Method for improving content of volatile oil in fruits of zanthoxylum simulans and application thereof
By employing comprehensive technical methods such as shaping and pruning, water and fertilizer management, and growth regulation, the problem of low volatile oil content in Dingtan pepper has been solved, resulting in a double improvement in yield and quality, reduced costs, and expanded market competitiveness and economic benefits.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUIZHOU NORMAL UNIVERSITY
- Filing Date
- 2026-04-22
- Publication Date
- 2026-06-09
Smart Images
Figure SMS_1
Abstract
Description
Technical Field
[0001] This invention belongs to the field of Sichuan pepper cultivation technology, and in particular relates to a method and application for increasing the volatile oil content of Sichuan pepper fruits. Background Technology
[0002] Current pepper cultivation techniques mainly focus on enhancing tree vigor and increasing yield. While ensuring a minimum yield is an important principle, they neglect the crucial indicator of volatile oil content in quality. This results in weak product competitiveness, a lack of market pricing power and influence, and even the phenomenon of inferior peppers being passed off as superior ones.
[0003] Currently, the research and development of volatile oil from Sichuan pepper mainly focuses on extraction, preparation and preservation. However, due to the low content of volatile oil, it poses a great challenge to the extraction process and equipment, affecting the extraction efficiency and resulting in a low overall extraction rate. Consequently, a large number of equipment are idle.
[0004] The invention patent, "A New Method for Cultivating Sichuan Pepper" (Application Publication No.: CN 109526507 A), mainly describes the cultivation method of Sichuan pepper from aspects such as seeds, seedling cultivation, transplanting, pruning, and fertilizer and water management. However, it does not cover key technical aspects such as fertilization areas, soil loosening, and frost protection, making it difficult to apply to the Dingtan Sichuan pepper, which grows in a karst habitat. Furthermore, it does not clearly define the level of volatile oil enhancement, thus constituting a qualitative description. Dingtan Sichuan pepper is a unique native plant growing in the dry-hot valley of the Huajiang River. The special nature of its habitat has led to long-term adaptive evolution, and its cultivation techniques should also be specific to a particular region; otherwise, it will be difficult to increase the volatile oil content.
[0005] Currently, technologies for increasing the volatile oil content of Sichuan pepper mainly rely on plant growth regulators, using exogenous drug stimulation. This not only affects tree health, accelerates stand decline, and increases management costs and risks, but also actually reduces volatile oil content, impacting overall fruit quality—a counterproductive effect. However, there are no reports of using comprehensive technologies to increase volatile oil content from the perspectives of habitat improvement, tree vigor control, and soil-plant system synergy. The weak self-regulation function of the tree is also a significant reason for increased management costs. Summary of the Invention
[0006] To address the above technical problems, this invention provides a method for increasing the volatile oil content of Sichuan pepper fruits.
[0007] This invention provides a method for increasing the volatile oil content of Sichuan pepper fruits, comprising the following steps: (1) Shaping and pruning: During the fruit harvesting period of the pepper tree (mid to late July), the branches are pruned to make the tree shape open-center; (2) Soil turning: Turn the soil once every 6 to 7 months after pruning; (3) Water and fertilizer management: Organic fertilizer is applied in July of the year after pruning, and compound fertilizer is applied once in August and once in March and April of the following year. The fertilization area extends horizontally 1.2 to 1.5 times beyond the tree canopy line and vertically 20 to 30 cm away from the soil surface. The water content is maintained at 25% to 30%. The reason why the fertilization area extends 1.2 to 1.5 times beyond the tree canopy drip line is that underground fissures are developed in the implementation area, nutrients do not flow vertically, and spatial heterogeneity is high, which leads to a wide distribution of underground roots. In addition, the canopy of the top-grown pepper tree has been pruned and is smaller than the canopy width under natural growth conditions.
[0008] (4) Application of plant growth regulators: Spray acetamiprid once each in September and October; (5) Frost control: When the temperature is below 0℃, burn the branches and leaves of Sichuan pepper; (6) Disease and pest control.
