A kind of prevention and control method of banana scab

Abstract

The present invention provides a method for preventing and treating banana scab, and relates to the technical field of banana planting. The method mainly comprises the following steps: using alocasia fermented extract, okra low-temperature extract, peppermint essential oil, ethanol and the like to prepare antibacterial agents for spraying banana plants, wherein the alocasia fermented extract is prepared by mixing alocasia slurry with Bacillus subtilis and lactic acid bacteria for fermentation, boiling and sterilizing, and then ultrasonically extracting with alcohol; and the okra low-temperature extract is prepared by mixing fresh okra with ice water, crushing, ultrasonically extracting, and then freeze-drying. The present invention overcomes the shortcomings of the prior art, and uses plant extract components as the main functional substances to prevent and treat banana scab, thereby reducing environmental pollution caused by chemical drugs on the basis of effectively achieving the prevention and treatment effect, and comprehensively improving the safety of banana planting.

Description

Technical Field

[0001] The invention relates to the technical field of banana planting, and in particular to a method for preventing and treating banana scab. Background Art

[0002] Banana belongs to the genus Musa of the family Musaceae. It is an important cash crop and food crop in tropical and subtropical regions, and is the fruit with the largest fresh fruit trade volume in the world. my country is the world's second largest banana producer and consumer. With the increasing degree of intensive banana cultivation, the banana industry is not only restricted by natural factors and the market, but also threatened by diseases. Banana scab is an important leaf and fruit disease in the growth process of bananas. The leaves of the affected plants are scorched, and the appearance quality and storage resistance of the fruit are reduced.

[0003] In recent years, banana scab has occurred widely in banana producing areas and the damage has become increasingly serious. It has become one of the important diseases in banana production, seriously affecting the yield and quality of bananas, causing the commercial value of bananas to drop by 30% to 70%, causing great economic losses and restricting the healthy development of the banana industry.

[0004] At present, the main control measure for banana black scab is the application of chemical pesticides, and the types of pesticides used are mostly triazole fungicides (such as myclobutanil) and strobilurin fungicides (such as azoxystrobin). However, long-term use of such pesticides has led to increased resistance of banana black scab to pesticides, thereby reducing the control effect. Conventional doses of pesticides often fail to achieve good control effects, and increasing the dosage of pesticides will affect the ecological balance and cause certain environmental pollution. Therefore, the development of green and pollution-free methods for banana black scab control is an important research direction at this stage. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a method for preventing and controlling banana scab, which uses plant extract components as main effective substances to prevent and control banana scab, reduces environmental pollution caused by chemical drugs on the basis of effectively achieving prevention and control effects, and comprehensively improves the safety of banana planting.

[0006] To achieve the above objectives, the technical solution of the present invention is implemented through the following technical solutions:

[0007] A method for preventing and treating banana scab, comprising the following steps:

[0008] S1. Prepare the plant-derived antibacterial agent according to the following ratio: water + 20-25 g / L of fermented calla lily extract + 10-12 g / L of low-temperature okra extract + 10-30 mL / L of peppermint essential oil + 40-60 mL / L of ethanol;

[0009] The preparation method of the Alocasia lily fermented extract mainly comprises the following steps:

[0010] S1-1, wash the rhizomes of Alocasia lily, add water and grind into pulp, and obtain a mixed pulp for later use;

[0011] S1-2, inoculating the mixed slurry with Bacillus subtilis and lactic acid bacteria for fermentation for 2-4 hours to obtain a fermented material for later use;

[0012] S1-3, boiling and sterilizing the fermented material and drying it, then adding ethanol solution for ultrasonic alcohol extraction, squeezing and filtering, and rotary evaporating the filtrate to remove the solvent to obtain the calla lily fermented extract;

[0013] The preparation method of the okra low-temperature extract is as follows: fresh okra mixed with ice water is placed in a wall-breaking machine for stirring and crushing, then subjected to ultrasonic treatment, centrifuged to remove precipitation, and then freeze-dried;

[0014] S2. Spray with antimicrobial agents in the early stage of banana black spot disease.

