Composite seed dressing agent for preventing and controlling corn stalk rot and preparation method thereof

Abstract

The invention discloses a composite seed dressing agent for preventing and treating corn stem base rot and a preparation method thereof, and belongs to the field of planting technology. The composite seed dressing agent for preventing and treating corn stem base rot of the invention comprises the following raw materials by mass percentage: 2-2.5% of captan, 2-3% of sunflower extract, 3-4% of cyperus rot extract, 5-6% of triethyl aluminum phosphate, 4-8% of glutamic acid, 5-7% of alanine, 10-15% of humic acid, 10-15% of plant ash, 10-12% of compound fertilizer, 4-5% of polyvinyl alcohol, 5-8% of silicon dioxide, and the balance is kaolin. The composite seed dressing agent of the invention can effectively prevent and treat corn stem base rot, has a stable prevention and treatment effect, and can reduce the dosage of chemical agents, avoiding the problems of pesticide residues and drug resistance.

Description

Technical Field

[0001] The invention relates to the field of planting technology, in particular to a composite seed dressing agent for preventing and treating corn stem base rot and a preparation method thereof. Background Art

[0002] Corn stalk rot is a common disease that is primarily caused by plant pathogens such as fungi or bacteria, but can also be caused by abiotic stresses such as drought and flooding. Stalk rot weakens the stalk and makes it unable to support the weight of the ear. Yield loss occurs when the stem and ear tissue below the main ear degenerate, making the stem brittle and prone to lodging near harvest. When the disease weakens or destroys the vascular tissue of the stem, the plant cannot effectively transport water or carbohydrates, ultimately leading to premature plant death and reduced grain filling.

[0003] At present, the prevention and control measures for corn stem base rot include agricultural measures, chemical control, and biological control. Among them, agricultural measures include timely sowing, planting resistant varieties, centralized burning or deep burial combined with deep plowing of the land, etc. Although they can prevent and control corn stem base rot to a certain extent, the operation is cumbersome, time-consuming and labor-intensive, and not suitable for large-scale promotion and application; chemical control, that is, the use of chemical fungicides to prevent and control corn stem base rot, is the most commonly used prevention and control method at present. Although it has achieved good prevention and control effects, long-term use of chemical agents will lead to problems such as drug resistance and pesticide residues; biological control makes up for the shortcomings of chemical pesticides because of its friendliness to humans and the environment, and has become a very promising research direction at present, but existing bacterial agents are difficult to colonize on crops, and even after colonization, the survival time is very short and the abundance is low. It can only have a good disease prevention effect in a short period of time after the use of bacterial agents. Therefore, it is urgent to find a prevention and control measure for corn stem base rot that is stable and safe in prevention and control effect and simple in use. Summary of the invention

[0004] The purpose of the present invention is to provide a composite seed dressing agent for preventing and treating corn stalk rot and a preparation method thereof, so as to solve the problems existing in the above-mentioned prior art.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] One of the technical solutions of the present invention is a composite seed dressing agent for preventing and treating corn stem base rot, which comprises the following raw materials, measured by mass percentage: 2-2.5% of captan, 2-3% of sunflower extract, 3-4% of cyperus rotundus extract, 5-6% of triethyl aluminum phosphate, 4-8% of glutamic acid, 5-7% of alanine, 10-15% of humic acid, 10-15% of wood ash, 10-12% of compound fertilizer, 4-5% of polyvinyl alcohol, 5-8% of silicon dioxide, and the balance is kaolin.

[0007] The extract of Xihuangcao is rich in diterpenoids, which have good antibacterial activity. They can inhibit the growth of pathogens by destroying the integrity of cell membranes and other mechanisms, and significantly control the area of ​​rot.

[0008] Sunflower extract can enhance the antibacterial activity of captan and avoid the development of drug resistance.

[0009] The synergistic effect of captan, cyperus rotundus extract and sunflower extract can achieve excellent disease prevention and control effects while reducing the amount of chemical agents used.

