CN115633684A

CN115633684A - Herbicide and application of 2-chloro-4-nitrophenol as active ingredient of herbicide

Info

Publication number: CN115633684A
Application number: CN202211319640.XA
Authority: CN
Inventors: 杨从军; 侯凯丽; 姜洋; 冯宇航
Original assignee: Qingdao Agricultural University
Current assignee: Qingdao Agricultural University
Priority date: 2022-10-26
Filing date: 2022-10-26
Publication date: 2023-01-24

Abstract

The invention discloses a herbicide and application of 2-chloro-4-nitrophenol as an active ingredient of the herbicide, wherein the herbicide comprises 2-chloro-4-nitrophenol as the active ingredient. The invention discovers for the first time that the 2-chloro-4-nitrophenol has excellent and broad-spectrum herbicidal activity, can be used for preparing herbicides, has better weed control effect than the main herbicide glufosinate-ammonium in the current market, and is a very competitive herbicidal compound. The composition has wide weeding spectrum, excellent weeding activity on various weeds, low toxicity risk, easy degradation by microorganisms in the environment, capability of being used as a carbon source, a nitrogen source and an energy source by the microorganisms, no residual risk and environmental safety risk, and thus, the composition has the advantage of safe use.

Description

Herbicide and application of 2-chloro-4-nitrophenol as active ingredient of herbicide

Technical Field

The invention relates to the technical field of herbicides, and in particular relates to an application of a herbicide and 2-chloro-4-nitrophenol as active ingredients of the herbicide.

Background

The growth of weeds in the field has serious harm to the normal growth of crops, and although the types of weeds are many, the harm to the crops is basically the same, so that the yield and the quality of agricultural products are seriously reduced, even the grains are not harvested, and the labor cost is greatly increased. Therefore, how to effectively control the farmland weeds becomes an important problem influencing the development of modern agricultural production.

At present, the methods for preventing and killing weeds are more, and comprise methods such as agricultural control, plant quarantine, biological control, chemical control and the like, wherein the chemical control method is trusted by farmers due to high speed, high efficiency and remarkable effect.

The chemical herbicides on the market are more in variety, wherein the main chemical herbicides on the market in the early stage are paraquat and glyphosate, and with the emergence of glyphosate-resistant weeds and the market withdrawal of paraquat, glufosinate replaces the former two herbicides to be mainly used for preventing and killing weeds in fields and orchards and becomes the third big biocidal herbicide after paraquat and glyphosate.

Glufosinate-ammonium is a low-toxicity, broad-spectrum, highly efficient biocidal herbicide developed by hester in germany in the 80's 20 th century. Its action mechanism is that it can inhibit photosynthetic phosphorylation by inhibiting glutamine synthetase to interfere glutamine synthesis, resulting in ammonia accumulation, and blocking photosynthesis of receptor plant to make plant die. Glufosinate has a conductivity that can be transported both up the xylem and phloem to the underground parts with transpiration currents, and will take effect in the field at a rate between that of paraquat and glyphosate.

However, from the aspects of preventing and removing weeds by glufosinate and practical application, the herbicide control spectrum of a single-agent product is far lower than that of paraquat and glyphosate, the effect of preventing and removing gramineous weeds is better than that of broadleaf weeds, the difference of the herbicide effects of preventing and removing weeds with different grass ages is large, and along with the wide application of glufosinate, resistant weeds such as resistant goosegrass and ryegrass are gradually shown.

Therefore, in view of the use of herbicides in the market at present, the emergence of new, fast-acting and broad-spectrum herbicides is urgently needed, and thus, the existing herbicides are yet to be further improved.

Disclosure of Invention

Aiming at the problems, the invention provides a herbicide taking 2-chloro-4-nitrophenol as an active ingredient and application of 2-chloro-4-nitrophenol as the herbicide, wherein the 2-chloro-4-nitrophenol has excellent herbicidal activity on various weeds, has low toxicity and safe use, and has good prospect in application of the herbicide.

In order to solve the above problems, the present invention provides the following technical solutions:

in a first aspect, the present application provides the use of 2-chloro-4-nitrophenol as an active herbicide ingredient. Heretofore, 2-chloro-4-nitrophenol has been used as an organic dye intermediate.

The structure and the physical and chemical properties of the 2-chloro-4-nitrophenol are as follows:

chinese name: 2-chloro-4-nitrophenol

English name: 2-chloroo-4-nitrophenol.

