Bactericide composition for preventing and treating soft rot of jackfruit flowers and fruits

Abstract

The invention belongs to the technical field of pesticides, and particularly relates to a bactericide composition for preventing and treating soft rot of jackfruit flowers and fruits. The bactericide composition for preventing and treating the soft rot of the jackfruit flowers and fruits comprises an active component, and the active component is formed by compounding meconazole and paeonol or eugenol. According to the invention, the meconazole and the paeonol or the eugenol are compounded, so that compared with a single agent, the prevention and treatment effect on the soft rot of the jackfruit flowers and fruits can be improved, the dosage of the agent can be reduced, and the prevention and treatment cost can be reduced. In addition, the sterilization mechanism of the meconazole is different from that of paeonol and eugenol, so that the drug resistance risk of the medicament is reduced, and the generation and development of drug resistance of pathogenic bacteria are delayed.

Description

Technical Field

[0001] The invention belongs to the technical field of pesticides, and particularly relates to a fungicide composition for preventing and treating jackfruit flower and fruit soft rot. Background Art

[0002] Jackfruit flower and fruit soft rot caused by Rhizopus stolonifer is a common fungal disease that harms the inflorescence and fruit of jackfruit. Jackfruit flower and fruit soft rot is common in all jackfruit producing areas in my country. After infection by the pathogen, the diseased part of the fruit initially becomes brown and water-soaked, becomes soft and rotten, and then a dense layer of white upright hairy hyphae is produced on the diseased part, and a gray-black or brown mold layer is formed in the middle of the rotten part of the diseased fruit, making the fruit lose its edible value, and finally the whole fruit rots. After the inflorescence is infected, it rots and falls off, affecting the fruit yield.

[0003] During the growth of jackfruit, spraying Bordeaux mixture, thiophanate-methyl, carbendazim or benomyl in the early flowering and young fruit stage can prevent and control jackfruit flower and fruit soft rot. However, with the long-term use of existing agents, pathogens have developed varying degrees of drug resistance, resulting in a decrease in the prevention and control effect.

[0004] Cyclopentadione is a triazole fungicide containing an isopropanol structure, which has preventive and protective effects. Cyclopentadione belongs to the class of sterol demethylation inhibitors. Like other triazole fungicides, cyclopentadione inhibits cell growth and destroys the function of bacterial cell membranes by preventing the biosynthesis of ergosterol. Unlike other triazole fungicides, the isopropanol group contained in the cyclopentadione molecule enables it to rotate freely from a free state to a bound state with the target, reducing pathogen mutations and delaying the generation and development of resistance.

[0005] So far, there is no report on the combination of clofoconazole with paeonol or eugenol. Summary of the invention

[0006] The object of the present invention is to provide a fungicide composition for preventing and treating soft rot of jackfruit flowers and fruits, so as to solve the problem that pathogens have developed different degrees of drug resistance due to long-term use of existing agents, resulting in reduced control effect.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A fungicide composition for preventing and treating soft rot of jackfruit flowers and fruits comprises an active ingredient, wherein the active ingredient is compounded by clofoconazole and paeonol or eugenol.

[0009] Furthermore, the compounding mass ratio of clofoconazole to paeonol is 1-9:18-1.

[0010] Furthermore, the compounding mass ratio of clofoconazole to eugenol is 1-6:6-1.

[0011] Furthermore, the fungicide composition also includes auxiliary components.

[0012] Furthermore, the pathogen of the jackfruit flower and fruit soft rot is Rhizopus stolonifer.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] The present invention compounds cyfluthrin with paeonol or eugenol, and compared with a single agent, can improve the control effect of jackfruit flower and fruit soft rot, help reduce the dosage of the agent, and reduce the control cost. In addition, the cyfluthrin of the present invention has a different bactericidal mechanism from paeonol and eugenol, which helps to reduce the risk of drug resistance of the agent and delay the generation and development of drug resistance of pathogens. DETAILED DESCRIPTION

[0015] The technical solution of the present invention is described clearly and completely below.

[0016] 1. Screening of control agents

[0017] 1.1 Test strains

[0018] Rhizopus stolonifer was isolated from diseased samples with typical symptoms of jackfruit flower and fruit soft rot in the jackfruit planting base of Guangxi South Asian Tropical Agricultural Science Research Institute.

[0019] 1.2 Culture medium formulation

[0020] PDA medium: 200 g peeled potato, 20 g glucose, 17 g agar, add water to make up to 1000 mL, natural pH.