[0009] Furthermore, in step (1), the number of pruned branches of the Sichuan pepper tree is 40-50, the angle between the branches and the ground is 20-25°, and the length of the branches is retained at 0.8-1 m. Pruning into an open-center tree shape is beneficial for leaf preservation, and also improves photosynthetic intensity, prolongs photosynthetic time, achieves efficient accumulation of nutrients, and promotes the increase of volatile oil content. Leaves are important photosynthetic organs. Since Sichuan pepper trees in Dingtan are prone to adapting to arid habitats by shedding leaves, leaf preservation has become an important technical means.
[0010] Furthermore, the organic fertilizer mentioned in step (3) is well-rotted cow manure, and the amount used per plant is 2 to 3 kg.
[0011] Furthermore, the N-P2O5-K2O percentage in the compound fertilizer described in step (3) is 15-15-15, and the dosage per plant is 0.25 kg. By improving soil fertility and nutrient self-regulation, the potential for nutrient supply is enhanced and nutrients are activated, promoting plant nutrient accumulation, increasing the lignification level of branches, which is beneficial for fruit formation and essential oil synthesis, and also enhances the self-regulation and self-stability of the system. By improving habitat conditions, such as soil moisture and soil compaction, the tree vigor is enhanced, and rapid lignification is achieved; the arid habitat in the region is also used to accelerate branch lignification. These methods are all conducive to increasing the volatile oil content.
[0012] Furthermore, in step (4), the uniconazole is prepared by mixing 80 g of uniconazole with 15 kg of tap water and spraying it on 20 prickly ash trees. The uniconazole used has functions such as controlling excessive growth, inhibiting vegetative growth, and promoting reproductive growth, thus playing a role in regulating growth; it also has the advantages of rapid decomposition, low residue, and being more environmentally friendly. Therefore, applying uniconazole is more convenient for tree shape control and soil management, and can reduce production costs.
[0013] Furthermore, step (4) also includes adding potassium dihydrogen phosphate while applying uniconazole. The method of adding is to mix 80 g of uniconazole + 100 g of potassium dihydrogen phosphate with 15 kg of tap water and spray it on 20 pepper trees.
[0014] Furthermore, the specific operation for frost control in step (5) involves burning dried Sichuan pepper branches and leaves in the pepper garden. Before burning, the branches and leaves are first crushed into pieces of 1–1.5 cm, and the radius of each fire pile is 18–20 m. Burning dried Sichuan pepper branches and leaves in the pepper garden has advantages over traditional methods such as fumigation and water spraying, including using local materials, sterilization, and nutrient return to the field, which can reduce production costs. Crushing the branches and leaves into pieces of 1–1.5 cm allows for full contact between the branches and leaves, reduces large gaps between them, slows down the burning rate, and prolongs the fumigation time, thus allowing them to exert their effects for a longer period. During this process, if the temperature rises, the embers can be extinguished.
[0015] Furthermore, the pest and disease control described in step (6) uses 75% oxamycin·tebuconazole and 5% acetamiprid EC.
[0016] This invention provides the application of the above method in increasing the volatile oil content of Sichuan pepper fruits.
[0017] Compared with the prior art, the present invention has the following beneficial effects: (1) The volatile oil content of the top-grade pepper fruit is over 10%, and is generally stable at 10% to 12%, which is 2 to 3 times higher than that of traditional technology, and has significant market competitiveness.
[0018] (2) The fruit appearance, numbing flavor, and yield of the top-grade pepper have also been significantly optimized, achieving a double improvement in yield and quality; ecological benefits have also been taken into account, achieving a win-win situation for both ecology and economy.
[0019] (3) The price of fresh Sichuan peppercorns from Dingtan has increased from 6-10 yuan / kg to 24-30 yuan / kg, resulting in significant economic benefits and reduced costs, with an increase in income of over 4,000 yuan per mu. By reducing costs and increasing efficiency, it is beneficial to mobilize the enthusiasm of pepper farmers and is in line with Guizhou Forestry's planning goal of "10,000 yuan per mu".
[0020] (4) The extraction rate of volatile oil from top-grade peppercorns has increased from 20% to 30% to over 80%, and the equipment is less prone to clogging, which reduces processing and maintenance costs and is conducive to the extension of the industrial chain.
