CN117859772A - Application of lavender leaf extract - Google Patents

Abstract

The invention discloses application of a lavender leaf extract, and aims to solve the problem that an existing pesticide herbicide can pollute the environment. The application of the lavender leaf extract in the invention is that the lavender leaf extract is used as a weed inhibitor, and the preparation method of the lavender leaf extract comprises the following steps: adding the dried lavender leaves into distilled water for soaking, then adopting a rotary evaporator to decompress at the vacuum temperature of 70+/-0.5 ℃ and the rotating speed of 50-70 r/min, distilling, concentrating until the mass ratio of the lavender leaves to the distilled water is 1 (0.8-1.2), obtaining a stock solution, and then uniformly mixing the stock solution with the distilled water to obtain the lavender leaf extract with the mass concentration of 2.5-20% of the mother solution. The invention uses the lavender leaf extract as the weed inhibitor, and chemical substances in the lavender leaf extract can effectively control the growth of crabgrass and nutgrass flatsedge, and has little influence on crops such as rice, corn and the like.

Description

Application of lavender leaf extract

Technical Field

The invention relates to a lavender leaf water extract and application thereof in inhibiting weeds.

Background technique

Lavender is an aromatic plant, and its unique ingredients give it unique pharmacological effects and aromatic smell. It can be used as a Chinese herbal medicine and a spice for food and cosmetics. Therefore, the application of lavender is currently mainly in the fields of medicine, health care, food and cosmetics, but its application in the fields of plant protection and ecology is less developed.

Through LC-MS testing of lavender leaves, it was found that the chemical substances in the leaves include flavonoids, organic acids, cinnamic acid, coumarins, alkaloids and other water-soluble active substances, which are important secondary metabolites of lavender. Farmland weeds compete with crops for sunlight, water and nutrients, thus affecting the growth of crops and even affecting the yield and quality. The secondary metabolites of plants have significant ecological effects such as inhibiting the germination rate, growth height, and fresh weight of weeds. This discovery provides new ideas for agricultural production, and also provides feasible solutions for reducing the use of pesticides and alleviating environmental pollution.

Summary of the invention

The purpose of the present invention is to solve the problem that existing pesticides and herbicides may pollute the environment, and to provide an application of lavender leaf extract.

The application of the lavender leaf extract of the present invention is to use the lavender leaf extract as a weed inhibitor;

The preparation method of lavender leaf extract is as follows:

1. Take fresh and complete lavender leaves, rinse and dry them to obtain dried lavender leaves;

2. Add the dried lavender leaves to distilled water in a mass ratio of 1:8-15, and then use a rotary evaporator to reduce pressure at a vacuum temperature of 70±0.5°C and a rotation speed of 50-70r/min to distill and concentrate until the mass ratio of lavender leaves to distilled water is 1:(0.8-1.2) to obtain a stock solution;

3. Evenly mix the stock solution with distilled water to obtain a lavender leaf extract (extract) with a mother solution mass concentration of 2.5% to 20%.

The present invention controls the vacuum temperature and rotation speed in the rotary evaporation process conditions to perform distillation, and volatile esters or alcohols such as linalyl, linalool, lavandin, lavandinol, α-terpineol, etc. may be lost from the lavender extract. The main components retained are water-soluble active substances such as flavonoids, organic acids, cinnamic acid, coumarin, alkaloids, etc. These allelopathic substances can affect the growth of weeds, such as inhibiting cell division and interfering with the metabolic process of weeds, thereby inhibiting their growth.

The invention uses lavender leaf extract as a weed inhibitor, effectively controls the growth of weeds through chemical substances in the lavender leaf extract, and has little effect on crops such as rice and corn.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a test diagram showing the effect of lavender leaf extract on rice germination process in an embodiment;

FIG2 is a test diagram showing the effect of lavender leaf extract on the germination process of sedge in the embodiment;

FIG3 is a test diagram showing the effect of lavender leaf extract on corn germination process in an embodiment;

FIG4 is a test diagram showing the effect of lavender leaf extract on the germination process of crabgrass in the embodiment;

FIG5 is a test diagram showing the effect of lavender leaf extract on the germination potential of weeds in the embodiment;

FIG6 is a test diagram showing the effect of lavender leaf extract on the germination index of rice in the embodiment;

FIG7 is a test diagram showing the effect of lavender leaf extract on the germination index of sedge in the embodiment;

FIG8 is a test diagram showing the effect of lavender leaf extract on the germination index of corn in the embodiment;

FIG9 is a test diagram showing the effect of lavender leaf extract on the germination index of crabgrass in the embodiment;

FIG. 10 is a test diagram showing the effect of the lavender leaf extract on the allelopathic index of weeds in the embodiment.

