A method for improving drought resistance of lawn grass

Abstract

The invention discloses a method for improving drought resistance of lawn grass, and belongs to the technical field of plant drought resistance. The method comprises spraying composition A and / or composition B on the leaves of lawn grass, wherein the active ingredients of composition A are paclobutrazol, mepiquat, phosphate fertilizer and sodium nitrophenolate, and the active ingredients of composition B are abscisic acid and brassinolide. Composition A and / or composition B of the invention can improve the quality of lawn under limited irrigation conditions in dry seasons and improve the drought resistance of lawn grass.

Description

Technical Field

[0001] The invention relates to the technical field of plant drought resistance, in particular to a method for improving the drought resistance of lawn grass. Background Art

[0002] Lawns are not only an important part of garden landscapes, but also play a very obvious role in regulating atmospheric temperature and humidity, reducing noise, preventing soil erosion, alleviating air pollution and purifying the air. To a certain extent, they reflect the appearance and characteristics of a city and are an effective indicator for judging the level of urban economic development.

[0003] Water is an important factor affecting the growth of lawn grass. 75% to 90% of the fresh weight of lawn grass is water. When the water content drops to 10%, the lawn grass dies. Maintaining proper soil moisture content is the key to the survival of the lawn. Most of northern my country is arid or semi-arid, with dry climate, strong evaporation, severe water shortage, and lack of irrigation conditions in most areas. The roots of lawn grass are shallow, drought resistance is poor, and water demand is large. Water shortage in lawns will lead to weak growth, lawn degradation, and eventual death. Long-term and frequent watering will leach nutrients from the soil, causing nutrient loss. Frequent watering and fertilization will increase additional lawn maintenance costs.

[0004] Breeding drought-resistant varieties, resistance training, scientific fertilization, and application of plant growth regulators are common means to improve the drought resistance of lawn grass. Among them, breeding drought-resistant varieties and resistance training take a long time and have high production costs, which are not suitable for large-scale promotion. Applying exogenous substances to regulate and induce lawn grass to improve its resistance to drought stress is a simple and effective method, which is of great significance to maintaining soil and water conservation capacity and improving regional ecological environment. Improving the tolerance of lawn grass to drought environment to improve the utilization rate of lawn water, reduce lawn water consumption, and reduce lawn water cost are important measures to solve water difficulties. Plant growth regulators and fertilizers have different regulatory mechanisms for lawn grass. Plant growth regulators mainly regulate lawn drought resistance by regulating hormones in plants, and fertilizers mainly provide nutrients for lawn grass to cope with adverse stress. However, most of the current technologies for applying plant regulators to improve lawn drought resistance are only for a single grass species, and some exogenous substances have a short duration of effect. Mixing regulators with different regulatory mechanisms can easily lead to confusion in plant growth, while the application of fertilizers is slow to take effect and the drought resistance effect is not obvious. Summary of the invention

[0005] In order to solve the defects in the prior art, the present invention provides a method for improving the drought resistance of lawn grass. The method is suitable for any grass species, can improve the quality of lawn under limited irrigation conditions in the dry season, and improve the drought resistance of lawn grass.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] The invention provides a method for improving drought resistance of lawn grass. The method comprises spraying composition A and / or composition B on the leaves of lawn grass, wherein the active ingredients of the composition A comprise paclobutrazol, mepiquat, phosphate fertilizer and sodium nitrophenolate, and the active ingredients of the composition B comprise abscisic acid and brassinolide.

[0008] Preferably, the mass ratio of paclobutrazol, mepiquat, phosphate fertilizer and sodium nitrophenolate in the composition A is (0.05-0.15): (0.05-0.15): 7: 0.01.

[0009] More preferably, the mass ratio of paclobutrazol, mepiquat, phosphate fertilizer and sodium nitrophenolate in the composition A is (0.05-0.1): (0.05-0.15): 7: 0.01.

[0010] Preferably, the mass ratio of abscisic acid to brassinolide in the composition B is (0.08-0.15):(0.1-0.3).

[0011] More preferably, the mass ratio of abscisic acid to brassinolide in the composition B is (0.1-0.15):(0.2-0.3).

[0012] Preferably, the composition A is applied during the lawn growing season.

[0013] Preferably, the composition B is applied to the lawn when it is about to be subjected to drought stress or when it is subjected to drought stress.

