Management method for improving cold resistance and drought resistance of macadamia nuts and increasing flowering amount

Abstract

The invention discloses a management method for improving cold resistance and drought resistance of macadamia nuts and increasing flowering quantity, which combines a four-stage dynamic management mode of soil improvement, cold resistance induction, drought resistance and tip control and flowering phase quality improvement, applies an organic fertilizer, a water-retaining agent and a composite slow-release fertilizer, induces root development, slowly releases the fertility of a chemical fertilizer, prolongs the action time of the chemical fertilizer, and improves the yield of the macadamia nuts. Brassinolide and potassium fulvate are compounded to activate cold-resistant gene expression of macadamia nut plants and improve cell membrane stability, so that cold resistance of the macadamia nut plants is improved, melatonin and methyl jasmonate perform double shoot control, an ABA signal channel of the plants is triggered, drought resistance of the plants is improved, flower bud differentiation is promoted, and growth of the macadamia nut plants is promoted. The synergistic effect of alginate oligosaccharide and gamma-aminobutyric acid enhances the elongation ability of a pollen tube, chemical agent stimulation is replaced by biological agent stimulation, the utilization rate of chemical agents is reduced, then the negative influence of the chemical agents on soil is reduced, and finally the fruit setting rate and the sustainable utilization of the soil are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of macadamia nut planting, and in particular relates to a management method for improving the cold resistance and drought resistance of macadamia nuts and increasing the flowering amount. Background Art

[0002] As a crop with high economic value, the planting efficiency of macadamia nuts is significantly affected by adverse stresses such as drought and low temperature, which leads to flower and fruit drop and seriously affects the yield. In recent years, global climate change has led to frequent extreme weather. Major macadamia producing areas in my country, such as Yunnan and Guangxi, often suffer from the dual stress of winter frost and seasonal drought, resulting in up to 30%-50% flower and fruit drop in macadamia nuts, which seriously restricts the sustainable development of the industry. Although current technology has explored the stress resistance of macadamia nuts, it still has the following defects: 1. The means are single and only target cold protection or drought resistance, and lack a systematic response to complex adversity resistance. For example, patent CN104855206A provides a solution of water retaining agent plus organic fertilizer. Although it can alleviate drought stress, it cannot solve the impact of low temperature. The frost damage index of macadamia nuts is still very high under low temperature environment. 2. Over-reliance on chemical pesticides leads to excessive environmental residues, severely damaging the soil. For example, while large-scale spraying of paclobutrazol-based pesticides can inhibit new shoot growth, it also creates an imbalance in endogenous hormones, leading to a reduced flower bud differentiation rate the following year. The blind application of high-concentration nitrogen and phosphorus in foliar fertilizers exacerbates nutrient leaching and causes excessive nitrate levels in the soil. 3. Extensive nutrient supply during the flowering period leads to a combination of nutrient competition and adverse environmental damage. Conventional urea application before flowering can promote flowering, but the vigorous growth of new shoots consumes a large amount of photosynthetic assimilates, resulting in a very low effective flowering rate.

[0003] In response to the above problems, there is an urgent need for a management method that can combine multiple effects to improve the stress resistance of macadamia plants, effectively reduce the flower and fruit drop rate of macadamia plants, and thus improve economic benefits. Summary of the Invention

[0004] In response to the defect that existing macadamia nuts are easily susceptible to drought and low temperature stress and reduce yield, the present invention provides a management method for improving the cold resistance and drought resistance of macadamia nuts and increasing the flowering amount, which significantly improves the tolerance of macadamia nuts in harsh environments and maintains stable yield.

[0005] The present invention is achieved through the following technical solutions: A management method for improving cold resistance, drought resistance and flowering of macadamia nuts, comprising the following steps: S1: From October to November, dig a 30-40 cm deep circular trench 50 cm away from the tree trunk. Apply 8-10 kg / tree of organic fertilizer containing 18-24% fermented macadamia nut peels to the bottom of the trench. Apply 0.4-0.6 kg / tree of calcium magnesium phosphate fertilizer and 280-320 g / tree of starch grafted acrylate water retaining agent to the middle layer of the trench. Apply 0.8-1.2 kg / tree of compound slow-release fertilizer with a N-P2O5-K2O ratio of 15-15-15 to the surface of the trench. S2: From November to January of the following year, spray the leaves of nut plants with a cold-resistant liquid at a rate of 300-400 mL / plant on sunny days with daytime temperatures ≥15°C. The cold-resistant liquid comprises the following components: 10-14 g / L of proline, 140-160 mg / L of salicylic acid, 2-3 g / L of potassium fulvate, 40-60 μg / L of brassinolide, and 0.4-0.6 g / L of polyglycerol ester; S3: From October to December, alternately spray 600 times of 20% paclobutrazol and 500 times of PBO containing 0.1% nano-silica carrier, with a spraying interval of 12-15 days; at the same time, spray a mixture of 180-220 μmol / L melatonin and 240-260 μmol / L methyl jasmonate. S4: In January and February of the following year, spray a mixed solution containing 240-260 g / L brown algae oligosaccharide, 40-60 g / L 5-aminolevulinic acid, 340-360 g / L γ-aminobutyric acid, 0.1-0.3% potassium dihydrogen phosphate, 0.1-0.2% fluid boron, and 0.1-0.2% gibberellic acid at a spraying rate of 300-400 mL / plant.