[0010] The synergistic effect of triethyl aluminum phosphate, glutamic acid and humic acid can promote the photosynthesis of corn after emergence, promote corn to produce more flavonoids that resist pathogens, and improve the ability of corn to resist diseases.

[0011] Furthermore, the preparation method of the sunflower extract comprises the following steps:

[0012] The sunflower disk is crushed, a mixed solvent of petroleum ether and ethanol is added, the mixture is evenly mixed, the mixture is heated and extracted, and the mixture is centrifuged. The supernatant is taken and the solvent is removed by rotary evaporation to obtain the sunflower extract.

[0013] Furthermore, the volume ratio of petroleum ether to ethanol is (2-3): (8-10);

[0014] The heating and leaching temperature is 40-50°C and the time is 12-15h;

[0015] The usage ratio of the sunflower disc and the mixed solvent is 1g:8-10mL;

[0016] The centrifugal speed is 5000-6000 r / min, and the time is 5 min.

[0017] Furthermore, the preparation method of the Herba Lycopodii extract comprises the following steps:

[0018] The herb is crushed and then added with ethyl acetate solution and mixed evenly, and then heated for extraction. The extract is concentrated and dried to obtain the herb extract.

[0019] Furthermore, the concentration of the ethyl acetate solution is 50 to 70 vol.%;

[0020] The dosage ratio of the herba scutellariae and the ethyl acetate solution is 1 g: 10-15 mL;

[0021] The temperature of the heating extraction is 70-80° C. and the time is 2-3 hours.

[0022] Furthermore, the compound fertilizer is a ternary compound fertilizer of diammonium phosphate, urea and potassium sulfate, and the molar ratio of nitrogen, phosphorus and potassium in the compound fertilizer is 1:1:1.

[0023] Furthermore, the silicon dioxide has a particle size of 10 to 20 μm and a specific surface area of ​​100 to 200 m 2 / g, pore volume is 3~10cm 3 / g, and the average pore size is 20-40nm.

[0024] The second technical solution of the present invention is: a method for preparing the above-mentioned composite seed dressing agent, comprising the following steps;

[0025] The sunflower extract and the cycad extract are dissolved in ethyl acetate, and then silicon dioxide is added, and the mixture is stirred and mixed evenly, and then the solvent is removed by drying to obtain a composite;

[0026] spraying a gum arabic solution on the surface of the composite, and obtaining a sustained-release composite after drying;

[0027] The slow-release compound and other raw materials are mixed evenly to obtain the composite seed dressing agent.

[0028] Furthermore, the stirring speed is 50-100 r / min, and the time is 10-15 min;

[0029] The dosage ratio of the complex to the gum arabic solution is 5 g: 0.5-0.8 mL;

[0030] The concentration of the gum arabic solution is 3-5 wt.%.

[0031] By loading the sunflower extract and the iris extract on silica and then coating them with gum arabic, the sunflower extract and the iris extract can be slowly and continuously released, thereby playing a long-term and stable role in resisting pathogens.

[0032] The third technical solution of the present invention: an application of the above-mentioned composite seed dressing agent in the preparation of a medicine for preventing and treating corn stalk rot.

[0033] The present invention discloses the following technical effects:

[0034] (1) The composite seed dressing agent of the present invention can effectively prevent and treat corn stalk rot with stable control effect, and can reduce the dosage of chemical agents, thereby avoiding the problems of pesticide residue and drug resistance.

