Pomegranate seed germination method

Abstract

The present application relates to the grafting technical field, especially to a pomegranate seedling grafting method in dry-hot valley area, and the pomegranate seedling grafting method specifically comprises the following steps: site selection: the nursery site is selected to be convenient for traffic, sufficient sunlight, deep soil layer, loose soil, convenient for irrigation and drainage, and the light soil or sandy soil block with good water storage and fertilizer preservation; land preparation: the pomegranate nursery block is subjected to 30-40 cm deep ploughing and fertilization; and the nursery is formed into a block; selection of scion: selecting two-year-old growth branches or new shoots grown this year with strong growth, full bud eyes, full development, no disease as the scion; rootstock planting; rootstock management; grafting at the right time; seedling stage management; fertilization.The present application improves the grafting survival rate of pomegranate seedlings, enhances the disease resistance of pomegranate trees, and improves the quality of pomegranate, and is an excellent method suitable for pomegranate seedling grafting in dry-hot valley areas.

Description

Technical Field

[0001] This invention relates to the field of grafting technology, and more particularly to a method for grafting pomegranate seedlings in arid and hot valley regions. Background Technology

[0002] In recent years, with the increasing demand in both international and domestic markets, pomegranate production in my country has received widespread attention, with rapid expansion in acreage and yield, gradual improvement in quality and grade, support and development of storage and processing industries, and the opening of export channels, indicating a promising market outlook. Some regions have already made the pomegranate industry a pillar industry for developing local rural economies, increasing farmers' income, and building new rural areas. The main propagation methods for pomegranates include cuttings, grafting, and division. Cuttings and division are asexual propagation methods that maintain varietal traits and are suitable for new and superior varieties. Grafting techniques are generally used for improving and updating older varieties, leveraging the advantages of the rootstock to encourage earlier fruiting of the scion variety, or for the rapid propagation and preservation of rare resources. However, pomegranate grafting generally suffers from insufficient grafting compatibility, poor control of rootstock germination time leading to premature or delayed water supply to the rootstock, resulting in "bud drop" or "bud dieback," and low grafting survival rates. Therefore, there is an urgent need for a pomegranate seedling grafting technique suitable for hot and dry valley regions to improve grafting survival rates. Summary of the Invention

[0003] The features and advantages of the present invention are set forth in part in the description which follows, or may be apparent from the description, or may be learned by practicing the invention.

[0004] To overcome the problems of existing technologies, this invention provides a method for grafting pomegranate seedlings in hot and dry valley regions, characterized in that the method specifically includes the following steps:

[0005] Site selection: The nursery site should be located in a light loam or sandy loam soil with convenient transportation, plenty of sunshine, deep soil, loose soil, convenient irrigation and drainage, and good water retention and fertilizer retention.

[0006] Land preparation: The pomegranate nursery plots need to be deeply tilled to a depth of 30-40 cm and fertilized; then the soil should be prepared into nursery beds;

[0007] Scion selection: Select vigorous, healthy, well-developed, and disease-free two-year-old branches or new shoots that have grown in the current year as scions;

[0008] Rootstock planting: Rootstock planting should be done in mid-December using short-branch cuttings. Two-year-old branches (0.5-1 cm in diameter) should be taken from local, mature pomegranate trees that are of pure variety, robust, free from pests and diseases, and have high yields. Select cuttings with more thorns at the base to encourage root development. Cut the cuttings short, ensuring each cutting retains at least one bud. Insert the basal and middle sections of the cuttings separately. Cover with plastic film after planting.

[0009] Rootstock management: When the nursery soil becomes dry, promptly remove the plastic film and irrigate. When the seedlings are ≥10 cm tall, retain one strong new shoot and prune all other branches and buds. When the new shoots grow to 15 cm, apply a quick-acting nitrogen fertilizer once, using 15 kg of urea per acre. Apply fertilizer again in mid-June and late July. Control pests and diseases during the seedling growth period.

[0010] Grafting at the right time: Three-cut grafting is performed in the spring, summer, and autumn of the following year; spring grafting uses branch grafting, summer grafting uses bud grafting, and autumn grafting uses branch grafting; the three-cut grafting includes the following steps:

[0011] The first cut grafted a Sichuan Huili pomegranate onto a local old variety of pomegranate seedling; the second cut grafted a Tunisian soft-seeded pomegranate onto a Sichuan Huili pomegranate branch; the third cut grafted an Israeli sweet and sour pomegranate onto a Tunisian soft-seeded pomegranate branch.

[0012] Seedling management: Remove the plastic film promptly when new buds appear at the grafting point. When the seedling height is ≥10 cm, retain one strong new shoot and prune all other branches and buds. Control pests and diseases during the seedling growth period.

