Natural herbicide using oil tea fruit shell as raw material and its preparation method and application

Abstract

The present application relates to the technical field of herbicide preparation, and particularly relates to a natural herbicide taking camellia oleifera shell as raw material, and a preparation method and application thereof.The natural herbicide is a camellia oleifera shell water leaching solution.The present application utilizes the "low promotion high inhibition" toxicant excitation effect in allelopathy to realize efficient inhibition of typical malignant weeds such as amaranthus retroflexus and digitaria sanguinalis.Especially, the inhibition rate of amaranthus retroflexus is close to 100% at a higher concentration, and the inhibition effect on digitaria sanguinalis is also very outstanding.Compared with chemical herbicides, the allelochemicals in camellia oleifera shell have outstanding advantages such as easy degradation, no residue and environmental friendliness, can significantly reduce the input of chemical pesticides, alleviate weed drug resistance and farmland ecological imbalance, highly fit the development trend of green agriculture and organic agriculture, and have ecological and economic benefits.

Description

Technical Field

[0001] This invention relates to the field of herbicide preparation technology, and in particular to a natural herbicide using camellia fruit shell as raw material, its preparation method and application. Background Technology

[0002] Camellia oleifera ( Camellia oleifera Camellia oleifera, along with olive, oil palm, and coconut, is one of the world's four major woody oil crops, widely cultivated in southern provinces such as Jiangxi, Hunan, and Guangxi, and is a core industry for increasing income in mountainous forestry. In recent years, with the continuous expansion of planting scale and camellia oil production, the output of processing residues such as camellia fruit shells has surged, accounting for 50% to 60% of the fresh fruit weight. Currently, the fruit shells are mostly disposed of by incineration or landfill, which not only wastes biomass resources but also causes environmental pollution and increased carbon emissions, becoming a prominent bottleneck restricting the green and high-quality development of the camellia oil industry.

[0003] Farmland weeds are a significant biological hazard affecting stable and high crop yields. Current control methods, primarily relying on chemical herbicides, are increasingly problematic due to long-term use leading to increased weed resistance, soil and water pollution, pesticide residues, and ecological imbalances in farmland. Against the backdrop of rapid development in green and organic agriculture, the research and development of environmentally friendly, residue-free, and resistance-resistant plant-derived herbicides has become an important direction. Allelopathic effects, where plants release secondary metabolites that promote or inhibit the seed germination and seedling growth of neighboring plants, exhibit species selectivity, concentration dependence, and easy degradation, making it an ideal approach for developing plant-derived herbicides.

[0004] Previous studies have confirmed that Camellia oleifera possesses significant allelopathic potential, with different organs exhibiting varying inhibitory effects on recipient plants. Specifically, the extract from Camellia oleifera fruit shells shows a marked inhibitory effect on the seed germination and growth of crops such as peanuts and soybeans, with a stronger inhibitory effect than that of the leaves. Camellia oleifera fruit shells are rich in lignin, cellulose, and hemicellulose, and also contain various secondary metabolites such as polyphenols, flavonoids, saponins, and tannins, possessing the potential to serve as a basis for allelopathic substances. However, current research has largely focused on the preparation of biochar, adsorbent materials, electrode materials, and biomass fuels from the fruit shells. Applications of its allelopathic effects in farmland weed control and systematic evaluations of its effects on recipient plants of different ecological types remain relatively scarce, and its biological weed-control activity has not yet been effectively explored.

[0005] The applicant's preliminary field trials have confirmed that Camellia oleifera fruit shells, when used as field mulch, can significantly inhibit weed occurrence and growth. Based on this, this study used the noxious weeds *Amaranthus retroflexus* and *Digitaria sanguinalis*, the facultative plant *Plantago asiatica*, and the beneficial plants *Clerodendrum trichotomum* and *Hemiberlesia serratifolia* as receptors to prepare aqueous extracts of Camellia oleifera fruit shells at different concentrations. The study systematically explored their allelopathic effects on seed germination and seedling growth of the receptor plants, aiming to clarify the mechanisms of action and sensitive species, and to provide theoretical basis and technical support for the high-value utilization of Camellia oleifera fruit shell resources and green pest control in farmland. Summary of the Invention

[0006] The purpose of this invention is to provide a natural herbicide made from camellia fruit shell, its preparation method, and its application.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides the application of water extract of Camellia oleifera fruit shell in the preparation of herbicides.