[0035] (2) The composite seed dressing agent of the present invention can improve the disease resistance and stress resistance of corn itself, simplify the prevention and control method of corn stem rot, and is easy to promote and apply. DETAILED DESCRIPTION

[0036] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0037] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0038] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0039] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0040] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0041] (I) Symptoms of corn stalk rot:

[0042] Corn stem rot can occur throughout the entire growth period of corn, mainly harming the stem base and roots of corn. The disease mainly shows obvious symptoms during the filling period (i.e. milk maturity). In the seedling stage of corn, the pathogen infects from the roots or the seeds are infected, causing the root system to develop poorly, the roots to turn brown, and rot. In severe cases, it leads to seed death and reduced germination rate. In the filling period of corn, the initial symptoms are not obvious. When the base of the plant stem is cut open, a small amount of vascular tissue can be seen to turn brown. In the later period, the infection continues to worsen, the tissue at the base of the stem gradually turns brown, constricts, softens, and becomes hollow inside, expanding from bottom to top, causing the base of the stem to easily fall over. White or reddish-pink hyphae can be seen in the autopsy of the base of the stem. Due to damage to the roots and stem base, the absorption of water and nutrients by the upper part of the plant is affected, resulting in green or yellow withering symptoms on the leaves of the plant, and in severe cases, large areas of withering. When the ears are formed, the ears droop and are not easy to break off. Due to nutrient deficiency, the grains are shriveled, seriously affecting the yield. According to the speed of onset and field symptoms, corn stem rot can be divided into two types: bacterial wilt and yellow wilt. 80% of the field is of the bacterial wilt type, also known as the acute type, which develops rapidly, with the whole plant withering within 1 to 2 days, the base of the stem rots in 7 days, and the ears drooping.

[0043] (II) Host range and spread of corn stalk rot:

[0044] Corn stalk rot is a typical soil-borne root disease. Its dominant pathogens, Fusarium graminearum, overwinter in the soil and diseased residues in the form of mycelium and Pythium in the form of oospores. Therefore, the diseased residues in the field, the seeds, and the fungi in the soil are the main initial infection sources of stalk rot. The pathogen has a good adaptability to the soil environment and can survive in the soil against adverse environmental conditions. At the same time, there is a process of re-infection in the field, which aggravates the occurrence of the disease to a certain extent. The pathogens of corn stalk rot can invade through natural incisions, such as stomata, wounds caused by insects and human operations, or directly from the root and stem tissues of the plant. When corn grows to 60cm, the tissue is tender and easy to get sick. The wounds caused by pests increase the possibility of pathogen invasion. Pests such as corn borers and cotton bollworms spread pathogens, making the disease serious. From the perspective of the infection process, the time required for different pathogens of the same variety to invade is different, which is restricted by conditions such as temperature and humidity. Generally, high humidity is conducive to the infection of Pythium, while low temperature and low humidity conditions are conducive to the infection of Fusarium.

[0045] (III) Prevention and control measures for corn stem rot

[0046] At present, the prevention and control measures for corn stalk rot include agricultural measures, chemical control, and biological control.

[0047] (1) Agricultural measures

[0048] Agricultural measures to prevent and control corn stem rot include timely sowing and planting resistant varieties. Choosing disease-resistant varieties suitable for the local area can improve the plant's resistance and high yield; reasonably control the planting density, determine the planting density according to the recommended density of the variety, improve the field ventilation and light conditions, and create a good external environment for plant growth; strengthen field management and pest control, timely drain low-lying plots after rain, and strengthen the control of insect pests such as wireworms and corn borers. Timely remove the remains of diseased plants in the field, and timely remove the diseased male and female plants when the seed corn is tasseled, and completely remove the diseased plants after the corn is harvested; concentrate on burning or burying them in combination with deep plowing to reduce the number of fungal sources; and reasonably rotate crops, implement corn and other non-host crops to prevent the accumulation of soil pathogens; plots with severe disease can be rotated with rice, potatoes, and vegetable crops for 2 to 3 years, which can further effectively control the occurrence of diseases. However, agricultural measures are cumbersome to implement, time-consuming and labor-intensive, and are not suitable for large-scale promotion and application.

