A method of planting to delay flowering and fruit set in citrus

Abstract

The application discloses a planting method for delaying flowering and fruit setting of citrus, and belongs to the technical field of citrus planting. The planting method comprises the following steps: S1, promoting autumn shoot budding and maturation: before autumn shoot budding, pruning existing branches, and applying nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer, and after the new shoots are cut, spraying 0.2-0.4% potassium dihydrogen phosphate+200-300 ml / L paclobutrazol; S2, inhibiting spring shoot budding: before spring shoot budding, avoiding rain and controlling water, and keeping the soil dry; S3, promoting early summer shoot budding: before early summer shoot budding, pruning existing branches, and applying nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer; and S4, fruit protection: respectively spraying a fruit protection agent during the last flowering period and after the first physiological fruit drop period ends. The method can delay the maturity and marketing time of the citrus, and prolongs the fresh fruit supply period by about 90 days compared with the conventional planting mode.

Description

Technical Field

[0001] This invention belongs to the field of citrus cultivation technology, specifically relating to a method for delaying flowering and fruit setting in citrus. Background Technology

[0002] Citrus fruits typically flower and set fruit in spring, expand in summer, and ripen in autumn and winter, with the main market season from mid-September to February of the following year, resulting in a fresh fruit supply period of only 5-6 months. In my country, citrus consumption is primarily for fresh fruit. Currently, production methods to extend the fresh fruit supply period mainly involve two approaches: on-tree preservation and storage preservation. However, on-tree preservation easily leads to fruit peeling, dehydration, and granulation, resulting in reduced quality and severe alternate bearing, impacting yield. Storage preservation, on the other hand, requires extremely high-quality infrastructure and advanced preservation techniques. Improper storage easily leads to fruit mold, rot, and off-odors, resulting in a very high loss rate, thus its practical application is limited, and there are also relatively few citrus varieties suitable for storage preservation.

[0003] It is evident that the concentrated ripening and market availability of citrus fruits and the short supply period of fresh fruit have become the main reasons for the low economic benefits of the citrus industry and insufficient consumer demand for fresh citrus fruits. Therefore, there is an urgent need for a new method to delay the ripening and market availability of citrus fruits and extend the supply period of fresh citrus fruits. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a planting method for delaying flowering and fruit setting of citrus, so as to solve the problem of short supply period of fresh citrus fruit in the existing technology.

[0005] The technical solution of this invention to solve the above-mentioned technical problems is as follows: A method for delaying flowering and fruit setting in citrus is provided, comprising the following steps: S1. Promote the growth and maturation of autumn shoots: Before the autumn shoots sprout, prune the existing branches and apply nitrogen, phosphorus and potassium fertilizers. After the new shoots are pruned, spray with 0.2~0.4% potassium dihydrogen phosphate + 200~300 ml / L paclobutrazol. S2. Suppress spring shoots: Before spring shoots sprout, protect the soil from rain and control watering to keep it dry; S3. Promote the sprouting of early summer shoots: Before the early summer shoots sprout, prune the existing branches and apply nitrogen, phosphorus and potassium fertilizers. S4. Fruit preservation: Spray fruit preservation agent during the final flowering period and after the first physiological fruit drop period.

[0006] The beneficial effects of this invention are: after pruning existing branches, it can stimulate the secretion of auxin at the cut site, promote the sprouting of new shoots, and facilitate the uniform emergence of new shoots; Paclobutrazol can inhibit the synthesis of gibberellin. At the same time, spraying potassium dihydrogen phosphate can inhibit excessive elongation of branches and promote the rapid maturation of new shoots. When the new shoots mature, they can carry out photosynthesis, produce and accumulate nutrients, which is conducive to the completion of flower bud physiological differentiation. Reducing soil moisture content and maintaining soil dryness in spring can stimulate the tree to produce abscisic acid. Abscisic acid inhibits the synthesis and transport of auxin and cell division activity, thereby suppressing the sprouting of spring shoots. Spraying fruit-setting agents can inhibit the tree's synthesis of ethylene and abscisic acid, suppress flower and fruit drop, improve fruit set rate, and ensure stable yield. By combining the measures at each stage, this invention, through precise nutrient and water regulation, combined with plant growth regulators, effectively delays the flowering and fruit set of citrus, postponing the fruit ripening period to May of the following year. This not only extends the fresh fruit supply period and avoids the concentrated market supply period, but also enhances economic value.

