A method for the cultivation and management of cherimoya adapted to greenhouse environments

Abstract

This invention discloses a cultivation and management method for custard apples suitable for greenhouse environments, comprising the following steps: Step 1: Early tree management; Measures: Combine deep tillage and soil improvement, apply organic fertilizer and compound fertilizer to each tree; simultaneously, spray foliar application of a micronutrient supplement; Step 2: Artificial pollination; Measures: Collect custard apple flowers in a semi-open state on the afternoon of the same day, at which time the petals are not fully open, the pistils are mature but the stamens have not split open; use a soft brush to brush pollen into a container; the next morning, when the pistils of another batch of flowers are mature, use a brush to dip the pollen collected in the container and apply it to the stigma of the pistil; Step 3: Nutritional and fruit-setting management; Measures: The method of using fruit-setting agents is as follows: use a sprayer to spray evenly onto the fruit stalk and young fruit, until dripping wet; focus on spraying the fruit stalk area to prevent the formation of the abscission layer. The above method of this invention can significantly improve the fruit setting rate and yield stability of greenhouse custard apples.

Description

Technical Field

[0001] This invention belongs to the field of custard apple cultivation technology, and in particular relates to a custard apple cultivation and management method suitable for greenhouse environments. Background Technology

[0002] Custard apple, also known as sugar apple or Buddha's head fruit, belongs to the genus Annonaceae in the family Annonaceae. It is a typical high-quality fruit cultivated in tropical and subtropical regions. Custard apples have a unique flavor and high nutritional value, rich in sugars, vitamins, and various minerals, giving them significant economic value in domestic and international markets. Therefore, they are widely cultivated in southern my country and some areas with greenhouse agriculture. In recent years, with the development of greenhouse agriculture, some regions have begun cultivating custard apples in greenhouse environments, artificially controlling temperature, humidity, and light conditions to achieve off-season production or expand suitable planting areas and improve economic benefits.

[0003] However, severe flower and fruit drop is a common problem in custard apple production, with a natural fruit set rate typically only 1%-3%. This results in a low number of viable fruits, hindering yield and marketability, and becoming a key factor restricting the development of the custard apple industry. From a plant biology perspective, custard apple flowers are hermaphroditic but dioecious, making self-pollination difficult and requiring external pollinators. Furthermore, climatic conditions during the flowering period are also crucial for fruit set. Custard apple pollen is highly sensitive to environmental conditions, especially in greenhouse cultivation. Poor ventilation or improper temperature and humidity control can negatively impact pollen viability and stigma receptivity, exacerbating flower and fruit drop. Summary of the Invention

[0004] The purpose of this invention is to provide a cultivation and management method for custard apples suitable for greenhouse environments, in order to solve the problems of severe flower and fruit drop and low fruit set rate of custard apples under existing cultivation techniques, as well as the difficulty in fully utilizing the advantages of the strong controllability of the greenhouse cultivation environment, which in turn affects the yield stability and economic benefits of custard apple facility cultivation.

[0005] The technical solution of this invention to solve the above-mentioned technical problems is as follows: A method for cultivating and managing custard apples suitable for greenhouse environments, comprising the following steps:

[0006] Step 1: Pre-planting tree management; Timing: November-December after autumn / winter pruning; Measures: Combine deep tilling and soil improvement, apply 5-10 kg of organic fertilizer per tree, along with 0.5-1 kg of compound fertilizer; Simultaneously, foliar spray with a micronutrient supplement, the formula of which is: 0.15-0.30 parts by weight of magnesium sulfate, 0.20-0.40 parts by weight of potassium dihydrogen phosphate, and 0.05-0.15 parts by weight of zinc sulfate. After dissolving, spray once every 10 days, for a total of 2 sprays.

[0007] Step Two: Artificial Pollination; Timing: During the flowering period of custard apple (May-September), choose a sunny evening between 4:00 PM and 6:00 PM; Method: Collect custard apple flowers that are in a semi-open state that afternoon, when the petals are not yet fully open, the pistils are mature but the stamens have not split open; Use a soft brush to brush the pollen into a container and immediately place it at a low temperature of 4℃ for short-term preservation; The next morning, when the pistils of another batch of flowers are mature, use a brush to dip the pollen collected in the container and apply it to the stigma of the pistil;

[0008] Step 3: Nutritional Fruit Preservation Regulation; Timing: 3-5 days after flowering and during the young fruit stage, when the fruit diameter is approximately 1-2 cm; Measures: The fruit preservation spray formula is: 20-30 g / L gibberellin, 10-15 g / L 6-benzyladenine, and 40-60 g / L amino acid chelated potassium; Application method: Use a sprayer to evenly spray the fruit stalk and young fruit until dripping wet; focus on spraying the fruit stalk area to prevent the formation of the abscission layer.

