A fungicide composition for preventing and controlling wax gourd damping-off disease

Abstract

The present invention belongs to the technical field of pesticides, and specifically relates to a fungicide composition for preventing and treating wax gourd damping-off disease. A fungicide composition for preventing and treating wax gourd damping-off disease, the fungicide composition is formed by binary compounding of cinnamaldehyde and benomyl or 2-methylbenzothiazole. When cinnamaldehyde and benomyl or 2-methylbenzothiazole are compounded in the fungicide composition of the present invention, the co-toxicity coefficient is greater than 120, showing a synergistic effect, which can improve the prevention and control effect of wax gourd damping-off disease, reduce the pesticide application dosage, and reduce pesticide residues and environmental pollution.

Description

Technical Field

[0001] The invention belongs to the technical field of pesticides, and particularly relates to a fungicide composition for preventing and treating wax gourd damping-off disease. Background Art

[0002] Winter melon damping-off is a winter melon disease caused by the hyphae fusion group of Rhizoctonia solani Kühn AG-4. Winter melon damping-off mainly occurs in the late stage of seedling raising, when the seedling tray is under high temperature conditions or in direct-seeding fields. It mainly harms the underground roots or the base of the stems of seedlings. Initially, irregular or nearly elliptical dark spots appear on the diseased part, which are slightly sunken. After the diseased part expands around the stem for a week, the stem wilts and dries up, causing the seedlings to die. The early stage is similar to damping-off, but damping-off develops rapidly, while the course of winter melon damping-off progresses slowly. The diseased part has inconspicuous or obvious ring patterns and light brown spider-like mold, which is the mycelium or sclerotia of the pathogen, which is different from damping-off.

[0003] Chemical agents are the main means of preventing and controlling winter melon damping-off disease, and commonly used chemical agents include Jinggangmycin, oxadipazole and thiram. However, long-term application of a single chemical agent easily leads to the generation and development of drug resistance, reducing the efficacy of the chemical agent, so it is necessary to screen for compound agents with synergistic effects. The inventor found through indoor biological activity tests that when cinnamaldehyde is compounded with oxadipazole or 2-methylbenzothiazole, the co-toxicity coefficient of cinnamaldehyde to winter melon damping-off pathogen is greater than 120, showing a synergistic effect. No relevant reports in this regard have been seen so far.

[0004] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0005] The purpose of the present invention is to provide a fungicide composition for preventing and controlling wax gourd blight, so as to solve the problems existing in the application of a single chemical agent.

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

[0007] A fungicide composition for preventing and treating wax gourd damping-off disease is prepared by binary compounding of cinnamaldehyde and benomyl or 2-methylbenzothiazole.

[0008] Preferably, the mass ratio of cinnamaldehyde to hydroxyzine is 1-5:30-1.

[0009] Preferably, the mass ratio of cinnamaldehyde to 2-methylbenzothiazole is 1-20:9-1.

[0010] Compared with the prior art, the present invention has the following beneficial effects:

[0011] (1) When the cinnamaldehyde of the present invention is compounded with benomyl or 2-methylbenzothiazole, the co-toxicity coefficient is greater than 120, showing a synergistic effect, which can improve the control effect of wax gourd damping-off disease, reduce the dosage of pesticide application, and reduce pesticide residues and environmental pollution.

[0012] (2) The fungicide composition of the present invention can delay the development of drug resistance in pathogens and reduce the risk of drug resistance. DETAILED DESCRIPTION

[0013] The following is a clear and complete description of the technical solution of the patent of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by technicians in this field without creative work are within the scope of protection of the present invention.

[0014] Example :Screening of control agents

[0015] 1. Test strain: DGLK strain of wax gourd wilt pathogen was collected from infected wax gourd plants, isolated, purified and back-inoculated in the laboratory, identified as Rhizoctonia solani Kühn AG-4 hyphae fusion group (Rhizoctonia solani Kühn AG-4), and preserved on PDA medium.

[0016] 2. Test reagents

[0017] 98.0% cinnamaldehyde, 98.0% carbendazim, 98.0% 2-methylbenzothiazole, all of which are commercially available.

