An ecological planting method that reduces the disease rate of Codonopsis pilosula and improves yield and quality by covering it with shade netting.

Abstract

The present invention discloses an ecological planting method for reducing the disease infection rate of Pseudostellaria heterophylla and improving its yield and quality by covering with shading screens, belonging to the technical field of medicinal plant cultivation. A shading facility is built in the middle and late growth stages of Pseudostellaria heterophylla under high temperature, strong light and rainy conditions; the method for building the shading facility is as follows: in the middle growth stage of Pseudostellaria heterophylla, a support is built above the planting area, and a shading screen is covered on the support to adjust the light intensity in the field. The planting method of Pseudostellaria heterophylla is applicable to the planting area of Pseudostellaria heterophylla in the south with high temperature and high humidity. The middle stage is the middle of April, and it is covered until the harvest of Pseudostellaria heterophylla in early July. By building a shading facility, the microclimate environment for the growth of Pseudostellaria heterophylla is optimized, thereby reducing the incidence of plant diseases, promoting photosynthetic growth, improving yield and quality, etc. This method has the advantages of simple operation, low cost, ecological environmental protection, etc., can significantly improve the yield and quality of Pseudostellaria heterophylla, and achieve the synergistic effect of disease prevention and control and growth regulation.

Description

Technical Field

[0001] The present invention relates to the technical field of medicinal plant cultivation, and particularly to an ecological planting method for reducing the disease incidence rate of Pseudostellaria heterophylla and improving its yield and quality by covering with a shading screen. Background Technique

[0002] Pseudostellaria heterophylla ( Pseudostellaria heterophylla ) as an important medicinal plant often faces the environment of strong light, high heat and high humidity during the planting process in subtropical regions, and is easily threatened by diseases such as leaf spot disease. Traditional open-field cultivation cannot solve the above problems, and traditional pesticide control methods have problems such as environmental pollution, high economic cost and enhanced pathogen drug resistance.

[0003] Shading treatment may affect the growth and development of plants by regulating light intensity and temperature. Shading cultivation can significantly reduce the disease incidence rate of various crops and improve the net photosynthetic rate, chlorophyll SPAD value, etc., and thus improve the yield. For example, shading treatment reduces the incidence rate of leaf spot disease of Aconitum carmichaelii by 40% and the transmission rate of kiwifruit canker by 30%; for Juglans mandshurica seedlings, the seedling height and biomass are the largest under 50% light treatment, and under low light conditions, the seedlings grow fast, with tall plant height, ground diameter, crown width and broad leaves, but the number of branches is significantly less than that under full light. And there is a synergistic effect between drought stress and disease occurrence. In addition, the existing shading devices lack a precise water regulation system, and the difference in soil water content in different regions can reach 35%, seriously affecting the planting uniformity. Summary of the Invention

[0004] The purpose of the present invention is to provide an ecological planting method for reducing the disease incidence rate of Pseudostellaria heterophylla and improving its yield and quality by covering with a shading screen, so as to solve the problems of the traditional Pseudostellaria heterophylla cultivation method being vulnerable to diseases, excessive pesticide use and low yield. The purpose of the present invention is to provide a shading cultivation method that is simple to operate, eco-friendly and can significantly improve the yield and quality of Pseudostellaria heterophylla. By constructing a shading facility to regulate the light environment in the field, while blocking the disease transmission route, maintaining suitable growth light and humidity, and realizing the improvement of the growth, yield and quality of Pseudostellaria heterophylla.

[0005] To achieve the above purpose, the present invention provides the following solutions: One of the technical solutions of the present invention, an ecological planting method for reducing the disease incidence rate of Pseudostellaria heterophylla and improving its yield and quality by covering with a shading screen, includes the following steps: in the middle and late growth stages of Pseudostellaria heterophylla, build a support above the planting area and cover the support with a shading screen to regulate the light intensity and humidity in the field, reduce the disease incidence rate, promote the growth of Pseudostellaria heterophylla, and improve its yield and quality.