[0009] The present invention provides a method for cultivating and managing custard apples in a greenhouse environment, as described above. Preferably, in step 1, the compound fertilizer contains 18-20 N, 6-8 P2O5, and 18-23 K2O.

[0010] The present invention provides a method for cultivating and managing custard apples in a greenhouse environment, as described above. Preferably, in step two, after pollen collection, pollen activation treatment is performed. The activation treatment involves placing the pollen in a solution containing 5-8 g / L sucrose and 0.01-0.02 g / L boric acid for 5-10 minutes to improve the pollen germination rate.

[0011] The present invention provides a method for cultivating and managing custard apples in a greenhouse environment, as described above. Preferably, before artificial pollination in step two, a stigma activation solution is sprayed onto the stigma of the pistil. The stigma activation solution is a mixed solution of 0.10-0.30 g / L chitosan oligosaccharide and 0.01-0.03 g / L seaweed oligosaccharide to improve the adhesion and germination ability of pollen on the stigma surface.

[0012] The present invention provides a method for cultivating and managing custard apples in a greenhouse environment, as described above. Preferably, between step two and step three, a post-flowering nutrient compensation step is included, in which a nutrient solution containing 0.10-0.30 g / L urea and 0.50-0.80 g / L potassium humate is sprayed on the leaves within 48 hours after pollination to promote the development of fertilized ovules.

[0013] The present invention provides a method for cultivating and managing custard apples in a greenhouse environment, as described above. Preferably, the fruit-preserving agent in step three further includes 0.01-0.02 g / L of ammonium molybdate to promote pollen tube elongation and early fruit development.

[0014] The method for cultivating and managing custard apples in a greenhouse environment as described above is preferably carried out by selective fruit thinning during the young fruit stage, retaining 1-2 fruits on each fruiting branch, and giving priority to retaining young fruits with symmetrical shape and thick pedicels, so as to reduce physiological fruit drop caused by nutrient competition.

[0015] The present invention provides a method for cultivating and managing custard apples in a greenhouse environment, as described above. Preferably, after selective fruit thinning, a fruit correction step is also included: when the young fruit develops to a diameter of 3-4 cm, the fruit is pretreated for bagging by uniformly spraying the fruit surface with a compound liquid containing 0.05-0.20 g / L seaweed extract and 0.02-0.10 g / L amino acids, and then bagging is performed.

[0016] The present invention provides a method for cultivating and managing custard apples in a greenhouse environment, as described above. Preferably, it also includes a step for controlling environmental stress. The timing is when the temperature is >35℃ or there is continuous rainy weather during the entire flowering and fruiting period. The measures are as follows: when the temperature is >35℃, cover the tree basin with straw or mulch, and spray water on the tree canopy every 3-5 days in the morning and evening; during rainy weather, dredge the drainage ditches in time, and shake the flowers after rain to remove the water accumulated on the petals and prevent the flowers from rotting.

[0017] The beneficial effects of this invention are:

[0018] 1. Significantly improves the fruit set rate and yield stability of greenhouse custard apples; This invention addresses the problems of heterozygous maturation of male and female custard apples and the difficulty of pollination in greenhouse environments. Through precise artificial pollination technology in step two (collecting semi-open flowers at a specific time, preserving them at low temperatures, and applying the pollen the next day), combined with pollen activation treatment (sucrose + boric acid) and stigma activation treatment (chitosan oligosaccharide + seaweed oligosaccharide) in the preferred technical solution, the pollen germination rate and pollination success rate are significantly improved. As shown in the data from the embodiments in the specification (Table 2), management method 1 using the complete technical solution achieves a fruit set rate as high as 73.6%, far exceeding the control example that omits key steps (such as management method 7, 42.6%), thus ensuring the basic stability of yield.

[0019] 2. Effectively reduces physiological fruit drop and improves fruit marketability. This invention addresses the problem of physiological fruit drop during the young fruit development period by precisely spraying a fruit-preserving agent containing gibberellin, 6-benzyladenine, and amino acid chelated potassium after flowering and during the young fruit stage, with a focus on spraying the fruit stalk to prevent abscission layer formation. This solves the problem from both hormonal and nutritional perspectives. Experimental data (Table 2) show that management method 11, which omits step three, has a significantly lower yield per plant (7.99 kg) than management method 1 with the complete scheme (9.23 kg), indicating that this step effectively transforms pollinated and set young fruits into mature marketable fruits, significantly improving the yield rate.

