A pesticide composition for controlling asparagus fusarium wilt and its preparation method

Abstract

The present invention relates to a pesticide composition for preventing and controlling asparagus fusarium wilt and a preparation method thereof, and relates to the technical field of agricultural biological control. The pesticide composition for preventing and controlling asparagus fusarium wilt of the present invention comprises the following raw materials in parts by mass: 10-20 parts of chitosan oligosaccharide, 10-30 parts of fungicide, 2-10 parts of alkali-modified corn cob, 2-5 parts of dispersant, and 100-200 parts of water. The pesticide composition for preventing and controlling asparagus fusarium wilt is obtained by mixing chitosan oligosaccharide, fungicide, alkali-modified corn cob, dispersant and water and then impregnating. The present invention combines alkali-modified corn cob, chitosan oligosaccharide and fungicide to prepare a slow-release pesticide composition, effectively improving the persistence and stability of the medicament, significantly improving the control effect on asparagus fusarium wilt, increasing the yield of asparagus, and improving the planting income of asparagus.

Description

Technical Field

[0001] The invention relates to the technical field of agricultural biological control, and in particular to a pesticide composition for controlling asparagus wilt disease and a preparation method thereof. Background Art

[0002] The pathogen of asparagus wilt is Phomopsis asparagus, which is a devastating disease distributed worldwide; the disease spreads rapidly under rainy and windy conditions, and can also be transmitted by rain splashes. In mild cases, it causes poor growth and development of asparagus, reducing yield and quality; in severe cases, the diseased plants die prematurely and the entire field is destroyed. The prevention and control of asparagus stem blight mainly relies on chemical control. However, the existing pesticide preparations have poor efficacy and cannot achieve long-term pest control effects, and also cause pesticides to be lost to the environment due to incomplete absorption of pesticides by crops. The short duration of pesticides and low drug utilization rate will cause many negative problems such as environmental pollution of pesticides. Therefore, how to more effectively improve the efficacy and utilization efficiency of pesticides is one of the main problems that need to be solved in the current pesticide field.

[0003] There are two main ways to improve the efficacy of pesticides: developing new environmentally friendly pesticides and developing slow / controlled release pesticide formulations. The development of new pesticides is difficult, requires a lot of funding, and has a long research cycle, while the difficulty and cost of developing slow / controlled release pesticide formulations are relatively low. Therefore, the application of pesticide slow / controlled release technology will be an effective way to solve the excessive use of pesticides and increase crop yields. Improving existing pesticide formulations can reduce the environmental hazards of pesticides, improve the stability of the active ingredients of the pesticides, extend the effectiveness of the same dose of pesticides, save resources, and improve biosafety. At present, the structure and performance of pesticide carriers are not good, resulting in insufficient dispersion and stability of pesticides, poor persistence of efficacy, and thus affecting the prevention and control effect.

[0004] Therefore, it is necessary to study a slow-release pesticide composition for controlling asparagus wilt disease, prolong the duration and stability of the efficacy, improve the control effect of asparagus wilt disease, and thus improve the benefits of asparagus planting. Summary of the invention

[0005] The purpose of the present invention is to provide a pesticide composition for preventing and controlling asparagus wilt disease, so as to solve the problems existing in the above-mentioned prior art, improve the prevention and control effect of asparagus wilt disease, and improve the benefit of asparagus planting.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] The present invention provides a pesticide composition for preventing and controlling asparagus wilt disease, comprising the following raw materials in parts by weight:

[0008] 10-20 parts of chitosan oligosaccharide, 10-30 parts of fungicide, 2-10 parts of alkali-modified corn cobs, 2-5 parts of dispersant, and 100-200 parts of water.

[0009] As a further preference of the present invention, the fungicide is carbendazim or thiophanate-methyl. More preferably, the carbendazim is 50% carbendazim wettable powder, and the thiophanate-methyl is 70% thiophanate-methyl wettable powder.

[0010] As a further preference of the present invention, the molecular weight of the chitosan oligosaccharide is 1000 - 2000 Da, preferably 1500 Da.

[0011] As a further preference of the present invention, the preparation method of the alkali-modified corncob includes the following steps:

[0012] Add the corncob into a sodium hydroxide solution, carry out the reaction, and dry it to obtain the alkali-modified corncob.