[0007] Based on the above technical solution, the present invention can be further improved as follows: Furthermore, it also includes: S5, Pest and Disease Prevention: Pest and disease prevention during the autumn shoot emergence and maturation, early summer shoot budding and growth, and flower and fruit growth and development stages.

[0008] Furthermore, the pruning method described in S1 is a moderate shortening, cutting off 1 / 3 to 1 / 2 of the original branch length; the pruning method described in S3 is a light shortening, cutting off 1 / 4 to 1 / 3 of the original branch length.

[0009] Furthermore, the application rates of nitrogen, phosphorus, and potassium fertilizers in S1 are 180-350 g of nitrogen fertilizer, 45-100 g of phosphorus fertilizer, and 75-150 g of potassium fertilizer per plant.

[0010] Furthermore, in S2, rain shelters are provided by covering the ground with a membrane or constructing a rain shelter.

[0011] Furthermore, the soil moisture content at a depth of 10-60 cm in S2 ranges from 6% to 10%.

[0012] Furthermore, the application rates of nitrogen, phosphorus, and potassium fertilizers in S3 are 117-300 g of nitrogen fertilizer, 27-90 g of phosphorus fertilizer, and 54-110 g of potassium fertilizer per plant.

[0013] Furthermore, in S1 and S3, nitrogen, phosphorus, and potassium fertilizers are applied by soil fertilization, followed by timely covering with soil and irrigation.

[0014] Furthermore, after covering and irrigating the soil in S3, the soil moisture content at a depth of 10-60 cm underground ranges from 17% to 23%.

[0015] The beneficial effects of adopting the above-mentioned further technical solutions are as follows: maintaining the soil humidity range of 17% to 23% in summer avoids both excessive soil moisture saturation causing root rot and drought stress, which can improve nutrient absorption efficiency and provide sufficient nutrition for early summer shoot budding, flowering, fruiting and fruit setting.

[0016] Furthermore, the fruit-preserving agent includes: 20~40 ml / L gibberellin + 0.2~0.4% potassium dihydrogen phosphate + 500~670 mg / L boric acid, or 10~20 mg / L 2,4-D sodium salt + 0.2~0.4% potassium dihydrogen phosphate + 500~670 mg / L boric acid.

[0017] The beneficial effects of adopting the above-mentioned further technical solutions are as follows: potassium dihydrogen phosphate and boric acid can promote fertilization and fruit setting, while gibberellin and 2,4-D sodium salt can inhibit the formation of abscission layer at the fruit stalk, reduce physiological fruit drop, and improve fruit set rate.

[0018] The present invention has the following beneficial effects: 1. This invention utilizes nutrient and water regulation at different growth stages of citrus, combined with plant growth regulators, to delay the flowering and fruit setting of citrus in spring to summer under the conventional planting model. This delays the overall growth stages of fruit expansion, color change, and ripening, extending the fresh fruit supply period from mid-September to February of the following year (approximately 165 days) to mid-September to May of the following year (approximately 255 days), which is about 90 days longer than the conventional planting model, significantly extending the fresh fruit supply period of citrus.

[0019] 2. This invention directly addresses the issue of short fresh citrus fruit supply from the planting stage, while effectively avoiding problems such as fruit dehydration and granulation, reduced quality, alternate bearing and unstable yields caused by current on-tree preservation methods, and high investment in facilities and equipment, technical difficulties, serious rotting, and significant losses associated with storage and preservation. Furthermore, in citrus breeding, it solves the problem of the difficulty in breeding extremely late-maturing citrus varieties. Moreover, the disaster prevention and mitigation management measures remain unchanged, and there is no impact on citrus yield or fruit quality. This method is technically mature, simple, practical, and easy to promote.

