Seed treatment suspension agent for preventing and treating millet white hair disease, preparation method and application thereof

Abstract

The present application relates to the technical field of pesticide preparation, and discloses a seed treatment suspension agent for preventing and treating millet white hair disease, and a preparation method and application thereof.The seed treatment suspension agent comprises azoxystrobin, TRST, an antifreezing agent, 500LQ, Atlox 4913, bronopol, a defoaming agent, Dow fungicide, benzoic acid, a film forming agent, 2# red, magnesium aluminum silicate, white carbon black, xanthan gum and water.The seed treatment suspension agent is prepared by taking azoxystrobin as a main active ingredient, combining other preservative and antibacterial ingredients and suitable auxiliaries, and has good suspension performance, appropriate viscosity and heat storage stability, and reaches the national standard, and has a high quality, and the control effect on the millet white hair disease is better than that of the existing registered metalaxyl dry powder agent, has little influence on the millet plant, and has a proper growth promoting effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pesticide preparation, in particular to a seed treatment suspension agent for preventing and treating millet white hair disease and a preparation method and application thereof. BACKGROUND

[0002] Millet white hair disease is a systemic invasive disease, which shows different symptoms such as bud rot, gray back, white tip and hedgehog head at different growth stages of millet. It occurs in various planting areas, and the incidence rate can reach more than 50% in special years, which seriously affects the yield and quality improvement of millet. Seed coating is one of the most effective prevention and control measures to control the damage of white hair disease.

[0003] Millet white hair disease is a systemic invasive disease, which shows different symptoms such as bud rot, gray back, white tip and hedgehog head at different growth stages of millet. It occurs in various planting areas, and the incidence rate can reach more than 50% in special years, which seriously affects the yield and quality improvement of millet. Seed coating is one of the most effective prevention and control measures to control the damage of white hair disease.

[0004] The registered pesticides for preventing and treating millet white hair disease on the pesticide information registration network are metalaxyl and metam. Among them, metalaxyl is a seed treatment dry powder, and metam is a water agent. However, the metalaxyl currently used for seed treatment has the following problems:

[0005] 1) Metalaxyl seed treatment dry powder or similar registered pesticides for millet white hair disease have poor performance in suspension and adhesion, and the seed coating or seed dressing is not sufficient and uniform, which leads to frequent occurrence of millet white hair disease and poor control effect; 2) Metalaxyl is a selective fungicide with antibacterial activity for oomycetes in the order of Peronosporales, and has a single action site, which has a potential risk of high-level drug resistance; 3) Metalaxyl has a certain inhibitory effect on the seed germination and growth of millet. Therefore, it is of great significance to develop a new type of seed treatment suspension agent for preventing and treating millet white hair disease. SUMMARY

[0006] Therefore, the purpose of the present application is to provide a seed treatment suspension agent for preventing and treating millet white hair disease and a preparation method thereof, so that the seed treatment suspension agent can effectively prevent and treat millet powdery mildew and has a low impact on the germination and growth of millet.

[0007] In order to achieve the above purpose, the present application provides the following technical solutions:

[0008] A seed treatment suspension agent for preventing and treating millet white hair disease, comprising azoxystrobin, TRST, antifreeze, 500LQ, Atlox 4913, bronopol, defoaming agent, Dow fungicide, benzoic acid, film forming agent, 2# red, magnesium aluminum silicate, white carbon black, xanthan gum and water.

[0009] Azoxystrobin is a kind of high-efficiency, low-toxicity and broad-spectrum internal absorption fungicide, which can effectively prevent and treat diseases caused by oomycetes and most fungi, has the characteristics of wide fungicidal spectrum and high fungicidal activity, and its action site is Cytb-c1 complex in complex III of respiratory chain, belongs to an energy synthesis inhibitor, has a strong inhibitory effect on spore germination of pathogenic bacteria. Moreover, due to its novel action target, it can effectively control pathogenic bacteria resistant to other types of fungicides, and this type of fungicide is a microbial source biochemical fungicide, which is safe to non-target organisms and environment. At present, azoxystrobin seed treatment suspension agent has been used for the prevention and treatment of soil-borne diseases such as cotton damping-off, corn head smut, wheat take-all disease and potato black scab, but has not been applied to the prevention and treatment of millet white hair disease.