Detailed ways

Specific implementation method 1: In this implementation method, the application of lavender leaf extract is to use lavender leaf extract as a weed inhibitor;

The preparation method of lavender leaf extract is as follows:

1. Take fresh and complete lavender leaves, rinse and dry them to obtain dried lavender leaves;

2. Add the dried lavender leaves to distilled water in a mass ratio of 1:8-15, and then use a rotary evaporator to reduce pressure at a vacuum temperature of 70±0.5°C and a rotation speed of 50-70r/min to distill and concentrate until the mass ratio of lavender leaves to distilled water is 1:(0.8-1.2) to obtain a stock solution;

3. Evenly mix the stock solution with distilled water to obtain a lavender leaf extract (extract) with a mother solution mass concentration of 2.5% to 20%.

Specific implementation method 2: The difference between this implementation method and specific implementation method 1 is that the lavender leaves in step 1 are selected from narrow-leaved lavender leaves.

Specific implementation method three: This implementation method is different from specific implementation methods one or two in that in step two, the air-dried lavender leaves are added to distilled water for soaking at a mass ratio of lavender leaves to distilled water of 1:10.

Specific implementation method 4: This implementation method is different from specific implementation methods 1 to 3 in that the soaking time in step 2 is 30 to 40 minutes.

Specific embodiment 5: The difference between this embodiment and specific embodiments 1 to 4 is that in step 2, a rotary evaporator is used to reduce pressure and distill at a vacuum temperature of 70° C. and a rotation speed of 60 r/min.

Specific implementation method 6: The difference between this implementation method and specific implementation method 5 is that in step 2, the mass ratio of lavender leaves to distilled water is concentrated to 1:1.

Specific embodiment 7: This embodiment is different from any one of specific embodiments 1 to 6 in that the mass concentration of the mother liquor in the lavender leaf extract in step 3 is 10% to 20%.

Specific embodiment eight: This embodiment is different from specific embodiment seven in that the mass concentration of the mother liquor in the lavender leaf extract in step three is 20%.

Specific embodiment 9: This embodiment is different from any one of specific embodiments 1 to 8 in that lavender leaf extract is used as crabgrass inhibitor.

Specific embodiment 10: This embodiment is different from specific embodiments 1 to 8 in that lavender leaf extract is used as sedge inhibitor.

Example: The application of lavender leaf extract in this example is to use lavender leaf extract as a weed inhibitor;

The preparation method of lavender leaf extract is as follows:

1. Take fresh and complete narrow-leaved lavender leaves, rinse and dry them to obtain dried lavender leaves;

2. Add the dried lavender leaves to distilled water and soak for 30 minutes according to the mass ratio of lavender leaves to distilled water of 1:10, and then use a rotary evaporator to reduce pressure at a vacuum temperature of 70±0.5°C and a speed of 60r/min for distillation for 2 hours to concentrate to a mass ratio of lavender leaves to distilled water of 1:1 to obtain a stock solution;

3. Add a certain volume of distilled water to the volumetric flask. According to the weighed mass of the stock solution, calculate the volume of the stock solution to be added according to a certain ratio, use a pipette to add the corresponding volume of stock solution to each volumetric flask, gently shake the volumetric flask to fully mix the mother solution and distilled water, and obtain lavender leaf extracts with a mother solution mass concentration of 2.5%, 5%, 10%, 15%, and 20%, respectively, and use an equal volume of distilled water as the control group.

Seed germination experiment:

The plant seeds were cleaned with running tap water, then disinfected with 70% alcohol for 30 seconds, and then rinsed with distilled water for several times. The plant seeds were divided into 6 treatment groups, each group included 4 plant seeds, and each plant seed was treated with five different concentrations of leaf extract (2.5%, 5%, 10%, 15% and 20%) and control solution (CK) (a total of 6 treatment concentrations, 30 seeds of each plant at each concentration). The light cycle was 14 hours of light and 10 hours of darkness, and the room temperature was maintained at 25±2°C for cultivation.

data analysis:

On the 2nd, 4th, 6th, 8th, 10th, 12th and 14th days, the number of germinated seeds, root length and sprout length were measured, and the germination rate was calculated. According to the preliminary experiment, the germination rate on the 4th day was used as the germination potential, and the germination progress, germination index and allelopathic index were calculated.

Germination rate (GP) = a/N1×100%

Inhibition rate = (control group value - treatment group value) / control group value

Germination potential (GE) = b/N1 × 100%

Germination index (GI) = ∑Gt/Dt

Allelopathic index (RI) = When T ≥ C: RI = 1-C/T

When T＜C: RI＝T/C－1

Where a-the number of seeds that germinate normally at the end of germination; b-the number of seeds that germinate normally at the peak of germination;

N1-the total number of seeds for the test; Gt-the net number of germinations per day from the time a seed is placed in the bed; Dt-the corresponding number of days;

S-sprout length + root length. C represents the control value; T represents the treated value.