[0006] The present invention combines a four-stage dynamic management model: soil improvement, cold-resistance induction, drought-resistance shoot control, and flowering quality improvement. Organic fertilizer, calcium magnesium phosphate fertilizer, water-retaining agent, and composite slow-release fertilizer are applied to the plant roots. The Bacillus subtilis spores and fertilizer loaded on the surface of the composite slow-release fertilizer can induce root development, while the fertility of the chemical fertilizer is slowly released, extending the duration of the chemical fertilizer's action. The use of brassinolide and potassium fulvate in combination can activate the expression of cold-resistance genes in macadamia plants, enhance cell membrane stability, and thus improve the cold resistance of macadamia plants. The dual shoot control of paclobutrazol and PBO dilution combined with melatonin and methyl jasmonate can effectively reduce the use of chemical agents, trigger the plant's ABA signaling pathway to improve the plant's drought resistance, and promote flower bud differentiation. The synergistic effect of brown algae oligosaccharides and γ-aminobutyric acid enhances pollen tube elongation. By replacing chemical stimulation with biological agent stimulation, the use rate of chemical agents is reduced, thereby reducing the negative impact of chemical agents on the soil, ultimately improving fruit set rate and sustainable soil utilization.

[0007] As a further improvement of the present invention, the preparation method of the composite slow-release fertilizer is as follows: (1) Potassium humate and polyvinyl alcohol were dissolved in deionized water at 60°C at a solid-liquid ratio of 1:8, genipin crosslinker was added, the pH was adjusted to 7.5-8.0, and then stirred into a uniform colloid with a viscosity of 800-1200 mPa·s; (2) Chitosan with a deacetylation degree of ≥90% was dissolved in a 1% acetic acid solution to prepare a solution with a concentration of 30 g / L, and then nano-silica with a particle size of 30-50 nm was added and ultrasonically dispersed for 20 min to obtain a modified chitosan solution; (3) Compound fertilizer particles with N-P2O5-K2O=15-15-15 are placed in a fluidized bed, preheated to 50-55°C, atomized and sprayed with the colloid prepared in step (1), and then allowed to stand and dry; the spraying rate is 8-10 mL / min; the inlet air temperature is 65-70°C; and the coating thickness is 50-80 μm; (4) The granules dried in step (3) are sprayed with the modified chitosan solution prepared in step (2) at 40-45° C., and then placed in an environment with a humidity of 60-70%, and cured by hot air circulation at 45° C. for 4-6 hours to obtain a composite slow-release fertilizer.

[0008] Nano-silica combined with chitosan is used as the slow-release outer layer, and potassium humate combined with polyvinyl alcohol is used as the slow-release inner layer to wrap the compound fertilizer to prepare a slow-release compound fertilizer. When the macadamia nut roots secrete organic acids, the inner layer of potassium humate and compound fertilizer are released. The chitosan shell can slowly release the compound fertilizer and potassium humate according to changes in soil temperature and humidity. The chitosan coating structure can ensure that fertilizer and potassium humate can also be released and play a role in drought seasons, thereby improving the drought resistance of macadamia nut plants.

[0009] As a further improvement of the present invention, the outer surface of the composite slow-release fertilizer is loaded with 0.1%-0.2% by mass of Bacillus subtilis spore powder by electrostatic adsorption technology; the number of viable bacteria of the Bacillus subtilis spore powder is ≥1×10 8 CFU / g.

[0010] The Bacillus subtilis loaded on the outermost layer can activate soil phosphorus and potassium, forming a "chemical and biological dual slow-release" mechanism with potassium humate, thereby significantly improving fertilizer utilization and reducing the negative impact of chemical fertilizers on the soil.

[0011] As a further improvement of the present invention, the surface of the annular groove is covered with a water-retaining film, and the preparation method of the water-retaining film is as follows: (1) Soaking Mentha serrata seeds in a 2% w / v chitosan solution for 30 minutes, and then drying to obtain coated seeds; the chitosan solution contains 0.1% gibberellic acid by volume; (2) The polylactic acid particles were mixed with 8%-10% of acetyl tributyl citrate by weight, and dried in an oven at 60°C for 4 h. Then, 3%-5% of the weight of the mixed particles of nano-titanium dioxide, 1%-2% of nano-silver-loaded montmorillonite, and 0.3%-0.5% of diisopropylbenzene peroxide were added, and premixed at 800 rpm for 10 min to obtain a premix; (3) The premix was blended into a blend using a twin-screw extruder; the length-to-diameter ratio of the twin-screw extruder was 40:1, the screw speed was 120 rpm, the vacuum degassing pressure was -0.08 MPa, and the temperature gradient was 160°C in zone 1, 175°C in zone 2, 185°C in zone 3, and 180°C in zone 4; (4) Add the coated seeds and the blended material from step (1) into an internal mixer and mix them at 95°C and 50 rpm for 5 min; the amount of coated seeds added is 10%-15% of the mass of the blended material; the mixed material is cast into a film with a die head temperature of 190°C, a cooling roller temperature of 25°C, a pulling speed of 8-10 m / min, and a film thickness controlled to be 0.08-0.12 mm; (5) Use a pulsed laser with a wavelength of 1064nm and a power of 20W to create micropores with an aperture of 50-100μm and 200-300 pores / cm on the membrane surface. 2 .

