Preparation method of turmeric rhizome extract and its product and application in preventing and controlling plant powdery mildew

Abstract

The present invention relates to a preparation method of a turmeric rhizome extract and its product and application in preventing and controlling powdery mildew of plants. The preparation method comprises: drying and crushing the turmeric rhizome raw material and then extracting it with an ethanol aqueous solution to obtain an extract; concentrating the extract and then extracting it with an organic solvent to obtain an aqueous phase product and an oil phase product; molecularly distilling the oil phase product to remove turmeric oleoresin. The prepared turmeric rhizome extract has excellent efficacy in preventing and treating powdery mildew of plants; it is safe, low-toxic, and rapidly biodegradable, and is not easy to produce drug resistance, which is conducive to sustainable development; it has stable physical and chemical properties and a long storage period; it has low toxicity to terrestrial environmental organisms and has good economic and ecological benefits.

Description

Technical Field

[0001] The invention belongs to the technical field of plant extract preparation technology, and relates to a preparation method of a turmeric rhizome extract, a product thereof and application of the extract in preventing and controlling plant powdery mildew. Background Art

[0002] Powdery mildew is a fungal disease that can occur throughout the plant's growth period, mainly harming leaves, stems and fruits. White spots appear in the early stages of the disease, and then the color gradually changes to light brown. Black ascocarps can be formed through self-pollination or hybridization. The mildew spots are scattered individually in the early stages, and then they combine into a large mildew spot, which can even cover the entire leaf, seriously affecting photosynthesis, disrupting normal metabolism, causing premature aging, and loss of plant yield and quality.

[0003] Powdery mildew of leguminous plants mainly harms leaves. When the disease first occurs, nearly circular powdery white mold will appear on the leaves, or purple-brown spots will appear on the back of the leaves, covered with a thin layer of white powder. These are the vegetative mycelium of the pathogen, which later fuse into powdery spots. The reproductive mycelium of the pathogen produces a large number of conidia. In severe cases, the powdery spots will connect into pieces and cover the entire leaf, causing the leaves to wither or fall off.

[0004] Rose is a plant that integrates ornamental, medicinal and edible uses. It has the effects of relieving depression and relieving spleen, promoting blood circulation and beautifying the face. With the improvement of people's living standards, the market demand for roses is getting bigger and bigger, especially in recent years, there has been a situation of supply exceeding demand. Powdery mildew is one of the common diseases of roses, which harms flowers such as roses and Rosaceae plants. After being harmed, a layer of white powder grows on the leaves and tender shoots. When it is serious, the leaves turn yellow and fall off, which seriously affects the growth and flowering of the plants. This causes huge economic losses to the farmers who plant. The existing prevention and control methods generally use 1000 times of 70% thiophanate-methyl solution or 2000 times of 50% mancozeb solution for spraying. However, due to long-term use, pathogens are easy to develop drug resistance, resulting in reduced efficacy and a corresponding increase in the amount of pesticide applied, which has a greater adverse impact on the environment and food safety.

[0005] Grapes have rich nutritional and medicinal value. The planting area in my country is expanding year by year. However, grape planting is prone to a variety of diseases. Grape powdery mildew is the main disease of grapes. Fruits, leaves, new branches and vines and other green parts can be affected, and the fruit is the most damaged. When the fruit is damaged, a layer of gray-white powdery mildew will appear on the surface of the fruit. When the leaves are damaged, a layer of gray-white powdery mildew will appear on the surface of the leaves, gradually spreading to the entire leaf. In severe cases, the diseased leaves will curl and wither. When new branches and vines are damaged, small gray-white spots will appear at first, and then expand and spread to make the whole vine diseased. The diseased vines change from gray-white to dark gray and finally black. Seriously affect the yield and quality of grapes. At present, the commonly used method is to spray 3-5 degrees Baume lime sulfur mixture and 0.2-0.5 degrees Baume lime sulfur mixture once before and after germination, or 500 times solution of 50% thiophanate, or 1000 times solution of 70% methyl thiophanate, or 1000 times solution of 25% triadimefon wettable powder respectively. However, the spraying of traditional chemical synthetic agents has caused a series of problems such as bacterial resistance and pesticide residues. Therefore, it is necessary to effectively improve the traditional prevention and control of grape powdery mildew.

[0006] In agricultural production, the use of chemical synthetic pesticides has long accounted for the vast majority of the total use of pesticides. However, with the continuous promotion and use of chemical synthetic pesticides, their disadvantages have gradually emerged. Chemical synthetic pesticides are difficult to degrade and have high toxicity. Long-term use can easily lead to drug resistance, thereby reducing or even losing their control effects. Moreover, chemical synthetic pesticides that enter the environment can easily cause environmental pollution. Some chemical pesticides that are difficult to degrade may even continue to accumulate through the food chain and eventually enter the human body, causing harm to human health. Nowadays, in the pursuit of green environmental protection, the use of chemical synthetic pesticides has gradually decreased, while biological pesticides have gradually developed. Biological pesticides refer to a type of pesticide preparation that uses living organisms themselves or their metabolites that can prevent and control pests such as pests, pathogens, weeds, nematodes, rodents, etc., or substances with specific effects synthesized through biomimetic synthesis as active ingredients. Its active ingredients mainly come from three major parts: animals, plants, and microorganisms. Botanical pesticides are a major component of biological pesticides.