[0010] The chemical component of TRST is phosphate amine salt, which mainly plays the roles of emulsification and dispersion, can prevent particles from coagulating with each other to form a stable suspension system, and is suitable for FS, SC and SE formulations. 500LQ is mainly a non-ionic hydroxyl polyethylene oxide block copolymer, which is a liquid wetting dispersant, provides a unique steric hindrance effect in the system, can effectively maintain the stability of the system, can be used as an emulsifier and a co-emulsifier, and is suitable for various formulations including EC, EW, ME, SC, WP and WDG. Atlox 4913 is a non-ionic dispersant, a modified carboxylic acid polymer, which can be used in high content systems, has the effects of anchoring, viscosity reduction and prevention of crystal growth, and provides long-term stability of the preparation; has a super molecular weight and has a strong steric hindrance effect.

[0011] On the basis of azoxystrobin, three antibacterial and antiseptic ingredients, namely, bronopol, Dow fungicide and benzoic acid, are further used in combination. Bronopol, also known as bromopol, is mainly used as an antiseptic and fungicide, and can effectively prevent and treat various plant pathogenic bacteria. Dow fungicide has the characteristics of high activity, no formaldehyde release, broad-spectrum antibacterial and excellent compatibility. Benzoic acid is generally used as a drug or antiseptic, and has the effect of inhibiting the growth of fungi, bacteria and molds. The antiseptic principle is to interfere with the enzyme system of microorganisms, destroy their normal metabolism, inhibit the activity of enzymes, make the protein of microorganisms coagulate and denature, interfere with their survival and reproduction, change the permeability of cell plasma membrane, inhibit the exclusion of enzymes and metabolic products in the body, and lead to inactivation.

[0012] 2# red is also called permanent red F2R. It has the effects of corrosion prevention and shielding. Magnesium aluminum silicate is a non-metallic nano material, which has a very large specific surface area and a very developed microporous system. It can be used as an adsorbent, an absorbent, a moisture-proof agent, etc. It can maintain appropriate viscosity, good automatic dispersibility and good stability. Magnesium aluminum silicate gel helps to coordinate the viscosity and yield value, making the suspension uniform in texture and maintaining uniform concentration. It is of great help to the appearance of the product after storage over time. White carbon black has a large specific surface area and strong adsorption performance. It can absorb a large number of water molecules in water and expand into extremely fine particles to form a stable suspension. Xanthan gum is a superior biological gum with the properties of thickening, suspending, emulsifying and stabilizing. Xanthan gum has good suspending effect on insoluble solids and oil droplets. Xanthan gum can be quickly dissolved in water and has good water solubility. Xanthan gum solution has the characteristics of low concentration and high viscosity, and is a high-efficiency thickening agent. The viscosity of xanthan gum solution does not change greatly with temperature. It is stable to heat, acid, alkali and salt. Its stable double helix structure makes it have strong antioxidant and anti-enzymatic ability.

[0013] In the specific embodiment of the present application, the seed treatment suspension agent comprises 10-20% azoxystrobin, 2-3g TRST, 4-5g antifreeze, 1-1.5g 500LQ, 1-1.5g Atlox 4913, 0.3-0.5g bronopol, 0.5-1g defoaming agent, 0.2-0.3g Dow fungicide, 0.2-0.3g benzoic acid, 4-5g film forming agent, 2-2.5g 2# red, 0.5-1g magnesium aluminum silicate, 2-3g white carbon black, 0.15-0.3g xanthan gum, and the balance is water per 100g. Preferably, the antifreeze is glycerol, and the defoaming agent is HS-18.

[0014] In the specific embodiment of the present application, the seed treatment suspension agent comprises 10.41g azoxystrobin, 2g TRST, 5g antifreeze, 1g 500LQ, 1g Atlox 4913, 0.3g bronopol, 0.5g defoaming agent, 0.2g Dow fungicide, 0.2g benzoic acid, 4.5g film forming agent, 2g 2# red, 0.5g magnesium aluminum silicate, 2g white carbon black, 0.15g xanthan gum, and the balance is water per 100g.

[0015] The above active ingredients and adjuvants work together to achieve the prevention and treatment effect on millet white hair disease, which has significant difference compared with metalaxyl dry powder (Duncan's new multiple range method); at the same time, the seed treatment suspension agent has good effects on seed germination and crop safety of millet, and has good product quality. Based on these beneficial technical effects, the application of the seed treatment suspension agent in preventing and treating millet white hair disease or in preparing a pesticide product is proposed. The pesticide product refers to a pesticide product prepared by adding other suitable ingredients to the seed treatment suspension agent of the application, which at least has the effect of preventing and treating millet white hair disease.

[0016] In addition, the application also provides a preparation method of the seed treatment suspension agent, comprising:

[0017] The components except xanthan gum and defoaming agent are mixed in proportion, grinded by using a high shear emulsifier, then the xanthan gum is pasted with glycerol and added to the system for continuous grinding, and the defoaming agent is added, and the seed treatment suspension agent is obtained by filtration.