[0012] The water-retaining film is loaded with the seeds of the Cordyceps liposa. Micropores are arranged on the surface of the film to ensure air permeability while promoting the germination of the Cordyceps. Nano-titanium oxide and polylactic acid are incorporated into the film body. The former will degrade under the action of light, and the latter will degrade in water. The Cordyceps released after degradation will grow and form a biological insect repellent belt, thereby reducing the use of pesticides.

[0013] As a further improvement of the present invention, the mint seeds in step (1) are first frozen with liquid nitrogen and then crushed to 10-100 mesh.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The present invention significantly enhances the antioxidant enzyme activity of macadamia nuts through proline-salicylic acid-melatonin multi-pathway activation, thereby improving the plant's cross-resistance to cold and drought.

[0015] 2. The present invention uses brown algae oligosaccharides and γ-aminobutyric acid as biostimulants instead of chemical stimulation, and combines a degradable water-retaining film to release insect repellent grass seeds to form an insect repellent belt, thereby reducing the use of pesticides and forming an environmentally friendly protection.

[0016] 3. The present invention uses compound slow-release fertilizer combined with organic fertilizer to promote plant root growth. The compound slow-release fertilizer can ensure the effective release of compound fertilizer and potassium humate during drought seasons, ensure plant growth, and thus improve the plant's drought resistance. DETAILED DESCRIPTION

[0017] The present invention will be further described below with reference to the examples. In the examples, unless otherwise specified, the technical means used are conventional technical means in the art.

[0018] The varieties used in the following examples are all macadamia nuts "JW", with an average tree age of 6-7 years; the planting locations are Zhoulu Town, Mashan County and Xingning District, Nanning City. Example 1

[0019] A management method for improving cold resistance, drought resistance and flowering of macadamia nuts, comprising the following steps: S1: From October to November, a 30 cm deep circular trench was dug 50 cm away from the tree trunk. 8 kg of organic fertilizer containing 18% fermented macadamia nut peel was applied to the bottom layer of the trench. 0.4 kg of calcium magnesium phosphate fertilizer and 280 g of starch grafted acrylate water retaining agent were applied to the middle layer of the trench. 0.8 kg of compound slow-release fertilizer with a concentration of N-P2O5-K2O of 15-15-15 was applied to the surface layer of the trench. S2: From November to January of the following year, spray the leaves of nut plants with a cold-resistant liquid at a rate of 300 mL / plant on sunny days with a daytime temperature ≥15°C. The cold-resistant liquid comprises the following components: 10 g / L proline, 140 mg / L salicylic acid, 2 g / L potassium fulvic acid, 40 μg / L brassinolide, and 0.4 g / L polyglycerol ester; S3: From October to December, alternately spray 600 times of 20% paclobutrazol and 500 times of PBO containing 0.1% nano-silica carrier, with a spraying interval of 12 days; at the same time, spray a mixture of 180 μmol / L melatonin and 240 μmol / L methyl jasmonate. S4: In January and February of the following year, spray a mixed solution containing 240 g / L brown algae oligosaccharide, 40 g / L 5-aminolevulinic acid, 340 g / L γ-aminobutyric acid, 0.1% potassium dihydrogen phosphate, 0.1% fluid boron, and 0.1% gibberellic acid at a spraying rate of 300 mL / plant.

[0020] The preparation method of the composite slow-release fertilizer is as follows: (1) Potassium humate and polyvinyl alcohol were dissolved in deionized water at 60°C at a solid-liquid ratio of 1:8, and genipin crosslinker was added. The pH was adjusted to 7.5 and stirred to form a uniform colloid with a viscosity of 800 mPa·s. (2) Chitosan with a deacetylation degree of ≥90% was dissolved in a 1% acetic acid solution to prepare a solution with a concentration of 30 g / L, and then nano-silica with a particle size of 30-50 nm was added and ultrasonically dispersed for 20 min to obtain a modified chitosan solution; (3) Compound fertilizer particles with N-P2O5-K2O=15-15-15 were placed in a fluidized bed, preheated to 50°C, and sprayed with the colloid prepared in step (1), and then allowed to stand and dry; the spraying rate was 8 mL / min; the inlet air temperature was 65°C; and the coating thickness was 50 μm; (4) The granules dried in step (3) were sprayed with the modified chitosan solution prepared in step (2) at 40° C., and then placed in an environment with a humidity of 60% and cured by hot air circulation at 45° C. for 6 h to obtain a composite slow-release fertilizer.