[0014] Preferably, the method is to spray composition A and composition B on the leaves of lawn grass, wherein the mass ratio of paclobutrazol, mepiquat, phosphate fertilizer and sodium nitrophenolate in composition A is (0.05-0.15): (0.05-0.15): 7: 0.01, and the mass ratio of abscisic acid and brassinolide in composition B is (0.08-0.15): (0.1-0.3).

[0015] More preferably, the method is to spray composition A and composition B on the leaves of lawn grass, wherein the mass ratio of paclobutrazol, mepiquat, phosphate fertilizer and sodium nitrophenolate in composition A is (0.05-0.1): (0.05-0.15): 7: 0.01, and the mass ratio of abscisic acid and brassinolide in composition B is (0.1-0.15): (0.2-0.3).

[0016] More preferably, the composition A is applied to the lawn during the growing season, and the composition B is applied to the lawn when it is about to be subjected to drought stress or when it is subjected to drought stress.

[0017] More preferably, the application amount of the composition A is 0.05 to 0.15 g / m 2, methylpiperidinium 0.05~0.15g / m 2 , phosphate fertilizer 7g / m 2 , sodium nitrophenolate 0.01g / m 2 The application amount of the composition B is 0.08-0.15 g / m 2 , Brassinolide 0.1~0.3g / m 2 .

[0018] The active ingredients in the composition of the present invention can be purchased through commercial channels for compounding, or the preparation containing the active ingredients can be purchased and directly compounded. The preparation can be any one of emulsifiable concentrates, microemulsions, aqueous emulsions, suspensions, oil suspensions, dry suspensions, wettable powders or water dispersible granules.

[0019] The beneficial effects of the present invention are:

[0020] The present invention sprays composition A and / or composition B on the leaves of lawn grass, studies the effects of the two compositions on the quality, relative water content, chlorophyll content, electrical conductivity and malondialdehyde content of lawn grass after application, and explores the action mechanism of the two compositions on the drought resistance of lawn grass. The results show that after the composition A and / or composition B of the present invention are applied, the quality of lawn grass, the relative water content and chlorophyll content of leaves can be effectively improved, and the electrical conductivity and malondialdehyde content can be reduced, indicating that the two compositions can improve the quality of lawn under limited irrigation conditions in the dry season, improve the drought resistance of lawn grass, and are suitable for any type of lawn.

[0021] The composition A of the present invention is a compound of four components, namely, paclobutrazol, mepiquat, phosphate fertilizer and sodium nitrophenolate, which can inhibit the growth of lawn grass during the lawn growing season, and improve drought resistance by reducing plant height, shortening internodes, improving grass layer structure, increasing green color, increasing lawn density, increasing the accumulation of photosynthetic products and affecting the photosynthetic rate and biochemical reaction of plants.

[0022] The composition B of the present invention is a compound of abscisic acid and brassinolide, and its main function is to be applied when the lawn is about to be subjected to drought stress or is subjected to drought stress, so as to increase the resistance of the lawn to drought environment by closing stomata, maintaining water balance in tissues, and enhancing root permeability to water.

[0023] The inventors have found through a large number of studies that the blade length of the lawn using composition A or composition B alone is longer than that of the lawn using composition A and B together, while the blade width is smaller than that of the lawn using composition A and B together. The quality, relative water content and chlorophyll content of the Bermuda grass lawn after the combination of composition A and B are better than those of the lawn using composition A or composition B alone, and are better than those of the control group. The conductivity and malondialdehyde content of the Bermuda grass lawn after the combination of composition A and B are lower than those of the lawn using composition A or composition B alone, and are lower than those of the control group, indicating that the drought resistance effect of the lawn after the combination of composition A and B is better than that of the lawn using composition A or composition B alone. This indicates that the present invention applies composition A in the early stage of lawn growth to dwarf the plants and improve drought resistance. When drought weather comes, spray composition B to adjust the hormone level in the lawn to achieve drought resistance. The combination of composition A and composition B has the best drought resistance effect. Composition A and composition B of the present invention can act synergistically at different times to improve the lawn quality under limited irrigation conditions in the dry season and improve the drought resistance of lawn grass.