[0007] Botanical pesticides are new pesticides developed using the effective active ingredients extracted from plants or plants that have a preventive effect on plant diseases, insect pests and weeds. Among the numerous plant resources in the world, many contain effective active substances for preventing and controlling diseases and insect pests, including pyrethrum, neem, etc. There are abundant plant resources that can be used to develop botanical pesticides, and botanical pesticides have broad prospects for industrialization.

[0008] Turmeric (Curcuma longa L.) is a perennial herbaceous plant of the Zingiberaceae family and the genus Curcuma. It is also a common Chinese herbal medicine in traditional Chinese medicine. Turmeric contains chemical components such as curcumin, turmeric oleoresin and volatile oil. Turmeric itself and the active substances it contains are used in many industries such as medicine, industry, agriculture, and food. In medicine: Turmeric has the effects of breaking blood and promoting qi, relieving pain, and has a long history of application; modern experimental studies have shown that the active substances contained in turmeric have effects in anti-tumor, anti-inflammatory, antibacterial, antioxidant, regulating cardiovascular function, and regulating blood system function. In industry: Turmeric extract can be used as a natural dye and cosmetic raw material. In the food industry: Turmeric can be used as a condiment and food coloring. In agriculture: Turmeric extract has a good repellent effect on red flour beetles, corn weevils, mung bean weevils, etc., and has an inhibitory effect on the growth of desert locusts and red bug nymphs. Studies have also shown that 3% neem oil and turmeric powder extract can effectively control wheat aphids and wheat aphids.

[0009] In summary, turmeric has a wide range of uses and is a plant with high use value. Therefore, it is very meaningful to develop more application fields of turmeric. Summary of the invention

[0010] In view of the deficiencies in the prior art, the present invention aims to provide a method for preparing a turmeric rhizome extract and its product and application in preventing and controlling plant powdery mildew.

[0011] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0012] In a first aspect, the present invention provides a method for preparing a turmeric rhizome extract, the preparation method comprising:

[0013] (1) drying and crushing the turmeric rhizome raw material, and then extracting it with an ethanol aqueous solution to obtain an extract;

[0014] (2) concentrating the extract and then extracting it with an organic solvent to obtain an aqueous phase product and an oil phase product;

[0015] (3) molecularly distilling the oil phase product to remove the turmeric oleoresin to obtain the turmeric rhizome extract.

[0016] The invention adopts a specific preparation process to prepare the turmeric rhizome extract, that is, the turmeric rhizome raw material is dried and crushed, ethanol extracted, extracted and molecular distilled in sequence to obtain the extract. The preparation method has strong operability and is suitable for industrialized large-scale production.

[0017] The obtained turmeric rhizome extract product is a light yellow, flowable, homogeneous, transparent liquid with a slight smell of ginger juice; experiments show that it has excellent efficacy in preventing and treating powdery mildew of plants, especially preventing and treating powdery mildew of leguminous plants, rosaceae plants and grape plants; compared with chemical synthetic pesticides, the turmeric rhizome extract obtained by the invention is derived from natural plants, will not be enriched in the environment to damage the environment, but will be degraded in the environment relatively quickly; it has low toxicity; at the same time, compared with chemical synthetic pesticides with a single component, the turmeric rhizome extract obtained by the invention has complex components, and the effect of preventing and treating powdery mildew of plants is the result of the mutual cooperation of multiple functional components, and some other non-functional components also play an auxiliary role, so the target is not easy to develop drug resistance.

[0018] The turmeric rhizome extract prepared by the specific preparation process of the present invention has stable properties and a long storage period; at the same time, the turmeric rhizome extract is very environmentally friendly, has low toxicity to terrestrial species such as birds, bees, silkworms, etc. in the application environment, and has broad application prospects.

[0019] Preferably, the concentration of the ethanol aqueous solution is 55-95%, for example 55%, 60%, 65%, 68%, 70%, 72%, 75%, 78%, 80%, 82%, 85%, 90%, 95%, etc. Other specific point values ​​within this numerical range can be selected and will not be described here one by one; 65-85% is more preferred.

[0020] The concentration of the ethanol aqueous solution is specifically selected to be 55-95% because the turmeric rhizome extract prepared by using the ethanol aqueous solution in this concentration range has a more significant effect of preventing and treating powdery mildew of plants, especially preventing and treating powdery mildew of leguminous plants, rosaceae plants, and grape plants. The more preferred concentration range is 65-85%.

[0021] Preferably, the solid-liquid ratio of the turmeric rhizome raw material to the ethanol aqueous solution is (20-150) g / L, for example 20 g / L, 25 g / L, 30 g / L, 35 g / L, 40 g / L, 45 g / L, 50 g / L, 55 g / L, 60 g / L, 65 g / L, 70 g / L, 80 g / L, 100 g / L, 150 g / L, etc. Other specific point values ​​within this numerical range can be selected, which will not be repeated here; more preferably (30-70) g / L.

[0022] The material-liquid ratio of the turmeric rhizome raw material to the ethanol aqueous solution is specifically selected to be (20-150) g / L because at this ratio, the turmeric rhizome extract obtained has a more significant effect of preventing and treating powdery mildew of plants, especially preventing and treating powdery mildew of leguminous plants, rosaceae plants, and grape plants. The more preferred ratio range is (30-70) g / L.