Chinese alias: 2-chloro-4-nitrophenol, o-chloro-p-nitrophenol, 4-nitro-o-chlorophenol, and 4-nitro-2-chlorophenol.

English alias: nitrofurgin, o-Chloro-p-nitrophenol, 4-Nitro-o-chlorophenol, 2-chlororanyl-4-Nitro-Phenol.

CAS No.：619-08-9

EINECS：210-578-8

The molecular formula is as follows: c ₆ H ₄ ClNO ₃

Molecular weight: 173.55g/mol

Light yellow needle crystal. Dissolving in ether, ethanol and chloroform, and hardly dissolving in water. Can be volatilized with water vapor and stored in a cool and dry place (Gaede chemical industry net). Melting point: 110-111 ℃ (SciFinder); density: 1.554g/cm ³ (Rockwell chemical network).

Through a large amount of researches, the applicant firstly discovers that the 2-chloro-4-nitrophenol has excellent and broad-spectrum herbicidal activity and can be used for preparing herbicides, and the research and development processes are as follows:

the applicant firstly uses the amaranthus retroflexus as a receptor plant and adopts an embryo elongation inhibition method to screen the weeding activity of 40 different plants, and the clove is found to have excellent weeding activity. Then, by activity tracing, eugenol (4-allyl-2-methoxyphenol) which is a herbicidal active ingredient was isolated from cloves.

Based on the analysis of the structure and the activity of the eugenol, the applicant obtains a large number of eugenol structural analogs through the substitution or derivation of 3 groups on a eugenol benzene ring. And 34 selected eugenol structural analogues are subjected to herbicidal activity screening, and the following results are found: among various eugenol structural analogues, 2-chloro-4-nitrophenol (2C 4 NP) has the strongest inhibition effect on the growth of amaranthus retroflexus seed embryos, and the inhibited EC ₅₀ Is 4.863mg/L, and has great weeding potential.

The actual control effect of 2C4NP on adult weeds was further determined by pot experiments to obtain: 2-chloro-4-nitrophenol can cause the leaves of the weeds to rapidly lose water and wither within 24 hours and die by gradual drying, the growth quantity of the overground part 7 days after the application of the herbicide is obviously reduced, and the weeding effect is not influenced by the light.

In a further experiment, 2-chloro-4-nitrophenol (glufosinate) was found to have 59.5% (12.8%), 84.8% (27.0%), 73.3% (19.4%), 100% (36.2%), 47.2% (11.3%), 62.3%, 82% (62.3%) and 97.3% (59.7%) fresh weight control of Chenopodium album, erigeron annuus, portulaca oleracea (Portulaca oleracea), orychophragmus violaceus (origrapevines), galium pauciflorum (erianum violaceus), galium palmatum (erianum davidii), commelina communis (Commelina communis), setaria viridis (eleusindica), respectively, at a concentration of 500mg/L with glufosinate as control. The test result proves that the control effect of the 2-chloro-4-nitrophenol on the same weed is obviously superior to that of the main herbicide glufosinate-ammonium in the current market, and the 2-chloro-4-nitrophenol is a competitive weeding component.

Preferably, the application method of the 2-chloro-4-nitrophenol as the active ingredient of the herbicide comprises the following steps: the 2-chloro-4-nitrophenol can be used as an active ingredient to be directly processed into different preparations for weed control. The preparation of the dosage form adopts the prior art and is not described in detail herein.

Or 2-chloro-4-nitrophenol is taken as a lead compound, and after the structure is further modified or modified to form a compound with higher herbicidal activity, the compound is applied to herbicides.

2-chloro-4-nitrophenol has broad-spectrum weeding performance, and experiments prove that the compound can be applied to the growth inhibition of the following weeds: chenopodium album (Chenopodium album), annual fleabane herb (Erigeron annuus), purslane herb (Portulaca oleracea), orychophragmus violaceus (Orychophragmus violaceus), potentilla chinensis (Erigeron canadens), commelina communis (Commelina communis), setaria viridis (Setaria viridis) and Eleusine indica (Eleusine indica). Based on the limitations of the test conditions and space limitations, only the test results of the above weeds are listed in the following examples. However, 2-chloro-4-nitrophenol can also be used for controlling other weeds, and the weed control spectrum is not limited to the weeds.

In a second aspect, the present invention also provides a herbicide comprising 2-chloro-4-nitrophenol as an active ingredient.

In the herbicide, 2-chloro-4-nitrophenol can be used as the only weeding active ingredient, and other weeding active ingredients with synergistic coordination can also be added for combined use, so that the weeding spectrum is further widened.