[0008] This invention provides a natural herbicide using camellia fruit shell as raw material, wherein the natural herbicide is an aqueous extract of camellia fruit shell.

[0009] Preferably, the mass concentration of the aqueous extract of Camellia oleifera fruit shell is 12.5~200 g·L. - ¹.

[0010] Preferably, the mass concentration of the aqueous extract of Camellia oleifera fruit shell is 25~200 g·L. - ¹.

[0011] This invention provides a method for preparing the aforementioned natural herbicide, comprising the following steps: (1) Mix the camellia fruit shell powder with water at a ratio of 100~300 g: 500~1500 mL, and perform ultrasonic-assisted extraction for 20~40 min at a frequency of 30~50 kHz and a power of 200~500 W. Then, extract at 20~30℃ for 18~30 h. Repeat the above ultrasonic-assisted extraction and extraction 1~3 times to obtain the extraction mixture. (2) Filter and centrifuge the extract mixture, and take the supernatant to obtain the camellia fruit shell water extract.

[0012] Preferably, the fineness of the camellia fruit shell powder in step (1) is 20~60 mesh.

[0013] Preferably, the filtration in step (2) is a double filtration process, in which the material is passed through two layers of gauze and a filter membrane with a pore size of 0.22~0.8 μm. The centrifugation conditions are a rotation speed of 3000~4000 r / min and a time of 8~15 min.

[0014] This invention provides the application of the aforementioned natural herbicide in inhibiting weed seed germination and / or seedling growth. Preferably, the weed is amaranth or crabgrass.

[0015] Preferably, the natural herbicide is applied by seed soaking or spraying.

[0016] Compared with the prior art, the present invention has the following beneficial effects: First, compared to existing technologies that focus only on a single type of receptor plant (such as noxious weeds or oil crops), this invention systematically evaluates multiple functional receptors, including noxious weeds (Amaranthus retroflexus, Digitaria sanguinalis), facultative plants (Plantago asiatica), and beneficial plants (Trifolium repens, Eriocaulon buergerianum), thus comprehensively revealing the allelopathic effects of Camellia oleifera fruit shell extract. By extracting natural active substances from the fruit shell through water extraction, a large amount of waste Camellia oleifera fruit shells is transformed into high-value-added green agricultural resources. This effectively solves the resource waste and environmental pollution problems caused by burning and landfilling fruit shells, opening up new avenues for the high-value utilization of Camellia oleifera processing by-products and strongly supporting the green and sustainable development of the circular economy and the Camellia oleifera industry.

[0017] Secondly, this invention clarifies the concentration dependence and species selectivity of Camellia oleifera pericarp extract on seed germination and seedling growth of five recipient plants, and preliminarily reveals its possible intrinsic allelopathic mechanism. The germination rate inhibition intensity was ranked as follows: Amaranthus retroflexus > Crataegus pinnatifida > Imperata cylindrica > Trifolium repens > Plantago asiatica; the seedling length inhibition intensity was ranked as follows: Amaranthus retroflexus > Imperata cylindrica > Plantago asiatica > Crataegus pinnatifida > Trifolium repens, indicating that the allelopathic substances may have different regulatory targets for root and stem elongation and germination processes. Its mechanism of action may lie in the polyphenols, flavonoids, saponins, and other active substances abundant in the pericarp, which synergistically regulate plant growth and development through multiple pathways, including disrupting cell membrane permeability, inhibiting key enzyme activity, interfering with endogenous hormone balance, and inducing oxidative stress damage. The differences in sensitivity among different receptors may be closely related to seed coat structure, endogenous detoxification capacity, and survival strategies such as r-countermeasures / K-countermeasures.

