Bactericidal composition for preventing and treating scab of big-fruit hawthorn

Abstract

The invention belongs to the technical field of pesticides, and particularly relates to a bactericidal composition for preventing and treating scab of big-fruit hawthorn. The invention relates to a bactericidal composition for preventing and treating scab of big-fruit hawthorn. The bactericidal composition is prepared by compounding bakuchiol and orysastrobin or dimethomorph. When the bakuchiol and the orysastrobin or the dimethomorph are compounded, in the compounding mass ratio ranges of (1-25): (10-1) and (1-40): (20-1), the combined action types of the bakuchiol and the orysastrobin and the combined action types of the bakuchiol and the dimethomorph on the scab of the big-fruit hawthorn respectively show a synergistic effect.

Description

Technical Field

[0001] The present invention belongs to the technical field of pesticides, and particularly relates to a bactericidal composition for preventing and controlling Venturia inaequalis of big-fruited hawthorn. Background Art

[0002] Big-fruited hawthorn is a plant of the genus Crataegus in the subfamily Pomoideae of the Rosaceae family. It is famous for its large fruits and is a rare variety in the genus Crataegus in China. The fruits of big-fruited hawthorn can be eaten fresh or made into various products such as preserved fruits, jams, fruit wines, hawthorn slices, and hawthorn cakes. It is rich in a variety of functional components and nutritional elements and is known as the "nutritional and health care fruit". It is a medicinal and edible plant with various functions such as promoting digestion and strengthening the stomach, promoting qi circulation and removing stasis, resolving turbidity and reducing lipids, lowering blood pressure and blood lipids, and enhancing the body's immunity. In recent years, due to the development of the big-fruited hawthorn processing industry, its industrial economic benefits have been further improved. Planting big-fruited hawthorn has become an effective way for growers to increase economic benefits, which has also promoted the continuous development and growth of the big-fruited hawthorn industry.

[0003] Fusicladium crataegi Aderhold can infect and cause Venturia inaequalis of big-fruited hawthorn. In the initial stage of the disease, sparse mildew-like substances are mostly produced along the veins on the back of the leaves, gradually expanding into irregular mildew spots of different sizes. The diseased spots on the front of the leaves turn chlorotic and yellow. If the seedlings are damaged in the early stage, the leaves are prone to wrinkling and even cracking. When the damage is severe, the diseased spots merge with each other to form irregular large spots. Once Venturia inaequalis of big-fruited hawthorn occurs generally, it will pose a serious threat to hawthorn.

[0004] Bakuchiol, bakuchalcone, bakuchiol dihydroflavone, furanocoumarin essence, and psoralidin are 5 compounds isolated and identified from the crude extract of Psoralea corylifolia. Existing technologies show that these 5 compounds have high inhibitory activities against Valsa mali. Among them, the structural formula of bakuchiol (CAS: 10309-37-2) is as follows:

[0005]

[0006] The inventor found by measuring using the indoor mycelial growth rate method that bakuchiol has high inhibitory activity against the pathogen Sclerotium rolfsii Sacc of Venturia inaequalis, which can provide ideas for developing biological agents for preventing and controlling Venturia inaequalis of big-fruited hawthorn. However, the efficacy of single bakuchiol against Venturia inaequalis of big-fruited hawthorn may be limited. If it is compounded with existing fungicides and a compounding formula with synergistic effects is screened, this can not only improve the control effect on Venturia inaequalis of big-fruited hawthorn but also improve the utilization rate of existing fungicides. Therefore, it is very meaningful to screen the synergistic compounding combinations of bakuchiol.

[0007] There has been no relevant report on the compounding of bakuchiol with trifloxystrobin or dimethomorph. Summary of the Invention

[0008] The object of the present invention is to provide a bactericidal composition for preventing and controlling Venturia inaequalis of big-fruited hawthorn, which can improve the virulence to big-fruited hawthorn compared with the single use of bakuchiol, and is helpful to improve the control effect on big-fruited hawthorn.