Preferably, 2-chloro-4-nitrophenol is used in the herbicide at a concentration of 0.5 g.L ^-1 Above this range, the control effect on weeds is better.

More preferably, 2-chloro-4-nitrophenol is used in a concentration of 0.5 to 1.0 g.L ^-1 The cost performance of the application is higher, and the use cost is reduced on the premise of ensuring the weeding effect.

The invention has the following beneficial effects:

1. the invention discovers for the first time that the 2-chloro-4-nitrophenol has excellent and broad-spectrum herbicidal activity, can be used for preparing herbicides, has better weed control effect than the main herbicide glufosinate-ammonium in the current market, and is a very competitive herbicidal compound.

2. The 2-chloro-4-nitrophenol has wide herbicidal spectrum and has excellent herbicidal activity against various weeds such as Chenopodium album (Chenopodium album), annual fleabane herb (Erigeron annuus), purslane herb (Portulaca oleracea), orychophragmus violaceus (oridiphragus), veronica canadensis (Erigeron canadensis), commelina communis (Commelina communis), setaria viridis (Setaria viridis) and Eleusine indica (Eleusine indica).

3. The 2-chloro-4-nitrophenol has low toxicity risk, is extremely easy to degrade by microorganisms in the environment, can be used as a carbon source, a nitrogen source and an energy source by the microorganisms, has no residual risk and environmental safety risk, and has the advantages of safe use and no pollution.

4. The toxic action of 2C4NP on orychophragmus violaceus is not influenced by the existence of light, the 2C4NP is supposed to cause the rapid dehydration of weeds and is related to the induction of the outbreak of weed Reactive Oxygen Species (ROS), and the action is completely different from the prior herbicides which act by inducing ROS, such as paraquat (PS I inhibitor), atrazine (PS II inhibitor), fluorosulfonyl ammonium oxalate (PPO inhibitor), topramezone (HPPD inhibitor), glufosinate (GS inhibitor) and the like. The 2C4NP action mechanism is deeply researched, a new action target can be discovered, the fundamental scientific problem of creating a novel green herbicide can be solved, and a solid and definite theoretical guidance is provided for the development of a green pesticide molecular structure.

Drawings

FIG. 1 shows the inhibition effect of ethanol extract of plant material such as clove on the elongation of amaranthus retroflexus embryos;

FIG. 2 is a graph showing activity measurements (200 mg/L) of the extracted versus extended amaranth embryos;

FIG. 3 shows the inhibition of the elongation of the amaranthus retroflexus embryos by the different fractions (200 mg/L);

FIG. 4 shows fraction F4 ¹ H NMR spectrum;

FIG. 5 shows fraction F4 ¹³ C NMR spectrum;

FIG. 6 is a eugenol structural formula;

FIG. 7 is a graph of the inhibition of Bacopa monniera embryo elongation by 2C4NP at various concentrations;

FIG. 8 shows the toxic effect of spraying 2C4NP on green bristlegrass;

FIG. 9 is a graph of typical toxicity symptoms of 2C4NP on Setaria viridis;

FIG. 10 shows the toxic effect of spraying 2C4NP on Chenopodium quinoa;

FIG. 11 is a typical toxic symptom of 2C4NP on Chenopodium quinoa;

FIG. 12 shows the toxic effect of 2C4NP on purslane after spraying;

FIG. 13 shows the poisoning effect of 2C4NP on goosegrass after spraying;

FIG. 14 shows the toxic effect of 2C4NP on Dryopteris Crassirhizoma;

FIG. 15 shows the poisoning effect of 2C4NP on Commelina communis after spraying;

FIG. 16 is a graph of the poisoning effect on annual fleabane herb after spraying 2C4 NP;

FIG. 17 shows the toxic effect of 2C4NP on orychophragmus violaceus after spraying;

FIG. 18 shows the effect of light on 2C4NP control against Brassica rapa;

FIG. 19 shows the toxic effect of 2C4NP and glufosinate on green bristlegrass (500 mg/L); a: post-dose 2d, b: 7d after the medicine is applied;

FIG. 20 shows the toxic effect of 2C4NP and glufosinate on Chenopodium quinoa (500 mg/L); a: post-dose 1d, b: 7d after the medicine is applied;

FIG. 21 is a graph of the toxic effect of 2C4NP and glufosinate on purslane (500 mg/L); a: post-dose 2d, b: 7d after the medicine is applied;

FIG. 22 shows the toxic effect of 2C4NP and glufosinate on goosegrass (500 mg/L); a: post-dose 2d, b: 7d after the medicine is applied;