[0013] As a further preference of the present invention, the mass fraction of the sodium hydroxide solution is 1 - 5%, the temperature of the reaction is 80 - 90 °C, and the reaction time is 1 - 2 h.

[0014] As a further preference of the present invention, the dispersant is dodecylbenzenesulfonate and / or lignosulfonate.

[0015] The present invention also provides a preparation method of the above-mentioned pesticide composition for preventing and controlling asparagus fusarium wilt, including the following steps:

[0016] Mix the chitosan oligosaccharide, the fungicide, the alkali-modified corncob, the dispersant and water, and then impregnate them to obtain the pesticide composition for preventing and controlling asparagus fusarium wilt.

[0017] As a further preference of the present invention, the temperature of the impregnation is 40 - 60 °C, and the time of the impregnation is 2 - 5 h.

[0018] As a further preference of the present invention, the impregnation is carried out under ultrasonic conditions, and the power of the ultrasonic is 100 - 300 W.

[0019] The present invention also provides an application of the above-mentioned pesticide composition for preventing and controlling asparagus fusarium wilt in preventing and controlling asparagus fusarium wilt. The pesticide composition for preventing and controlling asparagus fusarium wilt is diluted with water into a 500 - 800-fold solution for foliar spraying.

[0020] The present invention discloses the following technical effects:

[0021] 1) The present invention combines the alkali-modified corncob, chitosan oligosaccharide and fungicide to prepare a slow-release pesticide composition, effectively improving the persistence and stability of the medicament, significantly improving the control effect on asparagus fusarium wilt, increasing the yield of asparagus, and improving the planting income of asparagus.

[0022] 2) The present invention modifies corn cobs. By using sodium hydroxide, the ether bonds of lignin are broken, lignin is removed, the hydrogen bonds between cellulose and hemicellulose are weakened, and the ester bonds between hemicellulose and lignin are saponified. At the same time, cellulose swells and part of hemicellulose dissolves, increasing the porosity of corn cobs, facilitating the loading of fungicides, thereby improving the drug loading amount and stability. The pathogen of asparagus fusarium wilt attaches to the stems and leaves of asparagus in the form of dormant hyphae and pycnidia. While releasing fungicides, the alkali-modified corn cobs can also slowly release carbon sources. The presence of carbon sources is not conducive to the reproduction of the pathogen of asparagus fusarium wilt, thereby prolonging the persistence of the drug effect and improving the control effect on asparagus fusarium wilt. The control effect of the alkali-modified corn cobs is better than that of the acid-modified corn cobs because, compared with the acid-modified corn cobs, the porosity of the alkali-modified corn cobs is higher than that of the acid-modified ones, and the ability to release carbon sources is also better than that of the acid-modified ones.

[0023] 3) Due to its small relative molecular mass, chitosan oligosaccharide is easy to penetrate the bacterial cell membrane and enter the cytoplasm and nucleus, playing its role in anti-microbial activity; chitosan oligosaccharide can also induce the disease resistance of plants, and has an immune and killing effect on a variety of fungi, bacteria and viruses. The combined use of chitosan oligosaccharide and fungicides such as carbendazim and thiophanate-methyl can significantly improve the control effect on asparagus fusarium wilt.

[0024] 4) Carbendazim and thiophanate-methyl are broad-spectrum fungicides with a long service life, and can be used for foliar spraying, seed treatment, soil treatment, etc. Existing research results show that the control effect of carbendazim and thiophanate-methyl on asparagus stem blight is poor, and excessive application can produce drug resistance. The present invention finds that by loading fungicides such as carbendazim and thiophanate-methyl on alkali-modified corn cobs and adding chitosan oligosaccharide, the fungicides such as carbendazim and thiophanate-methyl can quickly inhibit the occurrence of asparagus fusarium wilt with the assistance of the above raw materials, reducing the harm brought by fusarium wilt to asparagus production. There is a synergistic effect between the alkali-modified corn cobs, chitosan oligosaccharide and fungicides, making the control effect of the pesticide composition of the present invention better than that of the fungicide with the same dosage. This pesticide composition can provide an effective management tool for the prevention and control of asparagus stem blight. Detailed implementation manners

[0025] The various exemplary implementation manners of the present invention will be described in detail below. This detailed description should not be regarded as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and implementation schemes of the present invention.