[0024] The present invention explores new organic growth regulating substances and conducts research on drought-resistant regulating technologies, which is helpful to maintain high lawn quality under drought conditions and has important theoretical and practical significance for saving water resources and improving the urban ecological environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a graph showing the effect of spraying different concentrations of composition A on lawn grass quality under drought stress in Example 1;

[0026] Figure 2 This is a graph showing the effect of spraying different concentrations of composition A on the relative water content of lawn grass under drought stress in Example 1;

[0027] Figure 3 This is a graph showing the effect of spraying different concentrations of composition A on the chlorophyll content of lawn grass under drought stress in Example 1;

[0028] Figure 4 This is a graph showing the effect of spraying different concentrations of composition A on the electrical conductivity of lawn grass under drought stress in Example 1;

[0029] Figure 5 This is a graph showing the effect of spraying different concentrations of composition A on the malondialdehyde content of lawn grass under drought stress in Example 1;

[0030] Figure 6 This is a graph showing the effect of spraying different concentrations of composition B on lawn grass quality under drought stress in Example 2;

[0031] Figure 7 This is a graph showing the effect of spraying different concentrations of composition B on the relative water content of lawn grass under drought stress in Example 2;

[0032] Figure 8 This is a graph showing the effect of spraying different concentrations of composition B on the chlorophyll content of lawn grass under drought stress in Example 2;

[0033] Fig. 9 This is a graph showing the effect of spraying different concentrations of composition B on the electrical conductivity of lawn grass under drought stress in Example 2;

[0034] Fig.10 This is a graph showing the effect of spraying different concentrations of composition B on the malondialdehyde content of lawn grass under drought stress in Example 2;

[0035] Fig.11 This is a graph showing the effect of spraying different treatment groups on the length of lawn grass leaves under drought stress in Example 3;

[0036] Fig.12 This is a graph showing the effect of spraying different treatment groups on the blade width of lawn grass under drought stress in Example 3;

[0037] Fig.13 This is a graph showing the effect of spraying different treatment groups on lawn grass quality under drought stress in Example 3;

[0038] Fig.14 This is a graph showing the effect of spraying different treatment groups on the relative water content of lawn grass under drought stress in Example 3;

[0039] Fig.15 This is a graph showing the effect of spraying different treatment groups on the chlorophyll content of lawn grass under drought stress in Example 3;

[0040] Fig.16 This is a graph showing the effect of spraying different treatment groups on the electrical conductivity of lawn grass under drought stress in Example 3;

[0041] Fig.17 This is a graph showing the effect of spraying different treatment groups on the malondialdehyde content of lawn grass under drought stress in Example 3. DETAILED DESCRIPTION

[0042] In order to enable those skilled in the art to better understand the technical solution of the invention, the present invention is further described in detail below in conjunction with specific implementation methods.

[0043] Example 1: Application of Composition A alone

[0044] 1. Experimental design

[0045] The experiment was conducted in the greenhouse of Guoguang Garden Technology Co., Ltd. in September 2015, with an average temperature of 25°C and a humidity of 45% to 50%. Mature healthy turf was dug and transplanted into a flower pot with an upper diameter of 17 cm. The substrate ratio was 2:1 of garden soil + vermiculite. Water was poured once every 2 days. The watering method was used to maintain the water holding capacity of the substrate. The stubble height was 4 cm. After the lawn had grown for one week and the growth was stable, the composition A was sprayed on the lawn leaves with a small spray pot. Specifically, the composition A was poured into 500 ml of water, fully stirred and dissolved, and the volume was fixed to 1000 ml. The dosage was 1 L / m 2 When spraying composition A with a small spraying pot, good atomization and uniform spraying are required, and water droplets do not fall into the soil. The control group was sprayed with an equal amount of distilled water instead of liquid medicine. Each treatment was repeated 3 times, and the spraying was continued for 3 days. Watering was stopped on the 4th day, and a drought treatment lasting 30 days was carried out. Random sampling was performed to measure various physiological indicators on the 0th, 10th, 20th and 30th days of drought.

[0046] According to the different proportions of the active ingredients in composition A, the test was divided into 4 groups, as follows:

[0047] Treatment A: Paclobutrazol + mepiquat + phosphate fertilizer + sodium nitrophenolate (0.15 g / m 2 +0.1g / m 2 +7g / m 2 +0.01g / m 2 )

[0048] Treatment B: Paclobutrazol + mepiquat + phosphate fertilizer + sodium nitrophenolate (0.05 g / m 2 +0.05g / m 2 +7g / m 2 +0.01g / m 2 )

[0049] Treatment C: paclobutrazol + mepiquat + phosphate fertilizer + sodium nitrophenolate (0.1 g / m 2 +0.15g / m 2 +7g / m 2 +0.01g / m 2 )

[0050] Treatment D: Clear water control

[0051] 2. Measurement indicators

[0052] (1) Turf quality

[0053] The evaluation of the drought resistance of lawn ground cover plants' appearance quality refers to the standards of the US NTEP (The National Turfgrass Evaluation Program). The density, color, uniformity and texture of lawn ground cover plants are used as indicators, and a nine-point system is used to score the appearance quality of lawn ground cover plants. The evaluation method is shown in Table 1.

