A 80% mancozeb wettable powder and its application

Abstract

The invention belongs to the field of pesticide preparations, and particularly relates to an 80% mancozeb wettable powder and an application thereof. The 80% mancozeb wettable powder comprises the following components in percentage by weight: 75-85% mancozeb, 1-5% dispersant, 1-3% wetting agent, 2-4% synergist, 0.3-1% deflocculant, and 100% filler; the dispersant is TERSPERSE 2700, the wetting agent is Terwet-1004, the synergist consists of tea saponin, PVP-K30 and pulverized powder BX, the deflocculant is sodium hexametaphosphate, and the filler is kaolin; wherein the mass ratio of the tea saponin, PVP-K30 and pulverized powder BX is 1-4:1-4:1-4. The wettable powder prepared by the invention is finer, has a higher suspension rate, better spreadability, stronger adsorption capacity, and is resistant to rain erosion. After application, a dense protective drug film can be formed on the surface of crops to prevent pathogenic bacteria from infecting, thereby achieving excellent disease prevention and treatment effects.

Description

Technical Field

[0001] The invention belongs to the field of pesticide preparations, and particularly relates to an 80% mancozeb wettable powder and application thereof. Background Art

[0002] Mancozeb is a thiocarbamate protective fungicide for fungal diseases. It inhibits and kills fungi mainly by inhibiting the oxidation of pyruvic acid in bacteria. It has multiple action sites on pathogens and can inhibit the activity of six enzymes in fungal metabolism. Mancozeb preparations are mainly registered as water-dispersible granules and wettable powder solid preparations. With the long-term use of the above two types of preparations, the resistance of pathogens has gradually increased, and the field control effect has gradually decreased. It is urgent to develop alternative and updated wettable powder or water-dispersible granule products.

[0003] Wettable powder (WP) is a flowable powder preparation that is ground into a certain fineness by a grinding device, which is composed of a solid raw material that is insoluble or difficult to dissolve in water, a surfactant (dispersant, wetting agent, etc.), an adjuvant (stabilizer, color alarm, etc.), and a carrier (kaolin, diatomaceous earth, white carbon black, etc.). The preparation is easily wetted by water and can form a stable form that can be sprayed in water. With the improvement of people's requirements for environmental protection, the development and emergence of new preparations such as granules, liquid preparations, and dry suspensions have forced the production of powders to decline year by year. Although wettable powders can still be maintained at the original level, further improvement and innovation are needed. Since the content of the raw material of mancozeb wettable powder preparations is high and the amount of adjuvants and fillers is low, the formulation development is more difficult. Summary of the invention

[0004] The object of the present invention is to provide an 80% mancozeb wettable powder having excellent suspension rate, low wetting time and excellent prevention effect and its application. The specific technical scheme is:

[0005] A mancozeb wettable powder, comprising the following ingredients in percentage by weight: 75-85% mancozeb, 1-5% dispersant, 1-3% wetting agent, 2-4% synergist, 0.3-1% deflocculant, and filler to make up 100%;

[0006] The dispersant is TERSPERSE 2700, the wetting agent is Terwet-1004, the synergist is composed of tea saponin, PVP-K30 and pull-open powder BX, the deflocculant is sodium hexametaphosphate, and the filler is kaolin; wherein the mass ratio of the tea saponin, PVP-K30 and pull-open powder BX is 1-4:1-4:1-4. In particular, the preferred mass ratio of the tea saponin, PVP-K30 and pull-open powder BX is 3:1:2.

[0007] Preferably, the mancozeb wettable powder comprises the following ingredients in percentage by weight: 80% mancozeb, 3% dispersant, 2% wetting agent, 3% synergist, 0.5% deflocculant, and 100% filler.

[0008] The mancozeb wettable powder is used for preventing and controlling crop diseases, especially for preventing and controlling tomato early blight.

[0009] By adopting the above technical solution, the present invention has the following beneficial effects:

[0010] The wettable powder prepared by the invention has finer particles, higher suspension rate, better spreadability, stronger adsorption capacity, and is resistant to rain erosion. After application, a dense protective drug film can be formed on the surface of crops to prevent pathogenic bacteria from infecting and achieve disease prevention and treatment.

[0011] By adding a synergistic adjuvant into the wettable powder formulation system of the present invention, the suspension rate of the formulation can be increased, thereby improving the field prevention effect of the formulation on tomato early blight. DETAILED DESCRIPTION

[0012] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present invention.

[0013] The present invention is further explained below in conjunction with specific implementation modes.

[0014] Example 1 Mancozeb wettable powder formulation

[0015] Contains the following ingredients: mancozeb, dispersant, wetting agent, synergist, deflocculant, filler;

[0016] Preparation method: accurately weigh and mix the pesticide technical, dispersant, wetting agent, synergist, deflocculant and filler materials, and then conduct preliminary mixing and crushing. After crushing, the coarse powder mixture is further crushed and mixed by a jet mill to make its particle size meet the requirements of wettable powder, and then collected.

[0017] The specific wettable powder formulations are shown in Tables 1 and 2.