[0021] (5) Because the management procedures and difficulties of branches are reduced, simplified cultivation is achieved, and the technology is easy to master, which is conducive to the promotion and transformation of the technology.
[0022] (6) This invention improves the metabolic activity of Sichuan pepper by improving light conditions and nutritional status, thereby increasing the time shift of metabolism and promoting the synthesis of volatile oils. Therefore, the increase in volatile oil content in this invention is achieved by combining multiple measures based on the above principles. Detailed Implementation
[0023] In the following embodiments, the method for determining soil volumetric moisture content is as follows: a WH-1 type soil moisture meter is used, and the soil moisture content is measured every 5 to 10 days depending on the weather conditions. If the moisture content is too low, it is replenished. When spraying water, the soil moisture content should not be too high.
[0024] Example 1 The implementation site is located in Jinjing Village, Beipanjiang Town, Zhenfeng County. The variety used is Qianjiao No. 1, which has been certified as a superior variety. The implementation period is one complete growing season from 2023 to 2024. The specific implementation steps are as follows: 1. Tree-based management (1) The tree shape is open-center, with 45 branches, the angle between the branches and the ground is 25°, and the length of the branches is 0.9 m. Due to the low carrying capacity of land resources and insufficient water supply in this area, it is not suitable to create a large tree shape, otherwise the branches will be thin, weak and brittle, and the top will be difficult to lignify.
[0025] On July 28, the fruit was harvested and the branches were pruned. On October 21, the branches were layered and pruned to cultivate an open-center tree shape.
[0026] (2) Spring shoots are used as main branches, autumn shoots are used as fruiting branches, and winter shoots are not retained. Branches that sprout in April and May are not retained. The reason is that branches that sprout at this stage are prone to leaf drop and compete for nutrients, which limits the accumulation of photosynthetic products.
[0027] During the implementation process, in the hot and dry weather from June to August, heavy pruning is not recommended; light pruning is preferable. This is mainly because the cut ends are easily sunburned, and without retained leaves, there is no transpiration pull, leading to insufficient water in the plant. Consequently, it becomes difficult to induce dormant buds to sprout new branches, artificially creating a low yield in the following year.
[0028] Bud removal is particularly crucial for Sichuan pepper trees. Only buds that sprout after the summer solstice can be cultivated as fruit-bearing branches. Buds should be retained in advance, and some buds growing to the sides and downwards should be kept to balance nutrients and utilize space. To ensure concentrated nutrient supply, a Sichuan pepper tree should have a maximum of 4 main branches, with 3 main branches being the standard. Too few branches can easily lead to excessive budding, wasted space, and reduced yield. Too many branches will cause overcrowding and insufficient nutrient supply, which will also lead to reduced yield. Therefore, the number of branches retained should be reasonable.
[0029] 2. Fertilizer Management (1) Fertilizer type and timing: On July 28, 2023, apply cow manure that has been decomposed for more than 200 days once, at a rate of 2.8 kg / plant; on August 17, 2023 and March 29 of the following year, apply compound fertilizer (N-P2O5-K2O percentage content of 15-15-15, produced by Guizhou Kailin Mineral Fertilizer Co., Ltd.), at a rate of 0.25 kg / plant each time. Using fermented cow manure as organic fertilizer improves the nutrient supply potential and can also give full play to the soil's regulating function.
[0030] (2) Fertilization area: Horizontally, it extends 1.2 times beyond the tree canopy line and vertically, it is 25 cm away from the soil surface.
[0031] Based on the habitat characteristics of this area, the amount of fertilizer should not be too high to avoid rapid sprouting of Sichuan pepper branches in May and June. This is because the drought in the early stages meant that fertilizer was not fully utilized in the soil, and rapid sprouting occurred when water and heat conditions improved in May and June. In addition, excessive fertilizer application can also cause root burn. Therefore, the timing and amount of fertilizer application in this area differ from those in other regions.
[0032] 3. The soil volumetric moisture content should be maintained at around 28%. The reason is that if the soil moisture content is too low, the leaves will curl and dry out, reducing or even losing their photosynthetic capacity; if the moisture content is too high, the dry habitat cannot be used to promote the lignification of branches, but instead increases the operating cost. In particular, excessive moisture during the fruit enlargement period of Sichuan pepper in March and April will cause fruit drop.