[0054] Table 1 Turfgrass drought resistance quality score

[0055]

[0056] (2) Relative moisture content of lawn grass

[0057] Take fresh sample and weigh fresh weight immediately f The sample was completely immersed in distilled water for 24 h, and the surface water was gently absorbed after removal. The saturated weight of the leaf was measured as W. t , put it in a 105℃ oven for 30 minutes, and bake it at 80℃ until it reaches constant weight W d , calculate the relative water content of leaves:

[0058] Relative water content (%) = (W f -W d ) / (W t -W d )×100%

[0059] (3) Electrical conductivity of lawn grass

[0060] Under normal circumstances, plant cell membranes have the ability to selectively permeate substances. When plants are affected by adverse environments, the cell membranes are damaged and the membrane permeability increases (the degree of increase in membrane permeability is related to the intensity of adverse stress and the strength of the plant's resistance to stress), which causes electrolytes in the cells to leak out, resulting in an increase in the conductivity of the cell extract. The large amount of electrolyte leakage in plant cells is an important sign of damage to the membrane system, which can be reflected by changes in relative conductivity. The greater the relative conductivity, the greater the degree of damage to the plant tissue and the more serious the leakage of molecular substances in the cells.

[0061] The conductivity was determined by the conductivity meter method. Weigh 0.2g of fresh lawn grass leaves, rinse with deionized water three times, then gently dry the surface moisture of the leaves, cut them into small pieces about 1cm long with scissors and put them into a small beaker, add 20ml of distilled water, immerse the leaves completely in the distilled water, and let them stand at a constant temperature of 25℃ for 20min. Then use the conductivity meter to measure the conductivity C1, then extract the beaker containing the sample in a boiling water bath for 15min, measure its conductivity C2 after cooling, and calculate the relative conductivity of lawn grass:

[0062] Relative conductivity (%) = C1 / C2×100%

[0063] (4) Chlorophyll content of lawn grass

[0064] The chlorophyll content is determined by ethanol extraction. Weigh 0.2g of fresh lawn grass leaves, add liquid nitrogen and grind them into powder quickly, then add 2ml of 95% ethanol and grind them into a homogenate, then add 8ml of 95% ethanol and grind until the plant tissue turns white, and let it stand for 2 to 5 minutes. Filter all the grinding liquid into a 25ml brown volumetric flask, and use ethanol to transfer all the pigments remaining on the filter paper to the volumetric flask, dilute to the scale with ethanol, shake well, and measure the absorbance values ​​at 665nm and 649nm wavelengths respectively:

[0065] C a =13.95A 665 -6.88A 649

[0066] C b =24.96A 649 -7.32A 665

[0067] Chlorophyll content chl (mg / g) = C × V / M

[0068] C a is the chlorophyll a concentration, C b is the chlorophyll b concentration; chl is the total chlorophyll content; C is the chloroplast pigment concentration; V is the volume of the extract; W is the fresh weight of the sample.

[0069] (5) MDA content in lawn grass

[0070] Malondialdehyde (MDA) is one of the main products of membrane lipid peroxidation and a recognized indicator for measuring the degree of membrane lipid peroxidation. The degree of drought stress suffered by the plant can be reflected by measuring the MDA content in the plant. The higher the content, the higher the degree of drought.

[0071] Malondialdehyde content was determined by the sulphobarbituric acid (TBA) colorimetric method. Weigh 0.5 g of the sample, add 5 ml of 5% trichloroacetic acid (TCA), continue grinding until homogenized, centrifuge at 3000 r / min for 10 minutes, take 2 ml of the supernatant, add 2 ml of 0.67% TBA, mix thoroughly, place in a 100°C water bath for 30 minutes, and measure the absorbance at wavelengths of 450, 532 and 600 nm respectively:

[0072]

[0073] A 450 , A 532 , A 600are the absorbance values ​​at 450, 532 and 600 nm respectively; Vt is the volume of the extract; W is the fresh weight of the sample; Vs is the volume of the sample used in the measurement.