[0018] 3. Test method: Refer to NY / T 1156.2-2006 "Guidelines for Indoor Bioassay of Pesticides - Fungicides Part 2: Plate Method for Inhibition of Pathogenic Fungal Mycelial Growth".

[0019] 4. Test methods

[0020] (1) Preparation of strains: Take out the DGLK strain of Rhizoctonia solani from a 4°C refrigerator, inoculate it on PDA medium, and culture it in a constant temperature incubator at 28°C for 3 days for later use;

[0021] (2) The original drug was first dissolved in dimethyl sulfoxide and then diluted into a single-dose stock solution; multiple groups of ratios were set, and each single-dose stock solution and the ratio mixture were set at a certain ratio, and each ratio was set with 5 mass concentration gradients. (3) The drug of different concentrations was mixed with PDA culture medium, poured onto plates, and prepared into plates containing culture medium of different concentrations. The cultured DGLK strain was cut with a 7mm diameter puncher and inoculated onto the PDA plate containing a series of drug concentrations; the corresponding dimethyl sulfoxide was used as the control, and a blank control was set. Each treatment was repeated 3 times, and all treatments were cultured in a constant temperature incubator at 28°C.

[0022] 5. Record results and calculations: When the diameter of the blank control colony grows to about 2 / 3 of the diameter of the culture dish, measure the colony diameter using the cross method and calculate the inhibition rate of mycelium growth by different treatments. Convert the mycelium growth inhibition rate into a probability value (y), convert the concentration of the drug (mg / L) into a logarithmic value with a base of 10, and use DPS software to calculate the toxicity regression equation of each test drug, and effectively inhibit the concentration (EC 50 ) and correlation coefficient, and calculated the co-toxicity coefficient (CTC value) of the mixture according to Sun Yunpei method.

[0023] Mycelium growth inhibition rate = [(control colony diameter - cake diameter) - (treated colony diameter - cake diameter)] / (control colony diameter - cake diameter) × 100%;

[0024] Measured Toxicity Index (ATI) = (Standard Agent EC 50 ÷Test drug EC 50 )×100;

[0025] Theoretical toxicity index (TTI) = toxicity index of agent A × percentage of A in the mixture + toxicity index of agent B × percentage of B in the mixture;

[0026] Co-toxicity coefficient (CTC) = [actual toxicity index of the mixture (ATI) ÷ theoretical toxicity index of the mixture (TTI)] × 100.

[0027] According to the classification standard of joint action: the co-toxicity coefficient (CTC) ≥ 120 shows synergistic effect; the co-toxicity coefficient (CTC) ≤ 80 shows antagonistic effect; 80 < co-toxicity coefficient (CTC) < 120 shows additive effect. The experimental results are shown in Table 1-2.

[0028] Table 1 Indoor biological activity of cinnamaldehyde and carbendazim against Rhizoctonia solani

[0029]

[0030]

[0031] As shown in Table 1, when cinnamaldehyde and carbendazim are compounded in a mass ratio of 1-5:30-1, the co-toxicity coefficient is greater than 120, showing a synergistic effect, which can improve the control effect on wax gourd damping-off disease.

[0032] Table 2 Indoor biological activity of cinnamaldehyde and 2-methylbenzothiazole against Rhizoctonia solani

[0033]

[0034] As shown in Table 2, when cinnamaldehyde and 2-methylbenzothiazole are compounded in a mass ratio of 1-30:9-1, the co-toxicity coefficient is greater than 120, showing a synergistic effect, which can improve the control effect of wax gourd damping-off disease.

[0035] In summary, when the cinnamaldehyde of the present invention is compounded with benomyl or 2-methylbenzothiazole, the co-toxicity coefficient is greater than 120, showing a synergistic effect, which can improve the control effect of wax gourd damping-off disease, reduce the application dosage of pesticides, and reduce pesticide residues and environmental pollution.

[0036] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. The scope of the present invention is intended to be limited by the claims and their equivalents.

Claims

1. A fungicide composition for preventing and treating wax gourd blight, characterized in that: The bactericide composition is formed by a binary compound of cinnamaldehyde and benomyl or 2-methylbenzothiazole; wherein: The mass ratio of cinnamaldehyde to hydroxyzine is 1-5:30-1; The mass ratio of the cinnamaldehyde to the 2-methylbenzothiazole is 1-20:9-1.

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