Rapid correction method for iron deficiency yellows of prunes

Abstract

The invention discloses a rapid correction method for iron deficiency yellows of prunes. A correction scheme for the iron deficiency yellows of the prunes comprises any one or a combination of any two or more of a correction scheme A, a correction scheme B and a correction scheme C; the correction scheme A comprises the following steps: spraying EDDHA chelated iron fertilizer to leaf surfaces of yellow prune trees; the correction scheme B is as follows: EDDHA chelated iron fertilizer and mineral source potassium fulvate are applied in soil root irrigation; according to the correction scheme C, the EDDHA chelated iron fertilizer is conveyed to the yellow prune tree by adopting a trunk hanging bag infusion method. The rapid correction method for the iron deficiency yellows of the prunes can solve the problems of abuse of chemical fertilizers, poor prevention and treatment effect, low utilization rate of iron fertilizers and the like in a current method for preventing and treating the iron deficiency yellows of the prunes.

Description

Technical Field

[0001] The present invention relates to the technical field of prevention and treatment of prune iron deficiency chlorosis, and in particular to a method for quickly correcting prune iron deficiency chlorosis. Background Art

[0002] Plum iron deficiency chlorosis, also known as chlorosis and iron depression, is a common physiological disease that harms a variety of crops in alkaline soils, especially calcareous soils. During the growing season, plum leaves lose their green color and turn yellow, and in severe cases, die. This phenomenon, known as "chlorosis," reduces photosynthetic capacity, thus affecting fruit yield and quality. Fruit trees are perennial crops that grow in fixed locations for long periods of time and can only absorb nutrients from the soil space within their root system. This can easily lead to a deficiency of certain nutrients in the soil, weakening the tree and significantly reducing the net photosynthetic rate of leaves, seriously affecting the synthesis of assimilates and reducing yield. Iron deficiency affects chlorophyll synthesis because the precursors for chlorophyll synthesis are affected by iron deficiency, resulting in impaired chlorophyll synthesis and the formation of leaf mesophyll cells and palisade tissue. In severe cases, organelle structure may be damaged, which is detrimental to the growth and development of the fruit tree.

[0003] Iron deficiency chlorosis is a serious problem in fruit cultivation. Plants on 25% to 30% of the world's land area are susceptible to the disease, especially perennial crops in arid regions. In North and Northwest my country, chlorosis of fruit trees is extremely common.

[0004] The main symptoms of plum chlorosis are: In early to mid-April, when plum leaf buds begin to sprout, the leaves are all green. As the leaves begin to unfold, chlorosis begins, first appearing on the tender leaves at the top of the new shoots. In severe cases, the new leaves take on a yellowish-white hue. In early to mid-May, when the plum leaves have fully expanded and become functional leaves, they exhibit typical iron deficiency symptoms: the mesophyll loses its green color and turns yellow, while the veins remain green, and the leaves develop a green reticular pattern. From June to July, the chlorosis worsens, with necrotic spots appearing on the leaves at the top of the new shoots. Brown scorch marks begin to form on the leaf edges, and the leaves gradually become necrotic. In severe cases, the leaves scorch and fall off, and the terminal buds die. The chlorosis reaches its peak in August, with scorch marks becoming common. Severe cases of chlorosis begin to necrotize and fall off, and even the plant begins to die.

[0005] In Xinjiang, with the increasing expansion of intensively managed plum orchards, rising fertilizer usage, and increasing yields, plum chlorosis is becoming increasingly common and more severe, becoming a pressing issue that must be addressed. Therefore, in-depth research into the causes of the disease and the development of effective corrective measures are crucial for Xinjiang's plum industry.

[0006] Soil iron application is the most commonly used correction method in production. The types of iron fertilizers used include ferrous sulfate, ferrous fulvic acid, amino acid iron, and chelated iron such as EDTA and EDDHA. Different types of iron fertilizers have certain effects on the correction of plum yellowing. The dosage of inorganic iron salt fertilizer is large, Fe 2+ Easily oxidized to Fe 3+ , the fertilizer effect is short-lived. Most organic chelated iron fertilizers are only stable in acidic soils and easily decompose and become inactive in alkaline and calcareous soils. There are many chelated and compound iron fertilizers on the market. These iron fertilizers have better corrective effects than inorganic iron fertilizers, but their corrective effects vary greatly for different fruit trees.