[0018] More specifically, the preparation method is that the components except xanthan gum and defoaming agent are mixed in proportion, about 1 times volume of zirconium beads is added, grinded by using a high shear emulsifier (AD500S-H) for 60 min, then the xanthan gum is pasted with glycerol and added to the system for continuous grinding for 30 min, and the defoaming agent is added, and the seed treatment suspension agent is obtained by filtration.

[0019] From the above technical solutions, it can be known that the application uses azoxystrobin as the main active ingredient, cooperates with other preservative and antibacterial ingredients and suitable adjuvants, and prepares a high-quality seed treatment suspension agent with good suspension performance, appropriate viscosity and heat storage stability reaching the national standard, the control effect on millet white hair disease is better than that of the existing registered metalaxyl dry powder, the influence on millet plants is almost nothing, and there is a proper growth promoting effect. DETAILED DESCRIPTION

[0020] The application discloses a seed treatment suspension agent for preventing and treating millet white hair disease and a preparation method and application thereof, and those skilled in the art can refer to the content of the present application and appropriately improve the process parameters. It should be particularly pointed out that all similar replacements and changes are obvious to those skilled in the art, and they are regarded as being included in the application. The seed treatment suspension agent, the preparation method and the application thereof have been described through preferred embodiments, and relevant personnel can obviously modify or appropriately change and combine the seed treatment suspension agent, the preparation method and the application thereof described in the present application without departing from the content, spirit and scope of the application, to realize and apply the application technology.

[0021] The seed treatment suspension agent quality determination results of the application show that the suspension agent has good suspension performance, appropriate viscosity, and heat storage stability, etc. all reaching the national standards, and the phytotoxicity determination shows that at high concentration, the influence on millet plants is almost none, and there is also appropriate growth promotion.

[0022] The seed treatment suspension agent for preventing and treating millet white hair disease, and the preparation method and application thereof provided by the application are further described below.

[0023] Example 1: 10% azoxystrobin seed treatment suspension agent

[0024] 1. Formula

[0025] See Table 1 (100g specification).

[0026] Table 1

[0027]

[0028] 2. Preparation method

[0029] The components except xanthan gum are mixed in proportion, and about 1 times volume of zirconium beads is added to be ground for 60 minutes by using a high shear emulsifier (AD500S-H). Then xanthan gum is pasted with glycerol and added to the system, and ground for another 30 minutes. The seed treatment suspension agent is obtained by filtration.

[0030] Example 2: Influence of different seed treatment suspension agents on millet germination potential

[0031] Since millet powdery mildew belongs to an oomycete disease, in this example, emamide, metalaxyl and pentazocine, which have good control effect on oomycete diseases, are selected as test agents, and are tested together with the seed treatment suspension agent of the application.

[0032] According to the formula of Example 1, 35% emamide, 35% metalaxyl, 6% pentazocine and 10% azoxystrobin seed coating treatment suspension agents are prepared. The components except xanthan gum are mixed in proportion, and about 1 times volume of zirconium beads is added to be ground for 60 minutes by using a high shear emulsifier (AD500S-H). Then xanthan gum is pasted with glycerol and added to the system, and ground for another 30 minutes. The seed treatment suspension agent is obtained by filtration.

[0033] Jin Gu 21 millet variety is used as the material, and the seeds are coated according to the preparation amount of each agent in Table 2. 100 healthy and full seeds in each treatment are placed in a culture dish containing filter paper, and are cultured at 25℃. After 5 days, the influence of different concentrations of the four seed coating suspension agents on seed germination rate and sprout length is determined, and the results are shown in Table 2.

[0034] Table 2

[0035]

[0036] Note: The statistical method adopts Duncan's new complex difference method to judge the significant difference. The same letter in the same column in the table indicates that there is no significant difference at the 0.05 level.

[0037] As can be clearly seen from the results in Table 2, only 10% azoxystrobin suspension agent among the four seed treatment suspensions has no obvious inhibitory effect on the germination and growth of millet seedlings under the concentration conditions of the tested agents. The other three agents have certain inhibitory effect on the germination of millet at medium and high concentrations. The most obvious inhibition of the growth of millet seedlings is 6% tebuconazole suspension agent, with an inhibition rate of 38.4%-52.8%. The second is 35% dimethomorph suspension agent, with an inhibition rate of 39.0% on the growth of seedling length when the dosage of the agent is 0.40 g per 100 g of seed.