[0020] 3. Comprehensive improvement of fruit appearance quality and intrinsic commercial value: This invention, through the fruit correction step in the optimized technical solution (spraying seaweed extract and amino acid compound liquid before bagging), not only provides physical protection but also actively regulates the development of fruit peel cells. Based on the data from the embodiments in the instruction manual (Table 3), management method 1 using this step resulted in a lower fruit brightness value (L=65.3) than the control group (management method 5, L=72.4), and superior color parameters (b value and C value). This effectively solved the problem of pale fruit peel that easily occurs in greenhouse cultivation, resulting in a more uniform and glossy peel color, significantly improving the fruit's appearance quality and market competitiveness. Detailed Implementation

[0021] The embodiments described herein are specific implementations of the present invention, used to illustrate the concept of the invention, and are illustrative and exemplary, and should not be construed as limiting the implementation or scope of the invention. In addition to the embodiments described herein, those skilled in the art can employ other obvious technical solutions based on the content disclosed in the claims and specification of this application. These technical solutions include those that make any obvious substitutions and modifications to the embodiments described herein.

[0022] This invention provides a method for cultivating and managing custard apples in a greenhouse environment, comprising the following steps:

[0023] Step 1: Pre-planting tree conditioning; Timing: November-December after autumn / winter pruning; Measures: Combine deep tilling and soil improvement, apply 5-10 kg of organic fertilizer per tree, along with 0.5-1 kg of compound fertilizer; simultaneously, foliar spray with a micronutrient supplement, the formula of which is: 0.15-0.30 parts by weight of magnesium sulfate, 0.20-0.40 parts by weight of potassium dihydrogen phosphate, and 0.05-0.15 parts by weight of zinc sulfate, dissolved and sprayed every 10 days, for two consecutive applications; In a preferred embodiment, in step 1, the compound fertilizer contains 18-20 parts nitrogen (N), 6-8 parts phosphorus (P2O5), and 18-23 parts potassium (K2O). In the following examples, the compound fertilizer is formulated in an 18-6-18 ratio. The addition amounts are: 300 kg of urea, 136 kg of monoammonium phosphate, 360 kg of potassium sulfate, and 204 kg of dolomite powder as filler.

[0024] Deep tilling and soil improvement after autumn and winter pruning, combined with the application of organic and compound fertilizers, can increase the soil organic matter content and improve root aeration, enabling the custard apple root system to quickly recover its absorption capacity after dormancy. At the same time, magnesium sulfate provides magnesium for chlorophyll synthesis, potassium dihydrogen phosphate promotes flower bud differentiation and energy metabolism, and zinc sulfate participates in the activation of various enzymes. These nutrients can be quickly absorbed into the plant through foliar application, thereby increasing the tree's nutrient accumulation level and promoting the uniformity of flower bud differentiation. This provides a good nutritional foundation for subsequent flowering and pollination, improving flower quality and potential fruit setting capacity.

[0025] Step Two: Artificial Pollination; Timing: During the flowering period of custard apple (May-September), choose a sunny evening between 4:00 PM and 6:00 PM; Method: Collect custard apple flowers that are in a semi-open state that afternoon, when the petals are not yet fully open, the pistils are mature but the stamens have not split open; Use a soft brush to brush the pollen into a container and immediately place it at a low temperature of 4℃ for short-term preservation; The next morning, when the pistils of another batch of flowers are mature, use a brush to dip the pollen collected in the container and apply it to the stigma of the pistil;

[0026] In a preferred embodiment, after pollen collection in step two, a pollen activation treatment is performed. This activation treatment involves placing the pollen in a solution containing 5-8 g / L sucrose and 0.01-0.02 g / L boric acid for 5-10 minutes to improve pollen germination rate. Sucrose serves as an energy source for pollen germination and maintains a suitable osmotic pressure environment. Boron is an essential trace element for pollen tube growth, promoting pollen tube cell wall formation and increasing pollen tube elongation rate. This activation treatment improves pollen germination rate and pollen tube elongation capacity, thereby increasing pollination success rate and fertilization efficiency.

[0027] In a preferred embodiment, before artificial pollination in step two, a stigma activating solution is sprayed onto the stigma of the pistil. This activating solution is a mixed solution of 0.10-0.30 g / L chitosan oligosaccharide and 0.01-0.03 g / L seaweed oligosaccharide to improve pollen adhesion and germination ability on the stigma surface. Chitosan oligosaccharide induces plant defense responses and enhances cell activity, while seaweed oligosaccharide stimulates plant cell metabolism and increases the activity of stigma secretions. Spraying this activating solution onto the stigma surface increases stigma mucus secretion and improves the stigma surface microenvironment, thereby increasing pollen grain adhesion and promoting pollen germination, thus improving the pollination success rate.

[0028] In a preferred embodiment, a post-flowering nutrient compensation step is included between steps two and three. Within 48 hours after pollination, a nutrient solution containing 0.10-0.30 g / L urea and 0.50-0.80 g / L potassium humate is sprayed on the leaves to promote the development of fertilized ovules. The 48 hours after pollination are a critical stage for ovule fertilization and early embryonic development. Foliar supplementation with readily available nitrogen and potassium humate can improve leaf photosynthetic capacity and promote nutrient transport to young fruit, thereby providing sufficient nutrition for the development of fertilized ovules and reducing early fruit drop due to insufficient nutrition.

