A protective control composition for strawberry bacterial leaf spot

Abstract

The present invention discloses an agricultural composition comprising ethionine and tetramycin, which comprises 1-15 parts of ethionine, 5-40 parts of potassium dihydrogen phosphate and 36-60 parts of tetramycin in parts by mass. The agricultural composition prepared by the present invention has a better inhibitory effect on strawberry Xanthomonas than other single agents, and a significantly better control effect on strawberry bacterial leaf spot than a single agent. In addition, the protective control composition provided by the present invention has a certain promoting effect on the growth of strawberry seedlings.

Description

Technical Field

[0001] The invention belongs to the field of agricultural compositions and relates to a protective control composition for strawberry bacterial leaf spot disease and an application thereof. Background Art

[0002] Strawberry bacterial leaf spot is also known as strawberry angular leaf spot and angular leaf spot. During the rainy season or sprinkler irrigation, bacteria in dry leaf tissues become active and are transmitted to healthy plants through splashing water droplets. At the optimal growth temperature of around 28°C, it can spread rapidly with the introduction of strawberry propagation materials, or seeds, soil, and diseased residues. The pathogen invades and spreads in the field through irrigation water, rainwater, wounds caused by insects or agricultural operations, or water holes at the leaf margins, first invading a few thin-walled cells, and then entering the vascular bundles to spread downward. Heavy nitrogen fertilizer application and excessive agricultural operations promote the spread of the disease. Leaf angular leaf spot is an important disease in nurseries. It often prevents some nursery stock dealers from passing certification. In severe cases, it leads to a lack of seedlings or broken ridges, causing huge economic losses to growers and a heavy blow to the development of the strawberry industry. In recent years, the disease has shown a trend of getting worse year by year.

[0003] Strawberry bacterial leaf spot is caused by the bacterium Xanthomonas fragariae of the genus Xanthomonas. In the early stages of the disease, small light green water-soaked spots appear on the back of the leaves. The spots become angular as they expand due to the restriction of the leaf veins. At this time, when they are observed against the light, they are translucent, which is different from the opaque spots of other leaf spots. Subsequently, irregular light reddish-brown spots with yellow edges appear on the front, and this symptom can be confused with other leaf spots. Finally, the diseased tissue dies and dries up, making the leaves uneven. When the leaves are wet, there will be a sticky substance formed by bacteria and bacterial exudates on the surface of the angular spots on the back of the leaves. When the sticky substance dries, it becomes light brown lacquer-like. The sticky substance or brown dry substance can help us distinguish leaf angular leaf spot from leaf spots caused by fungi.

[0004] Although there is no registered agent for biochemical control of bacterial leaf spot of strawberry, the key control period is from planting to the flowering period of the greenhouse. You can choose to spray 33.5% quinoline copper wettable powder 1500 times, or 3% Zhongshengmycin wettable powder 1500 times, or 20% thiazole zinc suspension 600 times, or 80% ethionyl emulsifiable concentrate 1500 times for foliar spraying. The spraying should be uniform and comprehensive, used once every 10 days, and sprayed 2 to 3 times in a row. By comparing the control effects of biochemical agents such as thiazole zinc, quinoline copper, ethionyl, and Zhongshengmycin, it is found that thiazole zinc has the best control effect and has a therapeutic effect; ethionyl and quinoline copper have the second best effect and have a protective effect; Zhongshengmycin has a general effect. The above single agents have certain drug resistance when used for a long time, and the control effect is not ideal. At present, there is no relevant research on the control effect of the composite composition of ethionine, tetramycin and potassium dihydrogen phosphate on strawberry bacterial leaf spot in the prior art. Summary of the invention

[0005] To solve this problem, the present invention aims to provide an agricultural composition which not only has a significant control effect on strawberry bacterial leaf spot, but also has a growth-promoting effect on strawberry plants. To achieve this purpose, the present invention prepares a composite composition in which ethiocarb, tetramycin and potassium dihydrogen phosphate are mixed according to a metered amount.