[0033] 4. Turn the soil once on June 27-28, 2023, to keep it loose. During the turning process, the understory herbaceous layer is also turned into the soil. This prevents the herbaceous cutting from exacerbating nutrient deficiencies outside the system and promotes internal nutrient cycling, achieving micronutrient return to the field and balance. Since traditional weed control and fruit harvesting operations accelerate the outflow of nutrients from within the system, this method helps to improve soil nutrient abundance.
[0034] 5. Plant growth regulator: On September 19 and October 6, 2023, spray uniconazole once each by foliar spraying. Mix 80 g of uniconazole with 15 kg of tap water and spray 20 pepper trees.
[0035] 6. Frost Prevention: During the period when the temperature is below 0℃ in January 2024, burn dried pepper branches and leaves in the pepper garden, crushing them into 1.2 cm lengths before burning. The radiation radius of each fire should be 20 m. Extinguish the embers when the temperature rises.
[0036] During implementation, the research findings of Professor Yang Maofa's team at Guizhou University on pest and disease control were also utilized. Yellow sticky traps were most effective against winged aphids, while wingless aphids were primarily controlled through a combination of natural enemy insects and chemical methods. Using aphid-eating gall midges as natural enemies to control pepper aphids resulted in a population reduction rate of over 75% after 8 days, achieving 100% control efficacy when the beneficial-to-harm ratio was 1:20. The pesticide used to control rust was 75% azoxystrobin·tebuconazole, and the pesticide used to control aphids was 5% acetamiprid EC.
[0037] The results were as follows: fruit yield was 5.7 kg / plant, volatile oil content was 11.7%, total flavonoids content was 28‰, and pericarp thickness was 0.43 mm. No obvious frost damage was observed in the leaves. The leaves were observed to be long, wide, and spread out, indicating a healthy condition conducive to physiological function. The comprehensive calculation showed that the management cost was 2000 yuan / mu, a 50% reduction compared to traditional techniques, while increasing net income by 4000 yuan / mu, achieving the comprehensive goal of cost reduction and efficiency improvement. This technology has been promoted and applied in the main and old production areas of Dingtan pepper, such as Zhenfeng County and Guanling County, with a coverage area of 1000 mu.
[0038] The relevant indicators were determined using the following methods: yield was calculated based on fresh fruit, using a weighing method; the volatile oil content of the fruit was determined by steam distillation, referring to "Determination of Volatile Oil Content in Spices and Seasonings: GB / T 30385—2013"; the content of salinomycin in the fruit was determined by high-performance liquid chromatography, referring to "Determination of Total Salinomycin Content in Sichuan Pepper and Processed Sichuan Pepper Products: GH / T 1291—2020"; and the peel thickness was measured directly with vernier calipers. The same applies below.
[0039] Example 2 The implementation site is located in Maomaozhai Village, Beipanjiang Town, Zhenfeng County. The variety used is Qianjiao No. 1, which has been certified as a superior variety. The implementation period is from 2023 to 2024. The specific implementation steps are as follows: 1. Tree-based management (1) The tree shape is open-center, with 50 branches, the angle between the branches and the ground is 20°, and the length of the branches is 1 m. The fruit was harvested and the branches were pruned on July 22. The branch layering and pruning were carried out on October 24 to cultivate the tree into an open-center shape.
[0040] (2) Spring shoots are used as main branches, autumn shoots are used as fruiting branches, and winter shoots are not retained. Branches that sprout in April and May are not retained because the leaves are easy to fall off and compete for nutrients. The pruning time for Sichuan pepper is mainly from September to November. Too many branches should not be thinned, otherwise too few branches will easily lead to vigorous growth and difficulty in lignification. After that, pruning should be done according to the agricultural schedule, space redundancy, labor conditions, etc. If the branches are too short, more attention should be paid to the pruning time.
[0041] 2. Fertilizer Management (1) Fertilizer type and timing: On July 13, 2023, 2.5 kg / plant of cow manure that had been composted for more than 190 days was applied once; compound fertilizer was applied once on August 26, 2023 and again on April 11 of the following year (same as step 2 in Example 1), with a dosage of 0.25 kg / plant each time. The cow manure came from a nearby cattle farm and achieved sterilization and disinfection through the composting process.