[0049] (2) Chemical control

[0050] Chemical control is a fast and effective control method, especially for soil-borne diseases and diseases transmitted by seeds. However, long-term use not only reduces the efficacy of the drug, but also causes environmental pollution problems such as pesticide residues. At present, the most effective measure for prevention and control during the corn sowing period is seed coating. The use of seed coating agents with disease prevention effects is very effective in controlling the occurrence of diseases. For example, 25% triadimefon wettable powder is used for seed coating at a dosage of 0.2% of the seed volume; 40% pentachloronitrobenzene and 50% thiram wettable powder are mixed and applied at a mass ratio of 1:1. The synergistic coefficient can reach 2.08, the prevention effect is 77.68-85.36%, and the yield increase rate is 17.05-18.60%. It has a good control effect on the prevention and control of corn stem base rot. BG-2 and Soilgard biological pesticides and domestically produced biological seed coating agents (ZSB) were used to control corn stem base rot and sheath blight in the fungus stage and adult stage. It was found that both BG-2 and Soilgard biological pesticides had good control effects on corn stem base rot, and the control effect was better when the two were used in combination. Lamardor 400FS, Baytan Plus 200FS, Weifu 400FS, Manshijin 35FS, and Lixue 60FS were used to control corn stem base rot and head smut. The results showed that Lamardor 400FS, Baytan Plus 200FS, and Lixue 60FS had good control effects on corn stem base rot and head smut. However, chemical control will cause large-scale pollution of farmland and water sources, and has certain harm to the human nervous system.

[0051] (3) Biological control

[0052] Biological control mainly refers to the combined control of fungi and drugs, combined control of fungi and fertilizers, and control by live microbial preparations. Among them, the most studied live microbial preparations are Trichoderma, Pseudomonas, Bacillus, and Actinomycetes, with Trichoderma and Bacillus occupying the main position. For Trichoderma, researchers have shown that the Trichoderma granules and seed coatings developed by Chen Jie and others can effectively prevent and control corn stem rot and sheath blight through soil hole application and seed coating. Among them, the prevention effect of Trichoderma granules is more than 65%, and the seed coating made of ZJSX5003 Trichoderma strain and the low-toxic chemical pesticide 35% Manshijin can achieve the highest prevention effect of 83% on stem rot; Wu Xiaoru and others showed that the field prevention effect of Trichoderma granules on corn stem rot is more than 50%, up to 80%, and the corn yield increase effect is more than 8%, indicating that Trichoderma granules have good biological control effect and yield increase effect. However, biological control is slow to take effect and the control effect is not very stable (the above-disclosed prior art has the problem that after the use of the microbial agent, the microbial species are difficult to colonize in the application area of ​​the crop or the survival time after colonization is short, the abundance is low, and the microbial species only have a good disease prevention effect within a short period of time after the use of the microbial agent).

[0053] The “parts” described in the following examples are all “parts by mass”.

[0054] Example 1

[0055] A preparation method of a composite seed dressing agent for preventing and controlling corn stalk rot:

[0056] (1) A composite seed dressing agent for preventing and controlling corn stem base rot, which is composed of the following raw materials, measured by mass percentage: 2.5% of captan, 3% of sunflower extract, 3% of cyperus rotundus extract, 6% of triethyl aluminum phosphate, 6% of glutamic acid, 7% of alanine, 12% of humic acid, 15% of plant ash, 12% of compound fertilizer, 4% of polyvinyl alcohol (molecular weight of 50,000 to 60,000), 8% of silicon dioxide, and the balance is kaolin.

[0057] Among them, the compound fertilizer is a ternary compound fertilizer of diammonium phosphate, urea and potassium sulfate, and the molar ratio of nitrogen, phosphorus and potassium in the compound fertilizer is 1:1:1.

[0058] The particle size of silica is 15 μm and the specific surface area is 150 m 2 / g, pore volume 8cm 3 / g, average pore size 30nm.