[0026] It should be understood that the terms used in the present invention are only for describing specific embodiments and are not intended to limit the present invention. Additionally, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0027] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0028] Without departing from the scope or spirit of the present invention, various improvements and changes can be made to the specific embodiments of the present invention specification, which are obvious to those skilled in the art. Other embodiments obtained from the present invention specification are obvious to those skilled in the art. The present invention specification and examples are merely exemplary.

[0029] Regarding "comprising", "including", "having", "containing", etc. used herein, they are all open-ended terms, meaning including but not limited to.

[0030] In the following examples and comparative examples of the present invention, "parts" shall represent parts by mass unless otherwise specified.

[0031] Example 1

[0032] Add 50 g of corncob to 1000 mL of a sodium hydroxide solution with a mass fraction of 2%, react at 90 °C for 1 h, take out and wash with water 3 times to wash away the excess sodium hydroxide solution, and dry at 80 °C for 5 h to obtain alkali-modified corncob. Mix 20 parts of chitosan oligosaccharide (molecular weight 1500 Da), 20 parts of 70% thiophanate-methyl wettable powder, 5 parts of alkali-modified corncob, 3 parts of sodium lignosulfonate and 200 parts of water, and impregnate to obtain a pesticide composition for controlling asparagus fusarium wilt.

[0033] Example 2

[0034] In this example, the preparation method of the alkali-modified corncob is the same as that in Example 1.

[0035] Mix 10 parts of chitosan oligosaccharide (molecular weight 1500 Da), 30 parts of 50% carbendazim wettable powder, 8 parts of alkali-modified corncob, 4 parts of sodium lignosulfonate and 200 parts of water, and then impregnate to obtain a pesticide composition for controlling asparagus fusarium wilt.

[0036] Example 3

[0037] In this example, the preparation method of the alkali-modified corncob is the same as that in Example 1.

[0038] Mix 15 parts of chitosan oligosaccharide (molecular weight 1000 Da), 10 parts of 70% thiophanate-methyl wettable powder, 3 parts of alkali-modified corncob, 2 parts of sodium lignosulfonate and 150 parts of water, and then impregnate to obtain a pesticide composition for controlling asparagus fusarium wilt.

[0039] Comparative Example 1

[0040] The difference between this comparative example and Example 1 is only that the 2% sodium hydroxide solution is replaced with 2% sulfuric acid by mass fraction.

[0041] Comparative Example 2

[0042] Mix 20 parts of 70% thiophanate-methyl wettable powder and 200 parts of water, and then impregnate to obtain a pesticide composition for controlling asparagus fusarium wilt.

[0043] Comparative Example 3

[0044] Mix 40 parts of 70% thiophanate-methyl wettable powder and 200 parts of water, and then impregnate to obtain a pesticide composition for controlling asparagus fusarium wilt.

[0045] Application Example

[0046] The test site is set in Tangshu Village, Xiangtang Town, Nanchang County, Jiangxi Province, where Jinggang 701 asparagus is planted in the open air, with a total area of about 1 hm 2 or so. The soil is loam, with a pH of about 6.5 and a moderate content of soil organic matter. The area of each test plot is 30 m 2 .

[0047] Use the pesticide compositions of Examples 1-3 and Comparative Examples 1-3 as treatment groups, and use water treatment as the blank control group. A total of 19 treatments are set, and a randomized block design is adopted, with 3 replicates.

[0048] Test method: The test is carried out during the peak period of asparagus fusarium wilt (May-June), with a total of 2 applications. The dosage of each spraying of the pesticide composition is 500 g / hm 2On May 15th, the first spraying was carried out, and on June 5th, the second spraying was carried out. The disease incidence was investigated 10 days and 20 days after the second application. The asparagus was harvested 1 day after the first application, and the asparagus yield of each experimental plot was recorded. It was harvested once a day until the day of disease investigation. The asparagus yield during the period from May 15th to June 25th was accumulated, and the yield increase rate was calculated.