[0015] Preferably, the preparation method of the antibacterial agent is to firstly place peppermint essential oil in ethanol and stir and mix, then add alocasia fermented extract, okra low-temperature extract and water and stir evenly.

[0016] Preferably, in step S1-1, the mass ratio of the material to the liquid for grinding into slurry with water is 1:4-5.

[0017] Preferably, in step S1-2, the inoculation amounts of Bacillus subtilis and lactic acid bacteria are both 0.2%-0.3% of the total mass of the mixed slurry.

[0018] Preferably, the boiling sterilization method in step S1-3 is heating to boiling and keeping warm for 5-8 minutes, and the drying temperature is 45-60°C.

[0019] Preferably, the material-liquid mass ratio of ultrasonic alcohol extraction in step S1-3 is 1:10-12, the concentration of the ethanol solution is 70%-80%, the ultrasonic power is 400-600W, and the alcohol extraction time is 20-30min.

[0020] Preferably, in the preparation process of the okra low-temperature extract, the mass ratio of fresh okra to ice water is 1:3-5, and the ice cubes in the ice water account for 30%-50% of the total mass.

[0021] Preferably, the stirring and crushing speed during the preparation of the okra low-temperature extract is 25000-40000 r / min, and the stirring and crushing time is 5-10 min.

[0022] Preferably, during the preparation of the okra low-temperature extract, the power of the ultrasonic treatment is 400-600 W, the treatment time is 10-15 min, the centrifugal speed is 4200-4500 r / min, and the centrifugal time is 10-15 min.

[0023] Preferably, the spraying method of step S2 is spraying once every 10-14 days, for a total of 3-5 times.

[0024] The present invention provides a method for preventing and controlling banana scab, which has the following advantages over the prior art:

[0025] The invention adopts plant components such as calla lily fermentation extract and okra low-temperature extract and compound peppermint essential oil as a functional agent for preventing and treating banana scab, which can effectively prevent and treat banana scab and inhibit the growth of banana scab pathogens. Moreover, the overall components are from plant sources, which is safer and more environmentally friendly, thereby ensuring the safety of banana planting and reducing pollution caused by chemical agents. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the pycnidium produced by the pathogen under the leaf epidermis in Example 1 of the present invention, wherein A is the pycnidium and conidia; B is the pycnidium with orifices and conidial cells; C is the morphology of the pycnidium, and the scale of A and B is 20 μm, and the scale of C is 100 μm;

[0027] Figure 2 This is a microscopic schematic diagram of the pathogen conidia in Example 1 of the present invention;

[0028] Figure 3 This is a bar graph of the growth diameter of the colonies after 7 days of culture with different antimicrobial agents in Example 2 of the present invention;

[0029] Figure 4 This is a schematic diagram of the growth of the bacterial colonies in Group 1 after 7 days of culture in Example 2 of the present invention;

[0030] Figure 5 This is a schematic diagram of the growth of the bacterial colonies in Group 7 in Example 2 of the present invention after 7 days of culture. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention is clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Bacillus subtilis Embodiment 1:

[0033] 1. Preparation of extracts:

[0034] 1.1. Preparation of Extract A:

[0035] (1) Wash the rhizomes of Alocasia lily, add water to the rhizomes in a mass ratio of 1:4, grind into a slurry, and obtain a mixed slurry for later use;

[0036] (2) The mixed slurry is inoculated with 0.2% of the total weight of Bacillus subtilis and lactic acid bacteria in sequence and fermented for 2 hours to obtain a fermented material for use;

[0037] (3) The fermented material was heated to boiling and kept warm for 8 min, then dried at 45°C, mixed with 70% ethanol solution at a material-liquid mass ratio of 1:10, and ultrasonically extracted at 400 W for 30 min, then squeezed and filtered, and the filtrate was rotary evaporated to remove the solvent to obtain extract A.