[0059] (2) Preparation of sunflower extract:

[0060] The sunflower disk (the sunflower disk after mature harvest, excluding sunflower seeds) is dried and crushed to 100 mesh to obtain sunflower disk powder;

[0061] Add a mixed solvent of petroleum ether and ethanol in a volume ratio of 2:10 to the sunflower disc powder (the ratio of the sunflower disc powder to the mixed solvent is 1 g:8 mL), mix well, heat and extract (the heating extraction temperature is 50°C, the time is 12 h), and then centrifuge (the centrifugal speed is 6000 r / min, the time is 5 min), take the supernatant and rotary evaporate to remove the solvent to obtain a sunflower extract.

[0062] (3) Preparation of Herba Lycopodiellae Extract:

[0063] Dry the scutellaria baicalensis and crush it into 100 meshes to obtain scutellaria baicalensis powder;

[0064] Add 60 vol.% ethyl acetate solution to the angelica dahurica powder and mix evenly (the dosage ratio of angelica dahurica powder and ethyl acetate solution is 1 g:12 mL), heat extract (the heating extraction temperature is 80°C and the time is 2 h), and then concentrate and dry the extract (temperature is 80°C) to obtain the angelica dahurica extract.

[0065] (4) Preparation of a composite seed dressing agent: According to the raw material ratio of step (1), sunflower extract and cycad extract were dissolved in ethyl acetate (the volume ratio of the total mass of sunflower extract and cycad extract to ethyl acetate was 1 g: 5 mL), and then silicon dioxide was added. The mixture was stirred and mixed evenly (stirring speed was 80 r / min, and the time was 15 min), and then the solvent was removed by drying (temperature was 80° C.) to obtain a composite;

[0066] A 4 wt.% gum arabic solution was sprayed on the surface of the composite (the ratio of the composite to the gum arabic solution was 5 g:0.6 mL), and then dried (at 40° C.) to obtain a sustained-release composite;

[0067] The slow-release compound and other raw materials (the particle size of the other raw materials is 500 meshes) are mixed evenly to obtain a compound seed dressing agent.

[0068] Example 2

[0069] A preparation method of a composite seed dressing agent for preventing and controlling corn stalk rot:

[0070] (1) A composite seed dressing agent for preventing and controlling corn stem base rot, which is composed of the following raw materials, measured by mass percentage: 2% of captan, 2% of sunflower extract, 4% of cyperus rotundus extract, 5% of triethyl aluminum phosphate, 4% of glutamic acid, 7% of alanine, 15% of humic acid, 10% of plant ash, 12% of compound fertilizer, 5% of polyvinyl alcohol (molecular weight of 50,000 to 60,000), 5% of silicon dioxide, and the balance of kaolin.

[0071] Among them, the compound fertilizer is a ternary compound fertilizer of diammonium phosphate, urea and potassium sulfate, and the molar ratio of nitrogen, phosphorus and potassium in the compound fertilizer is 1:1:1.

[0072] The particle size of silica is 20 μm and the specific surface area is 100 m 2 / g, pore volume 5cm 3 / g, average pore size 20nm.

[0073] (2) Preparation of sunflower extract:

[0074] The sunflower disk (the sunflower disk after mature harvest, excluding sunflower seeds) is dried and crushed to 100 mesh to obtain sunflower disk powder;

[0075] A mixed solvent of petroleum ether and ethanol in a volume ratio of 3:8 is added to the sunflower disc powder (the dosage ratio of the sunflower disc powder and the mixed solvent is 1 g: 10 mL), mixed evenly, heated and extracted (the heating extraction temperature is 40°C, the time is 15 h), and then centrifuged (the centrifugal speed is 5000 r / min, the time is 5 min), and the supernatant is taken and rotary evaporated to remove the solvent to obtain a sunflower extract.

[0076] (3) Preparation of Herba Lycopodiellae Extract:

[0077] Dry the scutellaria baicalensis and crush it into 100 meshes to obtain scutellaria baicalensis powder;

[0078] Add 70 vol.% ethyl acetate solution to the angelica dahurica powder and mix evenly (the dosage ratio of angelica dahurica powder and ethyl acetate solution is 1 g:10 mL), heat extract (the heating extraction temperature is 70°C and the time is 3 h), and then concentrate and dry the extract (temperature is 80°C) to obtain the angelica dahurica extract.