[0013] From January to March, water every 15 days; from April to May, water every 10 days; in June, during the rainy season, weed once a month and spray with lime sulfur solution at 15-17 Baume degrees every two months; in December, prune once, leaving one strong seedling per pond and cutting off the rest, and top the remaining strong seedling 20-30 cm above the ground;

[0014] Fertilization: Do not fertilize from January to March; start fertilizing from April to September, once a month, mainly with nutrient solution micro-fertilizer and water-soluble organic fertilizer, apply less nitrogen fertilizer, and apply appropriate amounts of phosphorus and potassium fertilizer.

[0015] Preferably, the amount of fertilizer applied during land preparation is 25-30 kg of high-quality organic fertilizer and 8-12 kg of phosphate fertilizer per mu.

[0016] Preferably, the nursery bed has a width of 90-120 cm, a ridge height of 15-30 cm, and a furrow width of 20-30 cm.

[0017] Preferably, in the scion selection step: when selecting scions using rootstock cleft grafting or bark grafting, two-year-old branches are selected; when selecting scions using bud grafting, new shoots grown in the current year are selected.

[0018] Preferably, the scions can be preserved using any one of the following methods: cellar storage, trench storage, or sand storage. When cellar storage is used, the storage temperature should be controlled at around 0°C. When trench storage is used, the scions should be covered with fine sand. When sand storage is used, fine sand should be used, and the moisture content of the fine sand should be controlled at 30%-40%. The scions should be buried in 20 cm thick fine sand. When transporting the scions, they should be sealed with wax, wrapped in straw bags or plastic bags, and the variety and quantity should be clearly marked. After arriving at the designated location, the bags should be opened immediately, and the scions should be buried in damp sand and stored in a cool place.

[0019] Preferably, the buds at the top of the cuttings should be 1-2 cm above the ground, the plant spacing should be 10-15 cm, the row spacing should be 30-35 cm, and 3-4 rows should be planted per bed, with 15,000-17,000 plants per acre.

[0020] Preferably, the pest control includes using 25% diflubenzuron suspension at 1500-2000 times dilution, 20% chlorantraniliprole emulsifiable concentrate at 3000-4000 times dilution, 10% lambda-cyhalothrin emulsifiable concentrate at 2000-2500 times dilution, 22% flonicamid suspension at 4000-5000 times dilution, 3% acetamiprid emulsifiable concentrate at 1500-2500 times dilution, 30% thiamethoxam aqueous solution at 4000-6000 times dilution, 24% spirotetramat suspension at 4000-5000 times dilution, and 24% spirodiclofen suspension at 3000 times dilution. For the control of aphids, thrips, lepidopteran pests, coleopteran pests, scale insects, and spider mites, at least one of the following pesticides: 0-5000 times dilution, 6000-7000 times dilution of 11% etoxazole suspension; and the placement of insecticidal lamps and sticky traps in the nursery. For the control of diseases, at least one of the following pesticides is used to control brown spot disease: 3000-4000 times dilution of 10% difenoconazole water-dispersible granules, 500-600 times dilution of 50% carbendazim wettable powder, or 6000-8000 times dilution of 40% flusilazole emulsifiable concentrate.

[0021] Preferably, the grafting interval between the first, second, and third grafting cuts is 80-100 days.

[0022] The beneficial effects of this invention are as follows: By combining techniques such as three-cut grafting and timely grafting, this invention enhances the grafting affinity, avoids death caused by "bud drop" or "bud dieback," improves the grafting survival rate of pomegranate seedlings, strengthens the disease resistance of pomegranate trees, and improves the quality of pomegranates. It is an excellent method for grafting pomegranate seedlings in arid and hot valley regions. Pomegranate seedlings grafted using the method of this invention produce pomegranates with a higher rate of large fruit, more juice and sweetness, and of extremely high quality after maturing. Detailed Implementation

[0023] The embodiments of the present invention will be described in further detail below with reference to examples. These examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0024] Example 1

[0025] This embodiment provides a method for grafting pomegranate seedlings in a hot and dry valley region, specifically including the following steps:

[0026] Site selection: The nursery site should be located in a place with convenient transportation, plenty of sunshine, deep soil, loose soil, convenient irrigation and drainage, and good water retention and fertilizer retention, such as light loam or sandy loam.

[0027] Land preparation: The pomegranate nursery plots should be deeply tilled to a depth of 30-35 cm; apply 25 kg of high-quality organic fertilizer and 10 kg of phosphate fertilizer per mu (unit of land area) during deep tilling. The nursery plots should be prepared with a width of 100 cm, a ridge height of 20 cm between the plots, and a furrow width of 20 cm.

[0028] Scion selection: For cleft grafting and bark grafting, select vigorous, healthy, well-developed, and disease-free two-year-old branches. For bud grafting, select vigorous, well-developed, and disease-free new shoots that have grown in the current year. Such scions have strong survival ability, heal quickly from wounds, and can grow and develop rapidly to survival.