[0038] 1.2. Preparation of Extract B:

[0039] (1) Wash the rhizomes of Alocasia lily, add water to the rhizomes in a mass ratio of 1:5, grind into a slurry, and obtain a mixed slurry for later use;

[0040] (2) The mixed slurry is inoculated with 0.3% of the total weight of Bacillus subtilis and lactic acid bacteria in sequence and fermented for 4 hours to obtain a fermented material for use;

[0041] (3) The fermented material was heated to boiling and kept warm for 5 min, then dried at 60°C, mixed with 80% ethanol solution at a material-liquid mass ratio of 1:12, and ultrasonically extracted at 600 W for 20 min. The material was then squeezed and filtered, and the filtrate was rotary evaporated to remove the solvent to obtain extract B.

[0042] 1.3. Preparation of Extract C:

[0043] (1) Wash the rhizomes of Alocasia lily, add water to the rhizomes in a mass ratio of 1:4, grind into a slurry, and obtain a mixed slurry for later use;

[0044] (2) The mixed slurry is inoculated with 0.2% of the total weight of Bacillus subtilis and lactic acid bacteria in sequence and fermented for 2 hours to obtain a fermented material for use;

[0045] (3) The fermented material was dried at 45°C, mixed with 70% ethanol solution at a material-liquid mass ratio of 1:10, and ultrasonically extracted at 400 W for 30 min. The mixture was then squeezed and filtered, and the filtrate was rotary evaporated to remove the solvent to obtain extract C.

[0046] 1.4. Preparation of Extract D:

[0047] (1) Wash the rhizomes of Alocasia lily, add water to the rhizomes in a mass ratio of 1:4, grind into a slurry, and obtain a mixed slurry for later use;

[0048] (2) The mixed slurry was heated to boiling and kept warm for 8 min, then dried at 45°C, and then mixed with 70% ethanol solution at a mass ratio of 1:10, and ultrasonically extracted at 400 W for 30 min, and then squeezed and filtered, and the filtrate was rotary evaporated to remove the solvent to obtain extract D.

[0049] 1.5. Preparation of Extract E:

[0050] (1) Wash the potatoes, add water and grind them into a slurry in a material-liquid mass ratio of 1:4 to obtain a mixed slurry for later use;

[0051] (2) The mixed slurry is inoculated with 0.2% of the total weight of Bacillus subtilis and lactic acid bacteria in sequence and fermented for 2 hours to obtain a fermented material for use;

[0052] (3) The fermented material was heated to boiling and kept warm for 8 min, then dried at 45°C, mixed with 70% ethanol solution at a material-liquid mass ratio of 1:10, and ultrasonically extracted at 400 W for 30 min, then squeezed and filtered, and the filtrate was rotary evaporated to remove the solvent to obtain extract E.

[0053] 2. Preparation of okra extract:

[0054] 2.1. Preparation of okra extract A:

[0055] (1) Mix fresh okra with ice water in a mass ratio of 1:3 (ice cubes in the ice water account for 30% of the total mass), directly place in a wall breaking machine and crush at a speed of 25000 r / min for 10 min to obtain a crushed slurry for use;

[0056] (2) The crushed slurry was treated at 400 W ultrasonic power for 15 min, and then centrifuged at 4200 r / min for 15 min. The precipitate was removed and freeze-dried to obtain okra extract A.

[0057] 2.2. Preparation of okra extract B:

[0058] (1) Mix fresh okra with ice water in a mass ratio of 1:5 (ice cubes in the ice water account for 50% of the total mass), directly place in a wall breaking machine and crush at a speed of 40000r / min for 5 min to obtain crushed slurry for use;

[0059] (2) The crushed slurry was treated at 600 W ultrasonic power for 10 min, and then centrifuged at 4500 r / min for 10 min. The precipitate was removed and freeze-dried to obtain okra extract B.