[0018] Table 1 Selection of synergistic adjuvant ingredients for 80% mancozeb wettable powder

[0019]

[0020] Table 2 80% Mancozeb WP - Selection of synergist content

[0021]

[0022] Performance index test of 80% mancozeb wettable powder

[0023] Table 3 Performance index test of preparations 1-5

[0024]

[0025] Remarks: Moisture content: GB / T 1600-2001; pH value: GB / T 1601; Suspension rate: GB / T 14825; Wetting time: GB / T 5451; Fineness: GB / T 16150-2003; Hot storage stability: GB / T 19136-2003.

[0026] Table 4 Performance index test of preparations 6-10

[0027]

[0028] Suspensibility refers to the ability of dispersed drug particles to remain suspended in the suspension for a certain period of time: when the preparation with good suspension is diluted with water, all the drug particles can be evenly suspended in the water and sprayed from the liquid storage tank through the nozzle. In the 80% mancozeb wettable powder preparation, due to the high content of the original drug and the small filling space of the auxiliary agent and filler, the formulation development is difficult, so the selection of a suitable excipient system is crucial to improve the suspension rate of the preparation.

[0029] As shown in Table 3, when only dispersant TERSPERSE 2700 and wetting agent Terwet-1004 are included in formula 5, the suspension rate of the preparation is only 73.5%. Although the performance index of mancozeb wettable powder in formula 5 meets the industry standard, the low suspension rate is not conducive to the efficacy of the drug. Further adding synergistic additives to formulas 1-4 can significantly improve the suspension rate of the preparation and reduce the wetting time.

[0030] As shown in Table 4, the content of the combination of the synergistic adjuvants tea saponin, PVP-K30 and pull-opening powder BX in the wettable powders in formulas 6 to 10 will have a certain impact on the suspension rate and wetting properties of the preparations. In preparation 9, when the ratio of the synergistic adjuvant tea saponin, PVP-K30 and pull-opening powder BX is 1.5:0.5:1, the suspension rate of the preparation is increased to 98.7%; the wetting time is 14s.

[0031] Example 2 Field control effect of 80% mancozeb wettable powder on tomato early blight

[0032] Test agent: Formula 1-10; commercially available 80% mancozeb wettable powder (Hunan Nonghai Special Agrochemical Co., Ltd.);

[0033] Test method:

[0034] The experiment set up 11 treatments and a water blank control. Each pesticide was designed with a plot area of ​​30 m2, 4 replicates, and the plots were randomly arranged. At the early stage of tomato early blight, the pesticide was sprayed twice in a row with an interval of 7 days. The liquid volume was 450 kg / hm 2 .

[0035] Efficacy investigation:

[0036] The incidence base was investigated before the application of pesticides and the incidence was investigated 28 days after the last application of pesticides. The incidence was recorded according to the grading standard, and the disease index and control effect were calculated.

[0037] Grading Standard:

[0038] Level 0: no lesions;

[0039] Level 1: The lesion area accounts for less than 5% of the entire leaf area;

[0040] Level 3: The lesion area accounts for 6%-10% of the entire leaf area;

[0041] Level 5: The lesion area accounts for 11%-20% of the entire leaf area;

[0042] Level 7: The lesion area accounts for 21%-50% of the entire leaf area;

[0043] Level 9: The lesion area accounts for more than 51% of the total leaf area.

[0044] Calculation formula:

[0045]

[0046]

[0047] Test results:

[0048] Good suspension can achieve uniform spraying, otherwise the drug particles will clump or settle, and the concentration of the drug solution before and after spraying cannot be kept consistent, affecting the uniformity of the application and even clogging the sprayer, which can seriously reduce the efficacy. As shown in Table 5, the control effect of Formula 5 is close to that of the commercially available 80% mancozeb wettable powder. Compared with other formulas, the suspension rate of the wettable powder in Formula 5 is lower, which will have a certain impact on the uniformity of the spraying of the drug, thereby affecting the control effect.

[0049] When synergistic adjuvants are added to the wettable powder formulation system, the suspension rate of the formulation can be increased, thereby improving the field control effect of the formulation on tomato early blight. The control effect of formulation 1, formulation 6-10 on tomato early blight is more than 88%, especially formulation 9, which has a control effect of up to 94.4%.

[0050] Table 5: Field efficacy of 80% mancozeb wettable powder against tomato early blight

[0051]

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit it.

Claims

1. A mancozeb wettable powder, characterized in that: The composition comprises the following weight percentages: 75-85% mancozeb, 1-5% dispersant, 1-3% wetting agent, 2-4% synergist, 0.3-1% deflocculant, and filler making up 100%; The dispersant is TERSPERSE 2700, the wetting agent is Terwet-1004, the synergist consists of tea saponin, PVP-K30 and pulverized powder BX, the deflocculant is sodium hexametaphosphate, and the filler is kaolin; wherein the mass ratio of tea saponin, PVP-K30 and pulverized powder BX is 1-4:1-4:1-4.

2. The mancozeb wettable powder according to claim 1, characterized in that The composition comprises the following weight percentages: 80% mancozeb, 3% dispersant, 2% wetting agent, 3% synergist, 0.5% deflocculant, and 100% filler.

3. The mancozeb wettable powder according to claim 2, characterized in that The mass ratio of tea saponin, PVP-K30 and lakai powder BX is 3:1:

2.

4. Use of the mancozeb wettable powder according to any one of claims 1 to 3 for preventing and controlling crop diseases.

5. The use according to claim 4, characterized in that The crop disease is tomato early blight.

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