[0029] Scion Preservation: Scions can be preserved using any of three methods: cellar storage, trench storage, or sand storage. When using cellar storage, the temperature should be controlled at around 0°C. When using trench storage, the scions must be covered with fine sand. When using sand storage, the moisture content of the sand should be controlled at 30%-40%, and the scions should be covered with 20 cm of fine sand on all sides. During transportation, scions can be sealed with wax, wrapped in straw bags or plastic bags, and labeled with the variety and quantity. Upon arrival, immediately open the bags and bury the scions in damp sand, storing them in a cool, dark place.

[0030] Rootstock Planting: Rootstock planting should be done in mid-December using short-branch cuttings. Two-year-old branches from purebred, robust, disease-free, and high-yielding local pomegranate varieties should be used as cuttings, with a thickness of 0.5-1 cm. Cuttings with more thorns at the base are preferred to encourage root development. The cuttings should be shortened to obtain scions, each retaining at least one bud. When planting, separate the basal cuttings from those in the middle to ensure uniform emergence, preventing larger seedlings from dominating smaller ones and facilitating graded management, thus increasing the rate of first-grade seedlings. The bud at the top of the cutting should be 1-2 cm above the ground. Planting spacing should be 10-15 cm between plants and 30-35 cm between rows, with 3-4 rows per bed. 15,000-17,000 cuttings can be planted per acre. After planting, cover with plastic film.

[0031] Rootstock management: When the soil covered with mulch dries out, remove the mulch and irrigate promptly. When the seedlings reach 10 cm in height, retain one strong new shoot and prune all other branches and buds. When the new shoots reach 15 cm in length, apply a quick-acting nitrogen fertilizer once, using 15 kg of urea per acre. Apply top dressing again in mid-June and late July, controlling nitrogen fertilizer application and appropriately using phosphorus and potassium fertilizers to prevent excessive vegetative growth. During the seedling growth period, use 25% diflubenzuron suspension at 1500-2000 times dilution, or 20% chlorantraniliprole EC at 3000-4000 times dilution, or 10% lambda-cyhalothrin EC at 2000-2500 times dilution, or 22% flonicamid suspension at 4000-5000 times dilution, or 3% acetamiprid EC at 1500-2500 times dilution, or 30% thiamethoxam Aqueous solution at 4000-6000 times dilution, or 24% spirotetramat suspension at 4000-5000 times dilution, or 24% spirodiclofen suspension at 3000-5000 times dilution, or 1 For the control of aphids, thrips, lepidopteran pests, coleopteran pests, scale insects, and spider mites, pesticides such as 1% etoxazole suspension at a dilution of 6000–7000 times are used. Insecticidal lamps are placed in nurseries to attract and kill lepidopteran and coleopteran pests, and yellow and green sticky traps are used to attract and kill thrips and aphids. For the control of diseases, pesticides such as 10% difenoconazole water-dispersible granules at a dilution of 3000–4000 times, 50% carbendazim wettable powder at a dilution of 500–600 times, or 40% flusilazole emulsifiable concentrate at a dilution of 6000–8000 times are used to control brown spot disease.

[0032] Grafting timing: Three-cut grafting is used, and grafting is carried out in spring, summer, and autumn. Spring grafting uses branch grafting, summer grafting uses bud grafting, and autumn grafting uses branch grafting.

[0033] The three-cut grafting process involves the following steps: The first cut is carried out in spring, grafting a Sichuan Huili pomegranate onto a local old variety of pomegranate seedling; the second cut is carried out in summer, 80 to 100 days after the first cut, grafting a Tunisian soft-seeded pomegranate onto the first-cut pomegranate seedling; the third cut is carried out in autumn, 80 to 100 days after the second cut, grafting an Israeli sweet and sour pomegranate onto the second-cut pomegranate seedling.

[0034] Seedling management: Once new buds appear at the grafting point, immediately remove the plastic film. When the seedlings reach 10 cm in height, retain one strong new shoot and prune all other branches and buds. Control aphids, spider mites, inchworms, tussock moths, and other pests with a 1000-fold dilution of 50% fenitrothion and a 3000-fold dilution of 25% deltamethrin.

[0035] From January to March, water every 15 days; from April to May (before the rainy season), water every 10 days; in June, when the rainy season begins, weed once a month and spray with lime sulfur solution at 15-17 Baume degrees every two months. From March to October, place insecticidal lamps and sticky traps in the nursery. Prune once in December. Many lateral branches will sprout from the soil around the seedlings. Leave one strong seedling per planting hole and cut off the rest. Top the remaining strong seedling 20-30 cm above the ground.

[0036] Fertilization: Do not fertilize from January to March; begin fertilizing from April to September, once a month. Use mainly nutrient solution micronutrients and water-soluble organic fertilizers, apply less nitrogen fertilizer, and apply appropriate amounts of phosphorus and potassium fertilizers to prevent excessive growth of seedlings that could lead to an imbalance between physiological and reproductive growth.