[0007] At present, the common methods for correcting iron deficiency and chlorosis in fruit trees include soil irrigation, foliar spraying, trunk hanging bag infusion, etc. 2+ Easily oxidized to Fe 3+ , iron is not easy to move after entering the leaves, so the spraying effect is not good. Soil irrigation is slow to take effect, and high-pressure injection of tree trunks is cumbersome and easy to cause fertilizer damage. Judging from the increase in chlorophyll and effective iron content in leaves after correction, EDDHA-Fe has the best correction effect, and root irrigation is used to prevent and correct iron deficiency chlorosis. In addition, considering the input cost and sustained effect, it is recommended to insist on increasing the application of organic fertilizers in plum orchards with higher pH values, improve the soil by planting forage grass, adjust the physical and chemical properties of the soil, balance the nutrients required by fruit trees, improve soil fertility, improve orchard chlorosis and increase fruit yield.

[0008] Currently, the following problems exist in the treatment of prune chlorosis: blindly applying chemical fertilizers without understanding the soil and plant nutrients, resulting in an overall nutritional imbalance in the prune trees; failing to select appropriate iron fertilizers and reasonable fertilizer amounts based on the actual soil and plant conditions; a one-sided pursuit of high yields, which leads to overloading and damage to the trees; and severe overuse of chemical fertilizers, resulting in poor control effectiveness. These unscientific cultivation and fertilization practices not only fail to improve prune quality but also reduce the economic benefits of fruit farmers. They also easily lead to adverse consequences such as soil nutrient imbalance and soil compaction due to the failure to replenish soil nutrients in a timely manner due to long-term cultivation. While some treatments for iron deficiency chlorosis in prune trees can achieve a high cure rate (up to 95% or more), the fertilizer utilization rate is low, and the time required to achieve regreening is long, and the control effect is short-lived. Therefore, the control efficiency is low. Summary of the Invention

[0009] To this end, the technical problem to be solved by the present invention is to provide a rapid correction method for iron deficiency chlorosis of plums. The present invention selects a correction scheme based on the yellowing level of individual yellow plums to achieve rapid greening of yellow plums. Then, iron fertilizer, mineral potassium humate, and organic fertilizer are applied according to the soil conditions of the yellow plum orchard to adjust the soil pH and replenish the soil with effective iron. This comprehensive correction method can effectively solve the problems of current methods for the prevention and control of iron deficiency chlorosis of plums, such as excessive use of chemical fertilizers, low prevention and control efficiency, low iron fertilizer utilization rate, and short-term prevention and control effects.

[0010] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0011] A method for rapidly correcting iron-deficiency chlorosis of plums. The correction schemes for chlorosis of plums include any one of Correction Scheme A, Correction Scheme B, and Correction Scheme C, or a combination of any two or more of them. Correction Scheme A comprises spraying EDDHA chelated iron fertilizer on the leaves of yellowing plum trees; Correction Scheme B comprises applying EDDHA chelated iron fertilizer and mineral-sourced potassium humate through soil root irrigation; and Correction Scheme C comprises delivering EDDHA chelated iron fertilizer to yellowing plum trees using a trunk hanging bag infusion method.

[0012] The above-mentioned rapid correction method for iron deficiency chlorosis of prunes is to adopt correction plan B after the soil around the prune roots thaws and before the prunes germinate.

[0013] The above-mentioned rapid correction method for iron deficiency chlorosis of prunes is to adopt correction plan A and correction plan B, or correction plan A and correction plan C, or correction plan B and correction plan C, or correction plan A, correction plan B and correction plan C, after chlorosis appears on the prune leaves.