[0006] Based on the above technical solutions, the present invention has the following technical effects: Based on data from two years of field trials, it is evident that during the later stages of Codonopsis pilosula's growth, constructing a support structure above the planting area and covering it with a white shade net significantly outperforms open-field planting in terms of disease prevention, promoting photosynthetic growth, and improving yield and quality. This approach also offers greater cost-effectiveness in production. 1. Effectively reduces disease: Shading creates a microenvironment unfavorable to pathogen transmission, significantly reducing the infection rate of Codonopsis pilosula leaf spot disease. 2. Promotes photosynthetic growth: Appropriate shading can significantly increase the net photosynthetic rate and chlorophyll SPAD value of Codonopsis pilosula leaves, enhancing its photosynthetic capacity. 3. Improves yield and quality: While controlling diseases, it ensures healthy plant growth, thereby significantly improving the dry weight yield and quality of Codonopsis pilosula tubers. 4. Environmental adaptability regulation: Shading treatment allows Codonopsis pilosula to grow in a suitable light and heat environment in the field, while blocking some pathogen transmission routes, keeping leaves dry, avoiding leaf spot disease outbreaks, ensuring healthy plant growth, and achieving high yield and high quality synergy. 5. Low cost and high efficiency: Compared with traditional open-field planting, this invention uses standardized supports and reusable netting for shading cultivation, combined with an automated drip irrigation system, significantly reducing input costs and making it suitable for large-scale planting. Attached Figure Description

[0007] Figure 1 This study compares the disease incidence, net photosynthetic rate, chlorophyll SPAD value, yield, and quality of *Pseudostellaria heterophylla* under different shading treatments and in open field cultivation. A: Disease incidence on June 23, 2023; B: Disease incidence on June 21, 2024; C: Net photosynthetic rate on June 21, 2024; D: SPAD on June 21, 2024; E: Yield; F: Percentage of Grade 1 products. Different letters in the columns indicate significant differences between treatments. p <0.05).

[0008] Figure 2 This shows the netting situation for the shading treatment over the past two years. a: Shaded field experiment in 2023; b: Shaded field experiment in 2024.

[0009] Figure 3 The growth of *Pseudostellaria heterophylla* under different shading treatments is shown. Group a: three layers of fine gauze netting; group b: two layers of fine gauze netting; group c: one layer of fine gauze netting; group d: one layer of coarse gauze netting; and group e: open-field control group. Detailed Implementation

[0010] Unless otherwise specified, the technical solutions described in this invention are all conventional solutions in the field, and the reagents or raw materials used are all purchased from commercial channels or are publicly available unless otherwise specified.

[0011] This invention aims to address the current situation of high disease rates, excessive pesticide use, weak photosynthetic capacity, and low yield and quality in traditional open-field cultivation of *Pseudostellaria heterophylla*. By implementing different levels of shading treatments, the plant height, chlorophyll SPAD, disease rate, and yield of *Pseudostellaria heterophylla* were compared to evaluate the promoting effect of shading on its growth and its possible physiological mechanisms. The goal is to provide optimized shading strategies for future agricultural cultivation of *Pseudostellaria heterophylla*, thereby improving its yield and quality and promoting the development of the *Pseudostellaria heterophylla* industry.

[0012] This invention provides an ecological planting method for reducing the disease rate of Codonopsis pilosula and improving its yield and quality by covering it with shading netting. The method includes the following steps: in the middle and late stages of Codonopsis pilosula growth, a support frame is erected above the planting area, and shading netting is covered on the support frame to regulate the light intensity and humidity in the field, reduce the incidence of diseases, promote the growth of Codonopsis pilosula, and improve its yield and quality.

[0013] In some specific implementations, the method of covering the shading net is to cover it with two layers of white fine netting.

[0014] In some specific implementations, the height of the support is 50-100 cm, and the distance between the shading net and the canopy of the Codonopsis pilosula plant is 30-50 cm.

[0015] In some specific implementations, the support frame is made of bamboo, wood or metal, and the spacing between the supports is set to 0.7 to 1.0 m according to the planting density.

[0016] In some specific implementations, the edge of the shading net extends 30-50cm to the outer edge of both sides of the planting ridge to form a continuous shading structure, preventing rainwater from directly contacting the plants and soil.

[0017] In some specific implementation plans, the *Pseudostellaria heterophylla* variety is *Zhe Shen No. 4*, planted in double rows in one furrow, with a row spacing of 12-15 cm and a furrow depth of 6-9 cm. The spacing between *Pseudostellaria heterophylla* plants is 5-7 cm. The seed roots are placed obliquely or horizontally with the buds facing upwards, and then covered with soil and compacted. The seed quantity is 40-50 kg per mu. No shading is required in the early stage of seedling emergence, but shading is required in the middle and late stages of the growth period.

[0018] In some specific implementation plans, the mid-to-late stage refers to the period from mid-April to early July.