[0037] After completing three grafting operations within a year, the survival rate of pomegranate seedlings can reach 98%. The fruit production and quality of the grafted seedlings are recorded as they grow. The pomegranates are of excellent quality, with a high rate of large fruits, large fruit size, thin skin, large seeds, soft flesh, and sweet, juicy flesh.

[0038] Example 2

[0039] This embodiment provides a method for grafting pomegranate seedlings in a hot and dry valley region, specifically including the following steps:

[0040] Site selection: The nursery site should be located in a light loam or sandy loam soil with convenient transportation, plenty of sunshine, deep soil, loose soil, convenient irrigation and drainage, and good water retention and fertilizer retention.

[0041] Land preparation: The pomegranate nursery plots should be deeply tilled to a depth of 30-40 cm; apply 28 kg of high-quality organic fertilizer and 8 kg of phosphate fertilizer per mu in conjunction with the deep tilling. The plots should be prepared with ridges 90 cm wide, ridges 15 cm high, and furrows 25 cm wide.

[0042] Scion selection: For cleft grafting and bark grafting, select vigorous, healthy, well-developed, and disease-free two-year-old branches. For bud grafting, select vigorous, well-developed, and disease-free new shoots that have grown in the current year. Such scions have strong survival ability, heal quickly from wounds, and can grow and develop rapidly to survival.

[0043] Scion Preservation: Pomegranate scions can be preserved using any of three methods: cellar storage, trench storage, or sand storage. For cellar storage, the temperature should be controlled at around 0°C. For trench storage, the scions must be covered with fine sand. For sand storage, the moisture content of the sand should be controlled at 30%-40%, with the scions covered in fine sand for 20 cm on each side. For transportation, pomegranate scions can be sealed with wax, wrapped in straw bags or plastic bags, and labeled with the variety and quantity. Upon arrival, immediately open the bags and bury the scions in damp sand in a cool, dark place.

[0044] Rootstock Planting: Rootstock planting should be done in mid-December using short-branch cuttings. Two-year-old branches of purebred, robust, disease-free, and high-yielding trees should be used as cuttings, with a thickness of 0.5-1 cm. Cuttings with more thorns at the base are preferred to encourage root development. Shorten the cuttings to obtain scions, ensuring each scion retains at least one bud. When planting, separate the basal cuttings from those in the middle to ensure uniform emergence, preventing larger seedlings from dominating smaller ones and facilitating graded management, thus increasing the rate of first-grade seedlings. The bud at the top of the cutting should be 1-2 cm above the ground. Plant spacing should be 10-15 cm, and row spacing 30-35 cm, with 3-4 rows per bed. 15,000-17,000 cuttings can be planted per acre. After planting, cover with plastic film.

[0045] Rootstock management: When the soil covered with mulch dries out, remove the mulch and irrigate promptly. When the seedlings reach 9 cm in height, retain one strong new shoot and prune all other branches and buds. When the new shoots reach 15 cm in length, apply a quick-acting nitrogen fertilizer once, using 15 kg of urea per acre. Apply top dressing again in mid-June and late July, controlling nitrogen fertilizer application and appropriately using phosphorus and potassium fertilizers to prevent excessive vegetative growth. During the seedling growth period, use a mixture of 25% diflubenzuron suspension at 1500-2000 times dilution, 20% chlorantraniliprole EC at 3000-4000 times dilution, 10% lambda-cyhalothrin EC at 2000-2500 times dilution, and 22% flonicamid suspension at 4000-5000 times dilution to control aphids, thrips, lepidopteran pests, coleopteran pests, scale insects, and spider mites. Also, place insecticidal lamps in the nursery to attract and kill lepidopteran and coleopteran pests, and place yellow and green sticky traps to attract and kill thrips and aphids. Disease control includes using 10% difenoconazole water-dispersible granules at 3000-4000 times dilution and 50% carbendazim wettable powder to control brown spot disease.

[0046] Grafting timing: Three-cut grafting is used, and grafting is carried out in spring, summer, and autumn. Spring grafting uses branch grafting, summer grafting uses bud grafting, and autumn grafting uses branch grafting.

[0047] The three-cut grafting process includes the following steps: The first cut is carried out in spring, grafting a Sichuan Huili pomegranate onto a local old variety of pomegranate seedling; the second cut is carried out in summer, 100 days after the first grafting, grafting a Tunisian soft-seeded pomegranate onto a Sichuan Huili pomegranate seedling; the third cut is carried out in autumn, 100 days after the second grafting, grafting an Israeli sweet and sour pomegranate onto a Tunisian soft-seeded pomegranate seedling.

[0048] Seedling management: Once new buds appear at the grafting point, immediately remove the plastic film. When the seedlings reach 11 cm in height, retain one strong new shoot and prune all other branches and buds. Control aphids, spider mites, inchworms, tussock moths, and other pests with 1000 times dilution of 50% fenitrothion or 3000 times dilution of 25% deltamethrin.