[0023] Preferably, the extraction temperature is 10-60°C, for example, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 60°C, etc. Other specific point values ​​within this numerical range can be selected and will not be described here one by one; 15-30°C is more preferred.

[0024] Preferably, the extraction time is 24-96h, for example 24h, 28h, 30h, 35h, 40h, 45h, 48h, 60h, 72h, 96h, etc. Other specific point values ​​within this numerical range can be selected and will not be described here one by one; 30-50h is more preferred.

[0025] The extraction temperature and time are preferably 10-60°C and 24-96h because further increase in temperature or further extension of time, further decrease in temperature or further shortening of time will have a certain negative impact on the effect of turmeric rhizome extract in preventing and controlling plant powdery mildew. The optimal temperature and time range is 15-30°C and 30-50h.

[0026] Preferably, the organic solvent comprises any one or a combination of at least two of n-hexane, petroleum ether, cyclohexane, isooctane, trifluoroacetic acid, trimethylpentane, cyclopentane, heptane, butyryl chloride, trichloroethylene, carbon tetrachloride, propyl ether or toluene.

[0027] The present invention provides a process in which a low-polarity organic solvent is used in the extraction step, and the above-mentioned types are more preferred. The obtained turmeric rhizome extract has a more significant effect on preventing and treating plant powdery mildew.

[0028] Preferably, the pressure condition of the molecular distillation is 0.1-10Pa, for example, 0.1Pa, 0.5Pa, 1Pa, 1.5Pa, 2Pa, 2.5Pa, 3Pa, 3.5Pa, 4Pa, 5Pa, etc. Other specific point values ​​within this numerical range can be selected and will not be described one by one here; 0.1-5Pa is more preferred.

[0029] Preferably, the temperature of the molecular distillation is 100-150°C, for example, 100°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, etc. Other specific point values ​​within this numerical range can be selected and will not be described one by one here; 110-130°C is more preferred.

[0030] The temperature and pressure of the molecular distillation are preferably 100-150° C. and 0.1-10 Pa because further increase in temperature or pressure, or further decrease in temperature or pressure, will have a certain negative impact on the effect of the turmeric rhizome extract in preventing and treating plant powdery mildew. The optimal temperature and pressure range is 110-130° C. and 0.1-5 Pa.

[0031] In a second aspect, the present invention provides a turmeric rhizome extract prepared according to the preparation method of the turmeric rhizome extract according to the first aspect.

[0032] The turmeric rhizome extract is a light yellow, flowable, homogeneous, transparent liquid with a slight smell of ginger juice; it has excellent efficacy in preventing and treating powdery mildew of plants, especially preventing and treating powdery mildew of leguminous plants, rosaceae plants, and grape plants; it can be degraded in the environment relatively quickly without polluting the environment; it is not easy to produce drug resistance, and is convenient for sustainable development; it has stable physical and chemical properties and a long storage period; more importantly, it is very friendly to the environment, has low toxicity to birds, bees, silkworms and other species in the application environment, and has broad application prospects.

[0033] In a third aspect, the present invention provides a use of the turmeric rhizome extract according to the second aspect in preventing and treating powdery mildew of plants, wherein the plants include leguminous plants, rosaceous plants, and vitiaceous plants.

[0034] It is well known to those skilled in the art that plants of the Leguminosae, Rosaceae or Vitaceae families are susceptible to powdery mildew, thereby causing huge economic losses. The present invention creatively develops a plant-derived active composition for controlling powdery mildew of the above-mentioned plants. Test data show that the composition has a good effect, which provides a new strategy for how to better control powdery mildew of plants.

[0035] In a fourth aspect, the present invention provides a method for controlling powdery mildew of plants, comprising: applying an effective dose of the turmeric rhizome extract as described in the second aspect to a leguminous plant, a Rosaceae plant or a Vitaceae plant.

[0036] In a fifth aspect, the present invention provides a preparation having the efficacy of preventing or treating powdery mildew of leguminous plants, wherein the effective ingredients of the preparation include the turmeric rhizome extract as described in the second aspect.

[0037] In a sixth aspect, the present invention provides a preparation having the efficacy of preventing or treating powdery mildew of Rosaceae plants, wherein the effective ingredients of the preparation include the turmeric rhizome extract as described in the second aspect.

[0038] In a seventh aspect, the present invention provides a preparation having the efficacy of preventing or treating powdery mildew of grape plants, wherein the effective ingredients of the preparation include the turmeric rhizome extract as described in the second aspect.

[0039] Preferably, the dosage form of the above-mentioned preparation includes but is not limited to suspension concentrate (SC), emulsifiable concentrate (EC), microemulsion (ME), emulsion in water (EW), soluble solution (SL), wettable powder (WP), water dispersible granules (WDG, also known as dry suspension concentrate), aqueous solution (AS), granules (GR), microcapsule suspension (CS), suspension concentrate (SC), and oil suspension concentrate (OF).