[0029] Step 3: Nutritional Fruit Preservation Regulation; Timing: 3-5 days after flowering and during the young fruit stage, when the fruit diameter is approximately 1-2 cm; Measures: The fruit preservation spray formula is: 20-30 g / L gibberellin, 10-15 g / L 6-benzyladenine, and 40-60 g / L amino acid chelated potassium; Application method: Use a sprayer to evenly spray the fruit stalk and young fruit until dripping wet; focus on spraying the fruit stalk area to prevent the formation of the abscission layer. Gibberellin can promote cell elongation and inhibit abscission layer formation, while 6-benzyladenine can promote cell division and delay organ senescence. The synergistic effect of the two can enhance the growth vigor of the young fruit; amino acid chelated potassium can improve nutrient absorption efficiency and enhance the metabolic activity of the fruit stalk tissue. By focusing on spraying the fruit stalk area, the differentiation of abscission layer cells in the fruit stalk can be inhibited, thereby reducing the physiological fruit drop rate and increasing the survival rate of young fruit, ultimately increasing the yield per plant.

[0030] In a preferred embodiment, the fruit-preserving agent in step three further includes 0.01-0.02 g / L of ammonium molybdate to promote pollen tube elongation and early fruit development. Molybdenum participates in nitrogen metabolism and various enzymatic reactions in plants, and also promotes pollen tube growth. By adding trace amounts of ammonium molybdate to the fruit-preserving agent, pollen tube elongation and post-fertilization embryo development can be further promoted, thereby improving the stability of young fruit development.

[0031] In a preferred embodiment, selective fruit thinning is performed during the young fruit stage, retaining 1-2 fruits per fruiting branch, with priority given to young fruits that are symmetrical in shape and have thick pedicels, to reduce physiological fruit drop caused by nutrient competition. In a further preferred embodiment, after the selective fruit thinning, a fruit correction step is included: when the young fruit develops to a diameter of 3-4 cm, the fruit undergoes pre-bagging treatment by uniformly spraying the fruit surface with a compound liquid containing 0.05-0.20 g / L seaweed extract and 0.02-0.10 g / L amino acids, followed by bagging. This method introduces a specific formulation of spray (seaweed extract + amino acids) before bagging, which not only provides physical protection but also actively regulates the division and development of fruit peel cells, preventing the problem of pale fruit peel and improving the appearance of the fruit.

[0032] In a preferred embodiment, the method further includes environmental stress control steps; timing: when the temperature is >35℃ or there is continuous rainy weather during the entire flowering and fruiting period; measures: when the temperature is >35℃: cover the tree basin with straw or mulch, and spray water on the tree canopy every 3-5 days in the morning and evening; during rainy weather: dredge the drainage ditches in time, and shake the flowers after the rain to shake off the water accumulated on the petals to prevent the flowers from rotting.

[0033] I. Experimental Materials and Location

[0034] Experimental materials: Greenhouse custard apple plants (variety AP custard apple) aged 5-6 years with uniform growth and free from pests and diseases were selected, with 10 plants per plot.

[0035] Test location: The test was conducted in a standard multi-span greenhouse equipped with basic temperature and humidity control facilities (including fans, wet curtains, and shade nets).

[0036] Experiment duration: At least one complete growth cycle (including autumn and winter pruning to fruit harvest).

[0037] II. Different Management Methods

[0038] Management Method 1

[0039] The method for cultivating and managing custard apples in a greenhouse environment, as described in this embodiment, includes the following steps:

[0040] S1: Early stage tree management; Timing: November-December after autumn and winter pruning; Measures: Combine deep tillage and soil improvement, apply 8 kg of organic fertilizer per tree, and apply 1 kg of compound fertilizer; At the same time, foliar spray with a micronutrient supplement combination agent, the formula of which is: 0.25 parts by weight of magnesium sulfate, 0.30 parts by weight of potassium dihydrogen phosphate, and 0.10 parts by weight of zinc sulfate. After dissolving, spray once every 10 days, for a total of 2 sprays;

[0041] S2: Artificial pollination; Timing: During the flowering period of custard apple (May-September), choose a sunny evening between 16:00 and 18:00; Measures: Collect custard apple flowers that are in a semi-open state that afternoon, when the petals are not yet fully open, the pistils are mature but the stamens have not split open; Use a soft brush to brush the pollen into a container and immediately place it at a low temperature of 4℃ for short-term preservation; The next morning, when the pistils of another batch of flowers are mature, use a brush to dip the pollen collected in the container and apply it to the stigma of the pistil;

[0042] S21. After pollen collection in step two, pollen activation treatment is performed. The activation treatment involves placing the pollen in a solution containing 6 g / L sucrose and 0.02 g / L boric acid for 5-10 minutes to improve the pollen germination rate.

