Active bactericide for crops

Abstract

The invention belongs to the technical field of crop bactericides, and particularly relates to a crop active bactericide. The invention relates to an active bactericide for crops, which is prepared from the following components in percentage by mass: 0.5-75% of active components and the balance of auxiliary components, wherein the active ingredient is formed by compounding hinokitiol and natamycin or isopyrazam. The hinokitiol and the natamycin or the isopyrazam are compounded according to a certain mass ratio, an indoor pot experiment shows that compared with a single component, the compounded combination shows a combined synergistic effect, and the prevention and treatment effect on crop diseases can be improved; meanwhile, generation and accumulation of drug resistance of pathogenic bacteria are delayed, and the risk of drug resistance is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of crop fungicides, and in particular relates to an active fungicide for crops. Background Art

[0002] Hinokitiol (CAS: 499-44-5) is a natural monoterpene compound extracted from the cypress tree. Existing studies have shown that hinokitiol can inhibit the mycelial growth and spore germination of pathogenic fungi such as Fusarium and Diplodia theobrominum, aggravate the lipid peroxidation of mycelial membranes, and destroy the subcellular structure of mycelium, with obvious antibacterial effect.

[0003] Natamycin (CAS: 7681-93-8) is a polyene macrolide antifungal antibiotic and a natural cyclic tetraene compound produced by Streptomyces. Natamycin has a strong inhibitory or killing effect on filamentous fungi such as yeast and mold. Its mechanism of action is to combine with ergosterol and other sterol groups of fungi to inhibit ergosterol biosynthesis, thereby deforming the cell membrane, eventually leading to leakage and causing cell death.

[0004] Pyraclostrobin (CAS: 881685-58-1) is a succinate dehydrogenase inhibitor (SDHI) developed by Syngenta and is also a pyrazole amide fungicide. Pyraclostrobin inhibits the action of succinate dehydrogenase reductase in the electron transport chain on the inner membrane of mitochondria, making it impossible for pathogenic fungi to generate energy through respiration, thereby disrupting the growth of pathogens. It is highly effective against pathogens resistant to triazole and strobilurin fungicides, and has excellent control effects on Septoria fungi. It can effectively prevent and control diseases such as powdery mildew and eye spot of cereals, leaf spot of wheat, brown rust, stripe rust, web spot of barley, moire, rust rot, leaf spot and eye spot.

[0005] In the process of crop production, it is inevitable to be harmed by diseases. At present, chemical agents are mainly used for these diseases, but due to unscientific use of drugs (such as long-term and large-scale application of single-component chemical agents), pathogens have developed different degrees of drug resistance, such as wheat powdery mildew caused by Gramineae Blumeria graminaceus has developed different degrees of drug resistance to agents such as triadimefon, tebuconazole, propiconazole, azoxystrobin and carbendazim, which reduces the control effect of chemical agents. Compounding different bactericidal components can effectively solve the above problems, but compounding any bactericidal component does not produce the effect of combined synergism, and some even produce antagonism.

[0006] 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

[0007] The purpose of the present invention is to provide an active fungicide for crops to solve the problem that pathogens develop different degrees of drug resistance due to unscientific use of drugs, thereby reducing the control effect of chemical agents.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A crop active fungicide is prepared from 0.5-75% of active ingredients and the remainder of auxiliary ingredients in terms of mass percentage; wherein the active ingredient is compounded from hinokitiol and natamycin or pyraclostrobin.

[0010] More specifically, the mass ratio of hinokitiol to natamycin is 1-30:9-1.

[0011] More specifically, the mass ratio of hinokitiol to pyraclostrobin is 1-15:25-1.

[0012] More specifically, the active ingredient accounts for 7.5-45% of the total mass of the crop active fungicide.

[0013] More specifically, the auxiliary ingredients are ingredients that are allowed to be added in pesticide science.

[0014] The invention also provides application of the crop active fungicide in preventing and controlling fungal diseases of crops.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The present invention compounds hinokitiol with natamycin or pyraclostrobin in a certain mass ratio. It is found through indoor pot plant experiments that, compared with a single component, the compound combination exhibits a combined synergistic effect on wheat powdery mildew fungi, and can improve the control effect on crop diseases such as wheat powdery mildew; at the same time, it is also helpful to delay the generation and accumulation of drug resistance of pathogens and reduce the risk of drug resistance. DETAILED DESCRIPTION

[0017] 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.

[0018] Indoor pot plant test

[0019] 1. Test crops

[0020] "Jingshuang 16" wheat seedlings that have been potted to the 2-3 leaf stage are planted in each pot with 5 plants numbered for future use.