[0040] Preferably, the components of the above-mentioned preparation also include auxiliary agents, which include but are not limited to emulsifiers, solubilizers, surfactants, and organic solvents. These auxiliary agents play a role in emulsifying oil substances, increasing the solubility of the agent in water, and enhancing the adhesion on the surface of plants, thereby achieving the effect of improving the utilization rate of effective substances and reducing the loss of agents. For the turmeric rhizome extract involved in the present invention, it is difficult to dissolve in water, so some auxiliary agents need to be added to increase its water solubility. The addition of auxiliary agents can also further reduce the degradation of effective substances caused by factors such as light and temperature.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] (1) The present invention adopts a specific preparation process to prepare the turmeric rhizome extract, that is, the turmeric rhizome raw material is dried and crushed, ethanol extracted, extracted, and molecular distilled in sequence. The preparation method is highly operable and suitable for industrial scale-up production.

[0043] (2) The obtained turmeric rhizome extract is a light yellow, flowable, homogeneous, transparent liquid with a slight smell of ginger juice; it has excellent efficacy in preventing and treating powdery mildew of plants, especially of Leguminosae, Rosaceae, and Vitaceae; it can be degraded in the environment relatively quickly without polluting the environment; it is not easy to develop drug resistance, which is convenient for sustainable development; it has stable physical and chemical properties and a long storage period; more importantly, it is very environmentally friendly and has low toxicity to birds, bees, silkworms and other species in the application environment. It has broad application prospects in the prevention and control of powdery mildew of plants and provides a new strategy for how to better prevent and control powdery mildew of plants. DETAILED DESCRIPTION

[0044] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0045] The dried turmeric rhizome raw materials involved in the following contents were purchased from Shanghai Traditional Chinese Medicine Market.

[0046] Example 1

[0047] This embodiment provides a turmeric rhizome extract, and the preparation method thereof is as follows:

[0048] (1) After the dried turmeric rhizome raw material is crushed, it is extracted with a 75% ethanol aqueous solution (the solid-liquid ratio is 50 g / L) at an extraction temperature of 20° C. and an extraction time of 48 h to obtain an extract;

[0049] (2) concentrating the extract and extracting it with n-hexane to obtain an aqueous phase product and an oil phase product;

[0050] (3) subjecting the oil phase product to molecular distillation at a pressure of 3 Pa and a temperature of 120° C. to remove the turmeric oleoresin to obtain the turmeric rhizome extract.

[0051] Example 2

[0052] This embodiment provides a turmeric rhizome extract, and the preparation method thereof is as follows:

[0053] (1) After the dried turmeric rhizome raw material is crushed, it is extracted with 85% ethanol aqueous solution (solid-liquid ratio is 30 g / L) at an extraction temperature of 15° C. and an extraction time of 50 h to obtain an extract;

[0054] (2) concentrating the extract and extracting it with petroleum ether to obtain an aqueous phase product and an oil phase product;

[0055] (3) subjecting the oil phase product to molecular distillation at a pressure of 1 Pa and a temperature of 130° C. to remove the turmeric oleoresin to obtain the turmeric rhizome extract.

[0056] Example 3

[0057] This embodiment provides a turmeric rhizome extract, and the preparation method thereof is as follows:

[0058] (1) After the dried turmeric rhizome raw material is crushed, it is extracted with a 65% ethanol aqueous solution (the solid-liquid ratio is 70 g / L) at an extraction temperature of 30° C. and an extraction time of 30 h to obtain an extract;

[0059] (2) concentrating the extract and extracting it with cyclohexane to obtain an aqueous phase product and an oil phase product;

[0060] (3) subjecting the oil phase product to molecular distillation at a pressure of 5 Pa and a temperature of 110° C. to remove the turmeric oleoresin to obtain the turmeric rhizome extract.

[0061] Example 4

[0062] This embodiment provides a turmeric rhizome extract, and the preparation method thereof is different from that of Preparation Example 1 only in that an equal amount of 75% ethanol aqueous solution is replaced by 55% ethanol aqueous solution, and other conditions remain unchanged.

[0063] Example 5

[0064] This embodiment provides a turmeric rhizome extract, and the preparation method thereof is different from that of Preparation Example 1 only in that an equal amount of 75% ethanol aqueous solution is replaced by 95% ethanol aqueous solution, and other conditions remain unchanged.

[0065] Example 6

[0066] This example provides a turmeric rhizome extract, and the preparation method thereof is different from that of Preparation Example 1 only in that the mass of the turmeric rhizome raw material remains unchanged, the solid-liquid ratio of 50 g / L is replaced by 20 g / L, and other conditions remain unchanged.

[0067] Example 7

[0068] This example provides a turmeric rhizome extract, and the preparation method thereof is different from that of Preparation Example 1 only in that the mass of the turmeric rhizome raw material remains unchanged, the solid-liquid ratio of 50 g / L is replaced by 150 g / L, and other conditions remain unchanged.

[0069] Example 8

[0070] This embodiment provides a turmeric rhizome extract, and the preparation method thereof is different from that of Preparation Example 1 only in that the molecular distillation temperature of 120° C. is replaced with 100° C., and other conditions remain unchanged.

[0071] Example 9

[0072] This embodiment provides a turmeric rhizome extract, and the preparation method thereof is different from that of Preparation Example 1 only in that the molecular distillation temperature of 120° C. is replaced with 150° C., and other conditions remain unchanged.