[0042] (2) Fertilization area: The horizontal space extends 1.5 times beyond the tree canopy line and the vertical distance from the soil surface is 30 cm. This is because underground fissures are well developed in the implementation area, nutrients do not flow vertically, and spatial heterogeneity is high, which leads to a wide distribution of underground roots. Therefore, the fertilization area extends 0.5 times beyond the tree canopy drip line.
[0043] 3. The soil volumetric moisture content should be maintained at around 25%–27%, in a dynamically stable state. Sichuan pepper is intolerant of waterlogging, therefore the soil moisture content should not be too high, especially the roots should not be exposed to a consistently moist soil environment; otherwise, root vitality and absorption function will actually decrease. Suitable soil moisture content, creating an alternating wet and dry growing environment, is beneficial for the lignification of branches, turning unfavorable habitat conditions into favorable ones.
[0044] 4. Soil turning: Turn the soil once on July 22, 2023. Turning the soil at this time will bring herbaceous plants and other ground cover into the soil, which will not only loosen the soil but also return the nutrients to the plants as fertilizer. Turning the soil at this time will also promote the germination of fine roots and facilitate nutrient absorption in the next growing season.
[0045] 5. Plant growth regulator: Spray uniconazole twice, on September 15th and October 9th, 2023. Use 80 g of uniconazole mixed with 15 kg of tap water to spray 20 Sichuan pepper trees. Spraying uniconazole twice allows the chemical to exert its "low-promoting, high-inhibiting" effect while also saving costs.
[0046] While applying uniconazole, add 100 g of potassium dihydrogen phosphate (produced by Sichuan Guoguang Co., Ltd.) to control excessive shoot growth. Apply after 4 PM and allow it to sit overnight to ensure effective absorption by the leaves. Do not apply in the morning, otherwise the high midday temperatures will cause rapid evaporation and reduce the effectiveness of the application.
[0047] Potassium dihydrogen phosphate and uniconazole are added simultaneously, i.e., 80 g of uniconazole + 100 g of potassium dihydrogen phosphate are mixed with 15 kg of tap water and sprayed on 20 pepper trees. This operation is performed twice.
[0048] 6. Frost Control: During January 2024, when temperatures were below 0℃, dry pepper branches and leaves were burned in the pepper orchard, crushed into 1.5 cm pieces, with each fire having a radius of 18 m. Traditional techniques neglected frost control, resulting in frost damage to the bark and leaves, affecting flower bud differentiation, flowering, and fruit setting the following year.
[0049] Since most of the Sichuan pepper trees in Dingtan are plantations, the fumigation process also serves to sterilize, disinfect, and kill insect eggs, thus suppressing large-scale outbreaks of pests and diseases.
[0050] The results were as follows: fruit yield was 5.5 kg / tree, volatile oil content was 11.5%, total flavonoids content was 29‰, and pericarp thickness was 0.42 mm; the trees showed no obvious pests or diseases, and the leaves were dark green, indicating that the Dingtan pepper trees have strong growth and resilience to adverse conditions; the fresh fruit price was 28 yuan / kg, giving it strong market competitiveness, and the product was sold to Sichuan, Chongqing, and other regions; management costs were reduced by 60% compared to traditional techniques, and alternate bearing was overcome artificially. In summary, the increase in volatile oil content in Dingtan pepper fruits is the result of the combined effect of multiple technologies, and the synergy between these technologies should be emphasized.
[0051] Comparative Example 1 Compared with Examples 1 and 2, except for the use of a bush-shaped tree, all other steps were completely identical. The operations were performed at the locations of Examples 1 and 2, respectively. Comparative Example 1 used a bush-shaped tree with branches forming an angle of 60–70° with the ground. Measurements showed that the fruit yield was 3.2 kg / tree, the volatile oil content was 4.8%, the total cannabinoid content was 22‰, and the pericarp thickness was 0.31 mm, significantly lower than Examples 1 and 2. The reasons for this were: the space for this tree shape was relatively crowded, resulting in insufficient light and ventilation, leading to severe pests and diseases and a low amount of photosynthetic products; the high humidity in the local microhabitat also reduced the lignification of the branches. Observations showed that the fruit-bearing rate at the lower part of the branches was low, resulting in resource waste. Examples 1, 2, and Comparative Example 1 demonstrate that tree shape construction plays a crucial role in the formation of volatile oil in the fruit of *Zanthoxylum bungeanum*, determining the utilization of light, temperature, water, and air factors.