[0043] S22, before artificial pollination in step two, a stigma activation solution is sprayed onto the stigma of the pistil. The stigma activation solution is a mixed solution of 0.20 g / L chitosan oligosaccharide and 0.02 g / L seaweed oligosaccharide to improve the adhesion and germination ability of pollen on the stigma surface.

[0044] S23, between step two and step three, also includes a post-flowering nutrient compensation step, in which a nutrient solution containing 0.20 g / L urea and 0.60 g / L potassium humate is sprayed on the leaves within 48 hours after pollination to promote the development of fertilized ovules.

[0045] S3, Nutritional Fruit Preservation Regulation; Timing: 3-5 days after flowering and during the young fruit stage, when the fruit diameter is approximately 1-2 cm; Measures: The fruit preservation spray formula is: 25 g / L gibberellin, 12 g / L 6-benzyladenine, 50 g / L amino acid chelated potassium, and 0.02 g / L ammonium molybdate; Application method: Use a sprayer to evenly spray the fruit stalk and young fruit until dripping wet; focus on spraying the fruit stalk area to prevent the formation of the abscission layer.

[0046] S4. Selective fruit thinning is carried out during the young fruit stage. 1-2 fruits are retained on each fruiting branch, and young fruits with symmetrical shape and thick pedicels are given priority to reduce physiological fruit drop caused by nutrient competition.

[0047] S5, after the selective fruit thinning, also includes a fruit correction step: when the young fruit develops to a transverse diameter of 3-4 cm, the fruit is pretreated for bagging by uniformly spraying the fruit surface with a compound liquid containing 0.10 g / L seaweed extract and 0.08 g / L amino acids, and then bagging is performed.

[0048] S6 also includes steps for controlling environmental stress; timing: when the temperature is >35℃ or there is continuous rainy weather during the entire flowering and fruiting period; measures: when the temperature is >35℃: cover the tree basin with straw or mulch, and spray water on the tree canopy every 3-5 days in the morning and evening; rainy weather: dredge the drainage ditch in time, and shake the flowers after the rain to shake off the water accumulated on the petals to prevent the flowers from rotting.

[0049] Management Method 2

[0050] The method for cultivating and managing custard apples in a greenhouse environment, as described in this embodiment, includes the following steps:

[0051] S1: Measures: Combine deep plowing and soil improvement, apply 5 kg of organic fertilizer per plant and 1 kg of compound fertilizer; at the same time, spray the leaves with a micronutrient supplementation agent, the formula of which is: 0.15 parts by weight of magnesium sulfate, 0.40 parts by weight of potassium dihydrogen phosphate, and 0.05 parts by weight of zinc sulfate.

[0052] S2: Artificial pollination;

[0053] S21, after pollen collection in step two, pollen activation treatment is performed first. The activation treatment is to place the pollen in a solution containing 8 g / L sucrose and 0.01 g / L boric acid for 5-10 minutes.

[0054] S22, before artificial pollination in step two, a stigma activation solution is sprayed onto the stigma of the pistil. The stigma activation solution is a mixed solution of 0.10 g / L chitosan oligosaccharide and 0.03 g / L seaweed oligosaccharide.

[0055] S23, between step two and step three, also includes a post-flowering nutrient compensation step, in which a nutrient solution containing 0.30 g / L urea and 0.50 g / L potassium humate is sprayed on the leaves within 48 hours after pollination.

[0056] S3, Nutritional Fruit Preservation Regulation; Measures: The formula for the fruit preservation spray is: 20g / L gibberellin, 15g / L 6-benzyladenine, 40g / L amino acid chelated potassium, and 0.01g / L ammonium molybdate.

[0057] S4 involves selective fruit thinning during the young fruit stage.

[0058] S5, after the selective fruit thinning, also includes a fruit correction step: when the young fruit develops to a transverse diameter of 3-4 cm, the fruit is pretreated for bagging by uniformly spraying the fruit surface with a compound liquid containing 0.05 g / L seaweed extract and 0.10 g / L amino acids, and then bagging is performed.

[0059] S6 also includes steps for preventing and controlling environmental stresses.

[0060] The details not repeated in the above steps are the same as the technical details in management method 1.

[0061] Management Method 3

[0062] The cultivation and management methods for custard apples suitable for greenhouse environments include the following steps:

[0063] S1: Measures: Combine deep plowing and soil improvement, apply 10 kg of organic fertilizer per plant and 0.5 kg of compound fertilizer; at the same time, spray the leaves with a micronutrient supplementation agent, the formula of which is: 0.30 parts by weight of magnesium sulfate, 0.20 parts by weight of potassium dihydrogen phosphate, and 0.15 parts by weight of zinc sulfate.