[0073] Example 10

[0074] This embodiment provides a turmeric rhizome extract, and the preparation method thereof is different from that of Preparation Example 1 only in that the extractant is replaced by an equal volume of n-hexane with a mixed solvent of n-hexane and isooctane in a volume ratio of 2:1.

[0075] Embodiment 11

[0076] This example provides a turmeric rhizome extract, and the preparation method thereof is different from that of Preparation Example 1 only in that the extractant is replaced by an equal volume of isooctane with n-hexane.

[0077] Application Example 1

[0078] This application example provides an emulsifiable concentrate preparation with turmeric rhizome extract as an active ingredient, and its formula composition is as follows: 50% of turmeric rhizome extract prepared in Example 1, 30% of methyl oleate, 10% of Tween 80, and 10% of calcium dodecylbenzene sulfonate.

[0079] Application Example 2-11

[0080] This application example provides ten emulsifiable concentrates with turmeric rhizome extract as the active ingredient, and the formula thereof is different from that of application example 1 only in that the turmeric rhizome extract prepared in example 1 is replaced by the turmeric rhizome extract prepared in examples 2-11 in equal amounts.

[0081] Test Example 1

[0082] The turmeric rhizome extracts obtained in Examples 1-3 were characterized by the following properties:

[0083] (1) Detection of the mass fraction (%) of turmeric flavonoids: The sample was dissolved in anhydrous methanol, and methanol and water were used as the mobile phase. The sample was separated by high performance liquid chromatography using a C18 (4.6 mm × 250 mm, 5 μm) chromatographic column. The turmeric flavonoids content in the sample was quantified by the external standard method at an ultraviolet wavelength of 242 nm.

[0084] (2) pH value test: according to GB / T 1601-1993;

[0085] (3) Moisture content (%) test: according to 2.1.2 of GB / T 1600-2001;

[0086] (4) Acetone insoluble matter (%) test: according to GB / T 19138-2003;

[0087] The results are shown in Table 1.

[0088] Table 1

[0089]

[0090] It can be seen from the data results in Table 1 that the turmeric root extract prepared by the preparation process of the present invention has a high content of aromatic turmeric flavonoids as one of the active ingredients; the pH is weakly acidic, which can ensure the stability of the effective ingredients in the product, reduce decomposition, and avoid corrosion to the packaging material; the moisture content is lower than 0.5%, which effectively prevents the decomposition of the effective ingredients in the product; and the acetone insoluble matter is lower than 0.5%, indicating that the purity of the product is high.

[0091] (5) The turmeric rhizome extract prepared in Example 1 was subjected to a hydrolysis test of turmeric flavonoids according to the test method specified in the national standard GB / T 31270.1-2014 "Chemical Pesticide Environmental Safety Assessment Test Guidelines Part 2: Hydrolysis Test". The turmeric flavonoids were determined by liquid chromatography using a Waters Xbridge column. TM C84.6×250mm, 5μm, the mobile phase was acetonitrile and water (volume ratio of 60:40), the injection volume was 20μL, the detector was a UV detector, and the wavelength was 242nm.

[0092] Test results: Under the condition of 25℃ constant temperature and light-proof, the degradation half-life of turmeric flavonoids at pH4, pH7, and pH9 were 9.5 days, 9.56 days, and 8.27 days respectively; under the condition of 50℃ constant temperature and light-proof, the degradation half-life of turmeric flavonoids at pH4, pH7, and pH9 were 0.819 days, 0.837 days, and 0.847 days respectively. According to the national standard for the classification of the degradation level of pesticides in hydrolysis, the degradation level of turmeric flavonoids at pH4, pH7, and pH9 is "Grade I (easy to degrade)".

[0093] (6) The turmeric rhizome extract prepared in Example 1 was subjected to a soil aerobic metabolism test of turmeric flavonoids according to the test method specified in the national standard GB / T 31270.1-2014 "Chemical Pesticide Environmental Safety Assessment Test Guidelines Part 1: Soil Degradation Test". The turmeric flavonoids were determined by liquid chromatography. The chromatographic column was: Waters Xbridge TM C8 4.6×250mm, 5μm, the mobile phase was acetonitrile and water (volume ratio 60:40), the detector was a UV detector, and the wavelength was 242nm.

[0094] Test results: Under aerobic conditions, the degradation half-life of turmeric flavonoids in red soil, black soil, paddy soil, and tidal brown soil were 2.75 days, 3.57 days, 3.09 days, and 3.41 days, respectively. According to the national standard for the classification of pesticide degradation levels in soil, the degradation level of turmeric flavonoids in the four soils is "Grade I (easily degradable)".

[0095] Test Example 2

[0096] Toxicological characterization of the turmeric rhizome extracts prepared in Examples 1-3:

[0097] (1) The acute oral median lethal dose of female and male SD rats was determined according to the method described in Part 4 of GB / T 15670.4-2017 “Toxicological Test Methods for Pesticide Registration”;

[0098] (3) The acute percutaneous median lethal dose of female and male SD rats was determined according to the method described in Part 5 of GB / T 15670.5-2017 “Toxicological Test Methods for Pesticide Registration”;

[0099] (4) Acute inhalation median lethal concentration of female and male SD rats was determined according to the method described in Part 6 of GB / T 15670.6-2017 “Toxicological Test Methods for Pesticide Registration”;

[0100] (5) New Zealand white rabbit eye irritation test, which was carried out according to the method described in Part 8 of GB / T 15670.8-2017 “Toxicological Test Methods for Pesticide Registration”;

[0101] (6) New Zealand white rabbit skin irritation test, which was carried out according to the method described in Part 7 of GB / T 15670.7-2017 “Toxicological Test Methods for Pesticide Registration”;

[0102] (7) Hartley guinea pig sensitization test: the test was carried out according to the method described in Part 9 of GB / T 15670.9-2017 “Toxicological Test Methods for Pesticide Registration”.