[0052] Comparative Example 2 Compared with Examples 1 and 2, except for the natural tree shape, all other steps were completely identical. The operations were performed at the locations of Examples 1 and 2, respectively. Comparative Example 2 used a natural tree shape, without any artificial intervention in branch growth, and the remaining operational steps remained unchanged. Measurements showed that the fruit yield was 2.4 kg / tree, the volatile oil content was 3.7%, the total flavonoid content was 23‰, and the peel thickness was 0.30 mm, all at relatively low levels. Comprehensive analysis revealed that the output and economic benefits of the natural tree shape were unsatisfactory. The reasons were analyzed as follows: due to the numerous and scattered branches, the load on nutrient and water transport increased, and excessive water diversion resulted in poor branch growth and the formation of many weak branches; insufficient nutrient and water supply made it difficult for the branches to lignify, leading to significantly lower yield and quality, with economic benefits only 35% of that of Example 1.
[0053] Comparative Example 3 Compared to Examples 1 and 2, fertilization along the canopy drip line was performed, with all other steps remaining identical. The procedures were conducted at the locations of Examples 1 and 2, respectively. Comparative Example 3 primarily involved fertilization along the canopy drip line, with all other measures being identical. Measurements showed that the fruit yield was 4.0 kg / tree, the volatile oil content was 5.9%, the total cannabinoid content was 22‰, and the pericarp thickness was 0.36 mm, significantly lower than Examples 1 and 2. The reasons for this are as follows: Because the Dingtan pepper plantation is located in a karst topography, the roots require ample space for horizontal and vertical growth to fully access nutrients. Fertilization along the canopy line prevents some roots from effectively obtaining readily available nutrients. Furthermore, due to the development of underground fissures and a high soil-to-rock ratio, nutrient distribution is not concentrated, and an excessively small fertilization area restricts root development. Additionally, the Dingtan pepper tree shape is pruned, reducing the canopy width, and the root distribution is not entirely consistent with the artificially shaped tree. Therefore, by considering the basic characteristics of the karst topography and developing reasonable management measures, the output value can be increased.
[0054] Comparative Example 4 Compared to Examples 1 and 2, only one application of compound fertilizer was made in November, with all other steps remaining identical. The procedures were performed at the locations of Examples 1 and 2, respectively. Comparative Example 4 involved applying compound fertilizer once in November 2023 at the same dosage, with all other implementation methods identical to Examples 1 and 2. Measurements showed a fruit yield of 2.7 kg / plant, a volatile oil content of 5.1%, a total flavonoid content of 20‰, and a peel thickness of 0.31 mm. Numerous new shoots were also observed. The reasons for this were analyzed as follows: severe drought occurred in the area from October to April of the following year, making it difficult for fertilizer to be effective. After the rainy season arrived in May, branches sprouted rapidly, consuming large amounts of nutrients and blocking sunlight, resulting in a decrease in yield and quality. Furthermore, the sprouted branches were difficult to prune, exhibiting a "the more you prune, the longer they grow" phenomenon, thus exacerbating the accumulation-consumption imbalance and increasing management costs.
[0055] Comparative Example 5 Compared to Examples 1 and 2, the fertilization depth was 0–5 cm, while all other steps were identical. The procedures were performed at the locations of Examples 1 and 2, respectively. In Comparative Example 5, the fertilization depth was set to 0–5 cm, with all other operations identical to Examples 1 and 2. Measurements showed that the fruit yield was 3.2 kg / plant, the volatile oil content was 6.3%, the total cannabinoid content was 21‰, and the pericarp thickness was 0.32 mm. The reasons for this were analyzed as follows: due to the shallow fertilization depth, the roots grew upwards, forming "aerial roots," making it difficult for most roots to effectively acquire nutrients, resulting in weak plant growth and poor disease resistance. Furthermore, the long-term drought in the area and the high heat caused high soil surface temperature and high evaporation, leading to the death of many fine roots and hindering their absorption function.