FIG. 23 shows the poisoning effect of 2C4NP and glufosinate on Potentilla chinensis (500 mg/L); a: post-dose 1d, b: 7d after the medicine is applied;

FIG. 24 shows the poisoning effect of 2C4NP and glufosinate on Commelina communis (500 mg/L); a: post-dose 1d, b: 7d after the medicine is applied;

FIG. 25 is a graph of the poisoning effect of 2C4NP and glufosinate on annual fleabane (500 mg/L); a: post-dose 2d, b: 7d after the medicine is applied;

FIG. 26 shows the poisoning effect of 2C4NP and glufosinate on orychophragmus violaceus (500 mg/L); a: post-dose 1d, b: and 7d after the medicine is applied.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention. In the present invention, the equipment and materials used are commercially available or commonly used in the art, if not specified. The methods in the following examples are conventional in the art unless otherwise specified.

EXAMPLE-discovery of herbicidal Activity of 2-chloro-4-nitrophenol

(I) screening of herbicidally active plants

1. Test method

The influence of the ethanol extract of 40 plant materials on the growth of the seed embryo of the amaranthus retroflexus is determined by taking the amaranthus retroflexus as a receptor plant and adopting a culture dish filter paper method. 0.3g of plant dry powder is weighed in a triangular flask, 30mL (10 mg/mL) of 95% ethanol is added, and the mixture is placed on a shaking bed and is shaken and extracted for 48 hours at the temperature of 25 ℃ and under the condition of 160 r/min. After filtration, 2mL of the supernatant was added to a petri dish with filter paper. And (3) after the ethanol is completely volatilized, adding 2mL of sterile water into the culture dish, and then adding 10 amaranthus retroflexus seeds with accelerating germination and uniform white and neat appearance. Placing the culture dish in a constant temperature box at 28 ℃, and carrying out moisture preservation culture under the dark condition. After 3d, measuring the length of the amaranthus retroflexus embryo, and calculating the inhibition rate of the ethanol extract of different plant materials on the elongation of the amaranthus retroflexus embryo.

2. Test results and analysis

The result shows that at 10mg/mL, the clove extract completely inhibits the elongation of the amaranthus retroflexus seed embryo, the inhibition rate of the length of the embryo (radicle and embryo) reaches 100% (table 1, figure 1), and the clove has excellent herbicidal activity.

TABLE 40 inhibition of Amaranthus retroflexus seed embryo elongation by ethanol extracts of plant materials (10 mg/mL)

Note: inhibition rate is mean value ± sem; lower case letters indicate significance of difference (p < 0.05)

(II) clove herbicidal active ingredient separation

1. Test method

Repeatedly leaching 2.5Kg of clove powder with 95% ethanol, filtering, combining the supernatants, and concentrating to obtain 723g of ethanol extract. Sequentially extracting the extract with petroleum ether, chloroform, ethyl acetate and methanol to obtain different polarity extraction phases. 20mg of the extract was dissolved in 200uL of DMF and diluted with 100ml of 0.1% Tween-80 aqueous solution to give a diluted solution having a concentration of 200mg/L. Adding 2mL of the diluent into a culture dish paved with filter paper, adding the amaranthus retroflexus seeds with accelerating germination and whitening, and determining the influence of each extraction on the elongation of the amaranthus retroflexus embryos (the method is the same as the method).

2. Test results and analysis

The results show that the inhibition rates of the petroleum ether extract phase, the chloroform extract phase, the ethyl acetate extract phase and the methanol extract phase to the length of the amaranthus retroflexus embryo are respectively 79.5%, 2.6%, 9.1% and 1.7%, and the inhibition effect of the petroleum ether extract phase is obviously better than that of other substances (figure 2).

Further, the petroleum ether extract phase was separated by silica gel column chromatography to obtain 9 fractions, wherein fractions F2, F3, and F4 had significant inhibitory effects on the length of amaranthus retroflexus embryos, and the inhibitory rates were 78.5%, 84.0%, and 83.5%, respectively (fig. 3). Silica gel TLC analysis showed that fraction F4 was a single compound with F2, F3 and F4 as the main components. Spectral identification of F4 based on ¹ H NMR、 ¹³ C NMR (FIGS. 4 and 5) showed that the active ingredient F4 was eugenol (4-allyl-2-methoxyphenol) (FIG. 6). Comparison of NMR spectra, F4, using a chemical database (www.organchem.csdb.cn) ¹³ The C NMR was completely consistent with eugenol, and it was further confirmed that F4 was eugenol.