[0074] 3. Test results

[0075] (1) Turfgrass quality

[0076] Figure 1 The effect of spraying different concentrations of composition A on the quality of Bermuda grass lawn under drought stress was studied. The results showed that after 10 days of drought treatment, the quality of the lawn not sprayed with composition A decreased, the leaf color was normal, and some leaf edges began to die; after 20 days of drought treatment, the quality of the lawn sprayed with composition A began to decrease, and some leaf edges began to die. The growth of the lawn not sprayed with composition A was affected, and some lawn grass began to wilt, the leaves lost water and curled, and the amount of leaf edge death accounted for 20% to 40%; after 30 days of drought treatment, the growth of the lawn sprayed with composition A was relatively normal, the amount of leaf edge death was low, and the landscape effect was good. The growth of the lawn not sprayed with composition A was inhibited, the leaf color was gray-green or yellow, the leaves were dry and wrinkled, and the leaf death rate reached 40% to 60%.

[0077] (2) Relative moisture content of lawn grass

[0078] Figure 2 The results show that the relative water content of the leaves of Bermuda grass sprayed with different concentrations of composition A under drought stress (different capital letters indicate significant differences (P<0.05), n=3). The results show that after 10 days of drought treatment, the relative water content of the leaves of lawn grass had no significant effect; after 20 days of drought treatment, there was no significant effect between treatment A and treatment B, both were significantly higher than treatment C and control treatment, and the relative water content of the leaves of lawn grass without composition A was reduced to 60.37%; after 30 days of drought treatment, the relative water content of the leaves of lawn grass sprayed with composition A was at a high level of 59.21% to 69.46%, and the relative water content of the leaves of lawn grass not sprayed with composition A was reduced to 38.79%, which was significantly lower than that of lawn grass sprayed with composition A.

[0079] (3) Lawn Grass Chlorophyll

[0080] Figure 3 The effect of spraying different concentrations of composition A on the chlorophyll content of Bermuda grass under drought stress (different capital letters indicate significant differences (P<0.05), n=3). The results show that starting from 10 days of drought, the chlorophyll content of lawn grass sprayed with composition A was significantly higher than that of lawn grass not sprayed with composition A.

[0081] (4) Electrical conductivity of lawn grass

[0082] Figure 4The effect of spraying different concentrations of composition A on the electrical conductivity of Bermuda grass under drought stress (different capital letters indicate significant differences (P<0.05), n=3). The results show that after 10 to 30 days of drought stress, the electrical conductivity of lawn grass not sprayed with composition A is significantly higher than that of lawn grass sprayed with composition A.

[0083] (5) Lawn grass MDA

[0084] Figure 5 The results show that the malondialdehyde content of turfgrass sprayed with composition A at different concentrations under drought stress was significantly lower than that of turfgrass not sprayed with A starting from 20 days after drought.

[0085] From the above test results, it can be seen that after spraying composition A under drought stress, the quality, relative water content and chlorophyll content of Bermuda grass turf are significantly higher than those of the control treatment, and the electrical conductivity and malondialdehyde content are significantly lower than those of the control treatment. Among them, treatment B has the best effect on improving the drought resistance of Bermuda grass. The experiment proves that spraying composition A under drought stress improves the drought resistance of Bermuda grass turf grass.

[0086] Example 2: Application of Composition B Alone

[0087] 1. Experimental design

[0088] The experiment was conducted in the greenhouse of Guoguang Garden Technology Co., Ltd. in September 2015, with an average temperature of 25°C and a humidity of 45% to 50%. Mature healthy turf was dug and transplanted into a flower pot with an upper diameter of 17 cm. The substrate ratio was 2:1 of garden soil + vermiculite. Water was poured once every 2 days. Watering was done by weighing to maintain the water holding capacity of the substrate. The stubble height was 4 cm. After the lawn had grown for a week and the growth was stable, drought treatment was carried out. During the treatment, the composition B was sprayed on the lawn leaves with a small spray pot. Specifically, the composition B was poured into 500 ml of water, fully stirred and dissolved, and then the volume was fixed to 1000 ml. The dosage was 1 L / m 2 When spraying composition B with a small spraying pot, good atomization and uniform spraying are required, and water droplets do not fall into the soil. The control group was sprayed with an equal amount of distilled water instead of liquid medicine. Each treatment was repeated 3 times, and the spraying was continued for 3 days. Watering was stopped on the 4th day, and a drought treatment lasting 30 days was carried out. Random sampling was performed to measure various physiological indicators on the 0th, 10th, 20th and 30th days of drought.

