emulsifiable concentrates, suspension concentrates, microemulsions, oil dispersibles, directly sprayable or dilutable solutions, spreadable pastes, dilute emulsions, soluble powders, dispersible powders, wettable powders, dusts, granules or capsules in a polymeric substance, the composition comprising at least one compound of the invention, the type of composition being chosen to suit the intended purpose and the prevailing circumstances.

[0048] Typically, these compositions comprise 0.1% to 99% (especially 0.1% to 95%) of a compound according to the invention and 1% to 99.9% (especially 5% to 99.9%) of at least one solid or liquid carrier, it being possible in principle that 0 to 60% (especially 0.1% to 50%) of the composition is a surfactant (% in each case denotes percentage by weight). Although for commercial purposes, concentrated compositions tend to be preferred, the final consumer generally uses diluted compositions with significantly lower concentrations of active ingredients.

[0049] In some embodiments, the compound is administered in the form of a suspension composition, preferably a suspension concentrate (SC).

[0050] In some embodiments, the concentration of the compound in the suspension is 100-1000 g / L, preferably 200-600 g / L, more preferably 300-500 g / L, and most preferably 450 g / L.

[0051] In some embodiments, the plant pathogenic nematode is any one or more of Meloidogyne, Heterodera, Aphelenchina, Ditylenchus, Nacobbus, Pratylenchus, and Bursaphelenchus xylophilus.

[0052] In a preferred embodiment, the plant pathogenic nematode is a root-knot nematode.

[0053] In some embodiments, the Cucumis plant is Cucumis sativus or Cucumis melon, preferably Cucumis.

[0054] In some embodiments, the Lycopersicon genus is Solanum lycopersicum.

[0055] In some embodiments, the compound is applied within 2 days or within 1 day after transplanting the plant seedlings.

[0056] In a preferred embodiment, the compound is applied on the day of transplanting the plant seedlings (eg, when watering the plant seedlings after transplanting). Applying the nematicide of the present invention on the day of transplanting the plant seedlings can achieve "zero-day protection" for the plant seedlings.

[0057] In a preferred embodiment, the plantlets are transplanted when they are 1-5 weeks old, more preferably, the plantlets are transplanted when they are 4 weeks old.

[0058] The application method (for example, drip irrigation, immersion irrigation or flooding irrigation) is selected according to the properties of the formulation, the intended purpose and the prevailing environment.

[0059] Example

[0060] In the following examples, the nematicides tested were used in the following forms:

[0061] Compound 1: 450 g / L suspension concentrate (SC)

[0062] Fluopyram: 500g / L suspension concentrate (SC)

[0063] Thiazole: 20% Emulsion in water (EW)

[0064] Example 1: Safety of different nematicides on cucumber crops (pot test)

[0065] A greenhouse pot trial of cucumber was conducted with soil treatment to evaluate the safety of different nematicides on the crop.

[0066] Four-week-old cucumber plants were transplanted and the different nematicides were drenched with 200 ml of water per plant at the time of transplanting or 7 days after transplanting. Safety to the crop was assessed 14 days after transplanting.

[0067] Trial Information

[0068] Place China Shandong Syngenta Qihe Experimental Station crop Cucumbers, Autumn Crown Varieties

[0069] Administration and Assessment Details

[0070] Application method Application by flooding Water volume 200ml / plant Application time At transplanting or 7 days after transplanting Evaluate 14 days after transplanting

[0071] Treatment List - Pot Trial

[0072]

[0073]

[0074] result:

[0075] Crop safety assessment was performed on the 14th day after transplanting. The root length of the crop was measured and the results are shown in the following table and Figure 1 shown.

[0076]

[0077] Each crop was photographed to assess phytotoxicity to the crop leaves. Figure 2 shown.

[0078] The test results showed that compound 1 had excellent safety to cucumber crops. Even when applied at the time of transplanting, compound 1 did not show any phytotoxicity to cucumber crops and did not damage the roots.

[0079] In contrast, fluopyram and thiathiazolyl were significantly phytotoxic to cucumber plants (discoloration of leaf margins) even when applied 7 days after transplanting. In addition, thiathiazolyl caused significant root damage even when applied 7 days after transplanting. Due to the foliar phytotoxicity and root damage caused by fluopyram and thiathiazolyl, fluopyram and thiathiazolyl cannot be applied at the time of crop transplanting.