[0060] 2.3. Preparation of okra extract C:

[0061] (1) Mix fresh okra with clean water at room temperature in a mass ratio of 1:3, and directly place it in a wall-breaking machine for crushing at a speed of 25,000 r / min for 10 min to obtain a crushed slurry for use;

[0062] (2) The crushed slurry was treated at 400 W ultrasonic power for 15 min, and then centrifuged at 4200 r / min for 15 min. The precipitate was removed and freeze-dried to obtain okra extract C.

[0063] 3. Preparation of plant-based antibacterial agents:

[0064] Prepare each group of plant-derived antimicrobial agents according to the following formula:

[0065] Antimicrobial agent 1: water + extract A 20 g / L + okra extract A 10 g / L + peppermint essential oil 10 mL / L + ethanol 40 mL / L;

[0066] Antimicrobial agent 2: water + extract B 25 g / L + okra extract B 12 g / L + peppermint essential oil 30 mL / L + ethanol 60 mL / L;

[0067] Antimicrobial agent 3: water + extract C 20 g / L + okra extract A 10 g / L + peppermint essential oil 10 mL / L + ethanol 40 mL / L;

[0068] Antimicrobial agent 4: water + extract D 20 g / L + okra extract A 10 g / L + peppermint essential oil 10 mL / L + ethanol 40 mL / L;

[0069] Antimicrobial agent 5: water + extract E 20 g / L + okra extract A 10 g / L + peppermint essential oil 10 mL / L + ethanol 40 mL / L;

[0070] Antibacterial agent 6: water + extract A 20 g / L + okra extract C 10 g / L + peppermint essential oil 10 mL / L + ethanol 40 mL / L.

[0071] When preparing each group of antibacterial agents, peppermint essential oil is first dissolved in ethanol and stirred and mixed, and then other ingredients are added and stirred evenly. Embodiment 2:

[0072] Detection of the resistance of each group of antimicrobial agents configured in Example 1 to banana scab pathogen:

[0073] 1. Acquisition of pathogens:

[0074] The laboratory collected diseased leaves of banana black scab in Hainan during the high incidence period in summer as raw material samples. The samples were disinfected with 75% ethanol and then dried to observe the conidiophores produced by the pathogen under the leaf epidermis under a microscope. Figure 1As shown, the pathogens on the leaf surface spots were scraped into sterile water with a sterile scalpel on a clean bench to prepare a spore suspension. The inoculation loop was sterilized and dipped into the spore suspension to streak on the PSA plate, which was then placed in a constant temperature of 20°C for 14 days. After the colonies appeared, a representative strain was selected as the pathogen (the conidia of the pathogen are as shown in Figure 2 Single spore purification was performed on the PSA medium at 20°C until the medium was full of bacteria, and the pathogens were obtained for use;

[0075] 2. Antibacterial experiment:

[0076] A sterilized cork puncher with a diameter of 0.5 cm was used to take several parts of the PSA medium full of pathogens and colonies, and inoculated them into new PSA medium. Each new PSA medium was sprayed with 2 mL of different antimicrobial agents, and cultured at 25°C for 7 days. The diameter of the colony growth in each group was recorded. The specific results are shown in Tables 1 and Figure 3 As shown:

[0077] Table 1

[0078]

[0079] It can be seen from the above table that antibacterial agents 1-6 can all play a certain antibacterial effect, and among them, antibacterial agent 1, antibacterial agent 2, antibacterial agent 3 and antibacterial agent 6 have better effects, and antibacterial agent 1 and antibacterial agent 2 have the best antibacterial effect. Embodiment 3:

[0080] Field experiment on prevention and control of banana scab:

[0081] Antimicrobial agents 1, 3 and 6 were selected as experimental antimicrobial agents, and the banana plantation in Danzhou, Hainan was used as the experimental area. The drugs were applied when black spot disease first occurred.