[0038] Example 3: Effectiveness determination of 10% azoxystrobin seed treatment suspension

[0039] Single diseased plants of millet white hair disease were collected in millet main producing areas, and the brown but not scattered "gun rod" was suitable. After the diseased tissue was dried in a cool place, it was crushed and sieved to obtain spore powder, and in 2018, it was expanded and stored in Shanxi Green Biological Pesticide Engineering Technology Research Center.

[0040] Jin Gu 21 was used as the test variety, and seed coating treatment was carried out before sowing. The agent was added to a suitable amount of water to stir into a paste, then the seeds were poured into the stirring to coat the seeds, and then spread out and placed in a well-ventilated cool place to dry for standby. The commercially available 35% metalaxyl dry powder was used as the control agent.

[0041] In order to determine the better control effect of 10% azoxystrobin seed treatment suspension, the test was carried out on the test material, that is, the spore powder was mixed with moistened fine soil at a ratio of 1:5, then the coated seeds were mixed with the fungus soil at a ratio of 10:1, and the seeds were sown at a ground temperature of 18-20℃. The disease investigation was carried out at 5-7 leaf stage and white tip and hedgehog head formation stage of millet plants. Five treatments, four times of repetition, a total of 20 plots. The experimental treatment is shown in Table 3.

[0042] Table 3

[0043]

[0044] Investigation method: five points were taken from each plot along the diagonal line, and 100-200 plants were investigated at each point to calculate the disease rate.

[0045] Disease rate (%) = number of diseased plants / total number of plants investigated x 100 (1)

[0046] Pharmacodynamic calculation method: control effect (%) = [(CK-PT) / CK] x 100 (2)

[0047] In the formula: CK - the disease incidence of the control area; PT - the disease incidence of the treatment area.

[0048] The results are shown in Tables 4 and 5.

[0049] Table 4 Field test results of 10% azoxystrobin seed treatment suspension on millet white hair disease (5-7 leaf stage)

[0050]

[0051]

[0052] Note: The statistical method adopts Duncan's new multiple range method to judge the significance of difference, and the same lowercase letters in the same column in the table indicate that the difference is significant at the 0.05 level. The same capital letters indicate that the difference is significant at the 0.01 level.

[0053] Table 5 Field test results of 10% azoxystrobin seed treatment suspension on millet white hair disease (adult stage)

[0054]

[0055] Note: The statistical method adopts Duncan's new multiple range method to judge the significance of difference, and the same lowercase letters in the same column in the table indicate that the difference is significant at the 0.05 level. The same capital letters indicate that the difference is significant at the 0.01 level.

[0056] As shown in Tables 4 and 5, at the 5-7 leaf stage of millet, the test agent 10% azoxystrobin seed treatment suspension was used for seed coating treatment at a dosage of 150 g / 100 kg of seeds, 250 g / 100 kg of seeds, and 350 g / 100 kg of seeds, and the control effect on the "gray back" of millet white hair disease was 98.49%, 98.17%, and 98.26%, respectively. The control agent 35% metalaxyl dry powder was used at a dosage of 250 g / 100 kg of seeds, and the control effect was 97.59%. The test results were analyzed by DMRT method, which showed that at the 0.05 and 0.01 levels, there was no significant difference between the three concentrations of the test agent, but compared with the control agent, the difference was significant at the 0.05 level.

[0057] The incidence of millet white hair disease "white tip" and "hedgehog head" was investigated during the heading and plant stage. The results showed that the 10% azoxystrobin seed treatment suspension had good and long-lasting effect. Under the test concentration of the test agent, the control effect on millet white hair disease was between 96.76% and 97.74%. At the 0.05 level, the difference in control effect between the 10% azoxystrobin seed treatment suspension at three concentrations was significant, and the difference between the test agent and the control agent was also significant. At the 0.01 level, the difference in control effect between the 10% azoxystrobin seed treatment suspension at three concentrations was not significant, but the difference between the test agent and the control agent was significant.

[0058] Example 4: Quality determination of 10% azoxystrobin seed treatment suspension

[0059] The average particle size of the sample was determined by a laser particle size distribution instrument (WJL-602); the viscosity of the suspension was determined by a rotary viscometer; the pH of the suspension was determined by a MIK-PH5022 type pH meter; the thermal storage stability and low temperature stability of the suspension were determined according to the method introduced in "Pesticide Experiment Guide" (Han Xiaojie, 2016); and the suspension rate of the preparation was determined according to GB / T 14825-2006: 1 g of sample (accurate to 0.0002 g) was accurately weighed and placed in a 200 mL beaker at 30°C to 2°C, and was shaken at a circular motion of 120 times / min for 2 min. Then the suspension was placed in a water bath at the same temperature for 13 min, and then all of it was washed into a 250 mL graduated cylinder with standard hard water at the same temperature and diluted to the mark. After covering the plug, the graduated cylinder was inverted 30 times in 1 min with the bottom as the axis. After opening the plug, it was left for 30 min, and then 9 / 10 of the suspension was removed from the graduated cylinder in 10-15 s with a pipette. The (25±1) mL of diluted liquid left in the graduated cylinder was separated from the solid by filtration, dried, and weighed. The average value of three parallel determinations was taken. The suspension rate calculation formula is as follows:

[0060] Suspension rate = (w-w1) / 0.9w*100%

[0061] In the formula: w - the mass of the sample taken for the preparation of the suspension (g); w1 - the mass of the solid in the 25 mL suspension left at the bottom of the graduated cylinder (g);

[0062] The results are shown in Table 6.

[0063] Table 6

[0064]

[0065]

[0066] The results show that, compared with 25% azoxystrobin suspension agent, the prepared 10% azoxystrobin seed treatment suspension agent has a uniform flowable yellowish viscous liquid appearance, no precipitation or stratification occurs after a certain period of heat storage and low-temperature storage, the particle size of the prepared sample is relatively uniform, the average particle size is 1.972 μm, the viscosity is 370.1 mPa·s, the suspension is 98.7% (still above 98% after 2-3 days at room temperature), and the pH also meets the national standard requirements. It is shown that the prepared 10% azoxystrobin seed treatment suspension agent has high quality.

[0067] Example 5: Safety determination of 10% azoxystrobin seed treatment suspension agent

[0068] Healthy and full grains of Jingu 21, Dabaigu, and Fenxuan No. 3 are selected, and seed coating is performed according to 10% azoxystrobin seed treatment suspension agent, 100 grains are treated each time, and sowing is performed in a flowerpot. Cultivation is performed in an artificial climate chamber under the condition of 20℃ darkness for 10h and 25℃ light for 14h, and regular watering is performed. After 10 days, the influence of different concentrations of treatment on the germination rate of the three varieties is determined, and after 20d and 30d, the plant height, stem diameter, main root length, and fresh weight of each treatment group are determined, and it is observed whether there are phytotoxicity phenomena such as leaf discoloration, deformation, shrinkage, curling, yellowing, and drying. The results are shown in Tables 7 and 8-10.

[0069] Table 7 Influence of 10% azoxystrobin seed treatment suspension agent on millet emergence

[0070]

[0071]

[0072] Note: X = 350g / 100kg of seeds. The Duncan's new multiple range method is used for judging the difference significance, and the same lowercase letters in the table indicate that the difference significance is at the 0.05 level. The same uppercase letters indicate that the difference significance is at the 0.01 level.

[0073] Table 8 Influence of 10% azoxystrobin seed treatment suspension agent on the plant height and stem diameter of Jingu 21

[0074]

[0075] Table 9 Influence of 10% azoxystrobin seed treatment suspension agent on the plant height and stem diameter of Dabaigu

[0076]

[0077]

[0078] Table 10 Influence of 10% azoxystrobin seed treatment suspension agent on the plant height and stem diameter of Fenxuan No. 3

[0079]

[0080]

[0081] Table 8-10 Note: X = 350 g / 100 kg seeds. Duncan's new multiple range test was used to determine the significance of differences. The same lower case letter in the same column indicates no significant difference at 0.05 level. The same upper case letter in the same column indicates no significant difference at 0.01 level.

[0082] The results of Table 7 and Table 8-10 show that the prepared 10% azoxystrobin seed treatment suspension concentrate has no adverse effect on millet growth at the dosage of 350 g / 100 kg seeds, 525 g / 100 kg seeds, 700 g / 100 kg seeds and 875 g / 100 kg seeds. The three varieties of millet have no wilting, abnormal leaf color, leaf necrosis, plant deformity and other phenomena, and there is no inhibition of seedling emergence and seedling growth. Moreover, at a certain concentration, the application can improve the agronomic characters of millet and promote the vegetative growth.

[0083] The above only describes the preferred embodiments of the present application, and it should be noted that for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A seed treatment suspension for preventing millet whitening disease, characterized in that, Each 100g contains 10.41g 96% azoxystrobin technical grade, 2g TRST, 5g glycerin, 1g 500LQ, 1g Atlox 4913, 0.3g 10% bromonitrophenol, 0.5g HS-18, 0.2g Dow fungicide, 0.2g benzoic acid, 4.5g film-forming agent 7205, 2g No. 2 red, 0.5g magnesium aluminum silicate, 2g silica, 0.15g xanthan gum, and the balance being water.

2. The application of the seed treatment suspension of claim 1 in the prevention and control of millet whitening disease or in the preparation of pesticide products.

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