[0080] Example 2: Safety of different nematicides on cucumber crops (field trial)

[0081] A cucumber field trial was conducted with soil treatment to evaluate the safety of different nematicides on the crop.

[0082] Four-week-old cucumber plants were transplanted and the different nematicides were drenched with 200 ml of water per plant at the time of transplanting or 7 days after transplanting. Safety to the crop was assessed 14 days after transplanting.

[0083] Trial Information

[0084] Place Syngenta Zengcheng Test Station, Guangdong, China crop Cucumber, Dasheng variety Plot size <![CDATA[15m 2 ]]>

[0085] Administration and Assessment Details

[0086] Application method Application by flooding Water volume 200ml / plant Application time At transplanting or 7 days after transplanting Evaluate 14 days after transplanting

[0087] Treatment List - Plot Trial

[0088]

[0089] result:

[0090] Crop safety assessment was conducted on day 14 after transplanting. Plant height was measured and the results are shown in the table below.

[0091]

[0092] Each crop was photographed to assess phytotoxicity to the crop leaves. Figure 3 shown.

[0093] The test results showed that compound 1 had excellent safety to cucumber crops. Even when applied at the time of transplanting, compound 1 did not show any phytotoxicity to cucumber crops.

[0094] In contrast, fluopyram and thiathiazolyl were significantly phytotoxic to cucumber plants (discoloration of leaf margins) even when applied 7 days after transplanting. Due to the foliar phytotoxicity caused by fluopyram and thiathiazolyl, fluopyram and thiathiazolyl cannot be applied at the time of crop transplanting.

[0095] Example 3: Effects of nematicides on tomato root-knot nematodes after application at different times (pot test)

[0096] A tomato greenhouse pot trial was conducted to evaluate the efficacy of nematicides against tomato root-knot nematodes (Meloidogyne spp.) after application at different times.

[0097] Four-week-old tomato plants were transplanted into pots with root-knot nematodes and drenched with different nematicides at 200 ml per plant at transplanting or 7 days after transplanting. The control efficacy on the crop was evaluated 30 days after transplanting.

[0098] Trial Information

[0099] Place China Shandong Syngenta Qihe Experimental Station crop Tomato, Zidali variety Target Root-knot nematodes (Meloidogyne spp.)

[0100] Administration and Assessment Details

[0101] Application method Application by flooding Water volume 200ml / plant Application time At transplanting or 7 days after transplanting Evaluate 30 days after transplanting

[0102] Treatment List - Pot Trial

[0103]

[0104] result:

[0105] Crop Safety Assessment:

[0106] Each crop was photographed to assess phytotoxicity to the crop leaves. Figure 4 As shown. Figure 4 It can be seen that even when compound 1 was applied at the time of transplanting, it did not produce phytotoxicity to tomatoes, while the application of fluopyram and thiathiazolyl both produced obvious phytotoxicity (leaf margin discoloration).

[0107] Evaluation of the efficacy of root-knot nematode control:

[0108] The roots of each crop were photographed to evaluate the nematicidal efficacy. Figure 5 As shown. Figure 5 It can be seen that the best effect was achieved by applying compound 1 at the time of transplanting. At the same time, crop safety issues (root damage) caused by fluopyram and thiabendazim were observed.

[0109] From the above results, it can be seen that due to the excellent crop safety of compound 1, it can be applied at the time of transplanting; and application at the time of transplanting is the best time to control root-knot nematodes and can achieve the best control effect.

[0110] However, other nematicides such as fluopyram and thiathiazolyl will cause serious crop safety problems (phytotoxicity to leaves and root damage) when applied at transplanting or even 7 days after transplanting. Therefore, it is not recommended to use nematicides such as fluopyram and thiathiazolyl at transplanting, and their efficacy is also significantly inferior to Compound 1.

[0111] Example 4: Control effect of nematicides on tomato root-knot nematodes (field test)

[0112] To evaluate the efficacy of different nematicides against tomato root-knot nematodes, seven tomato field trials were conducted in different regions of China.

[0113] Four-week-old tomato plants were transplanted into soil with root-knot nematodes and flooded with different nematicides at or 7 days after transplanting. The control efficacy was evaluated 90 days after transplanting.