(III) Effect of eugenol structural analogues on Amaranthus retroflexus embryo elongation

1. Test method

Based on the structural characteristics of p-eugenol, the p-eugenol has 3 substituent groups on a benzene ring, namely hydroxyl (-OH) and methoxyl (-OCH) ₃ ) Allyl (CH) ₂ ＝CH-CH ₂ -) further study the activity of its structural analogs by cloveThe substitution or derivation of 3 groups on the phenol benzene ring can obtain eugenol structural analogs with different herbicidal activities. The 34 collected eugenol structural analogues are subjected to herbicidal activity screening according to the experimental method.

2. Test results and analysis

As shown in Table 2, 2-chloro-4-nitrophenol (2C 4 NP) among 34 different eugenol structural analogs inhibited EC from retrogradation amaranth embryo elongation ₅₀ The value is the lowest, and is only 4.832mg/L, the elongation of the amaranthus retroflexus seed embryo is strongly inhibited, and the weeding potential is great. Therefore, 2-chloro-4-nitrophenol was subsequently selected as a subject for further study of its herbicidal activity.

TABLE 2 Effect of eugenol structural analogs on Amaranthus retroflexus embryo elongation

EXAMPLE further investigation of herbicidal Activity of bis 2-chloro-4-nitrophenol

(I) 2-chloro-4-nitrophenol inhibition of Amaranthus retroflexus seed embryo elongation

1. The test method comprises the following steps: dissolving 2C4NP with equal amount of N, N-Dimethylformamide (DMF), diluting with equal amount of 1 ‰ Tween 80 water solution, and making into medicinal liquid with 2C4NP concentration of 10, 8, 6, 4, 2 mg/L. And (3) determining the inhibition of the liquid medicine on the elongation of the amaranthus retroflexus seed embryo with the germination accelerating property and the whitening property by adopting a culture dish filter paper method at 28 ℃ under the dark condition. Measuring the total length of the embryos after 3d, calculating the inhibition rate of the liquid medicine to the total length, and calculating the EC of the 2C4NP for inhibiting the elongation of the amaranthus retroflexus embryos according to a concentration logarithm-probability value linear method ₅₀ The value is obtained.

2. Test results and analysis

The results showed that 2C4NP strongly inhibited the elongation of the amaranthus retroflexus seed embryos (fig. 7). Inhibitory virulence equation: y = 2.24fx +3.464; correlation coefficient: 0.964; inhibition of medium concentration EC50:4.832mg/L;EC ₅₀ 95% confidence limit of: 4.250-5.444mg/L.

Potted plant test for weed control with (di) 2-chloro-4-nitrophenol

Based on the strong inhibition of 2C4NP on the elongation of amaranthus retroflexus seed embryos, a pot experiment is further utilized to research the control effect of the 2C4NP on common 8 adult weeds (quinoa, annual fleabane herb, purslane, orychophragmus violaceus, pennisetum flaccidum, dayflower, setaria viridis and eleusine indica).

1. Test method

Dissolving 2C4NP in quantitative ethanol, diluting with 1 ‰ Tween 80 water solution, respectively preparing into 1000mg/L, 750mg/L, 500mg/L, 200mg/L, 100mg/L, and 50mg/L medicinal liquids, and uniformly spraying weed whole plant with spray bottle. Continuously observing the poisoning phenomenon of the weeds from 1 st to 7 th days after spraying, counting the fresh weight of the overground part of the weeds after 7 th days, and calculating the weeding effect by using the fresh weight.

2. Test results and analysis

The results of the tests on different weeds were as follows:

(1) Herb of common Setaria

Test green bristlegrass: the plant height is 18-21cm, and the plant height is 4-5 leaves.

After receiving the pesticide, most leaves rapidly lose water, wither, curl, partially yellow, and part of stems lose water, dry and fall down in later period, and then the whole plant dies. After spraying the

liquid medicines

2d and 7d, the toxic action of 2C4NP on green bristlegrass is shown in figure 8 respectively. Typical toxic symptoms to green bristlegrass are shown in figure 9.

The fresh weight inhibition rate after 7d of the drug is shown in Table 3. Under the concentration of 200mg/L, the inhibition rate of 2C4NP on green bristlegrass herb is more than 50%, and is 59.5%; the control effect on green bristlegrass reaches 100 percent under the concentration of 1000 mg/L.