[0049] From January to March, water every 15 days; from April to May (before the rainy season), water every 10 days; in June, when the rainy season begins, weed once a month and spray with lime sulfur solution at 15-17 Baume degrees every two months. From March to October, place insecticidal lamps and sticky traps in the nursery. Prune once in December. Many lateral branches will sprout from the soil around the seedlings. Leave one strong seedling per planting hole and cut off the rest. Top the remaining strong seedling 20-30 cm above the ground.

[0050] Fertilization: Do not fertilize from January to March; begin fertilizing from April to September, once a month. Use mainly nutrient solution micronutrients and water-soluble organic fertilizers, apply less nitrogen fertilizer, and apply appropriate amounts of phosphorus and potassium fertilizers to prevent excessive growth of seedlings that could lead to an imbalance between physiological and reproductive growth.

[0051] Three grafting operations were completed within one year. The following year, the survival rate of the grafted pomegranate seedlings was 98.2%. The fruit production and quality of the grafted seedlings were recorded as they grew. The pomegranates were of excellent quality, with a high rate of large fruits, large fruit size, thin skin, large seeds, soft flesh, and sweet, juicy flesh.

[0052] Example 3

[0053] This embodiment provides a method for grafting pomegranate seedlings in a hot and dry valley region, specifically including the following steps:

[0054] Site selection: The nursery site should be located in a light loam or sandy loam soil with convenient transportation, plenty of sunshine, deep soil, loose soil, convenient irrigation and drainage, and good water retention and fertilizer retention.

[0055] Land preparation: The pomegranate nursery plots should be deeply tilled to a depth of 30-40 cm; apply 30 kg of high-quality organic fertilizer and 12 kg of phosphate fertilizer per mu (unit of land area) during deep tilling. The nursery plots should be prepared with a width of 120 cm, a ridge height of 30 cm between plots, and a furrow width of 30 cm.

[0056] Scion selection: For cleft grafting and bark grafting, select vigorous, healthy, well-developed, and disease-free two-year-old branches. For bud grafting, select vigorous, well-developed, and disease-free new shoots that have grown in the current year. Such scions have strong survival ability, heal quickly from wounds, and can grow and develop rapidly to survival.

[0057] Scion Preservation: Pomegranate scions can be preserved using any of three methods: cellar storage, trench storage, or sand storage. When using cellar storage, the temperature should be controlled at around 0°C. When using trench storage, the scions must be covered with fine sand. For sand storage, the moisture content of the sand should be controlled at 30%-40%, and the pomegranate scions should be covered with 20 cm of fine sand on all sides. For transportation, pomegranate scions can be sealed with wax, wrapped in straw bags or plastic bags, and labeled with the variety and quantity. Upon arrival, immediately open the bags and bury the scions in damp sand in a cool, shaded place.

[0058] Rootstock Planting: Rootstock planting should be done in mid-December using short-branch cuttings. Two-year-old branches of purebred, robust, disease-free, and high-yielding trees should be used as cuttings, with a thickness of 0.5-1 cm. Cuttings with more thorns at the base are preferred to encourage root development. Shorten the cuttings to obtain scions, ensuring each scion retains at least one bud. When planting, separate the basal cuttings from those in the middle to ensure uniform emergence, preventing larger seedlings from dominating smaller ones and facilitating graded management, thus increasing the rate of first-grade seedlings. The bud at the top of the cutting should be 1-2 cm above the ground. Plant spacing should be 10-15 cm, and row spacing 30-35 cm, with 3-4 rows per bed. 15,000-17,000 cuttings can be planted per acre. After planting, cover with plastic film.

[0059] Rootstock Management: When the soil under the mulch dries out, promptly remove the mulch and irrigate. When the seedlings reach about 10 cm in height, retain one strong new shoot and prune all other branches and buds. When the new shoot reaches 15 cm, apply a quick-acting nitrogen fertilizer once, using 15 kg of urea per mu (approximately 0.067 hectares). Apply fertilizer again in mid-June and late July, controlling nitrogen fertilizer application and appropriately applying phosphorus and potassium fertilizers to prevent excessive vegetative growth. During the seedling growth period, control aphids, thrips, and lepidopteran pests with any two of the following pesticides: 22% flonicamid suspension at 4000–5000 times dilution, 3% acetamiprid EC at 1500–2500 times dilution, 30% thiamethoxam aqueous solution at 4000–6000 times dilution, 24% spirotetramat suspension at 4000–5000 times dilution, 24% spirodiclofen suspension at 3000–5000 times dilution, or 11% etoxazole suspension at 6000–7000 times dilution. The treatment includes controlling pests such as coleopteran pests, scale insects, and spider mites, as well as using insecticidal lamps in the nursery to trap lepidopteran and coleopteran pests, and using yellow and green sticky traps to trap thrips and aphids; disease control includes using any two of the following pesticides to control brown spot disease: 10% difenoconazole water-dispersible granules at a dilution of 3000-4000 times, 50% carbendazim wettable powder at a dilution of 500-600 times, or 40% flusilazole emulsifiable concentrate at a dilution of 6000-8000 times.