[0064] S2: Artificial pollination;

[0065] S21, after pollen collection in step two, pollen activation treatment is performed first. The activation treatment is to place the pollen in a solution containing 5 g / L sucrose and 0.01 g / L boric acid for 5-10 minutes.

[0066] S22, before artificial pollination in step two, a stigma activation solution is sprayed onto the stigma of the pistil. The stigma activation solution is a mixed solution of 0.30 g / L chitosan oligosaccharide and 0.01 g / L seaweed oligosaccharide.

[0067] S23, between step two and step three, also includes a post-flowering nutrient compensation step, in which a nutrient solution containing 0.10 g / L urea and 0.80 g / L potassium humate is sprayed on the leaves within 48 hours after pollination.

[0068] S3, Nutritional Fruit Preservation Regulation; Measures: The formula for the fruit preservation spray is: 30g / L gibberellin, 10g / L 6-benzyladenine, 60g / L amino acid chelated potassium, and 0.02g / L ammonium molybdate.

[0069] S4 involves selective fruit thinning during the young fruit stage.

[0070] S5, after the selective fruit thinning, also includes a fruit correction step: when the young fruit develops to a transverse diameter of 3-4 cm, the fruit is pretreated for bagging by uniformly spraying the fruit surface with a compound liquid containing 0.20 g / L seaweed extract and 0.02 g / L amino acids, and then bagging is performed.

[0071] S6 also includes steps for preventing and controlling environmental stresses.

[0072] The details not repeated in the above steps are the same as the technical details in management method 1.

[0073] Management Method 4

[0074] The cultivation and management methods for custard apples suitable for greenhouse environments include the following steps:

[0075] S3, Nutritional Fruit Preservation Regulation; Timing: 3-5 days after flowering and during the young fruit stage, when the fruit diameter is about 1cm-2cm; Measures: The fruit preservation spray formula is: 25g / L gibberellin, 12g / L 6-benzyladenine, and 50g / L amino acid chelated potassium.

[0076] The details not repeated in the above steps are the same as the technical details in management method 1.

[0077] Management Method 5

[0078] The cultivation and management methods for custard apples suitable for greenhouse environments include the following steps:

[0079] S5, following the selective fruit thinning, also includes a fruit correction step: when the young fruit develops to a transverse diameter of 3-4 cm, the fruit undergoes pre-bagging treatment. Spraying of the fruit with a compound liquid agent is not required before bagging.

[0080] The details not repeated in the above steps are the same as the technical details in management method 1.

[0081] Table 1 Other Management Methods

[0082]

[0083] In Table 1, during the implementation of Management Method 5, S1 in Management Method 1 is not performed. S1: Early Tree Conditioning; Timing: November-December after autumn / winter pruning; Measures: Combined with deep tillage and soil improvement, apply 8 kg of organic fertilizer per tree, along with 1 kg of compound fertilizer; Simultaneously, foliar spray with a micronutrient supplement formula: 0.25 parts by weight of magnesium sulfate, 0.30 parts by weight of potassium dihydrogen phosphate, and 0.10 parts by weight of zinc sulfate, dissolved and sprayed every 10 days for two consecutive applications; however, the remaining steps are exactly the same as in Management Method 1. The meaning and operation of other management methods are similar. Steps not included in Table 2 are not performed in the specific management methods. In Management Method 6, only S2: Artificial Pollination is performed; however, steps S21, S22, and S23 are not performed. Management methods 13 and 14 differ only in the activation environment of step S21 from management method 1, while management methods 15 and 16 differ only in the activation environment of step S22 from management method 1.

[0084] III. Indicators and Analysis

[0085] Indicator 1: Fruit set rate; count the number of young fruits that are ultimately retained during the young fruit stage; calculate the fruit set rate using the following formula: Fruit set rate (%) = (number of fruits set / total number of flowers) × 100%.

[0086] Index 2: Single fruit weight; When the custard apple fruit enters the ripening stage, mature fruits from each treatment plant are harvested in batches. Average single fruit weight determination: 10 mature fruits are randomly selected from each plant; the weight of each fruit is determined using an electronic balance; the average single fruit weight (g / fruit) is calculated.

[0087] Indicator 3: Yield per plant; weigh the total weight of fruit per plant (kg) after harvest. When the custard apple fruit reaches maturity, harvest mature fruits from each treatment plant in batches. Use an electronic balance to measure and record the weight of each fruit; calculate the total weight of all fruits to obtain the yield per plant (kg).

[0088] Table 2

[0089]

[0090] Indicator 4: Evaluation of custard apple fruit color

[0091] The color of the fruit peel was measured using a colorimeter, and the CIELAB color space parameters were used for evaluation.