[0020] 3. The citrus ripening period of this invention can be extended to May. From March to May, as temperatures gradually warm up in my country, the market demand for citrus is at its peak. Furthermore, during this period, no other fruits ripen and enter the market domestically, resulting in less competition. Statistics show that the average selling price of citrus during this period reaches 4.0-5.5 yuan / jin, which is 2.2-3.7 yuan / jin higher than the price of conventionally grown citrus, resulting in an average increase in income of 3700-6200 yuan / mu, demonstrating very considerable economic benefits. Attached Figure Description

[0021] Figure 1 The image shows the flowering of the Shiranui flower in June 2022, as described in Example 1. Figure 2 This is a picture of the flowering of the Daiyana in June 2022, as shown in Example 2. Detailed Implementation

[0022] The principles and features of the present invention are described below with reference to embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Unless otherwise specified, specific conditions or manufacturer-recommended conditions should be followed in the embodiments. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0023] Example 1: This embodiment provides a method for delaying flowering and fruit setting in citrus. The implementation site is an orchard in Nanchong City, Sichuan Province. The citrus variety is 5-year-old 'Shiranui', with a plant spacing of 3×4 m and 55 trees planted per mu (approximately 0.067 hectares). The specific implementation method includes the following steps: S1. Promote the growth and maturation of autumn shoots: In late July 2021, moderately prune existing branches (remove 1 / 3 to 1 / 2 of the original branch length). Apply 300 g of nitrogen fertilizer, 75 g of phosphorus fertilizer, and 125 g of potassium fertilizer in a circular trench along the drip line of the canopy for each tree. Then cover with soil and irrigate to promote the uniform growth of autumn shoots. At the same time, spray 0.3% potassium dihydrogen phosphate + 200 ml / L paclobutrazol on the terminal buds of the new shoots after self-pruning. Spray again after 12 days. S2. Suppress spring shoots: In early March 2022, cover the orchard ground with plastic film to protect it from rain and control the soil moisture content at a depth of 10-60 cm to be between 6% and 10%, keeping the soil dry. S3. Promote the sprouting of early summer shoots: In late May 2022, remove the plastic film covering the ground and lightly prune the existing branches (cut off 1 / 4 to 1 / 3 of the total length of the original branches). Apply 208 g of nitrogen fertilizer, 48 g of phosphorus fertilizer, and 96 g of potassium fertilizer in a circular trench along the drip line of the tree canopy for each tree, cover with soil and water, and keep the soil moisture content at a depth of 10 to 60 cm in the range of 17% to 23% to promote the sprouting of early summer shoots. S4. Fruit setting: From late June to mid-July 2022, spray with 30 ml / L gibberellin + 0.4% potassium dihydrogen phosphate + 600 mg / L boric acid during the late flowering period and after the first physiological fruit drop period to promote fruit setting. Figure 1 This is a picture of the Shiranui blooming in June 2022. S5. Pest and disease prevention: During the autumn shoot emergence and maturation, early summer shoot budding and growth, and flower and fruit growth and development stages, the same conventional pest and disease prevention measures as for citrus trees are used, with targeted alternating application of chemical agents to prevent pests and diseases, and to protect the healthy growth of new shoots and the normal development of flowers and fruits.

[0024] According to statistics, compared with the conventional planting model, the ripening period of the 'Shiranui' fruit in this embodiment is extended to May 21, 2023, which is 83 days later. The market price increases by 3.1 yuan / jin, resulting in an additional income of 5,400 yuan / mu.