[0006] In one aspect, the present invention provides an agricultural composition comprising ethionine and tetramycin, wherein the active ingredients include 1-15 parts of ethionine, 5-40 parts of potassium dihydrogen phosphate and 36-60 parts of tetramycin in parts by mass.

[0007] Preferably, in the agricultural composition containing ethionine and tetramycin provided by the present invention, the preparation raw materials include 11-13 parts of ethionine, 22-27 parts of potassium dihydrogen phosphate, and 40-50 parts of tetramycin, calculated by weight.

[0008] More preferably, in the agricultural composition comprising ethionine and tetramycin provided by the present invention, the preparation raw materials include 12 parts of ethionine, 25 parts of potassium dihydrogen phosphate, and 45 parts of tetramycin, calculated by weight.

[0009] In another aspect, the present invention relates to the use of an agricultural composition comprising ethionyl and tetramycin in controlling bacterial leaf spot of strawberry.

[0010] Furthermore, the application provided by the present invention includes the inhibition of Xanthomonas fragariae.

[0011] Furthermore, the application provided by the present invention includes improving the survival rate of strawberry plants and increasing the chlorophyll content of strawberries.

[0012] Furthermore, the application provided by the present invention comprises: diluting the composition 1500 times at the strawberry seedling stage for foliar spraying and root dipping treatment.

[0013] Furthermore, in the application provided by the present invention, the preparation process of the composition is carried out at room temperature, and the stirring speed is 360-380r / min.

[0014] Through the above technical scheme, combined with the embodiments, the protective composition for preventing and controlling strawberry bacterial leaf spot and its application method provided by the present invention have at least the following beneficial effects or advantages:

[0015] The present invention tests the inhibitory effect of the composition on Xanthomonas fragariae indoors. According to the test, the inhibitory effect of the composition provided by the present invention on Xanthomonas fragariae is significantly better than that of ethionine, tetramycin, zhongshengmycin, quinoline copper and thiazole zinc alone.

[0016] The present invention measures the effects of the above-mentioned agents on the survival rate, chlorophyll content and fruit setting rate of strawberry plants. The results show that the control effect of the composition provided by the present invention on strawberry bacterial leaf spot is better than that of a single agent. At the same time, it is found by comparison that the control composition provided by the present invention has a certain promoting effect on the growth of strawberry seedlings and has little effect on the fruit setting rate. DETAILED DESCRIPTION

[0017] The technical solution of the present invention is described below in conjunction with embodiments; however, the present invention is not limited to the following embodiments.

[0018] If the specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. If the manufacturers of the reagents or instruments are not specified, they are all conventional products available on the market.

[0019] Example 1

[0020] This example provides a method for preparing the control composition, and at the same time, compares and tests the inhibitory effects of different agents on Xanthomonas fragariae bacteria.

[0021] The test agents used in this embodiment include 80% ethoxypropane EC (Kaifeng Dadi Agrochemical Biotechnology Co., Ltd.), 0.3% tetramycin EC (Hubei Hengjingrui Chemical Co., Ltd.), potassium dihydrogen phosphate DP (Chengdu Wanxiang Hongrun Biotechnology Co., Ltd.), 3% sinomenine WP (Fujian Kaili Biological Products Co., Ltd.), 33.5% quinoline copper SC (Jinan Baxter New Materials Co., Ltd.), and 20% thiazole zinc SC (Hubei Jiufenglong Chemical Co., Ltd.).

[0022] The diseased strawberry plants used in this example were provided by the Modern Agriculture Exhibition Center of Chang'an District, Xi'an.

[0023] The test bacteria were derived from diseased strawberry plants. After isolation and identification, the pathogen was identified as Xanthomonas fragariae, a bacterium of the genus Xanthomonas, through morphological, physiological, biochemical and molecular identification.