[0018] Third, this invention utilizes the typical "low-promoting, high-inhibiting" toxicant excitatory effect in allelopathic processes to achieve highly efficient inhibition of typical noxious weeds such as Amaranthus retroflexus and Digitaria sanguinalis, especially at higher concentrations (e.g., 200 g·L⁻¹). - ¹) The inhibition rate against *Amaranthus retroflexus* is close to 100%, and the inhibition effect against *Digitaria sanguinalis* is also very prominent. Compared with chemical herbicides, the allelochemicals in *Camellia oleifera* fruit shells have outstanding advantages such as easy degradation, no residue, and environmental friendliness. They can significantly reduce the input of chemical pesticides, alleviate weed resistance and farmland ecological imbalance, and are highly consistent with the development trend of green agriculture and organic agriculture, combining ecological and economic benefits. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0020] Figure 1 This shows the cultivation of recipient plant seeds in extracts of different concentrations. Detailed Implementation

[0021] The camellia oleifera fruit shell provided by this invention: collected from Dexing City, Jiangxi Province, and identified by Researcher Wang Sheng of the Center for Chinese Materia Medica Resources, China Academy of Chinese Medical Sciences, as a plant of the Camellia genus in the Theaceae family (Camellia oleifera). Camellia oleifera Abel.).

[0022] Recipient plant seeds: including white clover (Trifolium repens, Fabaceae family) Creeping clover L.), *Gnaphalium* genus of grass (Poaceae family) Foxes, mules (L.) CC Gmel.) purchased from Zhengzhou Gengsen Agricultural and Animal Husbandry Technology Co., Ltd., Plantago asiatica (Plantago) Asian plantain L.) is a self-saved seed from the experimental training base of Dexing City Academy of Traditional Chinese Medicine, Amaranthaceae family, genus Amaranth ( ). Amaranthus retroflexus L.) and the genus Crataegus (of the Poaceae family) Bloody fingernail (L.) Scop. was purchased from Ganzhou Chunzai Technology Co., Ltd.

[0023] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0024] Example 1

[0025] This embodiment provides a natural herbicide using camellia fruit shell as raw material, and its preparation method includes the following steps: (1) Take dried camellia fruit shell, crush it through a 60-mesh sieve, weigh 300 g of powder, add 1500 mL of ultrapure water, mix and place it in an ultrasonic-assisted extraction device, ultrasonically assisted extraction for 40 min at a frequency of 50 kHz and a power of 500 W; then stand for 30 h at a constant temperature of 30 ℃; repeat the above ultrasonic-assisted extraction and stand extraction operations 3 times to obtain the extraction mixture.

[0026] (2) The extraction mixture was filtered through two layers of gauze and a filter membrane with a pore size of 0.8 μm, and the filtrate was collected. The filtrate was centrifuged at 4000 r / min for 15 min, and the supernatant was collected, which is the concentration of 200 g·L⁻¹. -¹The stock solution of aqueous extract of Camellia oleifera fruit shell. The obtained extract was refrigerated at 4 ℃ for later use. Before use, it was left at room temperature for about 2 hours to return to room temperature, and then diluted to the target concentration as needed.

[0027] Example 2

[0028] This embodiment provides a natural herbicide using camellia fruit shell as raw material, and its preparation method includes the following steps: (1) Take dried camellia fruit shell, crush it through a 20-mesh sieve, weigh 100 g of powder, add 500 mL of ultrapure water, mix and place it in an ultrasonic-assisted extraction device, ultrasonically assisted extraction for 20 min at a frequency of 30 kHz and a power of 200 W; then stand for 18 h at a constant temperature of 20 ℃; repeat the above ultrasonic-assisted extraction and stand extraction operation once to obtain the extraction mixture.

[0029] (2) The extraction mixture was filtered through two layers of gauze and a filter membrane with a pore size of 0.22 μm for double filtration, and the filtrate was collected. The filtrate was centrifuged at 3000 r / min for 8 min, and the supernatant was collected, which is the concentration of 200 g·L⁻¹. - ¹The stock solution of aqueous extract of Camellia oleifera fruit shell. The obtained extract was refrigerated at 4 ℃ for later use. Before use, it was left at room temperature for about 2 hours to return to room temperature, and then diluted to the target concentration as needed.