TABLE 3 Effect of 7d after spraying 2C4NP on the fresh weight of aerial parts of Setaria viridis

Note: lower case letters represent significance of difference (p < 0.05)

(2) Chenopodium quinoa (L.) Merr

Tested Chenopodium quinoa Roxb: the plant height is 12-14cm, and the plant height is 8-10 leaves.

After the drug is applied, the leaf blade at the top of the plant is dehydrated, dried and curled firstly, then the leaf edge is curled, the whole leaf blade is dehydrated and dried, and finally the petiole is dehydrated to cause the leaf blade to fall off. The toxic effect of 2C4NP on Chenopodium quinoa after spraying the

medicinal liquids

1d and 7d is shown in FIG. 10. Typical toxic symptoms to Chenopodium quinoa are shown in FIG. 11.

The fresh weight inhibition rate after 7d of the drug is shown in Table 4. Under the concentration of 500mg/L, the inhibition rate of 2C4NP on the fresh weight of the overground part of Chenopodium quinoa reaches more than half and is 53.4 percent; under the concentration of 1000mg/L, the control effect on the fresh weight of the overground part of the chenopodium quinoa reaches 80.4 percent.

TABLE 4 Effect of 7d on the fresh weight of aerial parts of Chenopodium quinoa after spraying 2C4NP

Note: lower case letters represent significance of difference (p < 0.05)

(3) Herba Portulacae

Test purslane: the plant height is 10-11cm, and 14-17 leaves.

After receiving the medicine, the initial leaves fall off in a large amount, and the initial leaves begin to be blackened from the base parts of the leaves and then spread to the whole leaves, so that the whole leaves become black, the stems of the plants become black and soft in the initial stage, the plants are wilted and lodging, and the stems and the leaves become black and dry after dehydration in the later stage. The toxic effect of 2d and 7d,2c4NP on herba Portulacae after spraying medicinal liquid is shown in FIG. 12.

The fresh weight inhibition rate after 7d of the drug is shown in Table 5. Under the concentration of 200mg/L, the control effect of the 2C4NP on the fresh weight inhibition of the overground part of the purslane is 58.7%, and under the concentration of 1000mg/L, the control effect reaches 100%.

TABLE 5 Effect of 7d after spraying 2C4NP on the fresh weight of aerial parts of Portulaca oleracea

Note: lowercase letters represent significance of difference (p < 0.05)

(4) All-grass of Bull's tendon

The tested eleusine indica: the plant height is 19-21cm,3-4 tillers each have 5-6 leaves.

After the plants are applied, the leaves are quickly dehydrated and curled, part of the leaf tips are yellowed, then the leaves are spread to the whole plant, and the stems are dehydrated, yellowed and dried up in the later period, so that the plants are dried up and die. The toxic action of 2d and 7d,2c4NP on herba Eleusines Indicae after spraying the medicinal liquid is shown in figure 13.

The fresh weight inhibition rate after 7d of the drug is shown in Table 6. Under the concentration of 500mg/L, the inhibition rate of 2C4NP on the upper fresh weight of the goosegrass lawn reaches 97.3 percent.

TABLE 6 influence of 7d after spraying 2C4NP on the fresh weight of the aerial parts of goosegrass

Note: lower case letters represent significance of difference (p < 0.05)

(5) All-grass of Chinese bugleweed

Testing the agrimony: the plant height is 21-23cm, and the plant height is 33-40 leaves.

After the plants are applied, the plants are firstly quickly dried and curled from the top leaves of the plants, then the whole leaves are dehydrated and dried and curled from the leaf tips, and finally the whole plants are dried and dead. The toxic action of 1d and 7d and 2c4NP on Eragrostis peltata after spraying the medicinal liquid is shown in figure 14 respectively.

The fresh weight inhibition rate after 7d of the drug is shown in Table 7. The inhibition rate of 2C4NP on Eragrostis peltata is 59.3% at the concentration of 750mg/L, and the control effect is 73.5% at the concentration of 1000 mg/L.

TABLE 7 Effect of 7d after spraying 2C4NP on aerial parts of Galium aparine

Note: lower case letters represent significance of difference (p < 0.05)

(6) Herba Commelinae

Dayflower for test: the plant height is 9-10cm, and the plant height is 4-5 leaves.

After receiving the medicine, the leaf margin begins to curl, the base part of the petiole is changed from green to brown, then the petiole loses water and shrinks, the supporting effect is lost, the leaves are laid down and turned yellow, part of the petiole is rotted, the stem is soft and rotted at the later stage, and the whole plant is laid down. The toxic action of 1d, 5d and 2c4NP on dayflower after spraying the liquid medicine is respectively shown in figure 15.