[0056] Comparative Example 6 Compared with Examples 1 and 2, the soil volumetric moisture content was maintained at approximately 32%–36%, and all other steps were identical. The operations were conducted at the locations of Examples 1 and 2, respectively. Comparative Example 6 maintained the soil volumetric moisture content at 32%–36% through moisture control. Measurements showed that the fruit yield was 3.2 kg / plant, the volatile oil content was 5.8%, the total cannabinoid content was 22‰, and the pericarp thickness was 0.33 mm, indicating unsatisfactory results. The reasons for this were analyzed as follows: The persistently moist environment around the fine roots of the Sichuan pepper plant negatively impacts root metabolism and nutrient absorption, inhibiting root activity; high soil moisture also hinders branch lignification, stimulating young shoot sprouting to some extent and increasing management costs and difficulty. The results indicate that due to the arid soil in this area, the Dingtan Sichuan pepper has developed its own adaptation mechanism. Cultivation measures should be formulated in conjunction with habitat characteristics and the ecological adaptation strategies of Dingtan Sichuan pepper, creating a moderately arid soil moisture environment, which is beneficial to plant growth.
[0057] Comparative Example 7 Compared to Examples 1 and 2, the soil turning time was late January, while all other steps were identical. The operations were conducted at the locations of Examples 1 and 2, respectively, while Comparative Example 7 involved soil turning in late January, with all other management practices remaining the same. Measurements showed that the fruit yield was 3.4 kg / tree, the volatile oil content was 4.9%, the total flavonoid content was 23‰, and the peel thickness was 0.34 mm, significantly lower than Examples 1 and 2. The reason for this is that turning the soil at this time disrupted the herbaceous and other ground cover layers, reducing the soil's water retention capacity. Given the severe winter and spring drought in this area, this exacerbated the soil drought, resulting in excessively low soil moisture content, which inhibited flower bud differentiation and reduced yield and quality. In conclusion, soil turning is not advisable in January and February. Therefore, only by combining technical improvements with regional ecological environment characteristics can suitable tree-planting techniques be developed for suitable locations.
[0058] Comparative Example 8 Compared to Examples 1 and 2, paclobutrazol and uniconazole were used simultaneously, with all other steps remaining identical. The procedures were performed at the locations of Examples 1 and 2, respectively. Comparative Example 8, based on Examples 1 and 2, added paclobutrazol, using 30 g of paclobutrazol mixed with 15 kg of tap water, and sprayed on 20 Sichuan pepper trees simultaneously with uniconazole. Measurements showed: fruit yield was 4.7 kg / tree, volatile oil content was 7.1%, total cannabinoids were 24‰, and pericarp thickness was 0.37 mm. Longer, narrower, and curled leaves were observed, affecting normal leaf function. The reasons for this were analyzed as follows: paclobutrazol has a long residual time, affecting the drought resistance of the Sichuan pepper trees; coupled with the severe drought in the area, a large amount of resources and energy were invested in drought resistance, impacting yield and quality. Uniconazole degrades more quickly, which is beneficial for promoting soil health and ecological safety.
[0059] Comparative Example 9 Compared to Examples 1 and 2, no anti-freezing measures were taken in winter, while all other steps remained identical. The operations were conducted at the locations of Examples 1 and 2, respectively. Comparative Example 9 did not employ anti-freezing measures in winter, but all other operational methods were identical. Measurements showed that the fruit yield was 3.5 kg / tree, the volatile oil content was 5.8%, the total flavonoid content was 23‰, and the pericarp thickness was 0.37 mm. Significant leaf frost damage was observed in high-altitude areas, followed by continuous leaf drop. The reason for this is that although the frost duration in this area was short, it still damaged the Sichuan pepper trees, softening the bark and hindering lignification, thus restricting nutrient and water transport. The consequences of this damage were greater than those caused by freezing rain or snowstorms. Using the smoke from burning Sichuan pepper branches and leaves to prevent frost damage can avoid tree injury and also accelerate nutrient return to the field to some extent.