[0114] Trial Information

[0115] crop Tomato, susceptible varieties Target Root-knot nematodes (Meloidogyne spp.)

[0116] Administration and Assessment Details

[0117]

[0118] Treatment List - Plot Test

[0119]

[0120]

[0121] result:

[0122] The control efficacy of different nematicides is shown in the following table:

[0123]

[0124] Representative photos of plant roots in each group are shown in Figure 2. Figure 6 shown.

[0125] From the above results, it can be seen that due to the excellent crop safety of compound 1, it can be applied at the time of transplanting; and application at the time of transplanting is the best time to control root-knot nematodes and can achieve the best control effect.

[0126] Other nematicides such as fluopyram and thiathiazolyl may cause phytotoxicity problems when applied at transplanting, therefore, nematicides such as fluopyram and thiathiazolyl are not recommended for application at transplanting.

[0127] In all 7 tomato trials, compound 1 applied at transplanting had better control than fluopyram and thiabendazim applied 7 days after transplanting.

[0128] Example 5: Control effect of nematicides on cucumber root-knot nematodes (field test)

[0129] To evaluate the efficacy of different nematicides against cucumber root-knot nematodes, 10 cucumber field trials were conducted in different regions of China.

[0130] Four-week-old cucumber plants were transplanted into soil with root-knot nematodes and flooded with different nematicides at the time of transplanting or 7 days after transplanting. The control effect was evaluated 90 days after transplanting.

[0131] Trial Information

[0132] crop Cucumber, susceptible variety Target Root-knot nematodes (Meloidogyne spp.)

[0133] Administration and Assessment Details

[0134]

[0135] Treatment List - Plot Test

[0136]

[0137] result:

[0138] The control efficacy of different nematicides is shown in the following table:

[0139]

[0140]

[0141] Representative images of plant roots in each group are shown in Figure 2. Figure 7 shown.

[0142] From the above results, it can be seen that due to the excellent crop safety of compound 1, it can be applied at the time of transplanting; and application at the time of transplanting is the best time to control root-knot nematodes and can achieve the best control effect.

[0143] Other nematicides such as fluopyram and thiathiazolyl may cause phytotoxicity problems when applied at transplanting, therefore, nematicides such as fluopyram and thiathiazolyl are not recommended for application at transplanting.

[0144] In all 10 cucumber trials, compound 1 applied at transplanting had better control than fluopyram and thiabendazim applied 7 days after transplanting.

[0145] Example 6: Effects of different nematicides on water and fertilizer utilization of tomatoes

[0146] A tomato greenhouse pot experiment and water and fertilizer monitoring were conducted at the Syngenta Qihe Experimental Station in Shandong, China, to evaluate the effects of different nematicide control effects on water and fertilizer use efficiency of tomatoes.

[0147] Four-week-old tomato plants were transplanted into pots with root-knot nematodes and different nematicides were applied at 200 ml of water per plant at transplanting or 7 days after transplanting. Water and fertilizer use efficiency was evaluated 72 days after transplanting.

[0148] Trial Information

[0149]

[0150] Administration and evaluation details

[0151]

[0152]

[0153] Treatment List - Pot Trial

[0154]

[0155] result:

[0156] Root-knot nematode control effects:

[0157] The roots of the plants were photographed 72 days after transplanting to evaluate the control efficacy against root-knot nematodes. Figure 8 As shown. Figure 8 It can be seen that the control effect of compound 1 applied at the time of transplanting is better than that of fluopyram applied 7 days after transplanting, and is much better than that of thiathiazolyl applied 7 days after transplanting.

[0158] Water and fertilizer utilization rate:

[0159] The plants were photographed 72 days after transplanting. Fig. 9 At the same time, the water and fertilizer utilization rates of each group of crops were calculated, and the results are shown in the following table.

[0160]

[0161]

[0162] From the above results, it can be seen that the plants in the compound 1 treatment group have higher water, nitrogen, phosphorus and potassium fertilizer utilization rates, which makes the plants in the compound 1 treatment group have higher root fresh weight and plant fresh weight than the plants in other groups. This ensures that the crops are stronger, have higher yields and better fruit quality.

[0163] Example 7: Demonstration test of the control effect of different nematicides on tomato root-knot nematodes

[0164] A tomato demonstration trial was conducted in Luxi, Yunnan, China to evaluate the effects of different nematicides on crop vigor and yield.