[0014] The above-mentioned rapid correction method for prune iron deficiency chlorosis includes the following steps:

[0015] Step (1), at the early stage of yellowing of new plum leaves, collecting leaves and soil from yellowed plum trees and normal fruit trees, respectively, and performing mineral element determination on the collected leaves and soil;

[0016] Step (2), determining the chlorosis grade of the individual chlorosis prune trees and the classification of the available iron content in the soil of the chlorosis prune orchard based on the comparative analysis results of the mineral elements in the leaves and soil of the chlorosis prune trees and the normal fruit trees;

[0017] Step (3), determining a correction plan for the yellowed plum tree according to the yellowing grade of the yellowed plum tree;

[0018] Step (4), treating the single yellowing prune tree according to the determined treatment plan for prune chlorosis;

[0019] After the step (5), according to the classification of the effective iron content in the soil of the yellowing prune apricot orchard, the mixed organic iron fertilizer is applied to the whole prune apricot orchard by the soil dry fertilization method; the mixed organic iron fertilizer includes organic fertilizer, chelated iron fertilizer and potassium humate.

[0020] Due to the multivalence of iron ions in the soil, the difficulty of iron movement in the plant body and the easy deactivation of the plant, the influencing factors of the absorption and transportation of iron by the plant are diverse, so when the iron deficiency chlorosis is remedied, the main factors causing the iron deficiency are comprehensively analyzed, and the targeted comprehensive measures are adopted, so that better effect can be obtained. Generally, the effective remedy of the iron deficiency chlorosis of the prune apricot can be started from the aspects of screening the high-efficiency rootstock variety, increasing the effective iron content in the soil, eliminating the iron deficiency causes, enhancing the absorption and transportation capacity of the tree body, promoting the reuse of the iron in the tree body and increasing the storage of the iron nutrition of the perennial fruit tree. According to the yellowing degree of the single prune apricot and the effective iron content in the soil, one or two or more than two combination methods of the soil root irrigation fertilization, the foliar spraying and the trunk bagging infusion method are reasonably selected to apply the chelated iron fertilizer to the yellowing prune apricot, so that the effective remedy of the iron deficiency chlorosis of the prune apricot is carried out from the aspects of increasing the effective iron content in the soil and increasing the storage of the iron nutrition of the perennial fruit tree, and the purposes of high prevention and treatment efficiency, high utilization rate of the iron fertilizer and long-lasting prevention and treatment effect can be achieved.

[0021] In the step (2) of the above rapid remedy method for the iron deficiency chlorosis of the prune apricot, the division standard of the yellowing grade of the single yellowing prune apricot is as follows:

[0022] The yellowing grade 1 is that the iron content of the leaf is greater than or equal to 35 mg / kg and less than 45 mg / kg;

[0023] The yellowing grade 2 is that the iron content of the leaf is greater than or equal to 25 mg / kg and less than 35 mg / kg;

[0024] The yellowing grade 3 is that the iron content of the leaf is greater than or equal to 15 mg / kg and less than 25 mg / kg;

[0025] The yellowing grade 4 is that the iron content of the leaf is greater than or equal to 5 mg / kg and less than 15 mg / kg;

[0026] The yellowing grade 5 is that the iron content of the leaf is less than 5 mg / kg;

[0027] The yellowing grade judgment standard of the single yellowing prune apricot is formulated according to the yellowing symptoms of the yellowing leaves of different yellowing grades, and the specific judgment method of the yellowing grade of the single yellowing prune apricot is as follows:

[0028] When the leaf periphery to the whole leaf appears spotted chlorosis, the yellowing level is 1; when the whole leaf mesophyll is light green and the leaf vein is green, the yellowing level is 2; when the leaf periphery to the whole leaf mesophyll is light yellow and the leaf vein is light green, the three or four level side veins can be seen to be in a network shape, the yellowing level is 3; only the main vein and the first level side vein are green, and the rest part is yellow or white; sometimes the leaf edge is scorched, there is a necrotic spot, the growth is stagnant, and the internode of the new shoot is obviously shortened, the yellowing level is 4; when the leaf is all yellow or white, sometimes a large area of necrosis appears, the yellowing level is 5. Since the symptoms of the yellowing plum leaf of different yellowing levels are different, in order to quickly judge the yellowing level of a single yellowing plum fruit tree, the present application formulates the above-mentioned rapid judgment method of the yellowing level according to the leaf yellowing symptoms corresponding to the yellowing level of different leaf iron contents, which can quickly judge the yellowing level of all single yellowing plum fruit trees without mineral element determination, thereby being beneficial to the targeted formulation of a correction scheme.