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] A bactericidal composition for preventing and controlling Venturia inaequalis of big-fruited hawthorn, which is composed of bakuchiol and trifloxystrobin or dimethomorph in combination.

[0011] Further, the compounding mass ratio of bakuchiol to trifloxystrobin is 1-25:10-1.

[0012] Further, the compounding mass ratio of bakuchiol to dimethomorph is 1-40:20-1.

[0013] Further, the compounding mass ratio of bakuchiol to dimethomorph is 15:1 or 1:7.

[0014] The present invention also provides a bactericide for preventing and controlling Venturia inaequalis of big-fruited hawthorn, and the bactericide for preventing and controlling Venturia inaequalis of big-fruited hawthorn uses the bactericidal composition for preventing and controlling Venturia inaequalis of big-fruited hawthorn as an active ingredient.

[0015] Further, the mass of the active ingredient accounts for 0.5-65% of the total mass of the bactericide for preventing and controlling Venturia inaequalis of big-fruited hawthorn.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] When bakuchiol of the present invention is compounded with trifloxystrobin or dimethomorph, within the compounding mass ratio range of 1-25:10-1 and 1-40:20-1, the combined action types of bakuchiol with trifloxystrobin and bakuchiol with dimethomorph on Venturia inaequalis of big-fruited hawthorn show a synergistic effect, which is helpful to improve the control effect on Venturia inaequalis of big-fruited hawthorn. In addition, it can also delay the development of pathogen drug resistance and reduce the cost of pathogen drug resistance management. Detailed Embodiments

[0018] The following clearly and completely describes the technical solutions of the present invention patent. Obviously, the described embodiments are part of the embodiments of the present invention. All other embodiments obtained by those skilled in the art without creative efforts based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0019] Example: Indoor bioactivity test

[0020] 1. Test strains

[0021] Fusicladium crataegi Aderhold, isolated from diseased large-fruited hawthorn.

[0022] 2. Test agents

[0023] 98% bakuchiol, 98% trifloxystrobin-oxime, 96% dimethomorph. All of the above agents are commercially available.

[0024] 3. Test methods

[0025] The mycelial growth rate method was adopted. The test agents were dissolved in dimethyl sulfoxide and diluted with 0.1% Tween-80 aqueous solution to prepare single-agent stock solutions. Multiple groups of ratios were set, and 5 mass concentration gradients were set for each single-agent stock solution and the mixed agents of ratios according to the equal ratio method.

[0026] 45 mL of pre-melted PDA medium was added to a sterile conical flask, 5 mL of the medicinal liquid was aspirated and added to the above conical flask. After shaking well, it was equally poured into 5 petri dishes (9 cm in diameter) to make drug-containing plates, and the treatment with 0.1% Tween-80 aqueous solution was used as the blank control. Each treatment was repeated 3 times, and each repetition had 5 plates.

[0027] The test strains were inoculated on the PDA medium. After propagating and culturing at 25 °C for 3 days, a mycelial disc (6 mm in diameter) was cut from the edge of the colony with a puncher. The mycelial disc was inoculated at the central position of the drug-containing plate and the blank control plate. After covering the petri dish lid, it was placed in an incubator at 25 °C for culturing. When the colony diameter of the blank control grew to about 7 cm, the colony diameter was measured by the cross method, and the inhibition rate of mycelial growth of different treatments was calculated.

[0028]

[0029] 4. Data analysis

[0030] Taking the logarithm value of the fungicide concentration as x and the probit value of the corresponding mycelial growth inhibition rate as y for linear regression to obtain the virulence regression equation and the virulence EC 50 value of the agent against the target pathogen, and the co-toxicity coefficient (CTC) was calculated by the Sun Yunpei method.

[0031]

[0032] In the above formula: ATI--the measured virulence index of the mixture; S--the EC 50 , unit: mg / L; M--the EC 50 , unit: mg / L.