[0089] According to the different proportions of the active ingredients in composition B, the test was divided into 4 groups, as follows:

[0090] Treatment A: abscisic acid + brassinolide (0.08 g / m 2 +0.1g / m2 )

[0091] Treatment B: abscisic acid + brassinolide (0.1 g / m 2 +0.3g / m 2 )

[0092] Treatment C: abscisic acid + brassinolide (0.15 g / m 2 +0.2g / m 2 )

[0093] Treatment D: Clear water control

[0094] 2. Measurement indicators

[0095] The determination method is the same as the determination index in Example 1.

[0096] 3. Test results

[0097] (1) Turfgrass quality

[0098] Figure 6 The effect of spraying different concentrations of composition B on the quality of Bermuda grass lawn under drought stress was studied. The results showed that after 10 days of drought treatment, the quality of the lawn not sprayed with composition B decreased, the growth was normal, the leaf color was normal, and some leaf edges began to die; after 20 days of drought treatment, the quality of the lawn sprayed with composition B began to decrease, and some leaf edges began to die. The growth of the lawn not sprayed with composition B was affected, and some lawn grass began to wilt, the leaves lost water and curled, and the leaf edge death rate was 20% to 40%; after 30 days of drought treatment, the growth of the lawn sprayed with composition B was partially affected, the leaf edge death rate was 20% to 40%, and the landscape effect was good. The growth of the lawn not sprayed with composition B was inhibited, the leaf color was gray-green or yellow, the leaves were dry and wrinkled, and the leaf death rate was 40% to 60%.

[0099] (2) Relative moisture content of lawn grass

[0100] Figure 7 The results show that the relative water content of Bermuda grass leaves sprayed with different concentrations of composition B under drought stress (different capital letters indicate significant differences (P<0.05), n=3). The results show that after 10 days of drought treatment, the relative water content of lawn grass leaves was not significantly affected; after 20 days of drought treatment, there was no significant effect between the treatments of spraying composition B, which were significantly higher than the control treatment, and the relative water content of lawn grass leaves without composition B was reduced to 58.40%; after 30 days of drought treatment, the relative water content of lawn grass leaves sprayed with composition B was at a high level of 55.12% to 59.88%, and the relative water content of lawn grass leaves not sprayed with composition B was reduced to 38.05%, which was significantly lower than the lawn grass sprayed with composition B.

[0101] (3) Chlorophyll content of lawn grass

[0102] Figure 8 The effect of spraying different concentrations of composition B on the chlorophyll content of Bermuda grass under drought stress (different capital letters indicate significant differences (P<0.05), n=3). The results show that starting from 10 days of drought, the chlorophyll content of lawn grass sprayed with composition B was significantly higher than that of lawn grass not sprayed with composition B.

[0103] (4) Electrical conductivity of lawn grass

[0104] Fig. 9 The effect of spraying different concentrations of composition B on the electrical conductivity of Bermuda grass under drought stress (different capital letters indicate significant differences (P<0.05), n=3). The results show that under drought stress, the electrical conductivity of lawn grass not sprayed with composition B is significantly higher than that of lawn grass sprayed with composition B.

[0105] (5) MDA content in lawn grass

[0106] Fig.10 The effect of spraying different concentrations of composition B on the malondialdehyde content of Bermuda grass under drought stress (different capital letters indicate significant differences (P<0.05), n=3). The results show that starting from 20 days of drought, the malondialdehyde content of lawn grass sprayed with composition B was significantly lower than the chlorophyll content of lawn grass not sprayed with composition B.

[0107] From the above test results, it can be seen that after spraying composition B under drought stress, the quality, relative water content and chlorophyll content of Bermuda grass turf are significantly higher than those of the control treatment, and the electrical conductivity and malondialdehyde content are significantly lower than those of the control treatment. The experiment proves that spraying composition B under drought stress can improve the drought resistance of Bermuda grass turf grass.