[0025] Example 2: This embodiment provides a planting method for delaying flowering and fruit setting of citrus. The implementation site is an orchard in Jiangjin District, Chongqing. The citrus variety is 8-year-old 'Daya'. The plant spacing is 3.5×4 m, and 47 trees are planted per mu (approximately 0.067 hectares). The specific implementation method includes the following steps: S1. Promote the growth and maturation of autumn shoots: In early August 2021, moderately prune existing branches (remove 1 / 3 to 1 / 2 of the original branch length), apply 315 g of nitrogen fertilizer, 90 g of phosphorus fertilizer and 135 g of potassium fertilizer in a circular trench along the drip line of the canopy for each tree, then cover with soil and irrigate to promote the uniform growth of autumn shoots. At the same time, spray 0.3% potassium dihydrogen phosphate + 300 ml / L paclobutrazol once after the terminal buds of the new shoots are pruned. S2. Suppress spring shoots: In late February 2022, bamboo and wood structures were erected in the orchard to shelter from rain and control the soil moisture content at a depth of 10-60 cm to 6%-10%, keeping the soil dry. S3. Promote early summer shoot budding: At the end of May 2022, lightly prune existing branches (cut off 1 / 4 to 1 / 3 of the original branch length), apply 210 g of nitrogen fertilizer, 63 g of phosphorus fertilizer and 77 g of potassium fertilizer in a circular trench along the drip line of the tree canopy for each tree, cover with soil and irrigate thoroughly to maintain the soil moisture content at a depth of 10 to 60 cm in the range of 17% to 23%, promote root absorption of nutrients and uniform budding and growth of early summer shoots; S4. Fruit setting: From late June to mid-July 2022, spray with 40 ml / L gibberellin + 0.2% potassium dihydrogen phosphate + 500 mg / L boric acid during the late flowering period. After the first physiological fruit drop period, spray with 10 mg / L 2,4-D sodium salt + 0.2% potassium dihydrogen phosphate + 500 mg / L boric acid to promote fruit setting. Figure 2 This is a picture of the flowers blooming in June 2022. S5. Pest and disease prevention: During the autumn shoot emergence and maturation, early summer shoot budding and growth, and flower and fruit growth and development stages, the same conventional pest and disease prevention measures as for citrus trees are used, with targeted alternating application of chemical agents to prevent pests and diseases, and to protect the healthy growth of new shoots and the normal development of flowers and fruits.

[0026] According to statistics, compared with the conventional planting model, the ripening period of the 'Daya' fruit in this embodiment is extended to April 27, 2023, which is 91 days later. The market price increases by 2.8 yuan / jin, resulting in an increase in income of 5,120 yuan / mu.

[0027] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for delaying flowering and fruit setting in citrus, characterized in that, Includes the following steps: S1. Promote the emergence and maturation of autumn shoots: Before the autumn shoots sprout, prune the existing branches and apply nitrogen, phosphorus and potassium fertilizers to the soil. After fertilization, cover the soil and water it in time. After the new shoots are pruned, spray with 0.2~0.4% potassium dihydrogen phosphate + 200~300 ml / L paclobutrazol. The pruning method is moderate shortening, cutting off 1 / 3~1 / 2 of the total length of the original branches. The amount of nitrogen, phosphorus and potassium fertilizers used is 180~350 g of nitrogen fertilizer, 45~100 g of phosphorus fertilizer and 75~150 g of potassium fertilizer per plant. S2. Suppress spring shoots: Before spring shoots sprout, protect the soil from rain and control watering to keep it dry. Rain protection can be achieved by covering the ground with plastic film or building rain shelters. When controlling watering, keep the soil moisture content at a depth of 10-60 cm between 6% and 10%. S3. Promote the sprouting of early summer shoots: Before the early summer shoots sprout, prune the existing branches and apply nitrogen, phosphorus and potassium fertilizers to the soil. After fertilization, cover the soil with soil and water it in time. After watering, the soil moisture content at a depth of 10-60 cm should be in the range of 17%-23%. The pruning method is light shortening, cutting off 1 / 4 to 1 / 3 of the total length of the original branches. S4. Fruit preservation: Spray a fruit preservation agent during the late flowering period and after the first physiological fruit drop period, respectively; the fruit preservation agent includes: 20~40 ml / L gibberellin + 0.2~0.4% potassium dihydrogen phosphate + 500~670 mg / L boric acid, or 10~20 mg / L 2,4-D sodium salt + 0.2~0.4% potassium dihydrogen phosphate + 500~670 mg / L boric acid.

2. The planting method according to claim 1, characterized in that, Also includes: S5. Pest and disease prevention: Pest and disease prevention should be carried out during the autumn shoot emergence and maturation, early summer shoot budding and growth, and flower and fruit growth and development stages.

3. The planting method according to claim 1, characterized in that, In S3, the application rates of nitrogen, phosphorus, and potassium fertilizers are 117-300 g of nitrogen fertilizer, 27-90 g of phosphorus fertilizer, and 54-110 g of potassium fertilizer per plant.

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