[0060] Grafting timing: Three-cut grafting is used, and grafting is carried out in spring, summer, and autumn. Spring grafting uses branch grafting, summer grafting uses bud grafting, and autumn grafting uses branch grafting.

[0061] The three-cut grafting process involves the following steps: The first cut is carried out in spring, grafting a Sichuan Huili pomegranate onto a local old variety of pomegranate seedling; the second cut is carried out in summer, 80 days after the first grafting, grafting a Tunisian soft-seeded pomegranate onto a Sichuan Huili pomegranate seedling; the third cut is carried out in autumn, 85 days after the second grafting, grafting an Israeli sweet and sour pomegranate onto a Tunisian soft-seeded pomegranate seedling.

[0062] Seedling management: Remove the plastic film promptly when new buds emerge from the grafting point. When the seedlings reach 12 cm in height, retain one strong new shoot and prune all other branches and buds. Control aphids, spider mites, inchworms, and tussock moths with 1000 times dilution of 50% fenitrothion or 3000 times dilution of 25% deltamethrin.

[0063] From January to March, water every 15 days; from April to May (before the rainy season), water every 10 days; in June, when the rainy season begins, weed once a month and spray with lime sulfur solution at 15-17 Baume degrees every two months. From March to October, place insecticidal lamps and sticky traps in the nursery. Prune once in December. Many lateral branches will sprout from the soil around the seedlings. Leave one strong seedling per planting hole and cut off the rest. Top the remaining strong seedling 20-30 cm above the ground.

[0064] Fertilization: Do not fertilize from January to March; begin fertilizing from April to September, once a month. Use mainly nutrient solution micronutrients and water-soluble organic fertilizers, apply less nitrogen fertilizer, and apply appropriate amounts of phosphorus and potassium fertilizers to prevent excessive growth of seedlings that could lead to an imbalance between physiological and reproductive growth.

[0065] Three grafting operations were completed within one year. In May of the following year, the survival rate of the grafted pomegranate seedlings was 96.8%. The fruit production and quality of the grafted seedlings were recorded as they grew. The pomegranates were of excellent quality, with a high rate of large fruits, large fruit size, thin skin, large seeds, soft flesh, and sweet, juicy flesh.

[0066] Comparative Example 1

[0067] In Example 3, a plot of land is reserved at the edge of the land parcel for the implementation of this example, specifically including the following steps:

[0068] Site selection: The nursery site should be located in a place with convenient transportation, plenty of sunshine, deep soil, loose soil, convenient irrigation and drainage, and good water retention and fertilizer retention, such as light loam or sandy loam.

[0069] Land preparation: The pomegranate nursery plots should be deeply tilled to a depth of 30-40 cm; apply 30 kg of high-quality organic fertilizer and 12 kg of phosphate fertilizer per mu (unit of land area) during deep tilling. The nursery plots should be prepared with a width of 1.2 meters, a ridge height of 30 cm between the plots, and a bottom width of 0.4 meters.

[0070] Select cuttings: Choose vigorous, healthy, well-developed, and disease-free two-year-old branches;

[0071] Scion Preservation: Scions can be preserved using any of three methods: cellar storage, trench storage, or sand storage. For cellar storage, the temperature should be controlled at around 0°C. For trench storage, the scions must be covered with fine sand. For sand storage, the moisture content of the sand should be controlled at 30%-40%, and the scions should be covered with 20 cm of fine sand on all sides. During transportation, scions can be sealed with wax, wrapped in straw bags or plastic bags, and labeled with the variety and quantity. Upon arrival, immediately open the bags and bury the scions in damp sand in a cool, dark place.

[0072] Rootstock Planting: Rootstock planting should be done in mid-December using short-branch cuttings. Two-year-old branches of purebred, robust, disease-free, and high-yielding local cultivars should be used as cuttings, with a thickness of 0.5-1 cm. Cuttings with more thorns at the base are preferred to encourage root development. Shorten the cuttings to obtain scions, ensuring each scion retains at least one bud. When planting, separate the basal cuttings from those in the middle to ensure uniform emergence, preventing larger seedlings from dominating smaller ones and facilitating graded management, thus increasing the rate of first-grade seedlings. The bud at the top of the cutting should be 1-2 cm above the ground. Plant spacing should be 10-15 cm, and row spacing 30-35 cm, with 3-4 rows per bed. Cover the bed with plastic film after planting.