[0024] The in vitro antibacterial activity against Xanthomonas fragariae was determined by absorbance method. First, Xanthomonas fragariae was cultured overnight in LB liquid culture medium (600nm absorbance value OD≈1). According to the grouping shown in Table 1, LB culture medium with drug addition containing a series of concentrations was prepared, and 40mL of drug was inoculated into 100mL Erlenmeyer flasks per bottle, and LB culture medium without drug addition was set as blank control. Then, 50μL of bacterial solution was inoculated into each treatment culture medium per bottle, and after shaking culture at 30℃ and 100rpm for 20h, it was adjusted to zero with LB culture medium, and the absorbance value OD at 600nm of each concentration treatment was measured. x1 Then subtract the absorbance value OD of the uninoculated solution at this concentration x2 , the obtained OD x Value = (OD x1 -OD x2 ) is the absorbance value of the bacterial solution, and the growth inhibition rate (%) of each agent concentration on bacteria is calculated according to the formula:

[0025] Inhibition rate (%) = [(drug OD value - OD x Value) / OD x value]×100%

[0026] Next, this example uses SPSS 26.0 software for statistical analysis to calculate the EC of each drug. 50 , the results are shown in Table 1-1.

[0027] Table 1-1, Indoor antibacterial effect determination

[0028]

[0029]

[0030]

[0031] Based on the fact that dipotassium hydrogen phosphate itself has no antibacterial ability, according to the indoor antibacterial effect determination results in Table 1-1, the synergistic coefficient (SR) of the binary compound composition of ethyllicin and tetramycin was calculated using the Wadley method, so as to evaluate the compounding effect of the composition described in the present invention. When ethyllicin and tetramycin are compounded in pairs, by mass ratio, when the ratio of ethyllicin to tetramycin is 1:36, 12:45, and 15:60, their SR values are 1.54, 1.69, and 1.52 respectively. According to the Wadley method, when SR ≤ 0.5, it is an antagonistic effect; when SR ≥ 1.5, it is a synergistic effect; when 0.5 < SR < 1.5, it is an additive effect. Thus, by mass parts, when 1-15 parts of ethyllicin and 36-60 parts of tetramycin are compounded, the technical effect of synergistic enhancement is achieved. Table 1-1 verifies that when 1-15 parts of ethyllicin, 5-40 parts of potassium dihydrogen phosphate, and 36-60 parts of tetramycin are compounded by mass parts, a better technical effect is obtained than the binary compounding of ethyllicin and tetramycin, and the antibacterial effect of this ternary complex is even better than that of zhongshengmycin, copper quinolate, or thiazole zinc.

[0032] Example 2

[0033] In this example, strawberry seedlings were respectively subjected to foliar spraying and root dipping treatments with different medicaments, the disease levels were detected, and the control effects were analyzed based on the results.

[0034] The sources of the test medicaments used in this example are the same as those in Example 1.

[0035] In this example, at the same time, the cps_A medicament with the optimal concentration provided in Example 1 (i.e., ethyllicin: dipotassium hydrogen phosphate: tetramycin = 12:25:45) was used as the test group, and sterile water was used as the blank control.

[0036] 80% ethyllicin EC and 0.3% tetramycin EC were used for medicament preparation. Based on the dosage of the active ingredient, the preparation method of the medicament was as follows: 1.2 g of ethyllicin, 2.5 g of potassium dihydrogen phosphate, 4.5 g of tetramycin, and it was diluted 1500 times with sterile water for foliar spraying and root dipping.

[0037] 80% ethyllicin EC was diluted 1500 times with sterile water, 0.3% tetramycin EC was diluted 400 times with sterile water, potassium dihydrogen phosphate DP was diluted 1500 times with sterile water, 3% zhongshengmycin WP was diluted 600 times with sterile water, 33.5% copper quinolate SC was diluted 750 times with sterile water, and 20% thiazole zinc SC was diluted 400 times with sterile water.

[0038] The test site of this example was set at the strawberry base of the Modern Agriculture Exhibition Center in Chang'an District, Xi'an City. The strawberry variety planted was Zhangji, and the strawberry seedlings were open-field production seedlings.