[0165] Four-week-old tomato plants were transplanted into soil with root-knot nematodes and different nematicides were applied by drip irrigation at transplanting or 5 or 15 days after transplanting. Yield was evaluated 90 days after transplanting.

[0166] Trial Information

[0167] Place Luxi, Yunnan, China crop Tomato, Zidali variety Target Tomato fruit yield Experimental plot area <![CDATA[150m 2 ]]>

[0168] Administration and Assessment Details

[0169] Application method Drip irrigation application Application time At transplanting or 5 or 15 days after transplanting Evaluate 90 days after transplanting

[0170] Treatment List - Pot Trial

[0171]

[0172]

[0173] result:

[0174] The plants were photographed 53 days after transplanting, and the tomato fruits harvested 90 days after transplanting were photographed. Fig.10 shown.

[0175] Depend on Fig.10 It can be seen that compared with the fluopyram and thiabendazim treatment groups, the tomato plants treated with compound 1 drip irrigation at the time of transplanting showed better plant vigor and harvested the most tomato fruits.

[0176] Plants treated with Compound 1 had healthier root systems, which provided more water and fertilizer to the crop, resulting in higher yields and better quality fruits.

[0177] In addition to those described herein, various modifications of the present invention will be apparent to those skilled in the art based on the foregoing description. Such modifications are also intended to fall within the scope of the appended claims. Each reference cited in this application (including all patents, patent applications, journal articles, books and any other disclosures) is incorporated herein by reference in its entirety.

Claims

1. A method for controlling or preventing plants from being infested by plant pathogenic nematodes, which comprises applying to the plants or their loci within 3 days after transplanting the plant seedlings one or more compounds selected from the following or their agriculturally acceptable salts: The plant is a plant of the genus Cucumis or a plant of the genus Lycopersicon.

2. The method according to claim 1, wherein the compound is selected from: or its agriculturally usable salt.

3. The method according to claim 1 or 2, wherein the compound is N-[(1,2 cis)-2-(2,4-dichlorophenyl)cyclobutyl]-2-(trifluoromethyl)pyridine-3-carboxamide or an agriculturally acceptable salt thereof.

4. The method according to any one of claims 1 to 3, wherein the compound comprises (1S, 2S) and (1R, 2R) enantiomers, and the ratio of (1S, 2S) enantiomer to (1R, 2R) enantiomer is greater than 4:1; Preferably, the compound is the pure (1S,2S) enantiomer.

5. The method according to any one of claims 1 to 4, wherein the compound is applied in an amount of 1 to 20 mg, preferably 2 to 15 mg, more preferably 3 to 10 mg per plant; Alternatively, the compound is applied in an amount of 50-1000 g, preferably 100-500 g, more preferably 250 g per hectare (ha).

6. The method according to any one of claims 1 to 5, wherein the compound is administered in the form of a suspension composition (preferably a suspension concentrate); Preferably, the concentration of the compound in the suspending agent is 100-1000 g / L, preferably 200-600 g / L, more preferably 300-500 g / L, most preferably 450 g / L.

7. The method according to any one of claims 1 to 6, wherein the plant pathogenic nematode is any one or more of a root-knot nematode (Meloidogyne), a cyst nematode (Heterodera), a blade nematode (Aphelenchina), a stem nematode (Ditylenchus), a root-knot nematode (Nacobbus), a root-rot nematode (Pratylenchus), and a pine wood nematode (Bursaphelenchus xylophilus); Preferably, the plant pathogenic nematode is a root-knot nematode.

8. The method according to any one of claims 1 to 7, wherein the plant of the genus Cucumis is Cucumber (Cucumissativus) or Melon (Cucumis melo), preferably Cucumber; The plant of the genus Solanum is tomato (Solanum lycopersicum).

9. The method according to any one of claims 1 to 8, wherein the compound is applied within 2 days or within 1 day after transplanting the plant seedlings; Preferably, the compound is applied on the day of transplanting the plant seedlings (for example, when watering the plant seedlings after transplanting); Preferably, the plantlets are transplanted when they are 1-5 weeks old, more preferably, the plantlets are transplanted when they are 4 weeks old.

10. The method according to any one of claims 1 to 9, wherein the compound is applied by drip irrigation, drench irrigation or flood irrigation.

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