[0108] Example 3 Combination of Composition A and Composition B

[0109] The experiment was carried out in the greenhouse of Guoguang Garden Technology Co., Ltd. in September 2015. The average temperature of the greenhouse was 25°C and the humidity was 45% to 50%. Mature healthy turf was dug and transplanted into a flowerpot with an upper diameter of 17 cm. The substrate ratio was garden soil + vermiculite 2:1. During this period, water was poured once every 2 days. The watering method was used to maintain the water holding capacity of the substrate. The stubble height was 4 cm. After the lawn had grown for a week and the growth was stable, the first stage composition A was applied. The lawn leaves were sprayed with a small spray pot. Specifically, the composition A was poured into 500 ml of water, fully stirred to dissolve, and then the volume was fixed to 1000 ml. The dosage was 1 L / m 2The control group was sprayed with an equal amount of distilled water instead of the liquid medicine. Each treatment was repeated 3 times for 3 consecutive days. On the 4th day, watering was stopped for 14 days of drought treatment. After 14 days, the second stage composition B was sprayed, specifically: the composition B was poured into 500 ml of water, stirred thoroughly to dissolve, and then fixed to 1000 ml. The dosage was 1 L / m 2 The control group used an equal amount of distilled water instead of the liquid medicine leaves and then subjected to drought treatment for another 14 days, with a total drought stress time of 28 days.

[0110] When spraying composition A and composition B with a small spray pot, good atomization and uniform spraying are required, and water droplets do not fall into the soil. Samples were taken at 0d, 7d, 14d, 21d, and 28d of drought to measure various physiological indicators.

[0111] According to the different proportions of active ingredients in composition A and composition B and the different treatments, the experiments were divided into 4 groups, as follows:

[0112] Treatment A: Composition A: paclobutrazol + mepiquat + phosphate fertilizer + sodium nitrophenolate (0.1 g / m 2 +0.15g / m 2 +7g / m 2 +0.01g / m 2 ), and apply an equal amount of clean water after 14 days;

[0113] Treatment B: Composition B: abscisic acid + brassinolide (0.1 g / m 2 +0.3g / m 2 ), and after 14 days, apply an equal amount of clean water;

[0114] Treatment C: Composition A: paclobutrazol + mepiquat + phosphate fertilizer + sodium nitrophenolate (0.1 g / m 2 +0.15g / m 2 +7g / m 2 +0.01g / m 2 ), Composition B: 14 days later, abscisic acid + brassinolide (0.1 g / m 2 +0.3g / m 2 )

[0115] Treatment D: Composition A: paclobutrazol + mepiquat + phosphate fertilizer + sodium nitrophenolate (0.05 g / m 2 +0.05g / m 2 +7g / m 2 +0.01g / m 2 ), Composition B: 14 days later, abscisic acid + brassinolide (0.15 g / m 2 +0.2g / m 2 )

[0116] Treatment E: Clear water control

[0117] 2. Measurement indicators

[0118] The determination method is the same as the determination index in Example 1.

[0119] 3. Test results

[0120] (1) Lawn grass blade length

[0121] Fig.11 The effect of spraying different treatment groups on the leaf length of bermudagrass under drought stress (different capital letters indicate significant differences (P<0.05), n=3). The results showed that the change trends of the treatment groups were the same at 7, 14, and 21 days of drought treatment, and the length of bermudagrass in the water treatment was significantly higher than that in treatment A and treatment B, and significantly higher than that in treatment C and treatment D; after 28 days of drought treatment, there were obvious differences between different treatments, and the leaf length was ranked as E>B>A>C, D.

[0122] (2) Lawn grass blade width

[0123] Fig.12 The results show that after 14 days of drought treatment, there were differences among the different treatments, and the leaf widths of treatments A, C, and D were significantly higher than those of treatments B and E. After 21 and 28 days of drought treatment, the trends among the different treatments were the same, and the leaf widths were ranked as C, D>A>B>E.

[0124] (3) Turfgrass quality

[0125] Fig.13 The effect of spraying different treatment groups on the quality of Bermuda grass lawn under drought stress was studied. After 7 days of drought treatment, the lawn quality of treatment groups A, B, C and D remained unchanged, while the lawn quality of the control group decreased significantly; after 14 days of drought treatment, the lawn quality of each treatment group began to decline, and there was no significant difference between different treatment groups; after 21 days of drought treatment, the lawn quality of treatment groups A and B began to decline further, while the lawn quality of treatment groups C and D could still maintain a good level; after 28 days of drought treatment, the lawn quality was ranked as C = D > A = B > E. The results showed that spraying composition A and composition B in stages was beneficial to maintaining the quality of lawn grass.

[0126] (4) Relative moisture content of lawn grass

[0127] Fig.14The results show that after 7 days of drought treatment, there was no significant difference in the relative water content of lawn grass leaves among different treatments; after 14 days of drought treatment, there were differences among different treatments, and the relative water content of treatments A, C, and D was significantly higher than that of treatments B and E; after 21 and 28 days of drought treatment, the trend of change among different treatments was the same, and the relative water content was ranked as C, D>A>B>E.