[0082] The experimental area was divided into four plots, each with an area of ​​70 m 2 , and each plot has 20 banana trees, the first application was carried out on July 29, 2024, the second application was carried out on August 9, 2024, and the third application was carried out on August 21, 2024. Each application was carried out in the evening, and the dosage of each application was 0.5 kg / tree. The black spot disease index of each plot before and 7 days after each application was counted. The statistical method was to randomly investigate 10 plants in each plot, and investigate 10 leaves from the top of each plant downwards, record the total number of investigated leaves and the number of diseased leaves, and divide the disease level of the diseased leaves according to the following Table 2:

[0083] Table 2

[0084]

[0085] The disease index is calculated as follows:

[0086] ;

[0087] The specific results are shown in Table 3 below:

[0088] Table 3

[0089]

[0090] As can be seen from the table above, antimicrobial agent 1 has a more superior anti-banana black spot effect than antimicrobial agent 3 and antimicrobial agent 6. In group 4, the clean water control was used. In the later period, the overall black spot gradually spread. Figure 5 As shown, it is a serious lesion.

[0091] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preventing and treating banana scab, characterized in that: The control method comprises the following steps: S1. Prepare a plant-derived antibacterial agent according to the following ratio: water + 20-25 g / L fermented calla lily extract + 10-12 g / L low-temperature okra extract + 10-30 mL / L peppermint essential oil + 40-60 mL / L ethanol; The preparation method of the Alocasia truncatula fermented extract mainly comprises the following steps: S1-1, wash the rhizomes of Alocasia lily, add water and grind into pulp, and obtain a mixed pulp for later use; S1-2, inoculating the mixed slurry with Bacillus subtilis and lactic acid bacteria for fermentation for 2-4 hours to obtain a fermented material for later use; S1-3, boiling and sterilizing the fermented material and drying it, adding an ethanol solution with a concentration of 70%-80% to perform ultrasonic alcohol extraction, squeezing and filtering, and rotary evaporating the filtrate to remove the solvent to obtain a calla lily fermented extract; The preparation method of the okra low-temperature extract is as follows: fresh okra mixed with ice water is placed in a wall-breaking machine for stirring and crushing, then subjected to ultrasonic treatment, centrifuged to remove precipitation, and then freeze-dried; S2. Spray with antimicrobial agents in the early stage of banana black spot disease.

2. The control method according to claim 1, characterized in that: The preparation method of the antibacterial agent comprises the following steps: firstly placing peppermint essential oil in ethanol and stirring and mixing, and then adding alocasia fermentation extract, okra low-temperature extract and water and stirring evenly.

3. The control method according to claim 1, characterized in that: In the step S1-1, the mass ratio of the material to the liquid for grinding into slurry with water is 1:4-5.

4. The control method according to claim 1, characterized in that: In the step S1-2, the inoculation amounts of Bacillus subtilis and lactic acid bacteria are both 0.2%-0.3% of the total mass of the mixed slurry.

5. The control method according to claim 1, characterized in that: The method of boiling and sterilizing in step S1-3 is to heat to boiling and keep warm for 5-8 minutes, and the drying temperature is 45-60°C.

6. The control method according to claim 1, characterized in that: In the step S1-3, the material-liquid mass ratio of ultrasonic alcohol extraction is 1:10-12, the ultrasonic power is 400-600W, and the alcohol extraction time is 20-30min.

7. The control method according to claim 1, characterized in that: In the preparation process of the okra low-temperature extract, the mass ratio of fresh okra to ice water is 1:3-5, and the ice cubes in the ice water account for 30%-50% of the total mass.

8. The control method according to claim 1, characterized in that: The stirring and crushing speed during the preparation of the okra low-temperature extract is 25000-40000 r / min, and the stirring and crushing time is 5-10 min.

9. The control method according to claim 1, characterized in that: During the preparation of the okra low-temperature extract, the power of ultrasonic treatment is 400-600W, the treatment time is 10-15min, the centrifugal speed is 4200-4500r / min, and the centrifugal time is 10-15min.

10. The control method according to claim 1, characterized in that: The spraying method of step S2 is spraying once every 10-14 days, for a total of 3-5 times.

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