[0049] Disease investigation method: Five-point sampling was adopted diagonally in each experimental plot. Five adjacent asparagus plants were taken at each point, and 3 asparagus plants were randomly investigated from each asparagus plant. A total of 75 asparagus plants from 25 asparagus plants were investigated, and the number of healthy plants and the number of diseased plants at each level were recorded.

[0050] Disease grading standard: Grade 0: No disease; Grade 1: The diseased area accounts for less than 6% of the total area; Grade 2: The diseased area accounts for 6 - 10% of the total area; Grade 3: The diseased area accounts for 11 - 20% of the total area; Grade 4: The diseased area accounts for 21 - 30% of the total area; Grade 5: The diseased area accounts for more than 30% of the total area.

[0051] Data processing calculation method: Disease index = ∑(number of diseased plants at each level × relative level value) / total number of plants investigated × 5 × 100;

[0052] Control effect = (disease index of the control area - disease index of the treatment area) / disease index of the control area × 100%;

[0053] Yield increase rate = (yield of the treatment area - yield of the blank control area) / yield of the blank control area × 100%;

[0054] Table 1

[0055] Spraying 10d protection effect after application / % 20d protection effect / % Yield increase rate / % Example 1 78.34±1.05 77.88±1.35 20.18±1.56 Example 2 77.63±1.27 75.94±1.26 18.45±1.08 Example 3 77.34±1.15 75.71±0.95 17.79±1.14 Comparative Example 1 52.58±1.42 43.05±1.02 14.32±1.21 Comparative Example 2 22.76±2.07 15.48±1.84 10.16±0.75 Comparative Example 3 30.23±0.84 20.12±1.38 12.34±1.36

[0056] The experimental results show that compared with the control group, the control effects after spraying the pesticide compositions of Examples 1 - 3 for 10 days are all above 75%, and excellent control effects are still shown 20 days after application, indicating that the pesticide composition of the present invention has a slow-release effect and significantly improves the control effect on asparagus fusarium wilt. By comprehensively comparing the control effects of Comparative Examples 1 - 3, it shows that the combined use of alkali-modified corn cob, chitosan oligosaccharide and fungicide plays a slow-release role, improves the persistence of drug efficacy, further improves the control effect on asparagus fusarium wilt, realizes the yield increase of asparagus, and reduces the usage amount of fungicide, reducing pesticide residues and control costs.

[0057] The above-described embodiments are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention should fall within the protection scope determined by the claims of the present invention.

Claims

1. A pesticide composition for controlling asparagus fusarium wilt, characterized in that, It comprises raw materials in the following parts by mass: 10 - 20 parts of chitosan oligosaccharide, 10 - 30 parts of fungicide, 2 - 10 parts of alkali-modified corncob, 2 - 5 parts of dispersant, 100 - 200 parts of water; The fungicide is carbendazim or thiophanate-methyl; The preparation method of the alkali-modified corncob comprises the following steps: Adding corncob into sodium hydroxide solution, reacting, and drying to obtain the alkali-modified corncob; The mass fraction of the sodium hydroxide solution is 1 - 5%, the reaction temperature is 80 - 90 °C, and the reaction time is 1 - 2 h.

2. The pesticidal composition for preventing and controlling asparagus fusarium wilt according to claim 1, wherein, The dispersant is dodecylbenzenesulfonate and / or lignosulfonate.

3. A method for preparing a pesticidal composition for controlling asparagus fusarium wilt according to any one of claims 1-2, characterized in that, It comprises the following steps: Mixing chitosan oligosaccharide, fungicide, the alkali-modified corncob, dispersant and water, and then impregnating to obtain the pesticide composition for preventing and controlling asparagus fusarium wilt.

4. The preparation method according to claim 3, characterized in that, The impregnation temperature is 40 - 60 °C, and the impregnation time is 2 - 5 h.

5. The preparation method according to claim 3, characterized in that, The impregnation is carried out under ultrasonic conditions, and the ultrasonic power is 100 - 300 W.

6. Use of the pesticide composition for preventing and treating asparagus fusarium wilt according to any one of claims 1-2 in preventing and treating asparagus fusarium wilt, characterized in that, The pesticide composition for preventing and controlling asparagus fusarium wilt is diluted with water to 500 - 800 times solution for foliar spraying.