[0029] The above-mentioned rapid correction method for iron deficiency chlorosis of plums, in step (3), the method for determining the correction scheme for iron deficiency chlorosis of plums is: when the yellowing level of the yellowing plum tree is level 1, correction scheme A is adopted for correction (the yellowing level of level 1 is relatively mild yellowing, and leaf spraying not only has high prevention and control efficiency, but also has high utilization rate of chelated iron fertilizer); when the yellowing level of the yellowing plum tree is level 2, correction scheme C is adopted for correction (the yellowing level of level 2 is mild yellowing, and the trunk hanging bag method can quickly transport iron elements to the tissues required by the yellowing fruit tree, with high prevention and control efficiency, and high utilization rate of chelated iron fertilizer); The utilization rate of chelated iron fertilizer is high and the amount of fertilizer used is also low); when the yellowing grade of the yellowing plum fruit tree is level 3, correction plan B is used for correction (the yellowing grade 3 is moderate yellowing. The moderately yellowing plum fruit trees need to supplement slightly more iron than the slightly yellowed fruit trees, so they need more recovery time. If foliar spraying is used, the utilization rate of iron fertilizer is not high. If the trunk hanging bag method is used, the efficiency is low. The soil root irrigation method, under the synergistic effect of mineral potassium humate, can promote the absorption of iron by the yellowing plum fruit trees, with high prevention and control efficiency and high utilization rate of chelated iron fertilizer); when When the yellowing grade of the chlorosis of the prune fruit tree is level 4, correction scheme A and correction scheme B are used simultaneously for correction (level 4 is a more serious chlorosis, which requires more iron supplementation, and therefore requires more recovery time. The prevention and control effects of using a single correction scheme are not ideal. The correction method of combining foliar spraying with soil root irrigation can, on the one hand, quickly supplement the leaves with the required iron, and on the other hand, the soil can continuously release iron to supply the fruit tree as a whole, achieving a prevention and control effect of treating both the symptoms and the root causes, and significantly improving the prevention and control efficiency and the utilization rate of chelated iron fertilizer); when the prune fruit tree is yellow, When the yellowing level is level 5, correction plan B and correction plan C are used simultaneously for correction (the yellowing level is level 4, which is severe yellowing and difficult to correct. At this time, due to the serious yellowing of the leaves, the direct absorption and utilization efficiency of iron is reduced, and the effect of foliar spraying is no longer applicable. Therefore, the correction method of trunk hanging bag infusion combined with soil root irrigation is adopted. On the one hand, it can quickly and directly supplement iron into the plant body. On the other hand, the soil can continuously release iron to supply the fruit tree as a whole, achieving the prevention and control effect of both the symptoms and the root causes, and significantly improving the prevention and control efficiency and the utilization rate of chelated iron fertilizer).

[0030] In the above-mentioned rapid correction method for prune iron deficiency chlorosis, in step (3), the correction scheme A for prune iron deficiency chlorosis is:

[0031] (A-1) Spraying time: spray in the morning or evening during the early development and flowering period of plum trees;

[0032] (A-2) Application rate: The application rate of chelated iron fertilizer is 30-50g / plant, divided into 2-4 sprays, once every 7 days;

[0033] (A-3) Spraying method: dilute the chelated iron fertilizer 1000-3000 times with water, i.e., dilute 1g of chelated iron fertilizer with 1000-3000mL of water to prepare a foliar spray; spray the foliar spray on the leaves of the prune trees using a plant protection drone, handheld sprayer or mechanical sprayer; spray once a week for 2-4 consecutive times;