[0021] 2. Test pathogens

[0022] Use a brush to brush fresh spores of wheat powdery mildew into 0.05% Tween-80 aqueous solution to prepare a conidia suspension, then spray the conidia suspension onto the test crop and wait for fresh spores of powdery mildew to appear on the leaves of the inoculated test crop for later use.

[0023] 3. Test reagents

[0024] 98% hinokitiol technical (Chengdu Zhibiao Huachun Biotechnology Co., Ltd.), 95% natamycin technical (Shanghai Yuanye Biotechnology Co., Ltd.), 92% pyraclostrobin technical (Syngenta Nantong Crop Protection Co., Ltd.)

[0025] 4. Test method (refer to NY / T 1156.4-2006 "Guidelines for Indoor Bioassay Tests of Pesticides - Fungicides Part 4: Pot Method for Control of Wheat Powdery Mildew")

[0026] The test agent was dissolved in dimethyl sulfoxide and diluted with 0.1% Tween-80 aqueous solution to form a single-dose mother solution, and then multiple groups of ratios were set. Each single agent and ratio mixture was set with 5 mass concentration gradients according to the equal ratio method. The above agents were prepared and used immediately. The liquid was sprayed evenly on the leaves of the test crop until they were completely wet. Each treatment had 5 pots, and the treatment containing only 0.1% Tween-80 aqueous solution was set as a blank control. After 24 hours, the fresh spores of powdery mildew produced on the leaves of the test crop within 24 hours were evenly shaken off and inoculated on the test crop treated with the liquid. After the treatment, the culture was continued at a temperature of 22°C, with alternating light for 14 hours and dark for 10 hours. After 7 days, the disease situation of each treatment was investigated in a graded manner. The disease index and control effect of each treatment were calculated. Among them, the grading standards are shown in Table 1.

[0027] Table 1 Disease grade assessment criteria

[0028]

[0029]

[0030] 5. Data Analysis

[0031] The EC values ​​of each pesticide against wheat powdery mildew were calculated by regression analysis based on the logarithmic values ​​of each pesticide concentration and the corresponding probability value of control effect. 50 The co-toxicity coefficient (CTC) of the mixture was calculated using the Sun Yunpei co-toxicity coefficient method to evaluate the type of combined action of the mixture: between 80-120 - additive effect; less than 80 - antagonistic effect; greater than 120 - synergistic effect. The results are shown in Tables 2 and 3.

[0032] Table 2 Indoor bioactivity test of hinokitiol and natamycin complex against wheat powdery mildew

[0033]

[0034]

[0035] As shown in Table 2, when the mass ratio of hinokitiol and natamycin is within 1-30:9-1, the co-toxicity coefficient is greater than 120, showing a combined synergistic effect, which can improve the control effect on wheat powdery mildew.

[0036] Table 3 Indoor bioactivity test of hinokitiol and pyraclostrobin against wheat powdery mildew

[0037]

[0038]

[0039] As shown in Table 3, when the mass ratio of hinokitiol and pyraclostrobin is within 1-15:25-1, the co-toxicity coefficient is greater than 120, showing a combined synergistic effect, which can improve the control effect on wheat powdery mildew.

[0040] In summary, the present invention compounds hinokitiol with natamycin or pyraclostrobin in a certain mass ratio. It is found through indoor pot plant experiments that, compared with a single component, the compound combination exhibits a combined synergistic effect on wheat powdery mildew fungi, and can improve the control effect on crop diseases such as wheat powdery mildew; at the same time, it is also helpful to delay the generation and accumulation of drug resistance of pathogens and reduce the risk of drug resistance.

Claims

1. A crop active fungicide, It is characterized in that The crop active fungicide is prepared from 0.5-75% of active ingredients and the remainder of auxiliary ingredients in terms of mass percentage; wherein the active ingredient is compounded from hinokitiol and natamycin or pyraclostrobin.

2. The crop active fungicide according to claim 1, It is characterized in that The mass ratio of hinokitiol to natamycin is 1-30:9-1.

3. The crop active fungicide according to claim 1, It is characterized in that The mass ratio of hinokitiol to pyraclostrobin is 1-15:25-1.

4. The crop active fungicide according to claim 1, It is characterized in that The active ingredient accounts for 7.5-45% of the total mass of the crop active fungicide.

5. The crop active fungicide according to claim 1, It is characterized in that The auxiliary ingredients are ingredients allowed to be added in pesticide science.

6. Use of the crop-active fungicide according to any one of claims 1 to 5 in preventing and controlling fungal diseases of crops.

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