[0073] Rootstock Management: When the soil mulched with plastic film dries out, promptly remove the film and irrigate. When the seedlings reach about 10 cm in height, retain one strong new shoot and prune all other branches and buds. When the new shoots reach 15 cm in length, apply a quick-acting nitrogen fertilizer, using 15 kg of urea per acre. Apply fertilizer again in mid-June and late July, controlling nitrogen fertilizer application and appropriately applying phosphorus and potassium fertilizers to prevent excessive vegetative growth. During the seedling growth period, control pests such as aphids, spider mites, inchworms, and tussock moths by successively applying 50% fenitrothion at a dilution of 1000 times and 25% deltamethrin at a dilution of 3000 times.

[0074] Grafting Timing: In this implementation, the entire plot was divided into three equal sections, and a single-cut grafting method was used. The grafting times for the three sections were spring, summer, and autumn, respectively. Spring grafting used branch grafting, summer grafting used bud grafting, and autumn grafting used branch grafting. During grafting, Israeli sweet and sour pomegranate seeds were grafted onto local old-variety pomegranate seedlings, completing the single-cut grafting.

[0075] Seedling management: Once new buds appear at the grafting point, immediately remove the plastic film. When the seedlings are about 10 cm tall, retain one strong new shoot and prune all other branches and buds. Control aphids, spider mites, inchworms, tussock moths, and other pests with 1000 times dilution of 50% fenitrothion or 3000 times dilution of 25% deltamethrin.

[0076] From January to March, water every 15 days; from April to May (before the rainy season), water every 10 days; in June, when the rainy season begins, weed once a month and spray with lime sulfur solution at 15-17 Baume degrees every two months. From March to October, place insecticidal lamps and sticky traps in the nursery. Prune once in December. Many lateral branches will sprout from the soil around the seedlings. Leave one strong seedling per planting hole and cut off the rest. Top the remaining strong seedling 20-30 cm above the ground.

[0077] Fertilization: Do not fertilize from January to March; begin fertilizing from April to September, once a month. Use mainly nutrient solution micronutrients and water-soluble organic fertilizers, apply less nitrogen fertilizer, and apply appropriate amounts of phosphorus and potassium fertilizers to prevent excessive growth of seedlings that could lead to an imbalance between physiological and reproductive growth.

[0078] In May of the following year, the survival rates of pomegranate seedlings in the three small plots were calculated, and were 88.3%, 92.1%, and 90.6% respectively, with an average survival rate of 90.3% for the entire plot. The fruit production and quality of the grafted seedlings were also recorded. The pomegranate fruit quality was generally poor, with a low rate of large fruit, and the fruit was large with thin skin, semi-soft seeds, and a sweet and sour taste.

[0079] After transplanting the grafted seedlings from Examples 1-3 and Comparative Example 1, they were managed using the same conventional care methods. The fruit production and quality were recorded in the fifth year after transplanting, as shown in Table 1.

[0080] Table 1. Statistical Record of Fruit Yield and Fruit Quality

[0081] Example 1 98％ 45.10％ 46.20％ 17.1 Example 2 98.20％ 41.50％ 47.80％ 16.8 Example 3 96.80％ 42.60％ 45.80％ 17.3 Comparative Example 1 90.30％ 22.60％ 41.4％ 11.5

[0082] As shown in Table 1, the survival rate of pomegranate seedlings grafted using the method of this invention remains at a high level. Compared with grafting methods involving only one grafting cut, the survival rate of pomegranate seedlings is significantly improved, making it more suitable for mass planting. Furthermore, after grafting pomegranate seedlings using the method provided by this invention, the resulting mature trees produce pomegranates with a higher rate of large fruits, higher sweetness, and excellent quality, better meeting market demand and offering a broader market prospect.

[0083] The above description illustrates preferred embodiments of the present invention. Contents not described herein are considered prior art, and those skilled in the art can implement the present invention in various modifications without departing from its scope and essence. For example, a feature shown or described in one embodiment can be used in another embodiment to obtain yet another embodiment. The above are merely preferred embodiments of the present invention and do not limit the scope of the present invention. All equivalent changes made based on the content of this specification are included within the scope of the present invention.