[0019] In some specific implementations, the ecological planting method is suitable for the cultivation areas of Codonopsis pilosula in the south, where temperatures are high and humidity is high.

[0020] In some specific implementation schemes, the optimal number of layers is two layers of fine mesh shading: two layers of fine mesh shading are significantly better than single-layer mesh in terms of disease prevention, promoting photosynthetic growth, and improving yield and quality, but there is no significant difference compared with three layers of fine mesh shading. From an economic perspective, two layers of fine mesh are chosen.

[0021] In some specific implementation plans, organic fertilizer and ternary compound fertilizer are applied before planting Codonopsis pilosula, and high-quality compound fertilizer is applied once in early March and once in mid-April; weeding is carried out after the seedlings emerge; and the tuberous roots are harvested when the stems and leaves of the plant turn yellow.

[0022] This invention establishes shading facilities during the mid-growth stage of *Pseudostellaria heterophylla*, a period characterized by high temperature, strong sunlight, and abundant rainfall. The method involves constructing a support frame above the planting area during the mid-growth stage and covering the frame with a fine white shading net to regulate the intensity of sunlight in the field. This method is suitable for *Pseudostellaria heterophylla* cultivation areas in southern regions with high temperature and humidity. The mid-growth stage is mid-April, and the shading continues until early July when the *Pseudostellaria heterophylla* is harvested. By establishing shading facilities, the microclimate environment for *Pseudostellaria heterophylla* growth is optimized, thereby reducing the incidence of plant diseases, promoting photosynthetic growth, and improving yield and quality. This method has the advantages of simple operation, low cost, and environmental friendliness, and can significantly improve the yield and quality of *Pseudostellaria heterophylla*, achieving a synergistic effect of disease control and growth regulation.

[0023] This invention uses shading cultivation to block the transmission vectors of pathogens, thus inhibiting pathogen outbreaks and providing a favorable light and heat environment for the growth of *Pseudostellaria heterophylla*. The shading facilities are installed during the mid-to-late growth stages of *Pseudostellaria heterophylla* (mid-April to early July), a period when the plant is growing vigorously and the local climate is hot and humid, making it susceptible to fungal diseases. The shading is removed during the remaining periods.

[0024] This invention addresses the problems of leaf spot and other diseases in traditional Codonopsis pilosula cultivation, and proposes an innovative ecological cultivation method to provide a suitable environment for its growth. By constructing shading facilities, the method aims to increase net photosynthetic rate, reduce disease incidence, and improve yield and quality. This method is simple to operate, low in cost, and environmentally friendly, significantly improving the yield and quality of Codonopsis pilosula and achieving a synergistic effect between disease control and growth regulation.

[0025] The system blocks the rainwater transmission route of pathogens through the shading structure. It innovatively applies shading cultivation technology to the cultivation of Codonopsis pilosula, effectively reducing the incidence of leaf spot disease while increasing the net photosynthetic rate and chlorophyll SPAD value to increase the dry weight of the tuber, thus achieving synergistic effects of disease control and growth regulation in the production of medicinal plants.

[0026] Example 1 (1) Construction of experimental site and shading system Within the standardized cultivation demonstration base of *Codonopsis pilosula* in Zherong County, Ningde City, Fujian Province, a representative plot with flat terrain and uniform soil fertility was selected as the experimental area. Shading netting was placed on a bamboo frame 70cm above the ground to ensure its stability and uniformity of shading effect, while not affecting normal field operations and ventilation.

[0027] The spacing between the supports is adjusted to 0.8m according to the planting density. White mesh with different mesh sizes and layers is used to cover the top of the supports, with the edges of the mesh extending 40cm to the outer edges of both sides of the planting ridge to form a continuous shade canopy, preventing rainwater from directly contacting the plants and preventing strong sunlight from directly hitting the soil.

[0028] (2) Community setup and treatment design (covering with shade netting) Shading facilities were constructed during the mid-to-late growth stages of *Pseudostellaria heterophylla*. Bamboo supports with a height of 70 cm were erected above the planting area and covered with white gauze of different apertures and layers to create five treatment groups: a control group with open-field planting on bamboo supports without gauze (100% light transmittance), a group covered with one layer of coarse gauze (75% light transmittance), a group covered with one layer of fine gauze (65% light transmittance), a group covered with two layers of fine gauze (51% light transmittance), and a group covered with three layers of fine gauze (44% light transmittance). The distance between the gauze and the plant canopy was 40 cm.