[0079] (4) Preparation of a composite seed dressing agent: According to the raw material ratio of step (1), sunflower extract and cycad extract were dissolved in ethyl acetate (the volume ratio of the total mass of sunflower extract and cycad extract to ethyl acetate was 1 g: 5 mL), and then silicon dioxide was added, stirred and mixed evenly (stirring speed was 50 r / min, time was 15 min), and then the solvent was removed by drying (temperature was 80° C.) to obtain a composite;

[0080] A 3 wt.% gum arabic solution was sprayed on the surface of the composite (the ratio of the composite to the gum arabic solution was 5 g:0.5 mL), and then dried (at 40° C.) to obtain a sustained-release composite;

[0081] The slow-release compound and other raw materials (the particle size of the other raw materials is 500 meshes) are mixed evenly to obtain a compound seed dressing agent.

[0082] Example 3

[0083] A preparation method of a composite seed dressing agent for preventing and controlling corn stalk rot:

[0084] (1) A composite seed dressing agent for preventing and controlling corn stem rot, which is composed of the following raw materials, measured by mass percentage: 2.5% of captan, 3% of sunflower extract, 3% of cyperus rotundus extract, 5% of triethyl aluminum phosphate, 8% of glutamic acid, 5% of alanine, 10% of humic acid, 12% of wood ash, 10% of compound fertilizer, 4% of polyvinyl alcohol (molecular weight of 50,000 to 60,000), 6% of silicon dioxide, and the balance of kaolin.

[0085] Among them, the compound fertilizer is a ternary compound fertilizer of diammonium phosphate, urea and potassium sulfate, and the molar ratio of nitrogen, phosphorus and potassium in the compound fertilizer is 1:1:1.

[0086] The particle size of silica is 10 μm and the specific surface area is 150 m 2 / g, pore volume 8cm 3 / g, average pore size 40nm.

[0087] (2) Preparation of sunflower extract:

[0088] The sunflower disk (the sunflower disk after mature harvest, excluding sunflower seeds) is dried and crushed to 100 mesh to obtain sunflower disk powder;

[0089] Add a mixed solvent of petroleum ether and ethanol in a volume ratio of 2:8 to the sunflower disc powder (the ratio of the sunflower disc powder to the mixed solvent is 1 g: 8 mL), mix well, heat and extract (the heating extraction temperature is 45°C, the time is 12 h), and then centrifuge (the centrifugal speed is 5000 r / min, the time is 5 min), take the supernatant and rotary evaporate to remove the solvent to obtain a sunflower extract.

[0090] (3) Preparation of Herba Lycopodiellae Extract:

[0091] Dry the scutellaria baicalensis and crush it into 100 meshes to obtain scutellaria baicalensis powder;

[0092] Add 50 vol.% ethyl acetate solution to the angelica dahurica powder and mix evenly (the dosage ratio of angelica dahurica powder and ethyl acetate solution is 1 g:15 mL), heat extract (the heating extraction temperature is 80°C and the time is 3 h), and then concentrate and dry the extract (temperature is 80°C) to obtain the angelica dahurica extract.

[0093] (4) Preparation of a composite seed dressing agent: According to the raw material ratio of step (1), sunflower extract and cycad extract were dissolved in ethyl acetate (the volume ratio of the total mass of sunflower extract and cycad extract to ethyl acetate was 1 g: 5 mL), and then silicon dioxide was added. The mixture was stirred and mixed evenly (stirring speed was 100 r / min, and the time was 10 min). After that, the solvent was removed by drying (temperature was 80° C.) to obtain a composite.