[0039] On August 25, 2021, 40 strawberry seedlings of the same batch with the same leaf size and root length were selected and divided into 8 groups, 5 plants in each group. The above 8 agents were sprayed on the leaves according to the grouping in the nursery. Two days later, the 8 groups of strawberry seedlings were dug out. Eight containers with a length of 50 cm, a height of 20 cm, and a width of 20 cm were used to load the above 8 agents into the containers, with a loading depth of 15 cm. The strawberry rhizomes were dipped for 2 minutes according to the grouping, and then taken out to dry and planted.

[0040] The occurrence of strawberry leaf spot in each group was measured 8 days and 16 days after transplanting, and the leaves were graded according to the disease situation. The grading standards are shown in Table 2-1. The disease index and prevention effect were calculated, and the results are shown in Table 2-2.

[0041] The survival rate of the strawberry plants and the chlorophyll content in the leaves were measured 25 days after transplanting, and the fruit setting rate of the strawberry plants was measured 90 days after transplanting. The results are shown in Table 2-3.

[0042] Table 2-1, Leaf Classification Standards

[0043]

[0044] The calculation formula of disease index and prevention and treatment effect is as follows:

[0045]

[0046]

[0047] Table 2-2, Effects of different agents on controlling strawberry bacterial leaf spot by dipping roots

[0048]

[0049] Note: Lowercase letters in the same column indicate significant differences at the 0.05 significance level.

[0050] Table 2-3, Effects of different pesticides on the growth of strawberry seedlings

[0051]

[0052]

[0053] According to Table 2-2, the strawberry seedlings were treated with the control composition provided by the present invention by dipping the roots and spraying the leaves, and the control effect of the strawberry bacterial leaf spot disease was significantly better than other agents or single agents of the raw materials used. According to Table 2-3, the results showed that the survival rate and chlorophyll content were also higher than other agents, and there was no significant difference in fruit setting rate among the agents.

[0054] In summary, the strawberry bacterial leaf spot protective control composition prepared by the present invention has a better inhibitory effect on strawberry Xanthomonas than other single agents, and its control effect on bacterial leaf spot after strawberry seedlings are planted is also significantly better than other agents. In addition, the protective control composition prepared by the present invention also has a promoting effect on the survival rate of strawberries and the content of chlorophyll in leaves.

[0055] As described above, the present invention can be well implemented. The above embodiments are only descriptions of the preferred implementation modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various changes and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the protection scope determined by the present invention.

Claims

1. An application of an agricultural composition comprising ethionine and tetramycin in preventing and controlling strawberry bacterial leaf spot, characterized in that: In parts by mass, the active ingredients of the agricultural composition are 1-15 parts of ethionine, 5-40 parts of potassium dihydrogen phosphate and 36-60 parts of tetramycin; The pathogen of strawberry bacterial leaf spot is Xanthomonas fragariae Xanthomonas fragariae .

2. Use of the composition according to claim 1 in preventing and treating strawberry bacterial leaf spot, characterized in that: Calculated by weight, the active ingredients of the agricultural composition are 11-13 parts of ethionine, 22-27 parts of potassium dihydrogen phosphate, and 40-50 parts of tetramycin.

3. Use of the composition according to claim 2 in preventing and treating strawberry bacterial leaf spot, characterized in that: Calculated by weight, the active ingredients of the agricultural composition are 12 parts of ethionine, 25 parts of potassium dihydrogen phosphate, and 45 parts of tetramycin.

4. Use of the composition according to claim 1 in preventing and treating strawberry bacterial leaf spot, characterized in that: The application is to use the agricultural composition to treat Xanthomonas fragariae Xanthomonas fragariae of inhibition.

5. Use of the composition according to claim 1 in preventing and treating strawberry bacterial leaf spot, wherein the use is to improve the survival rate of strawberry plants and increase the chlorophyll content of strawberries.

6. Use of the composition according to claim 1 in preventing and treating strawberry bacterial leaf spot, characterized in that: The composition is diluted 1500 times during the strawberry seedling stage for root dipping and foliar spraying.

7. Use of the composition according to claim 6 in preventing and treating strawberry bacterial leaf spot, characterized in that: The preparation process of the composition is carried out at room temperature, and the stirring speed is 360-380 r / min.

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