[0030] Example 3

[0031] This embodiment provides a natural herbicide using camellia fruit shell as raw material, and its preparation method includes the following steps: (1) Take dried camellia fruit shell, crush it through a 40-mesh sieve, weigh 200 g of powder, add 1000 mL of ultrapure water, mix and place it in an ultrasonic-assisted extraction device, ultrasonically assisted extraction for 30 min at a frequency of 40 kHz and a power of 350 W; then stand for 24 h at a constant temperature of 25 ℃; repeat the above ultrasonic-assisted extraction and stand extraction operations twice to obtain the extraction mixture.

[0032] (2) The extraction mixture was filtered through two layers of gauze and a filter membrane with a pore size of 0.45 μm for double filtration, and the filtrate was collected. The filtrate was centrifuged at 3500 r / min for 12 min, and the supernatant was taken, which is the concentration of 200 g·L⁻¹. - ¹The stock solution of aqueous extract of Camellia oleifera fruit shell. The obtained extract was refrigerated at 4 ℃ for later use. Before use, it was left at room temperature for about 2 hours to return to room temperature, and then diluted to the target concentration as needed.

[0033] Experimental Example 1

[0034] The dried camellia fruit shells were crushed and passed through a 30-mesh sieve. 200g of powder was weighed and added to 1000mL of ultrapure water. After extraction with ultrasonic assistance (40kHz, 400W, 30min), the mixture was placed at room temperature (25℃) for 24 hours. This ultrasonic-assisted extraction was repeated for 30min, and the extraction was stopped after 24 hours at room temperature. The aqueous extract was then filtered through two layers of gauze and a 0.45μm filter membrane, and centrifuged at 3260r / min for 10min. The supernatant was collected to obtain a concentration of 200g·L⁻¹. -1 The fruit shell extract was then diluted with ultrapure water to prepare concentrations of 12.5, 25, 50, and 100 g·L⁻¹, respectively. -1 The fruit shell extract. Store in a refrigerator at 4°C for later use. To avoid damage to seeds and seedlings from sudden cooling, let it stand at room temperature for about 2 hours before use.

[0035] Before the experiment, the seeds of the five tested plants—white clover, mousegrass, plantain, amaranth, and crabgrass—were soaked in ultrapure water at room temperature (25°C) for 24 hours for later use.

[0036] Seed germination experiments were conducted using the paper germination method. Uniformly sized, plump recipient plant seeds were repeatedly rinsed 3-4 times with ultrapure water, and the surface moisture was absorbed with filter paper. Thirty recipient plant seeds were evenly placed in a petri dish lined with two layers of filter paper, and 5 mL of different concentrations of extract solution were added to each treatment group. An equal volume of ultrapure water was added as a control (CK). Each treatment group was replicated three times. The petri dishes were placed in an artificial climate chamber at (25±0.5)℃ and 65% humidity, with alternating 12h light and 12h dark cycles. The extract solution or ultrapure water of the corresponding concentration was changed every 2 days. The number of germinated recipient plant seeds was counted at the same time every 24 hours (germination was considered to be when the seed radicle showed white). Day 1 was the day the seeds were placed, and germination ended after 7 days. Three seedlings were randomly selected from each dish, and their length (S, cm) was measured using calipers (accuracy 0.01 mm).

[0037] After germination terminates, since each recipient plant only has tiny young roots and newly unfolded cotyledons, it is difficult to measure the biomass of a single plant. Therefore, each petri dish is used as a unit. After the culture is completed, the total fresh weight (FW, mg) of 30 recipient plant seeds in each group is measured, and the total length of the seedlings (S, cm) of the germinated seeds is randomly selected.

[0038] The relevant calculation formula is as follows: Germination rate (GR) = (Number of germinated seeds at the end of the germination test / Number of tested seeds) × 100%; result: 1. The effects of different concentrations of Camellia oleifera fruit shell extract on the germination rate of five plant seeds are shown in Table 1.