[0029] The experimental area was divided into 15 sub-areas, each with an area of ​​2.1 square meters. 2 (Length 3 m, ridge width 0.7 m, furrow bottom width 0.5 m). Each treatment had 3 replicate plots, spaced 1 m apart to avoid mutual interference between shading treatments. Simultaneously, ensure consistent cultivation and management conditions across all plots, such as fertilization and pest and disease control. Regularly observe the health of the *Codonopsis pilosula* leaves, and leverage the rainwater-borne pathogen-blocking properties of shading treatments to reduce the use of chemical pesticides. If leaf spot disease appears in localized areas, use biological agents for targeted control.

[0030] Planting, management, and cultivation were carried out in accordance with the standardized production operation specifications for Huang Dongshou's Zherong Codonopsis pilosula. During the mid-growth period of Codonopsis pilosula in mid-May and the late growth period in mid-June, observations and photographs were taken of the Codonopsis pilosula in each plot, and the disease rate was estimated.

[0031] The detailed planting method is as follows: The *Pseudostellaria heterophylla* variety is Zheshen No. 4, planted in double rows in one furrow, with a plant spacing of 6cm. Furrows are dug with a row spacing of 13cm and a depth of 8cm. The seed roots are placed obliquely or horizontally with the buds facing upwards, then covered with soil and compacted. The seed quantity is 45kg per mu (approximately 0.067 hectares). Organic fertilizer and compound fertilizer are applied before planting. High-quality compound fertilizer is applied twice, once in early March and once in mid-April. Weeding and cultivation are carried out after the seedlings emerge in late February each year. The tubers are harvested from late June to early July, when the stems and leaves turn yellow. After harvesting, the tubers are processed into finished *Pseudostellaria heterophylla* using a standardized sun-drying or oven-drying method. Observations and measurements during the mid- and late-growth stages are completed within the corresponding time periods to ensure accurate reflection of individual growth differences at different growth stages.

[0032] (3) Soil moisture monitoring During the middle and late growth stages of Codonopsis pilosula, the soil moisture content at the center of each plot was measured using a TDR250 soil moisture meter (Spectrun Technologies Inc., USA).

[0033] (4) Illumination detection During the mid- and late-growth stages of *Pseudostellaria heterophylla*, on sunny days from 9:00 to 11:00, one leaf from each plot was selected for measurement, ensuring it was free from mechanical damage, pests, and diseases. Photosynthesis was measured using a portable photosynthesis analyzer TARGAS-1 (PP Systems Hansatech, USA) on sunny days from 9:00 to 11:00, with the light intensity controlled at 1000 μmol·m⁻¹. -2 ·s -1 The obtained plant physiological indicators include net photosynthetic rate (A). The relative chlorophyll SPAD value of the same leaf was measured using a SPAD520 chlorophyll meter (Konica Minolta, Japan).

[0034] (5) Yield measurement During the harvesting season of Codonopsis pilosula, all plots with 20% shading were excavated. To avoid the edge effect, only the middle 1 meter of plots with a length of 3m and a width of 0.7m was excavated, meaning the actual excavated area was 0.7m. 2 After harvesting, impurities are removed, and the tubers are then washed and dried in the sun for about 3 days until the moisture content is less than 8.0%. The dry weight of each plot sample is then weighed.

[0035] (6) Quality determination Tubers were randomly selected from each replicate area of ​​the five shading treatment groups for quality testing. 50g of washed and dried *Pseudostellaria heterophylla* tubers were randomly taken from each plot, and quality was graded based on the weight and diameter of individual tubers: Grade 1 tubers with a weight greater than 0.4g and a diameter greater than 0.4cm were graded as follows; Grade 2 tubers with a weight between 0.2 and 0.4g and a diameter between 0.3 and 0.4cm were graded as grade 2; and Grade 3 tubers with a weight less than 0.2g and a diameter less than 0.3cm were graded as mixed quality. This quality grading directly reflects the impact of shading treatment on the quality composition of *Pseudostellaria heterophylla*.

[0036] Experiments showed that different levels of shading treatments significantly increased the yield and proportion of first-grade ginseng, and significantly reduced the disease rate. In the later stages of growth (such as June), the net photosynthetic rate of the group covered with high-density fine mesh netting was significantly better than that of open-field cultivation.