[0033] TTI = TI A ×P A +TI B×P B

[0034] In the above formula: TTI--Theoretical toxicological index of the mixture; TI A --Toxicity index of agent A; P A --Percentage content of agent A in the mixture, in percentage (%) ; TI B --Toxicity index of agent B; P B --Percentage content of agent B in the mixture, in percentage (%).

[0035]

[0036] In the above formula: CTC--Coefficient of co-toxicity; ATI--Actual toxicological index of the mixture; TTI--Theoretical toxicological index of the mixture.

[0037] 5. Evaluation of combined action

[0038] Evaluate the synergistic effect of the agents according to the calculated coefficient of co-toxicity (CTC). CTC ≤ 80 indicates antagonistic effect, 80 < CTC < 120 indicates additive effect, and CTC ≥ 120 indicates synergistic effect. The results are shown in Table 1-2.

[0039] Table 1 Results of the combined action of bakuchiol and trifloxystrobin against Sphaceloma ambiens

[0040]

[0041] As can be seen from the results in Table 1, within the range of the compounding mass ratio of 1-25:10-1, the type of combined action of bakuchiol and trifloxystrobin against Sphaceloma ambiens of big-fruited hawthorn black spot pathogen shows a synergistic effect. It shows that compounding bakuchiol and trifloxystrobin helps to improve the control effect against big-fruited hawthorn black spot disease.

[0042] Table 2 Results of the combined action of bakuchiol and dimethomorph against Sphaceloma ambiens

[0043]

[0044] As can be seen from the results in Table 2, within the range of the compounding mass ratio of 1-40:20-1, the type of combined action of bakuchiol and dimethomorph against Sphaceloma ambiens of big-fruited hawthorn black spot pathogen shows a synergistic effect. Especially when the mass ratio is 15:1 and 1:7, the coefficients of co-toxicity reach 361.235 and 276.344 respectively, and the synergistic effect is the most significant. It shows that compounding bakuchiol and dimethomorph helps to improve the control effect against big-fruited hawthorn black spot disease.

[0045] In summary, when bakuchiol is compounded with trifloxystrobin or dimethomorph, within the compound mass ratio range of 1-25:10-1 and 1-40:20-1, the combined action types of bakuchiol with trifloxystrobin and bakuchiol with dimethomorph against Venturia inaequalis (Cooke) Wint. on big-fruited hawthorn show synergistic effects. This helps to improve the control effect against Venturia inaequalis on big-fruited hawthorn. In addition, it can also delay the development of pathogen drug resistance and reduce the cost of pathogen drug resistance management.

Claims

1. A bactericidal composition for preventing and treating Venturia inaequalis of big-fruited hawthorn, characterized in that, It is prepared by compounding bakuchiol with orysastrobin or dimethomorph.

2. The bactericidal composition for preventing and treating Venturia inaequalis of big-fruited hawthorn according to claim 1, characterized in that, The compounding mass ratio of bakuchiol to orysastrobin is 1-25:10-1.

3. The bactericidal composition for preventing and treating Venturia inaequalis of big-fruited hawthorn according to claim 1, wherein The compounding mass ratio of bakuchiol to dimethomorph is 1-40:20-1.

4. The bactericidal composition for preventing and treating Venturia inaequalis of big-fruited hawthorn according to claim 3, characterized in that, The compounding mass ratio of bakuchiol to dimethomorph is 15:1 or 1:

7.

5. A fungicide for preventing and controlling Venturia inaequalis of big-fruited hawthorn, characterized in that, The fungicide for preventing and treating Venturia inaequalis of big-fruit hawthorn takes the bactericidal composition for preventing and treating Venturia inaequalis of big-fruit hawthorn described in any one of claims 1-4 as the active ingredient.

6. The fungicide for preventing and treating Venturia inaequalis of big-fruited hawthorn according to claim 5, wherein The mass of the active ingredient accounts for 0.5-65% of the total mass of the fungicide for preventing and treating Venturia inaequalis of big-fruit hawthorn.

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