The fresh weight inhibition rate after 5 days of administration is shown in Table 8. Under the concentration of 500mg/L, the inhibition rate of 2C4NP on dayflower is 57.2%, and the control effect reaches 100% under the concentration of 1000 mg/L.

TABLE 8 Effect of 7d after spraying 2C4NP on the fresh weight of the aerial parts of Commelina communis

Note: lower case letters represent significance of difference (p < 0.05)

(7) One year fluffy

Annual fleabane test: the plant height is 9-11cm, and the plant height is 4-5 leaves.

After receiving the medicine, the leaf margin is firstly withered and curled, the whole leaf loses water and becomes dry, then the stem loses water, and the whole plant becomes dry and lodged. The toxic effect of 2d and 7d,2c4NP on annual fleabane after spraying the liquid medicine is shown in figure 16 respectively.

The fresh weight inhibition rate after 7d of the drug is shown in Table 9. The inhibition rate of 2C4NP on annual fleabane reaches 84.8% at the concentration of 500mg/L, and the control effect is 100% at the concentration of 750 mg/L.

TABLE 9 Effect of 7d after spraying 2C4NP on aerial parts of Galium aparine

(8) Radix Brassicae Rapae

For the test orychophragmus violaceus: the plant height is 7-8cm, and the plant height is 4-5 leaves.

After the drug is applied, the leaf edge is rapidly dehydrated, curled and dried up, part of leaves are changed from green to transparent, the whole leaf is dehydrated and dried up in the later period, the stem is dehydrated and thinned, and the whole plant is lodged. The toxic effect of 1d, 5d,2c4NP on orychophragmus violaceus after spraying the liquid medicine is respectively shown in figure 17.

The fresh weight inhibition rate after 5 days of administration is shown in Table 10. The inhibition rate of 2C4NP on orychophragmus violaceus is 55.4% at the concentration of 200mg/L, and the control effect reaches 100% at the concentration of 750 mg/L.

TABLE 10 Effect of 5d after spraying 2C4NP on the aerial parts of Orychophragmus violaceus

EXAMPLE III Effect of light on the efficacy of 2-chloro-4-nitrophenol in weed control

1. Test method

The orychophragmus violaceus is used as a test weed, and a pot experiment is adopted to verify the influence of illumination on the weeding effect of 2C4 NP. Dissolving 2C4NP in a small amount of absolute ethanol, diluting with 1 ‰ tween-80 water solution to obtain 500mg/L medicinal liquid, and spraying onto weed leaves. After spraying, partial plants are placed under natural light conditions, partial plants are placed under complete darkness conditions, and control groups without spraying are respectively arranged.

2. Test results and analysis

The toxic effect of 2d and 4d,2c4NP on orychophragmus violaceus after spraying the liquid medicine is shown in figure 18.

Test results show that the toxic action of the 2C4NP on the orychophragmus violaceus is not influenced by the existence of illumination, and the 2C4NP causes the orychophragmus violaceus to be quickly dehydrated under the conditions of illumination or no illumination. It is speculated that 2C4 NPs cause rapid dehydration of weeds in relation to their induction of weed Reactive Oxygen Species (ROS) outbreaks, unlike existing herbicides.

EXAMPLE comparison of herbicidal efficacy of 2-chloro-4-nitrophenol and glufosinate-ammonium

1. Test method

Dissolving 2C4NP and glufosinate-ammonium with a small amount of absolute ethyl alcohol, then diluting with 1 per mill of Tween 80 aqueous solution to obtain 500mg/L liquid medicine, and uniformly spraying the liquid medicine on weed plants by using a spray bottle. Observing the toxic reaction of 8 different weeds (Chenopodium quinoa, annual fleabane herb, purslane, orychophragmus violaceus, pennisetum flabellatum, dayflower, setaria viridis and eleusine indica) to the two medicaments, calculating the control effect of the medicaments according to the fresh weight of the overground part of the weeds, and comparing the control effect difference of the two medicaments.

2. Results and analysis of the experiments

(1) The toxic response of 8 different weeds to two agents is shown in detail in FIGS. 19-26.

(2) The control effect calculated from the toxic symptom to the weeds and the fresh weight of the overground parts of the weeds shows that the control effect t test of the 2C4NP and the glufosinate-ammonium has significant difference for each weed to be tested, and the result shows that the control effect of the 2C4NP is significantly better than that of the glufosinate-ammonium.