[0128] (5) Chlorophyll content of lawn grass

[0129] Fig.15 The results show that the chlorophyll content of bermudagrass in different treatment groups under drought stress was significantly different (P<0.05), n=3). The results show that after 7 days of drought treatment, the chlorophyll content of treatment E was significantly lower than that of treatments A, B, C, and D; after 14 days of drought treatment, the chlorophyll content of treatments A, C, and D was significantly higher than that of treatments B and E; after 21 and 28 days of drought treatment, the change trend among the treatments was the same, and the chlorophyll content of treatments C and D was significantly higher than that of treatments A, B, and E. The chlorophyll content was ranked as C, D>A>B>E.

[0130] (6) Electrical conductivity of lawn grass

[0131] Fig.16 The results show that the electrical conductivity of bermudagrass was significantly higher in E treatment than in A, B, C, and D treatments after 7 and 14 days of drought stress (different capital letters indicate significant differences (P<0.05), n=3). The results show that after 7 and 14 days of drought treatment, the change trend among treatments was the same, and the electrical conductivity of E treatment was significantly higher than that of A, B, C, and D treatments; after 21 and 28 days of drought treatment, the electrical conductivity of E treatment was significantly higher than that of A, B, C, and D treatments, and that of A and B treatments was significantly higher than that of C and D treatments, and the electrical conductivity was ranked as E>A, B>C, D.

[0132] (7) MDA content in lawn grass

[0133] Fig.17 The results show that the effects of spraying different treatment groups on MDA in Bermuda grass under drought stress (different capital letters indicate significant differences (P<0.05), n=3). The results show that after 7 and 14 days of drought treatment, the change trends among the treatments were the same, and the MDA in the E treatment was significantly higher than that in the A, B, C, and D treatments; after 21 and 28 days of drought treatment, the MDA in the E treatment was significantly higher than that in the A, B, C, and D treatments, and the A and B treatments were significantly higher than the C and D treatments, and the MDA ranking was E>A, B>C, D.

[0134] It can be seen from the above that the blade length of the lawn using composition A or composition B alone is longer than that of the lawn using composition A and B together, while the blade width is smaller than that of the lawn using composition A and B together, indicating that the lawn using composition A and B together can reduce plant height, shorten internodes, and improve grass layer structure, so as to increase the accumulation of photosynthetic products and affect the photosynthetic rate and biochemical reactions of plants to improve drought resistance. The quality, relative water content and chlorophyll content of the Bermuda grass lawn after using composition A and B together are better than those using composition A or composition B alone, and are better than the control group. The conductivity and malondialdehyde content of the Bermuda grass lawn after using composition A and B together are lower than those using composition A or composition B alone, and are lower than the control group, indicating that the drought resistance effect of the lawn using composition A and B together is better than that of composition A or composition B alone.

[0135] The above are only preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be regarded as limiting the present invention, and the protection scope of the present invention should be based on the scope defined by the claims. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A method for improving drought resistance of lawn grass, characterized in that: The method comprises spraying composition A on the foliage of lawn grass during the lawn growing season, wherein the active ingredients of composition A include paclobutrazol, mepiquat, phosphate fertilizer and sodium nitrophenolate in a mass ratio of (0.05-0.15): (0.05-0.15): 7: 0.01; and spraying composition B on the foliage of lawn grass when the lawn is about to be subjected to drought stress or is subjected to drought stress, wherein the active ingredients of composition B include abscisic acid and brassinolide in a mass ratio of (0.08-0.15): (0.1-0.3).

2. The method according to claim 1, characterized in that The mass ratio of paclobutrazol, mepiquat, phosphate fertilizer and sodium nitrophenolate in the composition A is (0.05-0.1): (0.05-0.15): 7: 0.

01.

3. The method according to claim 1, characterized in that: The mass ratio of abscisic acid to brassinolide in the composition B is (0.1-0.15):(0.2-0.3).

4. The method according to claim 1, characterized in that The application amount of the composition A is 0.05-0.15 g / m 2 , methylpiperidinium 0.05~0.15g / m 2 , phosphate fertilizer 7g / m 2 , sodium nitrophenolate 0.01g / m 2 The application amount of the composition B is 0.08-0.15 g / m 2 , Brassinolide 0.1~0.3g / m 2 .

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