[0092] 1. Evaluation parameter, L: brightness value, range: 0–100. The larger the value, the brighter and whiter the color. When the color of custard apple is pale, the L value is usually higher.

[0093] Evaluation parameter a: Red-green index, positive value: reddish, negative value: greenish.

[0094] Evaluation parameter b: Yellow-blue index, positive value: yellowish, negative value: blueish.

[0095] Evaluation parameters, overall chromaticity C

[0096] C=

[0097] 2. Test method: 10-20 mature custard apple fruits were randomly selected, and the measurements were taken at 3 different locations on each fruit: shoulder, belly, and top. The values ​​L, a, and b were recorded using a colorimeter (KonicaMinoltaCR-400), and the average value was taken as the color index of the treatment. The results are shown in Table 3.

[0098] Table 3

[0099]

[0100] Explanation: Compared with management method 5, management method 1 shows that L decreases, indicating that the custard apple fruit is no longer pale; b increases, indicating that the yellow-green color of the custard apple peel increases; and C indicates that the color of the custard apple fruit is more normal.

[0101] Sensory evaluation was conducted on the custard apples grown under management methods 1 and 11. Color uniformity: The base color of the peel (usually green or yellowish-green) was more uniform under management method 1 compared to 11. Gloss: The peel surface of management method 1 was shinier than that of 11, and the waxy layer on the peel surface of management method 1 remained intact.

[0102] Comparing management method 1 (73.6%) and management method 6 (62.2%): Management method 6 omitted the entire first step. The results showed that although management method 6 had the highest single fruit weight (296.4g) among all treatments, its fruit set rate (62.2%) was significantly lower than that of management method 1. This directly demonstrates the importance of the first step: sufficient nutrient reserves in the tree are a key prerequisite for ensuring fruit set. The higher single fruit weight may be due to fewer fruits set, resulting in more concentrated nutrient supply to a smaller number of fruits.

[0103] Comparing Management Method 1 (73.6%) and Management Method 7 (42.6%): Management Method 7 only performed simple artificial pollination, omitting all optimization steps (S21, S22, S23). Its fruit set rate of 42.6% was the lowest among all treatments, strongly demonstrating that simply performing basic artificial pollination without refined management still resulted in poor fruit set. Simultaneously, while it had the highest single fruit weight (318.6g), it had the lowest yield per plant (6.01kg), indicating severe fruit drop and a very low number of fruits.

[0104] Comparing management methods 1 with methods 8, 9, and 10: omitting S21 (pollen activation), S22 (stigma activation), and S23 (post-flowering nutrient compensation) respectively resulted in varying degrees of decrease in fruit set rate (58.3%, 53.6%, and 65.4%, respectively), all lower than the 73.6% of management method 1. This indicates that each optimization step contributes independently to improving the final fruit set rate. The decrease in fruit set rate (53.6%) was most significant when omitting stigma activation (S22), demonstrating that improving the stigma microenvironment is crucial for successful pollination of custard apples in a greenhouse environment. The decrease in fruit set rate (65.4%) when omitting post-flowering nutrient compensation (S23) was relatively smaller, but still not negligible.

[0105] Comparing management methods 13 and 14 with 15 and 16: these treatments simplified S21 and S22, respectively. For example, the fruit set rate (63.1%, 59.6%) and yield per plant (8.33 kg, 7.95 kg) of management method 13 (using only boric acid) and management method 14 (using only sucrose) were significantly lower than those of management method 1, which used a combination of both (sucrose + boric acid). Similarly, the effects of management methods 15 (using only chitosan oligosaccharide) and management method 16 (using only seaweed oligosaccharide) were far less than those of management method 1, which used a combination of both. This demonstrates that the components in the activating solution have a synergistic effect, and the combined use is far superior to using them individually.

[0106] Comparing Management Method 1 (9.23 kg) and Management Method 11 (7.99 kg): Management Method 11 omitted step three, which involved nutritional fruit preservation control. The results showed that its yield per plant (7.99 kg) was significantly lower than that of Management Method 1. Although there were differences in fruit set rate (60.7% vs. 73.6%) and single fruit weight (295.2 g vs. 283.7 g), the decrease in yield per plant was the greatest. This indicates that step three played a crucial role in transforming the young, set fruit into mature, economically valuable fruit, reducing subsequent fruit drop.

[0107] Comparing management method 1 (73.6%, 9.23 kg) and management method 4 (70.6%, 8.91 kg): Ammonium molybdate was omitted from the fruit-setting agent in management method 4. Data showed a slight decrease in both fruit set rate and yield per plant. This confirms that molybdenum, as a micronutrient, has a weak but positive effect on promoting pollen tube elongation and early fruit development.