[0021] The surface of the annular groove is covered with a water-retaining film, and the preparation method of the water-retaining film is as follows: (1) Soaking Mentha serrata seeds in a 2% w / v chitosan solution for 30 minutes, and then drying to obtain coated seeds; the chitosan solution contains 0.1% gibberellic acid by volume; (2) Polylactic acid particles were mixed with 8% by weight of acetyl tributyl citrate, dried in an oven at 60°C for 4 h, and then 3% by weight of the mixed particles of nano-titanium dioxide, 1% of nano-silver-loaded montmorillonite, and 0.3% of diisopropylbenzene peroxide were added, and premixed at 800 rpm for 10 min to obtain a premix; (3) The premix was blended into a blend using a twin-screw extruder; the length-to-diameter ratio of the twin-screw extruder was 40:1, the screw speed was 120 rpm, the vacuum degassing pressure was -0.08 MPa, and the temperature gradient was 160°C in zone 1, 175°C in zone 2, 185°C in zone 3, and 180°C in zone 4; (4) Add the coated seeds and the blended material from step (1) into an internal mixer and mix them at 95°C and 50 rpm for 5 min; the amount of coated seeds added is 10% of the mass of the blended material; the mixed material is cast into a film with a die head temperature of 190°C, a cooling roller temperature of 25°C, a pulling speed of 8 m / min, and a film thickness controlled to be 0.08 mm; (5) Use a pulsed laser with a wavelength of 1064nm and a power of 20W to create micropores with a diameter of 50μm on the membrane surface, with a density of 200 pores / cm 2 . Example 2

[0022] A management method for improving cold resistance, drought resistance and flowering of macadamia nuts, comprising the following steps: S1: From October to November, a 40 cm deep circular trench was dug 50 cm from the trunk. 10 kg of organic fertilizer containing 24% fermented macadamia nut green peel was applied to the bottom layer of the trench. 0.6 kg of calcium magnesium phosphate fertilizer and 320 g of starch grafted acrylate water retaining agent were applied to the middle layer of the trench. 1.2 kg of compound slow-release fertilizer with a ratio of N-P2O5-K2O=15-15-15 was applied to the surface layer of the trench. S2: From November to January of the following year, spray the leaves of nut plants with a cold-resistant liquid at a rate of 400 mL / plant on sunny days with a daytime temperature ≥15°C. The cold-resistant liquid comprises the following components: 14 g / L proline, 160 mg / L salicylic acid, 3 g / L potassium fulvate, 60 μg / L brassinolide, and 0.6 g / L polyglycerol ester; S3: From October to December, alternately spray 600 times of 20% paclobutrazol and 500 times of PBO containing 0.1% nano-silica carrier, with a spraying interval of 12-15 days; at the same time, spray a mixture of 220μmol / L melatonin and 260μmol / L methyl jasmonate. S4: In January and February of the following year, spray a mixed solution containing 260 g / L brown algae oligosaccharide, 60 g / L 5-aminolevulinic acid, 360 g / L γ-aminobutyric acid, 0.3% potassium dihydrogen phosphate, 0.2% fluid boron, and 0.2% gibberellic acid at a spraying rate of 400 mL / plant.

[0023] The preparation method of the composite slow-release fertilizer is as follows: (1) Potassium humate and polyvinyl alcohol were dissolved in deionized water at 60°C at a solid-liquid ratio of 1:8, genipin crosslinker was added, the pH was adjusted to 8.0, and the mixture was stirred into a uniform colloid with a viscosity of 1200 mPa·s; (2) Chitosan with a deacetylation degree of ≥90% was dissolved in 1% acetic acid solution to prepare a solution with a concentration of 30 g / L, and then nano-silica with a particle size of 50 nm was added and ultrasonically dispersed for 20 min to obtain a modified chitosan solution; (3) Compound fertilizer particles with N-P2O5-K2O=15-15-15 were placed in a fluidized bed, preheated to 55°C, and sprayed with the colloid prepared in step (1), and then allowed to stand and dry; the spraying rate was 10 mL / min; the inlet air temperature was 70°C; and the coating thickness was 80 μm; (4) The particles dried in step (3) are sprayed with the modified chitosan solution prepared in step (2) at 45° C., and then placed in an environment with a humidity of 60-70%, and cured by hot air circulation at 45° C. for 4 hours to obtain a composite slow-release fertilizer.

[0024] The outer surface of the composite slow-release fertilizer is loaded with 0.1% by mass of Bacillus subtilis spore powder by electrostatic adsorption technology; the number of viable bacteria of the Bacillus subtilis spore powder is ≥1×10 8 CFU / g.