[0060] Comparative Example 10 For the natural tree shape, fertilization was applied along the drip line of the canopy, using only compound fertilizer and relying on natural rainfall. Other steps were the same as in Examples 1 and 2. Measurements showed that the fruit yield was 2.3 kg / tree, the volatile oil content was 3.9%, the total flavonoid content was 22‰, and the peel thickness was 0.35 mm. Both yield and quality were low, failing to achieve good economic benefits. The reasons were analyzed as follows: traditional techniques did not effectively coordinate the relationship between water, fertilizer, and light, leading to disordered tree shape and nutrient deficiencies. Due to insufficient water and fertilizer supply, the top-grown pepper trees prioritized vegetative growth, making it difficult to transition to the reproductive growth stage, thus lacking the foundation for yield and quality formation. Therefore, improving fruit essential oil content should be the result of a synergistic effect of multiple methods, emphasizing the comprehensiveness of the techniques.
[0061] The method of this invention is highly advanced, realizing the synergistic coupling of ecological factors, significantly increasing the yield and volatile oil content of Sichuan pepper (see Table 1 for details), producing high-quality Sichuan pepper with excellent appearance and high price, and greatly improving economic benefits.
[0062] Table 1. Quality of Sichuan pepper obtained by different methods
[0063] As shown in Table 1, tree shape, water and fertilizer have a significant impact on the quality of Dingtan pepper fruit, which is attributed to their coordinated effect among ecological factors. At the same time, improving the essential oil content of Dingtan pepper fruit is the result of the synergistic effect of multiple technologies, and it is difficult to achieve excellent results by relying on a single technology.
[0064] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.
Claims
1. A method for increasing the volatile oil content of Sichuan pepper fruits, characterized in that, Includes the following steps: (1) Shaping and pruning: During the fruit harvesting period of the pepper tree, the branches are pruned, and in mid-to-late October, the branches are pressed and pruned to make the tree shape open-center. (2) Soil turning: Turn the soil once every 6 to 7 months after pruning; (3) Water and fertilizer management: Apply organic fertilizer in July of the year after pruning, and apply compound fertilizer once in August and once in March or April of the following year. The fertilization area should extend horizontally 1.2 to 1.5 times beyond the tree canopy line and vertically 20 to 30 cm away from the soil surface; the water content should be maintained at 25% to 30%. (4) Application of plant growth regulators: Spray acetamiprid once each in September and October; (5) Frost control: When the temperature is below 0℃, burn the branches and leaves of Sichuan pepper; (6) Disease and pest control.
2. The method according to claim 1, characterized in that, In step (1), the number of prickly ash tree branches after pruning is 40 to 50, the angle between the branches and the ground is 20 to 25°, and the length of the branches is 0.8 to 1 m.
3. The method according to claim 1, characterized in that, The organic fertilizer mentioned in step (3) is well-rotted cow manure, and the amount used per plant is 2-3 kg.
4. The method according to claim 1, characterized in that, The compound fertilizer mentioned in step (3) has a N-P2O5-K2O percentage content of 15-15-15 and a dosage of 0.25 kg per plant.
5. The method according to claim 1, characterized in that, In step (4), the uniconazole is prepared by mixing 80 g of uniconazole with 15 kg of tap water and spraying it on 20 pepper trees.
6. The method according to claim 5, characterized in that, Step (4) also includes adding 100 g of potassium dihydrogen phosphate while applying uniconazole. The method of adding is to mix 80 g of uniconazole and 100 g of potassium dihydrogen phosphate with 15 kg of tap water and spray it on 20 pepper trees.
7. The method according to claim 1, characterized in that, The specific operation for frost prevention in step (5) is to burn dried pepper branches and leaves in the pepper garden. Before burning, the branches and leaves are first crushed into 1-1.5 cm pieces, and the radiation radius of each fire pile is 18-20 m.
8. The method according to claim 1, characterized in that, The pest and disease control described in step (6) uses 75% oxamycin·tebuconazole and 5% acetamiprid EC.
9. The application of the method according to any one of claims 1 to 8 in increasing the volatile oil content of Sichuan pepper fruit.