[0108] The technical features disclosed above are not limited to the combinations of the disclosed features with other features. Those skilled in the art can also make other combinations of the technical features according to the purpose of the invention to achieve the purpose of the invention.

Claims

1. A method for cultivating and managing custard apples suitable for greenhouse environments, characterized in that, Includes the following steps: Step 1: Pre-planting tree management; Timing: November-December after autumn / winter pruning; Measures: Combine deep tilling and soil improvement, apply 5-10 kg of organic fertilizer per tree, along with 0.5-1 kg of compound fertilizer; Simultaneously, foliar spray with a micronutrient supplement, the formula of which is: 0.15-0.30 parts by weight of magnesium sulfate, 0.20-0.40 parts by weight of potassium dihydrogen phosphate, and 0.05-0.15 parts by weight of zinc sulfate. After dissolving, spray once every 10 days, for a total of 2 sprays. Step Two: Artificial Pollination; Timing: During the flowering period of custard apple (May-September), choose a sunny evening between 4:00 PM and 6:00 PM; Method: Collect custard apple flowers that are in a semi-open state that afternoon, when the petals are not yet fully open, the pistils are mature but the stamens have not split open; Use a soft brush to brush the pollen into a container and immediately place it at a low temperature of 4℃ for short-term preservation; The next morning, when the pistils of another batch of flowers are mature, use a brush to dip the pollen collected in the container and apply it to the stigma of the pistil; Step 3: Nutritional Fruit Preservation Regulation; Timing: 3-5 days after flowering and during the young fruit stage, when the fruit diameter is approximately 1-2 cm; Measures: The fruit preservation spray formula is: 20-30 g / L gibberellin, 10-15 g / L 6-benzyladenine, and 40-60 g / L amino acid chelated potassium; Application method: Use a sprayer to evenly spray the fruit stalk and young fruit until dripping wet; focus on spraying the fruit stalk area to prevent the formation of the abscission layer.

2. The method for cultivating and managing custard apples in a greenhouse environment according to claim 1, characterized in that, In step 1, the compound fertilizer contains 18-20% nitrogen (N), 6-8% phosphorus (P2O5), and 18-23% potassium (K2O).

3. The method for cultivating and managing custard apples in a greenhouse environment according to claim 1, characterized in that, In step two, after pollen collection, pollen activation treatment is performed. The activation treatment involves placing the pollen in a solution containing 5-8 g / L sucrose and 0.01-0.02 g / L boric acid for 5-10 minutes to improve the pollen germination rate.

4. The method for cultivating and managing custard apples in a greenhouse environment according to claim 1, characterized in that, Before artificial pollination in step two, a stigma activating solution is sprayed onto the stigma of the pistil. The stigma activating solution is a mixed solution of 0.10-0.30 g / L chitosan oligosaccharide and 0.01-0.03 g / L seaweed oligosaccharide to improve the adhesion of pollen to the stigma surface and its germination ability.

5. The method for cultivating and managing custard apples in a greenhouse environment according to claim 1, characterized in that, Between steps two and three, there is also a post-flowering nutrient compensation step, in which a nutrient solution containing 0.10-0.30 g / L urea and 0.50-0.80 g / L potassium humate is sprayed on the leaves within 48 hours after pollination to promote the development of fertilized ovules.

6. The method for cultivating and managing custard apples in a greenhouse environment according to claim 1, characterized in that, The fruit-preserving agent in step three also includes 0.01-0.02 g / L of ammonium molybdate to promote pollen tube elongation and early fruit development.

7. The method for cultivating and managing custard apples in a greenhouse environment according to claim 1, characterized in that, Selective fruit thinning should be carried out during the young fruit stage, retaining 1-2 fruits on each fruiting branch, and giving priority to retaining young fruits with symmetrical shape and thick pedicels, in order to reduce physiological fruit drop caused by nutrient competition.

8. The method for cultivating and managing custard apples in a greenhouse environment according to claim 7, characterized in that, Following the selective fruit thinning, a fruit correction step is also included: when the young fruit develops to a transverse diameter of 3-4 cm, the fruit is pretreated before bagging by uniformly spraying the fruit surface with a compound liquid containing 0.05-0.20 g / L seaweed extract and 0.02-0.10 g / L amino acids, and then bagging is performed.

9. The method for cultivating and managing custard apples in a greenhouse environment according to claim 1, characterized in that, It also includes steps for controlling environmental stress; timing: when the temperature is >35℃ or there is continuous rainy weather during the entire flowering and fruiting period; measures: when the temperature is >35℃: cover the tree basin with straw or mulch, and spray water on the tree canopy every 3-5 days in the morning and evening; rainy weather: dredge the drainage ditch in time, and shake the flowers after the rain to shake off the water accumulated on the petals to prevent the flowers from rotting.

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