[0025] The surface of the annular groove is covered with a water-retaining film, and the preparation method of the water-retaining film is as follows: (1) Peppermint seeds were first frozen with liquid nitrogen and then crushed into 10 meshes, then soaked in a 2% w / v chitosan solution for 30 minutes, and then dried to obtain coated seeds; the chitosan solution contained 0.1% gibberellic acid by volume; (2) Polylactic acid particles were mixed with 10% of acetyl tributyl citrate by weight, dried in an oven at 60°C for 4 h, and then 5% of the mixed particles by weight of nano-titanium dioxide, 2% of nano-silver-loaded montmorillonite, and 0.5% of diisopropylbenzene peroxide were added, and premixed at 800 rpm for 10 min to obtain a premix; (3) The premix was blended into a blend using a twin-screw extruder; the length-to-diameter ratio of the twin-screw extruder was 40:1, the screw speed was 120 rpm, the vacuum degassing pressure was -0.08 MPa, and the temperature gradient was 160°C in zone 1, 175°C in zone 2, 185°C in zone 3, and 180°C in zone 4; (4) The coated seeds and the blended material from step (1) were added to an internal mixer and mixed at 95°C and 50 rpm for 5 min; the amount of coated seeds added was 15% of the mass of the blended material; the mixed material was cast into a film with a die head temperature of 190°C, a cooling roller temperature of 25°C, a pulling speed of 10 m / min, and a film thickness of 0.12 mm; (5) Use a pulsed laser with a wavelength of 1064nm and a power of 20W to create micropores with a diameter of 100μm and 300 pores / cm on the membrane surface. 2 . Example 3

[0026] A management method for improving cold resistance, drought resistance and flowering of macadamia nuts, comprising the following steps: S1: From October to November, a 32cm deep circular trench was dug 50cm from the trunk. 9kg / plant of organic fertilizer containing 18-24% fermented macadamia nut peel was applied to the bottom layer of the trench. 0.4-0.6kg / plant of calcium magnesium phosphate fertilizer and 300g / plant of starch grafted acrylate water retaining agent were applied to the middle layer of the trench. 1.0kg / plant of compound slow-release fertilizer with N-P2O5-K2O=15-15-15 was applied to the surface layer of the trench. S2: From November to January of the following year, spray the leaves of nut plants with a cold-resistant liquid at a rate of 350 mL / plant on sunny days with a daytime temperature ≥15°C. The cold-resistant liquid comprises the following components: 12 g / L proline, 150 mg / L salicylic acid, 2 g / L potassium fulvic acid, 50 μg / L brassinolide, and 0.5 g / L polyglycerol ester; S3: From October to December, alternately spray 600 times of 20% paclobutrazol and 500 times of PBO containing 0.1% nano-silica carrier, with a spraying interval of 13 days; at the same time, spray a mixture of 200 μmol / L melatonin and 250 μmol / L methyl jasmonate. S4: In January and February of the following year, spray a mixed solution containing 250 g / L brown algae oligosaccharide, 50 g / L 5-aminolevulinic acid, 350 g / L γ-aminobutyric acid, 0.2% potassium dihydrogen phosphate, 0.15% fluid boron, and 0.15% gibberellic acid at a spraying rate of 350 mL / plant.

[0027] The preparation method of the composite slow-release fertilizer is as follows: (1) Potassium humate and polyvinyl alcohol were dissolved in deionized water at 60°C at a solid-liquid ratio of 1:8, genipin crosslinker was added, the pH was adjusted to 7.8, and the mixture was stirred into a uniform colloid with a viscosity of 1000 mPa·s; (2) Chitosan with a deacetylation degree of ≥90% was dissolved in 1% acetic acid solution to prepare a solution with a concentration of 30 g / L, and then nano-silica with a particle size of 40 nm was added and ultrasonically dispersed for 20 min to obtain a modified chitosan solution; (3) Compound fertilizer particles with N-P2O5-K2O=15-15-15 were placed in a fluidized bed, preheated to 52°C, and atomized and sprayed with the colloid prepared in step (1), and then allowed to stand and dry; the spraying rate was 9 mL / min; the inlet air temperature was 66°C; and the coating thickness was 70 μm; (4) The granules dried in step (3) are sprayed with the modified chitosan solution prepared in step (2) at 42°C, and then placed in an environment with a humidity of 65% and cured in a hot air circulation at 45°C for 5 hours to obtain a composite slow-release fertilizer. The outer surface of the composite slow-release fertilizer is loaded with 0.2% by mass of Bacillus subtilis spore powder by electrostatic adsorption technology; the number of viable Bacillus subtilis spore powder is ≥1×10 8 CFU / g.