[0039] Table 1. Average germination rate of five recipient plants at different extract concentrations (unit: %)

[0040] As shown in Table 1, high concentration treatments significantly inhibited seed germination. P <0.05). The germination rates of white clover, bulrush, and crabgrass generally decreased with increasing extract concentration. Among them, the germination rate of white clover remained above 80% at all extract concentrations, at 100 g·L⁻¹. - ¹The germination rate reached its lowest level after treatment with the extract, significantly decreasing by 11.6% compared to the control group. P <0.05); *Gnaphalium affine* and *Digitaria sanguinalis* at 200 g·L⁻¹ - ¹The treatment group showed a significant decrease of 43.6% and 45.5% compared to the control group, respectively. P <0.05). The germination rates of Plantago asiatica and Amaranthus retroflexus showed a trend of first increasing and then decreasing. The overall decrease in Plantago asiatica was relatively slow, around 100 g·L⁻¹. - The concentration of *Amaranthus retroflexus* reached its lowest point at 12.5 g / L, a decrease of 10.8% compared to the control group. - ¹The germination rate of the treatment was slightly improved, while the germination rate of all other treatments was lower than that of the control, and at 200 g·L⁻¹ - ¹The differences were significant under the treatment, with the germination rate dropping to near 0. It was highly sensitive to the extract and showed a significant germination inhibition effect.

[0041] 2. The effects of different concentrations of Camellia oleifera fruit shell extract on the fresh weight of seedlings of five recipient plants are shown in Table 2.

[0042] Table 2. Average fresh weight of five recipient plants at different extract concentrations (unit: mg)

[0043] Table 2 shows that the effect of Camellia oleifera fruit shell extract on the fresh weight of seedlings of the five plants generally exhibited a concentration-dependent effect of "low concentration promoting high concentration inhibiting," but significant differences existed among different recipient plants. White clover showed the best effect at 12.5 g·L⁻¹. - ¹ and 25 g·L - ¹The fresh weight under the treatment was significantly increased by 36.7% and 25.8% compared with the control, respectively. P <0.05), then gradually decreased with increasing concentration; both *Gnaphalium affine* and *Plantago asiatica* showed an overall inhibitory trend, with *Gnaphalium affine* showing an inhibitory effect at concentrations of 12.5–50 g·L⁻¹. - ¹ No significant difference was found between the control and the control, 100 g·L - ¹Fresh weight was significantly reduced by 21.0% compared to the control, 200 g·L - ¹The rate was significantly reduced by 61.3% compared to the control, reaching the lowest level ( P <0.05); Plantago asiatica at 50 g·L- ¹、100 g·L - ¹ and 200 g·L - ¹The fresh weight was significantly reduced by 24.9%, 25.5%, and 60.0% respectively compared to the control. P <0.05); Amaranthus retroflexus is more sensitive to low concentrations, 12.5 g·L⁻¹. - ¹Fresh weight increased significantly by 37.8% compared to the control ( P <0.05), but decreases sharply at high concentrations, 100 g·L - ¹The rate was significantly lower than the control by 47.7% (¹). P <0.05), 200 g·L - ¹Fresh weight was the lowest, with a decrease of 76.6%; crabgrass weight ranged from 12.5 to 50 g·L⁻¹. - ¹No significant difference between the treated and control groups, 100 g·L - ¹ and 200 g·L - ¹The fresh weight was significantly reduced by 50.4% and 39.3% respectively compared to the control. P <0.05). Overall, low-concentration extracts showed significant promoting effects on white clover and amaranth, but no significant effect on bulrush, plantain, and crabgrass; high concentrations inhibited all five plants to varying degrees, with the inhibitory effects on the other four plants reaching significant levels except for white clover.

[0044] 3. The effects of different concentrations of Camellia oleifera fruit shell extract on the total length of seedlings of the five recipient plants are shown in Table 3.

[0045] Table 3. Average total length (cm) of seedlings of five recipient plants under different extract concentrations.