[0034] Foliar spraying, also known as foliar fertilization, is widely used. Foliar spraying is a method in which nutrients are diffused through the stomata on the surface and back of the leaves and penetrated through the cuticle to allow the nutrients to enter the body of the crop to nourish itself. It is of great significance to agricultural production because it can be carried out when the soil is too dry, too wet, too acidic or too alkaline, which causes the roots to absorb nutrients. At the same time, it can also avoid the disadvantage that nutrients such as iron are fixed in the soil and reduce their effectiveness. Drones can spray pesticides accurately, which can not only reduce the amount of pesticides used, but also ensure the quality and safety of agricultural products. In order to reduce the yellowing of plum trees, To prevent the damage caused by chlorosis, spraying should be carried out early, that is, when the symptoms begin to appear on new leaves or the fruit trees have a considerable leaf area. The present invention uses a plant protection drone to spray the leaves with a chelated iron solution prepared with domestic EDDHA chelated iron fertilizer. This method can effectively and quickly prevent and correct plum iron deficiency chlorosis, and can reduce the incidence of chlorosis to about 2%, achieving the effects of promoting tree rooting and growth, promoting green leaves, regulating acidity and alkali, and effectively preventing and controlling plum iron deficiency chlorosis. Traditional spraying is labor-intensive, has high labor costs, is difficult to control the amount of spraying, and is prone to soil and environmental pollution.

[0035] Treatment plan B for prune iron deficiency chlorosis:

[0036] (B-1) Application time: Apply after the plum trees bloom and during the fruit growth period, on sunny days;

[0037] (B-2) Application amount: The application amount of domestic EDDHA chelated iron fertilizer is 30-50g / plant, and the application amount of mineral potassium fulvate is 20-25g / plant;

[0038] (B-3) Application method: Dig a trench 30-40 cm wide and 15-45 cm deep around the prune trees. Add 30-50 g of domestic EDDHA chelated iron fertilizer and 20-25 g of mineral potassium humate to 20-25 kg of clean water, mix well, pour into the trench, and immediately cover with soil to fill the trench. Maintain the soil moisture content within 60-70% (measured with a soil moisture meter) within 72 hours to promote the absorption of nutrients in the domestic EDDHA chelated iron fertilizer and mineral potassium humate by the yellow prune trees.

[0039] The correction scheme B for iron deficiency chlorosis of plums of the present invention can not only increase the iron content of fruit trees, but also promote the rejuvenation of fruit trees, improve the color and quality of fruits, and enhance the yield and taste of fruits; the application of domestic EDDHA chelated iron fertilizer and mineral source potassium humate can also enhance the immunity of fruit trees, making them more resistant to external factors such as pests and diseases; generally speaking, the amount of domestic EDDHA chelated iron fertilizer and mineral source potassium humate applied should depend on the size of the fruit trees and their chlorosis level. The application amount given in the present invention is for mature fruit trees and is determined according to their chlorosis level; for large-scale plum orchards, when iron is uniformly supplemented by soil fertilization, the application amount of domestic EDDHA chelated iron fertilizer is usually 2.5-5 kg / mu, and the application amount of mineral source potassium humate is usually 2-3 kg / mu (the specific amount should also be adjusted according to the effective iron content of the plum orchard soil);

[0040] Treatment plan C for iron deficiency chlorosis of prunes:

[0041] (C-1) Application time: between May and June;

[0042] (C-2) Application amount: The application amount of chelated iron fertilizer is 5-10g / plant;

[0043] (C-3) Application method: dilute the chelated iron fertilizer 1000 to 1500 times with water, that is, 1 g of chelated iron fertilizer is diluted with 1000 to 1500 mL of water to prepare the chelated iron solution; then fill the chelated iron solution into infusion bags, with each infusion bag filled with 1.0 to 1.5 L of chelated iron solution; use the trunk hanging bag infusion method to infuse all the filled chelated iron solution into the yellow plum fruit trees at one time, and the infusion time of a single bag of chelated iron solution is controlled at 3 to 6 days.