[0028] The surface of the annular groove is covered with a water-retaining film, and the preparation method of the water-retaining film is as follows: (1) Peppermint seeds were first frozen with liquid nitrogen and then crushed to 100 mesh, then soaked in a 2% w / v chitosan solution for 30 minutes, and then dried to obtain coated seeds; the chitosan solution contained 0.1% gibberellic acid by volume; (2) The polylactic acid particles were mixed with 8%-10% of acetyl tributyl citrate by weight, dried in an oven at 60°C for 4 h, and then 4% of nano-titanium dioxide, 1.5% of nano-silver-loaded montmorillonite, and 0.4% of diisopropylbenzene peroxide were added to the mixed particles, and premixed at 800 rpm for 10 min to obtain a premix; (3) The premix was blended into a blend using a twin-screw extruder; the length-to-diameter ratio of the twin-screw extruder was 40:1, the screw speed was 120 rpm, the vacuum degassing pressure was -0.08 MPa, and the temperature gradient was 160°C in zone 1, 175°C in zone 2, 185°C in zone 3, and 180°C in zone 4; (4) The coated seeds and the blended material of step (1) were added to an internal mixer and mixed at 95°C and 50 rpm for 5 min; the amount of coated seeds added was 12% of the mass of the blended material; the mixed material was cast into a film with a die head temperature of 190°C, a cooling roller temperature of 25°C, a pulling speed of 9 m / min, and a film thickness of 0.10 mm; (5) A pulsed laser with a wavelength of 1064 nm and a power of 20 W was used to create micropores with an aperture of 80 μm and a density of 250 pores / cm on the membrane surface. 2 . Example 4

[0029] A management method for improving cold resistance, drought resistance and flowering of macadamia nuts, comprising the following steps: S1: From October to November, a 38 cm deep circular trench was dug 50 cm from the trunk. 9 kg of organic fertilizer containing 22% fermented macadamia nut peel was applied to the bottom layer of the trench. 0.6 kg of calcium magnesium phosphate fertilizer and 280-320 g of starch grafted acrylate water retaining agent were applied to the middle layer of the trench. 0.8 kg of compound slow-release fertilizer with a N-P2O5-K2O ratio of 15-15-15 was applied to the surface layer of the trench. S2: From November to January of the following year, spray the leaves of nut plants with a cold-resistant liquid at a rate of 360 mL / plant on sunny days with a daytime temperature of ≥15°C. The cold-resistant liquid comprises the following components: 13 g / L proline, 150 mg / L salicylic acid, 2 g / L potassium fulvic acid, 55 μg / L brassinolide, and 0.6 g / L polyglycerol ester; S3: From October to December, alternately spray 600 times of 20% paclobutrazol and 500 times of PBO containing 0.1% nano-silica carrier, with an interval of 12-15 days; at the same time, spray a mixture of 195μmol / L melatonin and 245μmol / L methyl jasmonate. S4: In January and February of the following year, spray a mixed solution containing 255g / L brown algae oligosaccharide, 55g / L 5-aminolevulinic acid, 350g / L γ-aminobutyric acid, 0.3% potassium dihydrogen phosphate, 0.1% fluid boron, and 0.1% gibberellic acid at a spraying rate of 400mL / plant.

[0030] The preparation method of the composite slow-release fertilizer is as follows: (1) Potassium humate and polyvinyl alcohol were dissolved in deionized water at 60°C at a solid-liquid ratio of 1:8, genipin crosslinker was added, the pH was adjusted to 8.0, and the mixture was stirred to form a uniform colloid with a viscosity of 1100 mPa·s; (2) Chitosan with a deacetylation degree of ≥90% was dissolved in 1% acetic acid solution to prepare a solution with a concentration of 30 g / L, and then nano-silica with a particle size of 40 nm was added and ultrasonically dispersed for 20 min to obtain a modified chitosan solution; (3) Compound fertilizer particles with N-P2O5-K2O=15-15-15 were placed in a fluidized bed, preheated to 50°C, and sprayed with the colloid prepared in step (1), and then allowed to stand and dry; the spraying rate was 8 mL / min; the inlet air temperature was 70°C; and the coating thickness was 70 μm; (4) The granules dried in step (3) are sprayed with the modified chitosan solution prepared in step (2) at 45°C, and then placed in an environment with a humidity of 60-70%, and cured by hot air circulation at 45°C for 6 hours to obtain a composite slow-release fertilizer. The outer surface of the composite slow-release fertilizer is loaded with 0.2% by mass of Bacillus subtilis spore powder by electrostatic adsorption technology; the number of viable Bacillus subtilis spore powder is ≥1×10 8 CFU / g.