[0046] Table 3 shows that, compared with fresh weight, the total seedling length is more sensitive to the extract, exhibiting an overall concentration effect of "slight promotion at low concentrations and significant inhibition at medium and high concentrations," with the inhibitory effect gradually increasing with increasing concentration. From the low-concentration response, both *Amaranthus retroflexus* and *Plantago asiatica* showed significant promoting effects on low-concentration extracts. *Amaranthus retroflexus* showed a significantly promoting effect at 12.5 g·L⁻¹. - ¹ and 25 g·L - ¹The total length of seedlings increased significantly by 30.9% and 26.6% respectively compared with the control. P <0.05); the carbohydrate concentration was 12.5 g·L. - ¹The percentage increased significantly by 19.2% compared to the control (¹). P <0.05), but 25 g·L - ¹ No significant difference was found between the control and the control; white clover, gnaphalium, and crabgrass at 12.5 g·L⁻¹ -¹ The total length of seedlings increased slightly compared to the control, but none of the increases were statistically significant. From the perspective of medium- and high concentration responses, seedling elongation was significantly inhibited to varying degrees in all five plant species. White clover at 25 g·L⁻¹... - ¹The total length of seedlings was significantly reduced by 35.0% compared to the control. P <0.05), and thereafter it was significantly inhibited with increasing concentration, 200 g·L - ¹The decrease reached 53.9%; *Gnaphalium affine* at 50 g·L⁻¹ - ¹The level decreased by 7.4% compared to the control, at 100 g·L⁻¹ - ¹ and 200 g·L - ¹The levels were significantly lower than the control by 25.1% and 68.4%, respectively. P <0.05); from 50 g·L - ¹The rate was significantly lower than the control by 40.4% ( P <0.05), with inhibition exacerbated at high concentrations. Crataegus pinnatifida at 25 g·L⁻¹... - ¹The concentration decreased by 14.7% compared to the control, at 50 g·L⁻¹ - ¹ and 100 g·L - ¹The levels were significantly lower than the control by 38.6% and 49.3%, respectively. P <0.05), 200 g·L - ¹The reduction reached 66.5%. The inhibitory effect of *Amaranthus retroflexus* was most pronounced from medium to high concentrations, at 50 g·L⁻¹. - ¹The concentration was significantly reduced by 51.8% compared to the control, at 200 g·L⁻¹. - ¹The decrease was as high as 96.1% and reached a significant level ( P <0.05), almost completely inhibiting seedling elongation. Overall, low concentrations (12.5 g·L) showed good results. - ¹) The extract only showed a significant promoting effect on amaranth and plantain, but had no significant effect on white clover, bulrush, and crabgrass; when the concentration exceeded 25 g·L⁻¹ - ¹ After treatment, the total seedling length of all five plants was significantly inhibited, with the inhibitory effect being particularly prominent in *Amaranthus retroflexus* and in high-concentration treatments of *Trifolium repens*, *Hemiberlesia lataniae*, and *Digitaria sanguinalis*.

[0047] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. Application of Camellia oleifera fruit shell aqueous extract in the preparation of herbicides.

2. A natural herbicide made from camellia fruit shells, characterized in that, The natural herbicide is an aqueous extract of camellia fruit shell.

3. The natural herbicide according to claim 2, characterized in that, The mass concentration of the aqueous extract of Camellia oleifera fruit shell is 12.5~200 g·L. - ¹.

4. The natural herbicide according to claim 2, characterized in that, The mass concentration of the aqueous extract of Camellia oleifera fruit shell is 25~200 g·L. - ¹.

5. The method for preparing the natural herbicide according to any one of claims 2 to 4, characterized in that, Includes the following steps: (1) Mix the camellia fruit shell powder with water at a ratio of 100~300 g: 500~1500 mL, and perform ultrasonic-assisted extraction for 20~40 min at a frequency of 30~50 kHz and a power of 200~500 W. Then, extract at 20~30℃ for 18~30 h. Repeat the above ultrasonic-assisted extraction and extraction 1~3 times to obtain the extraction mixture. (2) Filter and centrifuge the extract mixture, and take the supernatant to obtain the camellia fruit shell water extract.

6. The preparation method according to claim 5, characterized in that, The fineness of the camellia fruit shell powder in step (1) is 20~60 mesh.

7. The preparation method according to claim 5, characterized in that, The filtration in step (2) is a double filtration process, in which the material is passed through two layers of gauze and a filter membrane with a pore size of 0.22~0.8 μm. The centrifugation conditions are a rotation speed of 3000~4000 r / min and a time of 8~15 min.

8. The use of the natural herbicide according to any one of claims 2 to 4 in inhibiting the germination of weed seeds and / or the growth of seedlings.

9. The application according to claim 8, characterized in that, The weeds mentioned are amaranth or crabgrass.

10. The application according to claim 8, characterized in that, The natural herbicide is applied by soaking seeds or spraying.

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