[0044] The method of applying domestic EDDHA chelated iron fertilizer using the trunk hanging bag infusion method is as follows: drill 1 to 2 downward-sloping infusion holes at a height of 0.5 to 1 meter from the ground on the main trunk of the plum tree, with a hole diameter of 4 to 6 mm and a depth of 4 to 5 cm; hang the infusion bag upside down at a high place on the plum tree, screw or insert the needle of the trunk syringe connected to the infusion bag into the infusion hole, straighten the infusion tube, turn on the switch, adjust the flow rate and start infusion; after the infusion is completed, pull out the needle and seal the infusion hole with tape or cotton; finally, irrigate the plum tree after the infusion;

[0045] The trunk hanging bag infusion method relies on the transpiration pull of the tree itself or external force to forcibly input a certain amount of mineral nutrients, plant growth regulators, pesticides or other substances into the tree body, which can improve the nutritional level of fruit trees, promote flowering and fruiting, prevent and treat nutrient deficiencies, regulate tree growth, improve yield and quality, and prevent and treat diseases and insect pests. It is an efficient and pollution-free method and way of fertilizing and applying plants. In an era when the contradiction between chemical fertilizers and pesticides and the ecological environment is becoming increasingly acute, trunk injection technology has shown its unique advantages, especially in fruit trees, where its application prospects are better. The present invention uses the trunk hanging bag infusion method for the rapid correction of iron deficiency chlorosis of plums for the first time. The trunk hanging bag infusion method is an effective treatment method for fruit tree chlorosis. The present invention adopts the trunk hanging bag infusion method, and directly inputs a chelated iron solution prepared with domestic EDDHA chelated iron fertilizer into the main trunk or main branches of the tree, and utilizes the internal juice flow transmission system of the tree to transport the agent to all parts of the tree, thereby achieving the effect of protecting fruit trees and preventing and treating iron deficiency chlorosis of plums. This method can increase the prevention and control rate of plum iron deficiency chlorosis to more than 98%, does not require spraying large amounts of pesticides, will not cause pollution to the soil and environment, and is highly safe.

[0046] The above-mentioned method for rapid correction of iron deficiency chlorosis of plums is as follows: the chelated iron fertilizer is domestic EDDHA chelated iron fertilizer (sodium ethylenediamine di-o-hydroxyphenyl ferric acetate), and the iron content in the domestic EDDHA chelated iron fertilizer is greater than or equal to 6wt%, and the local value is 4.8; the fulvic acid content in the mineral potassium fulvate is greater than or equal to 52wt%, and the potassium oxide content is greater than or equal to 12wt%; the organic matter content in the organic fertilizer is greater than or equal to 30wt%, the water content is 20-40wt%, and the pH is 5.5-6.5.

[0047] EDDHA-Fe and EDTA-Fe iron chelates are relatively stable and can exist stably at pH levels between 4 and 9. Their cure rate for iron deficiency chlorosis in plum trees can reach over 95%. Observations of leaf chlorophyll content and fruit quality revealed that EDDHA-Fe is superior to EDTA-Fe and other iron fertilizers, and that EDDHA-Fe is a good fertilizer that can be widely promoted. Therefore, the present invention prefers domestically produced EDDHA-chelated iron fertilizer, EDDHA-Fe, for the treatment of iron deficiency chlorosis in plum trees. Mineral-derived potassium humate is a very effective plant growth regulator that can improve soil, stimulate root growth, and significantly increase chlorophyll content. This is done to provide fruit trees with a certain amount of iron, thereby increasing their immunity and nutritional levels. In cases where fruit trees are experiencing poor growth or yellowing and leaf loss, applying domestically produced EDDHA-chelated iron fertilizer and mineral-derived potassium humate can promote healthy growth and improve chlorosis in plum trees.

[0048] The quick remediation method for the iron deficiency chlorosis of the above-mentioned Prunus domestica, in step (2), when collecting the soil, the soil samples are collected by the five-point sampling method within the vertical projection range of the Prunus domestica crown, and the sampling depth is 20-25 cm (the soil samples collected at this position can best reflect the content of the effective iron in the soil of the Prunus domestica garden); the classification method for the content of the effective iron in the chlorotic Prunus domestica garden soil is as follows:

[0049] When the content of the effective iron in the soil is less than 2.5 mg / kg, the content of the effective iron in the soil is classified as "deficiency";

[0050] When the content of the effective iron in the soil is greater than or equal to 2.5 mg / kg and less than 4.5 mg / kg, the content of the effective iron in the soil is classified as "low amount";

[0051] When the content of the effective iron in the soil is greater than or equal to 4.5 mg / kg and less than 20 mg / kg, the content of the effective iron in the soil is classified as "normal";

[0052] When the content of the effective iron in the soil is greater than or equal to 20 mg / kg and less than 60 mg / kg, the content of the effective iron in the soil is classified as "excess".