[0021] 1.3 Test agents

[0022] 97% clofoconazole technical, 98% paeonol (CAS: 552-41-0), 98.5% eugenol (CAS: 97-53-0)

[0023] 1.4 Test methods

[0024] The mycelium growth rate method was used to determine the toxicity of clofoconazole, paeonol and eugenol alone and their mixtures against Rhizopus stolonifer (test strain), a soft rot pathogen of jackfruit.

[0025] 1.4.1 Preparation of drugs: Dissolve the test drug in an organic solvent and dilute it with 0.1% Tween 80 aqueous solution to an effective single-dose stock solution of 10,000 mg / L. Set up multiple groups of mixed drugs, and dilute the single-dose stock solution and each group of mixed drugs with 0.1% Tween 80 aqueous solution to 5 mass concentration gradients. The above drugs are prepared and used immediately.

[0026] 1.4.2 Make plates: Add 4 mL of drug solution to 36 mL of PDA culture medium (about 50°C), mix well, pour into multiple sterile culture dishes (9 cm in diameter), pour 10 mL into each dish, and cool to form drug-containing plates. Set up a plate made of an equal amount of 0.1% Tween 80 aqueous solution as a blank control. Set up 3 replicates for each mass concentration of drug solution, and each replicate has 4 plates.

[0027] 1.4.3 Propagation and inoculation: Inoculate the test strain onto PDA medium and culture at 28℃ for 36h. Use a hole puncher to punch a 6mm diameter bacterial cake along the edge of the colony with the same radius. Inoculate the bacterial cake in the center of the plate, and inoculate one bacterial cake on each plate. Culture and observe at 28℃. When the colony diameter of the blank control grows to about 7cm, measure the colony diameter using the cross method, take the average value, and calculate the inhibition rate of mycelial growth by different treatments.

[0028]

[0029] 1.5 Data Analysis

[0030] The logarithmic value of fungicide concentration and the probability value of mycelial growth inhibition rate were regressed to calculate the toxicity EC of different agents on the test strains. 50 The co-toxicity coefficient (CTC) of the mixture was calculated using the Sun Yunpei method. CTC ≤ 80 was antagonistic, 80 < CTC < 120 was additive, and CTC ≥ 120 was synergistic. The results are shown in Table 1-3.

[0031] Table 1 EC of single agent against Rhizopus stolonifer 50 Relative toxicity index TI

[0032]

[0033] The results in Table 1 show that the EC values ​​of clofoconazole, paeonol and eugenol against Rhizopus stolonifer were 50 They are 6.073 mg / L, 53.642 mg / L and 22.359 mg / L respectively.

[0034] Table 2 Indoor activity test results of clofoconazole and paeonol against jackfruit soft rot pathogen Rhizopus stolonifer

[0035]

[0036] As shown in Table 2, when the compounding mass ratio of cypermethrin and paeonol is 1-9:18-1, the co-toxicity coefficient to Rhizopus stolonifer of jackfruit soft rot is between 125.152-159.463, which is greater than 120, showing a synergistic effect. This indicates that compounding cypermethrin and paeonol in the present invention can improve the control effect of jackfruit soft rot.

[0037] Table 3 Indoor activity test results of clofoconazole and eugenol complex against jackfruit soft rot fungus Rhizopus stolonifer

[0038]

[0039] As shown in Table 3, when the compounding mass ratio of cypermethrin and eugenol is 1-6:6-1, the co-toxicity coefficient to Rhizopus stolonifer of jackfruit soft rot is between 120.510-146.159, which is greater than 120, showing a synergistic effect. This indicates that the compounding of cypermethrin and eugenol in the present invention can improve the control effect of jackfruit soft rot.

Claims

1. A fungicide composition for preventing and treating soft rot of jackfruit flowers and fruits, characterized in that: The fungicide composition comprises an active ingredient, and the active ingredient is compounded by clofoconazole and paeonol or eugenol.

2. The fungicide composition for preventing and treating jackfruit flower and fruit soft rot according to claim 1, characterized in that: The compounding mass ratio of clofoconazole to paeonol is 1-9:18-1.

3. The fungicide composition for preventing and treating jackfruit flower and fruit soft rot according to claim 1, characterized in that, The compounding mass ratio of clofoconazole to eugenol is 1-6:6-1.

4. The bactericide composition for preventing and treating jackfruit flower and fruit soft rot according to claim 1, characterized in that, The fungicide composition further comprises auxiliary ingredients.

5. The fungicide composition for preventing and treating jackfruit flower and fruit soft rot according to claim 1, characterized in that: The pathogen of the jackfruit flower and fruit soft rot is Rhizopus stolonifer.

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