[0037] This embodiment focuses on demonstrating the technical effects of the preferred scheme of using a two-layer fine mesh netting cover. Experimental data shows that this scheme, while ensuring excellent disease prevention and yield increase, has significant cost-effectiveness advantages. On June 5th and June 21st, 2024, the net photosynthetic rate of *Codonopsis pilosula* in the two-layer fine mesh netting cover group was significantly increased by 53.18% and 102.33% compared to the open-field planting group (Table 4); the chlorophyll SPAD value of *Codonopsis pilosula* leaves in the two-layer fine mesh netting cover group was significantly increased by 44.72% compared to the open-field planting group on June 21st, 2024 (Table 5); the disease infection rate of *Codonopsis pilosula* leaves in the two-layer fine mesh netting cover group was significantly lower than that in the open-field planting group on June 21st, 2024 (Table 5). Compared with the open-field planting group, the dry weight of the two-layer fine mesh group was significantly reduced on May 23, 2023, June 23, 2023 and June 21, 2024, with reductions of 75.66%, 69.95%, 71.03% and 56.66% respectively (Table 3, Table 6); the dry weight of the two-layer fine mesh group of Codonopsis pilosula was significantly increased in 2023 and 2024 compared with the open-field planting group, with increases of 130.42% and 17.59% respectively (Table 7).

[0038] Table 1. Net photosynthetic rate of *Pseudostellaria heterophylla* under different shading treatments in 2023 (μmol·m³) -2 ·s -1 )

[0039] Table 2. chlorophyll SPAD values ​​of *Codonopsis pilosula* under different shading treatments in 2023

[0040] Table 3. Infection rate of Codonopsis pilosula under different shading treatments in 2023

[0041] Table 4. Net photosynthetic rate of Codonopsis pilosula under different shading treatments in 2024 (μmol·m³)-2 ·s -1 )

[0042] Note: Representative leaves from each treatment were randomly selected on June 5th and June 21st, 2024. The light intensity for the control group (CK) was 1000 μmol·m⁻¹. -2 ·s -1 The light intensity of group AAA was controlled at 440 μmol·m. -2 ·s -1 The light intensity for group AA was controlled at 510 μmol·m. -2 ·s -1 Group A light intensity controlled at 650 μmol·m -2 ·s -1 Group B light intensity controlled at 750 μmol·m -2 ·s -1 During the remaining time, healthy leaves from each treatment group were randomly selected, and the light intensity was controlled at 1000 μmol·m⁻¹. -2 ·s -1 Measurement.

[0043] Table 5. chlorophyll SPAD values ​​of *Codonopsis pilosula* under different shading treatments in 2024

[0044] Table 6. Infection rate of Codonopsis pilosula under different shading treatments in 2024

[0045] Table 7. Codonopsis pilosula yield under different shading treatments in 2023 and 2024 (g / m³) 2 )

[0046] Table 8. Weight percentage of Grade 1 Codonopsis pilosula under different shading treatments in 2023 and 2024

[0047] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An ecological planting method for reducing the disease rate of Codonopsis pilosula and improving yield and quality by covering with shading netting, characterized in that, The process includes the following steps: In the middle and late stages of the growth of Codonopsis pilosula, a support frame is erected above the planting area, and a shading net is covered on the support frame to regulate the light intensity and humidity in the field, reduce the incidence of diseases, promote the growth of Codonopsis pilosula, and improve its yield and quality.

2. The ecological planting method according to claim 1, characterized in that, The method of covering with shade netting is as follows: cover with two layers of white fine netting.

3. The ecological planting method according to claim 1, characterized in that, The height of the support is 50-100 cm, and the distance between the shading net and the canopy of the Codonopsis pilosula plant is 30-50 cm.

4. The ecological planting method according to claim 1, characterized in that, The support frame is made of bamboo, wood, or metal, and the spacing between the supports is set to 0.7–1.0 m according to the planting density.

5. The ecological planting method according to claim 1, characterized in that, The edge of the shading net extends 30-50 cm to the outer edge of both sides of the planting ridge to form a continuous shading structure, preventing rainwater from directly contacting the plants and soil.

6. The ecological planting method according to claim 1, characterized in that, The Codonopsis pilosula mentioned is the Zhe Shen No. 4 variety, which is planted in two rows in one furrow, with a row spacing of 12-15cm and a furrow depth of 6-9cm. The spacing between Codonopsis pilosula plants is 5-7cm.

7. The ecological planting method according to claim 1, characterized in that, The middle and late stages refer to the period from mid-April to early July.

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