[0103] The measurement results are shown in Table 2:

[0104] Table 2

[0105]

[0106]

[0107] It can be seen from the data results in Table 2 that the turmeric root extract involved in the present invention is highly safe, slightly toxic, low irritant and weakly allergenic.

[0108] Test Example 3

[0109] Environmental impact tests were performed on the turmeric rhizome extracts obtained in Examples 1-3:

[0110] The environmental impact tests were completed by Shenyang Chemical Research Institute Co., Ltd. The results are as follows:

[0111] (1) Acute oral toxicity test for quail, the method was based on the contents recorded in Part 9 of GB / T 31270.9-2014 “Test Guidelines for Environmental Safety Assessment of Chemical Pesticides” (48h, female);

[0112] (2) Acute oral toxicity to honey bees, the method is based on the contents recorded in Part 10 of GB / T 31270.10-2014 "Test Guidelines for Environmental Safety Assessment of Chemical Pesticides" (48h, female);

[0113] (3) Acute contact toxicity to honey bees, the method is based on the contents recorded in Part 10 of GB / T 31270.10-2014 “Test Guidelines for Environmental Safety Assessment of Chemical Pesticides” (48h, male);

[0114] (4) Acute toxicity to silkworms: the method was based on the contents of Part 11 of GB / T 31270.11-2014 “Test Guidelines for Environmental Safety Assessment of Chemical Pesticides” (48 h).

[0115] The measurement results are shown in Table 3:

[0116] Table 3

[0117] nature Example 1 Example 2 Example 3 <![CDATA[Acute oral toxicity LD of quail 50 > >2000mg / kg >2000mg / kg >2000mg / kg <![CDATA[Acute oral toxicity LD of bees 50 > >99.6μg / bee >99.0μg / bee >99.1μg / bee <![CDATA[Acute contact toxicity LD of bees 50 > >100μg / bee >99.5μg / bee >99.0μg / bee <![CDATA[Acute toxicity LC of silkworm 50 > >534mg / L >483mg / L >508mg / L

[0118] It can be seen from the data results in Table 3 that the turmeric root extract involved in the present invention is very friendly to the environment and has low toxicity to birds, bees, silkworms and other organisms in the environment.

[0119] Test Example 4

[0120] The emulsifiable concentrate prepared according to Example 1-11 was used to test the control of pea powdery mildew:

[0121] (1) Cultivation of pea seedlings: Place pea seeds (variety "sweet snap peas") in a culture dish and soak them in water for 24 hours at room temperature, then pour out the water, place moistened cotton wool on the bottom of the culture dish, and evenly spread the pea seeds in the dish. Water the dish every day to keep the cotton wool moist. After about a week, when the pea seedlings grow to about 2-3 cm in height, they can be transplanted into small pots. Water the pots every two days. When the first true leaf of the pea seedlings grows and the second true leaf unfolds, healthy seedlings with the same growth momentum can be selected for the experiment.

[0122] (2) Preparation of spore suspension of pea powdery mildew pathogen (Erysphe pist DC.): The pea seedlings are inoculated with a conidia suspension of the pathogen by spraying, so it is necessary to prepare a spore suspension of appropriate concentration, and the method is as follows:

[0123] (2.1) Pour pure water into a small spray bottle, select the freshest white powdery spots on the leaves of the diseased plants, and use the spray bottle to spray the spores into a clean beaker;

[0124] (2.2) Mix the obtained spore suspension, take a drop on a glass slide, and use a microscope to observe whether the spores are full and the number of spores in a field of view at a magnification of 15*10 times to see if they meet the requirements. Requirements for spore suspension: The spores should be full to ensure vitality; the number of spores in a field of view at a magnification of 15*10 times should be around 20-30, not too few or too many; in order to ensure the activity of the spores, the time from preparation to use of the spore suspension should not exceed 2 hours.

[0125] (3) Inoculation of pea powdery mildew pathogen:

[0126] (3.1) Spray the prepared spore suspension evenly on pea leaves;

[0127] (3.2) Move the inoculated pea seedlings into a box, spray the remaining spore suspension into the box to form a high humidity environment inside the box, then cover the box with a lid and incubate at a temperature of about 25°C for 24 hours;

[0128] (3.3) After 24 hours, you can open the lid and take out the pea seedlings. After the moisture on the leaves has dried, you can start the treatment with the pesticide.

[0129] (4) Application method:

[0130] (4.1) Dilute 0.1 ml of each emulsifiable concentrate 200 times with deionized water and place in a small spray bottle and mark for later use;

[0131] (4.2) Preparation of the adjuvant control group: According to the formulation, replace the turmeric extract with water to prepare an adjuvant solution with the same concentration as the adjuvant contained in the formulation. Take 0.1 ml and dilute it 200 times with water. Put it into a small spray bottle and mark it for later use.