[0094] A 5 wt.% gum arabic solution was sprayed on the surface of the composite (the ratio of the composite to the gum arabic solution was 5 g:0.8 mL), and then dried (at 40° C.) to obtain a sustained-release composite;

[0095] The slow-release compound and other raw materials (the particle size of the other raw materials is 500 meshes) are mixed evenly to obtain a compound seed dressing agent.

[0096] Comparative Example 1

[0097] Same as Example 1, except that the Herba Lycopodiellae extract is replaced with an equal mass of tea extract, and the preparation method of the tea extract is the same as the preparation method of the Herba Lycopodiellae extract.

[0098] Comparative Example 2

[0099] Same as Example 1, except that the sunflower extract is replaced with an equal mass of captan.

[0100] Comparative Example 3

[0101] The same as Example 1, except that the composite seed dressing agent does not contain sunflower extract and iris extract.

[0102] Comparative Example 4

[0103] The same as Example 1, except that the composite seed dressing agent does not contain triethyl aluminum phosphate, glutamic acid and alanine.

[0104] Comparative Example 5

[0105] The same as Example 1, except that the glutamic acid in the composite seed dressing agent is replaced by an equal mass of threonine, and the alanine is replaced by an equal mass of leucine.

[0106] Comparative Example 6

[0107] The same as Example 1, except that the solvent used to prepare the sunflower extract is petroleum ether and ethyl acetate in a volume ratio of 2:10.

[0108] Comparative Example 7

[0109] The same as Example 1, except that the preparation of the composite seed dressing agent is as follows: the raw materials are mixed uniformly according to the raw material ratio in step (1) to obtain the composite seed dressing agent.

[0110] Effect Example 1

[0111] (1) The compound seed dressing agent (prepared in the embodiment and the comparative example) is used at a ratio of 100 g of the compound seed dressing agent per 2 kg of corn seeds (the variety is Tiannong No. 9). Specifically, the compound seed dressing agent and water are first stirred and mixed in a ratio of 1:1, and then the corn seeds are added. After mixing, the mixture is placed at room temperature for 24 hours in a dark place to obtain corn seeds containing the compound seed dressing agent.

[0112] (2) Divide the test site into several 100m 2 The plots were sown with corn seeds containing the composite seed dressing prepared in the embodiment or the comparative example, 2 seeds were sown in each hole, the plant spacing was 50 cm, the row spacing was 40 cm, and the sowing depth was about 6 cm. Each composite seed dressing was repeated in 3 plots, and conventional field management was carried out. During the period, no other agents for preventing and controlling corn stem base rot were applied, and corn without seed dressing was used as a blank control group.

[0113] (3) At 30 days after sowing, the five-point sampling method was used to investigate the emergence rate of corn under different compound seed dressing agents;

[0114] The prevalence of corn stalk rot in the test field was investigated three times from the flowering stage to the maturity stage using the 5-point sampling method: fixed-point and fixed-plant surveys were conducted at the flowering stage, filling stage, and maturity stage, with 50 plants surveyed at each sampling point. The disease was graded, and the disease index and control effect were calculated; the yield of corn was measured after it matured (the moisture content of corn was between 12% and 15% when the yield was measured).

[0115] The disease classification standards are:

[0116] Level 0, disease-free, green leaves;

[0117] Level 1: The lower leaves of the plant show symptoms of greening, yellowing and withering, while the base of the stem grows normally;

[0118] Level 3: The leaves of the whole plant show symptoms of green and yellowing, and the base of the stem changes color and becomes slightly soft;

[0119] Level 5: The whole plant shows typical wilt symptoms, and the base of the stem becomes noticeably soft;

[0120] Level 7: The whole plant is dead and the grains are not plump.

[0121] Disease index = [∑(number of diseased plants × relative grade) / (total number of plants investigated × highest grade)] × 100;

[0122] The control effect (%) = [(disease index of the blank control group - disease index of the treated group) / disease index of the blank control group] × 100%.