From the results in table 11, it is known that the weeding spectrum of the existing glufosinate-ammonium is narrow, and among 8 weeds, the glufosinate-ammonium only has the control effect on green bristlegrass and goosegrass about 60%, and has poor control effect on other 6 weeds; the 2C4NP of the application shows a wide weeding spectrum and has excellent control effects on the 8 weeds, wherein the control effect on orychophragmus violaceus is as high as 100%, and the control effect on eleusine indica is as high as 97.3%.

TABLE 11 comparison of the fresh weight control of the aerial parts of weeds by 2C4NP and glufosinate-ammonium (500 mg/L)

Note: * Shows that the two agents have significant difference on the same weed control effect by t test (p < 0.05)

Example safety of penta-2-chloro-4-nitrophenol

Toxicity of (mono) 2-chloro-4-nitrophenol

The risk of 2C4NP toxicity is low. According to the data of European chemical administration (ECHA), rats orally take acute toxicity LD ₅₀ 900mg/kg (low toxicity), acute toxicity LC inhaled by rats ₅₀ 1024mg/kg (moderate toxicity); 2C4NP not shownThe method comprises the following steps of classifying occupational disease hazard factors of the people's republic of China (2015), dangerous chemicals easily exploding (2017), first and second dangerous chemicals with important supervision, important environment management dangerous chemicals, narcotics and psychopharmaceuticals.

Degradation of (di) 2-chloro-4-nitrophenol in the environment

Research shows that the 2C4NP is easily degraded by microorganisms in the environment, can be used as a carbon source, a nitrogen source and an energy source by the microorganisms, and has no residual risk and environmental safety risk. Xu Lingxue finds that cuprianidus CNP-8 not only can degrade 2C4NP through a phloroglucinol pathway, but also can grow by using 2C4NP as a unique carbon source. Under the condition of natural soil, when the addition concentration of the 2C4NP is 40 mug/g, 12 days can be completely degraded; and CNP-8 can be added into naturally treated soil for 10 days to be completely removed. 2C4NP at a concentration of 0.3mM in wastewater could be completely degraded within 48h.

Ghosh et al isolated from pesticide contaminated soil a Rhodococcus rhodococcus imtechnensis RKJ300 strain capable of utilizing 2C4NP as the sole carbon source to completely utilize and degrade 70. Mu.g/g of 2C4NP within 20 days.

Arora et al utilize enrichment method to separate Arthrobacter SJCon and Burkholderia RKJ 800 from pesticide contaminated site soil, both can use 2C4NP as sole carbon source and energy source, degrade 2C4NP and release nitrite and chloride ions. 2C4NP was completely degraded by either strain SJCon or RKJ 800 within 48h when grown in 1L Erlenmeyer flasks containing 250mL of minimal medium, with 0.3mM 2C4NP as the sole carbon and energy source. In the experimental microcosmic of sterile soil, strain RKJ 800 completely removed 100 μ g/g 2C4NP in 8 d.

Min Jun et al found that inoculation of Burkholderia SJ98 completely removed 2C4NP at an initial concentration of 40. Mu.g/g on day 8, and that 2C4NP contamination had no significant effect on bacterial abundance and diversity in the soil.

Therefore, the 2C4NP can be degraded by microorganisms in the environment, can be used as a carbon source and a nitrogen source by the microorganisms, has no residual risk and environmental safety risk, and has the advantage of safe use.

It should be understood that equivalents and modifications to the disclosed embodiments and concepts may occur to one skilled in the art, and all such modifications and alterations are intended to fall within the scope of the appended claims.

Claims

The application of 2-chloro-4-nitrophenol as an active ingredient of a herbicide.
2. The use of 2-chloro-4-nitrophenol as a herbicide active ingredient according to claim 1, characterized in that the method of application is: 2-chloro-4-nitrophenol can be used as an active ingredient to be directly processed into a preparation for weed control; or, the compound is used as a lead compound, and after the compound is further subjected to structural modification or modification to form a compound with higher herbicidal activity, the compound is applied to a herbicide.
3. Use according to claim 2, wherein the weeds applied comprise: chenopodium quinoa, annual fleabane herb, purslane, orychophragmus violaceus, pennisetum flaccidum, dayflower, green bristlegrass and goosegrass herb.
4. A herbicide characterized by comprising 2-chloro-4-nitrophenol as an active ingredient.
5. The herbicide formulation according to claim 2, wherein 2-chloro-4-nitrophenol is used at a concentration of 0.5 g-L ^-1 As described above.