[0132] (4.3) Preparation of the positive control group: dilute the fungicide 430 g / L tebuconazole suspension 2000 times with water and put it into a small spray bottle, mark it and set it aside;

[0133] (4.4) Preparation of blank control group: Fill a small spray bottle with deionized water and mark it for later use;

[0134] (4.5) Spraying: Split the pea seedlings inoculated with fungi and cultured for 24 hours into 4 replicates for each treatment agent, and spray the corresponding agents evenly on the leaf surface, with the standard being that the leaf surface is completely covered with the drug solution;

[0135] (4.6) Cultivation: Place the sprayed pea seedlings in an environment with a temperature of about 25°C and a humidity of about 70%, and water them every two days;

[0136] (4.7) Observation: Observe the damage caused by pesticides 24 hours and 5 days after spraying. Discard the formulations with serious damage according to the damage. After 6 days, count the incidence of the remaining formulations, calculate the control effect, and observe and record the changes in control effect for several consecutive days.

[0137] (5) Efficacy evaluation:

[0138] Ten plants were evaluated in each sample group, and all leaves of each plant were investigated. The grading standards were as follows: Grade 0: no disease spots;

[0139] Level 1: The lesion area accounts for less than 5% of the entire leaf area;

[0140] Level 3: The area of ​​lesions accounts for less than 6-15% of the total leaf area; Level 5: The area of ​​lesions accounts for less than 16-25% of the total leaf area; Level 7: The area of ​​lesions accounts for less than 26-50% of the total leaf area; Level 9: The area of ​​lesions accounts for more than 51% of the total leaf area.

[0141]

[0142]

[0143] The control effect data are shown in Table 4:

[0144] Table 4

[0145]

[0146]

[0147] It can be seen from the data in Table 4 that the turmeric root extract of the present invention has an excellent effect on preventing and treating pea powdery mildew, wherein the preparation process conditions of the turmeric root extract also affect the prevention and treatment effect.

[0148] Test Example 5

[0149] The emulsifiable concentrate prepared according to Example 1-3 was used for field efficacy test on grape powdery mildew:

[0150] (1) Test targets and crop varieties

[0151] Grape variety: red grape; Target: grape powdery mildew;

[0152] (2) Test reagent: dilute 500 times with water as in Example 1-3 for later use;

[0153] Positive control agent, 325 g / L pyraclostrobin SC, Zhejiang Tianfeng Biological Science Co., Ltd., registration number: PD20172823, batch number: 20210318; diluted 1000 times for standby use; a clean water control was also set up.

[0154] (3) Test location: Zengjiaying, Binchuan, Dali, Yunnan

[0155] Plot arrangement: The experiment was set up with 5 treatments, each treatment had 4 plots, and the area of ​​each plot was 15 square meters;

[0156] (4) Application method: Use a 20-type backpack electric sprayer from Zhengzhou Xinxiu Agricultural Machinery Co., Ltd. to apply pesticides. Prepare the pesticide according to the experimental design and spray the plants of each treatment evenly until small water droplets are formed.

[0157] Apply the pesticide at the early stage of the disease (i.e. when there are sporadic lesions on the lower leaves of the plant), apply the pesticide twice, with an interval of 8 days, and record the time of application;

[0158] (5) Survey methods:

[0159] Five points were surveyed for each treatment, with two plants at each point and all leaves of each plant were surveyed.

[0160] Disease classification standard:

[0161] Level 0: no lesions;

[0162] Level 1: The lesion area accounts for less than 5% of the entire leaf area;

[0163] Level 3: The lesion area accounts for 6%-10% of the entire leaf area;

[0164] Level 5: The lesion area accounts for 11%-20% of the entire leaf area;

[0165] Level 7: The lesion area accounts for 21%-40% of the entire leaf area;

[0166] Level 9: The lesion area accounts for more than 40% of the total leaf area.

[0167] (6) Calculation method of drug efficacy:

[0168] Disease index = (∑(number of diseased leaves at each level × relative level value) / total number of leaves investigated × 9) × 100

[0169] Prevention effect (%) = (1-(disease index of treatment area / disease index of control group)) × 100

[0170] The results are shown in Table 5:

[0171] Table 5

[0172] Survey time Control group Positive control group Application Example 1 Application Example 2 Application Example 3 8 days after 1 dose of medication 0.075 0.038 0.025 0.029 0.030 8 days of efficacy after 1 dose / 61.47％ 72.16％ 65.43％ 64.42％ 8 days after 2 doses of medication 0.101 0.047 0.027 0.031 0.029 8 days after 2 doses of medication / 64.15％ 78.22％ 72.63％ 70.82％

[0173] From the data results in Table 5, it can be seen that the turmeric root extract involved in the present invention has an excellent effect of preventing and treating grape powdery mildew, wherein the preparation process conditions of the turmeric root extract also affect this prevention and treatment effect.

[0174] Test Example 6

[0175] The emulsifiable concentrate prepared according to Example 1-3 was used for field efficacy test on rose powdery mildew:

[0176] (1) Test targets and crop varieties

[0177] Rose variety: Su Xing; Target: Rose powdery mildew;

[0178] (2) Test reagent: dilute 500 times with water as in Example 1-3 for later use;

[0179] Positive control agent, 25% ethidium bromide sulfonate ME, Xi'an Modern Science and Technology Industrial Co., Ltd., registration number: PD20190149, batch number: 20201023018; diluted 1000 times for standby use; a clean water control group was set up at the same time.