[0123] Table 1 Corn planting situation

[0124]

[0125]

[0126] Table 2 Prevalence of corn stalk rot

[0127]

[0128] It can be seen from Table 1 and Table 2 that the composite seed dressing agent prepared by the present invention can improve the emergence rate and yield of corn and reduce the incidence of corn stem base rot.

[0129] The embodiments described above are only descriptions of the preferred 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 modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A composite seed dressing agent for preventing and treating corn stalk rot, characterized in that: Calculated by mass percentage, the raw materials include: 2-2.5% of captan, 2-3% of sunflower extract, 3-4% of iris extract, 5-6% of triethyl aluminum phosphate, 4-8% of glutamic acid, 5-7% of alanine, 10-15% of humic acid, 10-15% of wood ash, 10-12% of compound fertilizer, 4-5% of polyvinyl alcohol, 5-8% of silicon dioxide, and the balance is kaolin.

2. The composite seed dressing agent for preventing and treating corn stalk rot according to claim 1, characterized in that: The preparation method of the sunflower extract comprises the following steps: The sunflower disk is crushed, a mixed solvent of petroleum ether and ethanol is added, the mixture is evenly mixed, the mixture is heated and extracted, and the mixture is centrifuged. The supernatant is taken and the solvent is removed by rotary evaporation to obtain the sunflower extract.

3. The composite seed dressing agent for preventing and treating corn stalk rot according to claim 2, characterized in that: The volume ratio of petroleum ether to ethanol is (2-3): (8-10); And / or, the heating leaching temperature is 40-50°C and the time is 12-15h; And / or, the usage ratio of the sunflower disc and the mixed solvent is 1 g: 8-10 mL; And / or, the centrifugal speed is 5000-6000 r / min and the time is 5 min.

4. The composite seed dressing agent for preventing and treating corn stalk rot according to claim 1, characterized in that: The preparation method of the Herba Lysimachiae extract comprises the following steps: The herb is crushed and then added with ethyl acetate solution and mixed evenly, and then heated for extraction. The extract is concentrated and dried to obtain the herb extract.

5. The composite seed dressing agent for preventing and treating corn stalk rot according to claim 4, characterized in that: The concentration of the ethyl acetate solution is 50-70 vol.%; And / or, the dosage ratio of the herba scutellariae and the ethyl acetate solution is 1 g: 10-15 mL; And / or, the temperature of the heating extraction is 70-80° C. and the time is 2-3 hours.

6. The composite seed dressing agent for preventing and treating corn stalk rot according to claim 1, characterized in that: The compound fertilizer is a ternary compound fertilizer of diammonium phosphate, urea and potassium sulfate, and the molar ratio of nitrogen, phosphorus and potassium in the compound fertilizer is 1:1:

1.

7. The composite seed dressing agent for preventing and treating corn stalk rot according to claim 1, characterized in that: The silicon dioxide has a particle size of 10 to 20 μm and a specific surface area of ​​100 to 200 m 2 / g, pore volume is 3~10cm 3 / g, and the average pore size is 20-40nm.

8. A method for preparing the composite seed dressing agent according to any one of claims 1 to 7, characterized in that: The steps include: The sunflower extract and the cycad extract are dissolved in ethyl acetate, and then silicon dioxide is added, and the mixture is stirred and mixed evenly, and then the solvent is removed by drying to obtain a composite; spraying a gum arabic solution on the surface of the composite, and obtaining a sustained-release composite after drying; The slow-release compound and other raw materials are mixed evenly to obtain the composite seed dressing agent.

9. The preparation method according to claim 8, characterized in that: The stirring speed is 50-100 r / min and the stirring time is 10-15 min; and / or, the ratio of the complex to the gum arabic solution is 5 g: 0.5-0.8 mL; And / or, the concentration of the gum arabic solution is 3-5wt.%.

10. Use of the composite seed dressing agent according to any one of claims 1 to 7 in the preparation of a medicament for preventing and treating corn stalk rot.

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