[0031] The surface of the annular groove is covered with a water-retaining film, and the preparation method of the water-retaining film is as follows: (1) Peppermint seeds were first frozen with liquid nitrogen and then crushed to 50 mesh, then soaked in a 2% w / v chitosan solution for 30 minutes, and then dried to obtain coated seeds; the chitosan solution contained 0.1% gibberellic acid by volume; (2) Polylactic acid particles were mixed with 9% by weight of acetyl tributyl citrate, dried in an oven at 60°C for 4 h, and then 3% by weight of the mixed particles of nano-titanium dioxide, 2% of nano-silver-loaded montmorillonite, and 0.5% of diisopropylbenzene peroxide were added, and premixed at 800 rpm for 10 min to obtain a premix; (3) The premix was blended into a blend using a twin-screw extruder; the length-to-diameter ratio of the twin-screw extruder was 40:1, the screw speed was 120 rpm, the vacuum degassing pressure was -0.08 MPa, and the temperature gradient was 160°C in zone 1, 175°C in zone 2, 185°C in zone 3, and 180°C in zone 4; (4) The coated seeds and the blended material of step (1) were added to an internal mixer and mixed at 95°C and 50 rpm for 5 min; the amount of coated seeds added was 15% of the mass of the blended material; the mixed material was cast into a film with a die head temperature of 190°C, a cooling roller temperature of 25°C, a pulling speed of 8 m / min, and a film thickness of 0.12 mm; (5) A pulsed laser with a wavelength of 1064 nm and a power of 20 W was used to create micropores with an aperture of 88 μm and a density of 260 pores / cm on the membrane surface. 2 .

[0032] Comparative Example Conventional macadamia plant management practices were adopted, as follows: (1) October-November: Apply 5-10kg of organic fertilizer, 0.5kg of calcium magnesium phosphate fertilizer, and 1kg of compound fertilizer; (2) From November to January: spray 20g / L potassium fulvic acid to improve cold resistance; (3) From October to December: spray 20% paclobutrazol 600-800 times diluted and 500 times PBO diluted to improve drought resistance; (4) During January and February: spray 0.2% potassium dihydrogen phosphate, 0.1% liquid boron, and 0.1% gibberellic acid.

[0033] The ratio of the depth to the width of the plant's roots is used as the standard for cold resistance: when the ratio of the root depth to the root width is 1.7-1.9, the cold resistance is strong; when the ratio of the root depth to the root width is 1.5-1.6, the cold resistance is average; when the ratio of the root depth to the root width is 2.0-2.2, the cold resistance is weak.

[0034] The flowering amount, drought resistance, chlorophyll content and root depth to width ratio distribution of macadamia nut plants after treatment in Examples 1-3 and the comparative example are shown in Tables 1-4 respectively.

[0035] Table 1: Effects of different treatments on flowering rate deal with Average tip thickness mm Average flower spike length cm Flowering ratio of fruiting mother branches Comparative Example 2.9 22.6 23.8% Example 1 3.3 25.2 75.2% Example 2 3.2 24.8 68.3% Example 3 3.5 26.3 81.7% Example 4 3.3 27.4 69.5% Table 2: Physiological effects of different treatments on drought resistance deal with Soluble sugar mg / g Proline ug / g Soluble protein ug / g Malondialdehyde nmol / g Comparative Example 21.6 12.8 11.4 4.8 Example 1 39.4 31.3 28.2 7.5 Example 2 35.8 27.6 26.5 6.9 Example 3 37.1 28.7 19.8 8.2 Example 4 32.5 24.1 24.6 9.1 Table 3: Effects of different treatments on chlorophyll content deal with Chlorophyll amg / g Chlorophyll bmg / g Chlorophyll (a+b) mg / g Comparative Example 1.33 0.21 1.54 Example 1 1.78 0.31 2.09 Example 2 1.86 0.34 2.2 Example 3 1.92 0.39 2.31 Example 4 2.26 0.43 2.69 Table 4: Distribution of root depth to width ratios of plants under different treatments deal with The proportion of plants with a root depth-to-width ratio of 1.7-1.9 The proportion of plants with a root depth-to-width ratio of 1.5-1.6 The proportion of plants with a root depth-to-width ratio of 2.0-2.2 Comparative Example 55% 29% 16% Example 1 70% 21% 9% Example 2 68% 32% 10% Example 3 72% 18% 10% Example 4 73% 18% 9% It can be seen from the data in Tables 1-4 that the flowering volume of macadamia nut plants planted using the management method of the present invention is significantly improved, the drought resistance is high, and the high chlorophyll content in the branches and leaves can enhance photosynthesis, providing more energy for the plants to cope with low temperature stress. The proportion of plants with strong cold resistance is higher than 68%, and the proportion of plants with average cold resistance is less than 10%.

[0036] The above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the scope of the present invention. The scope of protection of the present invention is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present invention within the spirit and scope of protection of the present invention, and such modifications or equivalent substitutions shall also be deemed to fall within the scope of protection of the present invention.