[0180] (3) Test location: Goujie Town, Yiliang, Kunming, Yunnan

[0181] Plot arrangement: The experiment was set up with 5 treatments, each treatment had 4 plots, and the area of ​​each plot was 15 square meters;

[0182] (4) Application method: Use a 20-type backpack electric sprayer from Zhengzhou Xinxiu Agricultural Machinery Co., Ltd. to apply pesticides. Prepare the pesticide according to the experimental design and spray the plants of each treatment evenly until small water droplets are formed.

[0183] Apply the pesticide once at the early stage of the disease (i.e. when there are sporadic lesions on the lower leaves of the plant), and record the time of application;

[0184] (5) Survey methods:

[0185] Five points were surveyed for each treatment, with two plants at each point and all leaves of each plant were surveyed.

[0186] Disease classification standard:

[0187] Level 0: no lesions;

[0188] Level 1: The lesion area accounts for less than 5% of the entire leaf area;

[0189] Level 3: The lesion area accounts for 6%-10% of the entire leaf area;

[0190] Level 5: The lesion area accounts for 11%-20% of the entire leaf area;

[0191] Level 7: The lesion area accounts for 21%-40% of the entire leaf area;

[0192] Level 9: The lesion area accounts for more than 40% of the total leaf area.

[0193] (6) Calculation method of drug efficacy:

[0194] Disease index = (∑(number of diseased leaves at each level × relative level value) / total number of leaves investigated × 9) × 100

[0195] Prevention effect (%) = (1-(disease index of treatment area / disease index of control group)) × 100

[0196] The results are shown in Table 6:

[0197] Table 6

[0198] Group 1 dose of medication 7 days after the disease index 7 days of protection after 1 dose Control group 0.054 / Positive control group 0.014 67.36％ Application Example 1 0.009 72.59％ Application Example 2 0.015 63.42％ Application Example 3 0.017 61.74％

[0199] From the data results in Table 6, it can be seen that the turmeric root extract involved in the present invention has an excellent effect of preventing and treating rose powdery mildew, wherein the preparation process conditions of the turmeric root extract also affect this prevention and treatment effect.

[0200] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the preparation method of a turmeric root extract and its product and its application in preventing and controlling plant powdery mildew, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0201] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0202] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A method for preparing a turmeric rhizome extract, characterized in that: The preparation method comprises: (1) drying and crushing the turmeric rhizome raw material, and then extracting it with an ethanol aqueous solution to obtain an extract; (2) concentrating the extract and then extracting it with an organic solvent to obtain an aqueous phase product and an oil phase product; (3) molecularly distilling the oil phase product to remove turmeric oleoresin to obtain the turmeric rhizome extract; The concentration of the ethanol aqueous solution is 65-85%; The material-liquid ratio of the turmeric rhizome raw material to the ethanol aqueous solution is (30-70) g / L; The organic solvent includes n-hexane and isooctane.

2. The method for preparing the turmeric rhizome extract according to claim 1, characterized in that: The extraction temperature is 10-60°C.

3. The method for preparing the turmeric rhizome extract according to claim 2, characterized in that: The extraction temperature is 15-30°C.

4. The method for preparing the turmeric rhizome extract according to claim 1, characterized in that: The extraction time is 24-96h.

5. The method for preparing the turmeric rhizome extract according to claim 4, characterized in that: The extraction time is 30-50h.

6. The method for preparing the turmeric rhizome extract according to claim 1, characterized in that: The pressure condition of the molecular distillation is 0.1-10Pa.

7. The method for preparing the turmeric rhizome extract according to claim 6, characterized in that: The pressure condition of the molecular distillation is 0.1-5Pa.

8. The method for preparing the turmeric rhizome extract according to claim 1, characterized in that: The temperature of the molecular distillation is 100-150°C.

9. The method for preparing the turmeric rhizome extract according to claim 8, characterized in that: The temperature of the molecular distillation is 110-130°C.

10. The turmeric rhizome extract obtained by the method for preparing the turmeric rhizome extract according to any one of claims 1 to 9.

11. The use of the turmeric rhizome extract in preventing and treating powdery mildew of plants according to claim 10, characterized in that: The plants include plants of the Leguminosae family, plants of the Rosaceae family, and plants of the Vitaceae family.

12. A method for preventing and controlling powdery mildew of plants, characterized in that: The control method comprises: applying an effective dose of the turmeric rhizome extract of claim 10 to a leguminous plant, a rosaceous plant or a vitiaceous plant.

13. A preparation having the effect of preventing or treating powdery mildew of leguminous plants, characterized in that: The effective ingredients of the preparation include the turmeric rhizome extract according to claim 10.

14. A preparation having the effect of preventing or treating powdery mildew of Rosaceae plants, characterized in that: The effective ingredients of the preparation include the turmeric rhizome extract according to claim 10.

15. A preparation having the effect of preventing or treating powdery mildew of grape plants, characterized in that: The effective ingredients of the preparation include the turmeric rhizome extract according to claim 10.

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