As shown in Figures 1 to 4, the lavender leaf extract has a significant inhibitory effect on the germination rate of weeds such as crabgrass and sedge, and the inhibitory effect becomes more obvious as the concentration increases. When the mother liquor mass concentration is 20%, the inhibitory effect is most significant, and the germination rates of crabgrass and sedge decrease by 90% and 80%, respectively. The decrease in rice is only 3.33%. At the same time, the germination potential also shows a similar trend, and the germination potential of crabgrass and sedge decreases by 86.68% and 83.35%, respectively. It can be shown that the lavender leaf extract has little effect on the germination rate of rice and corn, but has a significant inhibitory effect on the germination rate of weeds. This result shows that lavender leaf extract can be used as an efficient, pollution-free natural herbicide.

As shown in Figures 6 to 9, as the concentration increases, the germination index of rice is not significantly different from that of the control group. The germination index shows a significant trend of difference as time increases. The germination index reaches a peak on the fourth day and does not change with time thereafter. When the concentration of lavender leaf extract is 20%, the germination index of crabgrass and sedge is the lowest and is significantly different from that of low concentrations. The germination index of crabgrass and sedge may decrease as the concentration of lavender leaf extract increases. The compounds contained in lavender leaves have an inhibitory effect on the germination and growth of crabgrass seeds. These compounds may inhibit cell division, growth, and metabolism. As the concentration of the extract increases, the concentration of these compounds will also increase, thereby enhancing the effect on the germination index.

The allelopathic index was calculated by obtaining data from seed vigor. As shown in Figure 10, the allelopathic index (RI) was negative, indicating that leaf extracts of different concentrations had an inhibitory effect on seeds, and the correlation between the inhibitory effect and the concentration showed significant differences, but the inhibitory effect on different seeds was also different. The inhibitory degree on rice was low, indicating that the impact on its growth was low and did not show significant differences with the concentration, but the inhibitory degree on crabgrass and sedge was higher at the same concentration. The allelopathic effect of crabgrass decreased by 133.86%, 170.44%, 176.34%, 189.44%, and 197.12% with increasing concentration, and the allelopathic effect of sedge decreased by 125.99%, 153.68%, 163.65%, 183.29%, and 185.15% with increasing concentration. This shows that the chemical substances in the lavender leaf extract have an inhibitory effect on the growth of weeds. As the concentration increases, this inhibitory effect will also increase. In other words, lavender chemicals can effectively control the growth of weeds, and this control effect will increase as the concentration of lavender chemicals increases.

Claims (10)

1. The application of the lavender leaf extract is characterized in that the lavender leaf extract is used as a weed inhibitor;

the preparation method of the lavender leaf extract comprises the following steps:

1. taking fresh and complete lavender leaves, washing and airing to obtain aired lavender leaves;

2. adding the dried lavender leaves into distilled water according to the mass ratio of the lavender leaves to the distilled water of 1:8-15, soaking, then adopting a rotary evaporator to decompress at the vacuum temperature of 70+/-0.5 ℃ and the rotating speed of 50-70 r/min, distilling, concentrating until the mass ratio of the lavender leaves to the distilled water is 1 (0.8-1.2), and obtaining stock solution;

3. mixing the stock solution with distilled water uniformly to obtain the lavender leaf extract with the mass concentration of the mother solution of 2.5-20%.

2. The use of a lavender leaf extract according to claim 1, characterized in that in step one, lavender leaves are selected from the group consisting of lavandula angustifolia leaves.

3. The use of the lavender leaf extract according to claim 1, characterized in that in the second step, the dried lavender leaves are added into distilled water for soaking according to the mass ratio of the lavender leaves to the distilled water of 1:10.

4. The use of a lavender leaf extract according to claim 1, characterized in that the soaking time in the second step is 30-40 min.

5. The use of the lavender leaf extract according to claim 1, wherein in the second step, distillation is performed under reduced pressure by using a rotary evaporator at a vacuum temperature of 70 ℃ and a rotation speed of 60 r/min.

6. The use of the lavender leaf extract according to claim 5, wherein in the second step, the concentration is carried out until the mass ratio of the lavender leaf to distilled water is 1:1.

7. The use of the lavender leaf extract according to claim 1, characterized in that in the third step the mother liquor mass concentration in the lavender leaf extract is 10% -20%.

8. The use of the lavender leaf extract according to claim 7, characterized in that the mother liquor mass concentration in the lavender leaf extract in the step three is 20%.

9. Use of a lavender leaf extract according to claim 1, characterized in that the lavender leaf extract is used as a crabgrass inhibitor.

10. Use of a lavender leaf extract according to claim 1, characterized in that the lavender leaf extract is used as a cyperus inhibitor.