Claims

1. A management method for improving the cold resistance and drought resistance of macadamia nuts and increasing the flowering amount, characterized in that: The following steps are involved: S1: From October to November, dig a 30-40 cm deep circular trench 50 cm away from the tree trunk. Apply 8-10 kg / tree of organic fertilizer containing 18-24% fermented macadamia nut peels to the bottom of the trench. Apply 0.4-0.6 kg / tree of calcium magnesium phosphate fertilizer and 280-320 g / tree of starch grafted acrylate water retaining agent to the middle layer of the trench. Apply 0.8-1.2 kg / tree of compound slow-release fertilizer with a N-P2O5-K2O ratio of 15-15-15 to the surface of the trench. S2: From November to January of the following year, spray the leaves of nut plants with a cold-resistant liquid at a rate of 300-400 mL / plant on sunny days with daytime temperatures ≥15°C. The cold-resistant liquid comprises the following components: 10-14 g / L of proline, 140-160 mg / L of salicylic acid, 2-3 g / L of potassium fulvate, 40-60 μg / L of brassinolide, and 0.4-0.6 g / L of polyglycerol ester; S3: From October to December, alternately spray 600 times of 20% paclobutrazol and 500 times of PBO containing 0.1% nano-silica carrier, with a spraying interval of 12-15 days; at the same time, spray a mixture of 180-220 μmol / L melatonin and 240-260 μmol / L methyl jasmonate. S4: In January and February of the following year, spray a mixed solution containing 240-260 g / L brown algae oligosaccharide, 40-60 g / L 5-aminolevulinic acid, 340-360 g / L γ-aminobutyric acid, 0.1-0.3% potassium dihydrogen phosphate, 0.1-0.2% fluid boron, and 0.1-0.2% gibberellic acid at a spraying rate of 300-400 mL / plant.

2. The management method for improving cold resistance, drought resistance and flowering amount of macadamia nuts according to claim 1, characterized in that: The preparation method of the composite slow-release fertilizer is as follows: (1) Potassium humate and polyvinyl alcohol were dissolved in deionized water at 60°C at a solid-liquid ratio of 1:8, genipin crosslinker was added, the pH was adjusted to 7.5-8.0, and the mixture was stirred into a uniform colloid with a viscosity of 800-1200 mPa·s; (2) Chitosan with a deacetylation degree of ≥90% was dissolved in a 1% acetic acid solution to prepare a solution with a concentration of 30 g / L, and then nano-silica with a particle size of 30-50 nm was added and ultrasonically dispersed for 20 min to obtain a modified chitosan solution; (3) Compound fertilizer particles with N-P2O5-K2O=15-15-15 are placed in a fluidized bed, preheated to 50-55°C, atomized and sprayed with the colloid prepared in step (1), and then allowed to stand and dry; the spraying rate is 8-10 mL / min; the inlet air temperature is 65-70°C; and the coating thickness is 50-80 μm; (4) The granules dried in step (3) are sprayed with the modified chitosan solution prepared in step (2) at 40-45° C., and then placed in an environment with a humidity of 60-70%, and cured by hot air circulation at 45° C. for 4-6 hours to obtain a composite slow-release fertilizer.

3. The management method for improving cold resistance, drought resistance and flowering of macadamia nuts according to claim 2, characterized in that: The outer surface of the composite slow-release fertilizer is loaded with 0.1%-0.2% by mass of Bacillus subtilis spore powder by electrostatic adsorption technology; the number of viable bacteria of the Bacillus subtilis spore powder is ≥1×10 8 CFU / g.

4. The method for improving cold and drought resistance and increasing flowering of macadamia nuts according to claim 1, characterized in that: The surface of the annular groove is covered with a water-retaining film, and the preparation method of the water-retaining film is as follows: (1) Soaking Mentha serrata seeds in a 2% w / v chitosan solution for 30 minutes, and then drying to obtain coated seeds; the chitosan solution contains 0.1% gibberellic acid by volume; (2) The polylactic acid particles were mixed with 8%-10% of acetyl tributyl citrate by weight, and dried in an oven at 60°C for 4 h. Then, 3%-5% of the weight of the mixed particles of nano-titanium dioxide, 1%-2% of nano-silver-loaded montmorillonite, and 0.3%-0.5% of diisopropylbenzene peroxide were added, and premixed at 800 rpm for 10 min to obtain a premix; (3) The premix was blended into a blend using a twin-screw extruder; the length-to-diameter ratio of the twin-screw extruder was 40:1, the screw speed was 120 rpm, the vacuum degassing pressure was -0.08 MPa, and the temperature gradient was 160°C in zone 1, 175°C in zone 2, 185°C in zone 3, and 180°C in zone 4; (4) Add the coated seeds and the blended material from step (1) into an internal mixer and mix them at 95°C and 50 rpm for 5 min; the amount of coated seeds added is 10%-15% of the mass of the blended material; the mixed material is cast into a film with a die head temperature of 190°C, a cooling roller temperature of 25°C, a pulling speed of 8-10 m / min, and a film thickness controlled to be 0.08-0.12 mm; (5) Use a pulsed laser with a wavelength of 1064nm and a power of 20W to create micropores with an aperture of 50-100μm and 200-300 pores / cm on the membrane surface. 2 .

5. The management method for improving cold resistance, drought resistance and flowering amount of macadamia nuts according to claim 4, characterized in that: The mint seeds described in step (1) are first frozen with liquid nitrogen and then crushed to 10-100 mesh.