Claims

1. A method for grafting pomegranate seedlings in arid and hot valley regions, characterized in that, The pomegranate seedling grafting method specifically includes the following steps: Site selection: The nursery site should be located in a light loam or sandy loam soil with convenient transportation, plenty of sunshine, deep soil, loose soil, convenient irrigation and drainage, and good water retention and fertilizer retention. Land preparation: The pomegranate nursery plots need to be deeply tilled to a depth of 30-40 cm and fertilized; then the soil should be prepared into nursery beds; Scion selection: Select vigorous, healthy, well-developed, and disease-free two-year-old branches or new shoots that have grown in the current year as scions; Rootstock planting: Rootstock planting should be done in mid-December using short-branch cuttings. Two-year-old branches (0.5-1 cm in diameter) should be taken from local, mature pomegranate trees that are of pure variety, robust, free from pests and diseases, and have high yields. Select cuttings with more thorns at the base to encourage root development. Cut the cuttings short, ensuring each cutting retains at least one bud. Insert the basal and middle sections of the cuttings separately. Cover with plastic film after planting. Rootstock management: When the nursery soil becomes dry, promptly remove the plastic film and irrigate. When the seedlings are ≥10 cm tall, retain one strong new shoot and prune all other branches and buds. When the new shoots grow to 15 cm, apply a quick-acting nitrogen fertilizer once, using 15 kg of urea per acre. Apply fertilizer again in mid-June and late July. Control pests and diseases during the seedling growth period. Grafting at the right time: Three-cut grafting is performed in the spring, summer, and autumn of the following year; spring grafting uses branch grafting, summer grafting uses bud grafting, and autumn grafting uses branch grafting; the three-cut grafting includes the following steps: The first cut grafted a Sichuan Huili pomegranate onto a local old variety of pomegranate seedling; the second cut grafted a Tunisian soft-seeded pomegranate onto a Sichuan Huili pomegranate branch; the third cut grafted an Israeli sweet and sour pomegranate onto a Tunisian soft-seeded pomegranate branch. Seedling management: Remove the plastic film promptly when new buds appear at the grafting point. When the seedling height is ≥10 cm, retain one strong new shoot and prune all other branches and buds. Control pests and diseases during the seedling growth period. From January to March, water every 15 days; from April to May, water every 10 days; in June, during the rainy season, weed once a month and spray with lime sulfur solution at 15-17 Baume degrees every two months; in December, prune once, leaving one strong seedling per pond and cutting off the rest, and top the remaining strong seedling 20-30 cm above the ground; Fertilization: Do not fertilize from January to March; start fertilizing from April to September, once a month, mainly with nutrient solution micro-fertilizer and water-soluble organic fertilizer, apply less nitrogen fertilizer, and apply appropriate amounts of phosphorus and potassium fertilizer.

2. The method for grafting pomegranate seedlings in a hot and dry valley region according to claim 1, characterized in that, The amount of fertilizer applied during land preparation is 25-30 kg of high-quality organic fertilizer and 8-12 kg of phosphate fertilizer per mu.

3. The method for grafting pomegranate seedlings in a hot and dry valley region according to claim 1, characterized in that, The nursery ridges are 90-120 cm wide, the ridges between the ridges are 15-30 cm high, and the furrows are 20-30 cm wide.

4. The method for grafting pomegranate seedlings in a hot and dry valley region according to claim 1, characterized in that, In the scion selection process: when selecting scions using cleft grafting or bark grafting, select two-year-old branches; when selecting scions using bud grafting, select new shoots that have grown in the current year.

5. The method for grafting pomegranate seedlings in a hot and dry valley region according to claim 1, characterized in that, The scions can be preserved using any of the following methods: cellar storage, trench storage, or sand storage. When cellar storage is used, the storage temperature should be controlled at around 0°C. When trench storage is used, the scions must be covered with fine sand. When sand storage is used, fine sand should be used with a moisture content of 30%-40%, and the scions should be buried in a 20 cm thick layer of fine sand. When transporting the scions, they should be sealed with wax, wrapped in straw bags or plastic bags, and labeled with the variety and quantity. After arriving at the designated location, the bags should be opened immediately, and the scions should be buried in damp sand and stored in a cool place.

6. The method for grafting pomegranate seedlings in a hot and dry valley region according to claim 1, characterized in that, The buds at the top of the cuttings should be 1-2 cm above the ground. The plant spacing should be 10-15 cm, the row spacing should be 30-35 cm, and 3-4 rows should be planted per bed, with 15,000-17,000 cuttings per acre.

7. The method for grafting pomegranate seedlings in a hot and dry valley region according to claim 1, characterized in that, The pest control methods include using 25% diflubenzuron suspension at 1500-2000 times dilution, 20% chlorantraniliprole emulsifiable concentrate at 3000-4000 times dilution, 10% lambda-cyhalothrin emulsifiable concentrate at 2000-2500 times dilution, 22% flonicamid suspension at 4000-5000 times dilution, 3% acetamiprid emulsifiable concentrate at 1500-2500 times dilution, 30% thiamethoxam aqueous solution at 4000-6000 times dilution, 24% spirotetramat suspension at 4000-5000 times dilution, and 24% spirodiclofen suspension at 3000-5000 times dilution. For the control of aphids, thrips, lepidopteran pests, coleopteran pests, scale insects, and spider mites, at least one of the following pesticides: 5000 times dilution, 6000-7000 times dilution of 11% etoxazole suspension; and the placement of insecticidal lamps and sticky traps in the nursery. For the control of diseases, at least one of the following pesticides is used to control brown spot disease: 3000-4000 times dilution of 10% difenoconazole water-dispersible granules, 500-600 times dilution of 50% carbendazim wettable powder, or 6000-8000 times dilution of 40% flusilazole emulsifiable concentrate.

8. The method for grafting pomegranate seedlings in a hot and dry valley region according to claim 1, characterized in that, The grafting interval between the first, second, and third incisions is 80-100 days.