[0053] The quick remediation method for the iron deficiency chlorosis of the above-mentioned Prunus domestica, in step (5), when the soil is dry fertilized, a groove with a width of 30-40 cm and a depth of 15-45 cm is excavated along the two sides of the Prunus domestica fruit tree, the mixed organic iron fertilizer is buried in the groove, and the groove is immediately filled with soil to be flat; the application amount of the mixed organic iron fertilizer is 50-100 kg per mu, and the mass ratio of the chelated iron fertilizer to the potassium of the mineral source fulvic acid is 2:(1-1.5); (when the water content in the organic fertilizer is 20-40 wt% and the pH is in the range of 5.5-6.5, the organic fertilizer can cooperate with the potassium of the mineral source fulvic acid to improve the soil pH, and the slow-release effect of the domestic EDDHA chelated iron fertilizer is the most ideal);

[0054] When the classification of the content of the effective iron in the soil is "deficiency", the mass fraction of the domestic EDDHA chelated iron fertilizer in the mixed organic iron fertilizer is 8-10 wt%; when the classification of the content of the effective iron in the soil is "low amount", the mass fraction of the domestic EDDHA chelated iron fertilizer in the mixed organic iron fertilizer is 5-7 wt%; when the classification of the content of the effective iron in the soil is "normal", the mass fraction of the domestic EDDHA chelated iron fertilizer in the mixed organic iron fertilizer is 2-3 wt%; and when the classification of the content of the effective iron in the soil is "excess", the mass fraction of the domestic EDDHA chelated iron fertilizer in the mixed organic iron fertilizer is less than or equal to 1.5 wt%;

[0055] After the correction of yellowing of a single plum tree is completed, the present invention applies a targeted topdressing of mixed organic iron fertilizer according to the classification of the effective iron content in the soil of the entire plum garden. By adjusting the content of the chelated iron fertilizer in the mixed organic iron fertilizer, and controlling the ratio of the chelated iron fertilizer to the mineral potassium humate, as well as the application amount of the mixed organic iron fertilizer, the mixed organic iron fertilizer can be slowly released in the soil, thereby improving the utilization rate of iron by the plum trees, ensuring that the yellowed plums that have regreened do not recur within one year, and preventing the abuse of chemical fertilizers.

[0056] The technical solution of the present invention achieves the following beneficial technical effects:

[0057] 1. How to solve the bottleneck problem that restricts the development of the prune industry? The key is to understand the soil nutrient status of the prune orchard in the entire production area, clarify the limiting factors of nutrient management, formulate nutrient diagnosis standards, apply fertilizers scientifically, and optimize the overall management level of prunes. The present invention analyzes the mineral elements of the soil and leaves of the yellowed prune orchard, and formulates a targeted correction plan based on the yellowing level of the individual yellowed fruit trees. It can not only make the yellowed fruit trees quickly regreen, but also significantly improve the utilization rate of iron fertilizers. After the yellowed fruit trees regreen, the mixed organic iron fertilizer is applied in a targeted manner according to the effective iron content in the soil of the prune orchard, which can improve the soil pH and increase the effective iron and organic matter content in the soil, thereby ensuring that the yellowing prevention and control effect of the yellowed prune trees is maintained for at least 10 months.

[0058] 2. The present invention first determines the effective iron content in the leaves of yellowed plum fruit trees, reasonably divides the yellowing grades of the yellowed plum fruit trees according to the effective iron content of the leaves, and then formulates a rapid judgment standard for the yellowing grade of the yellowed plum fruit trees according to the performance characteristics of the leaves of plum fruit trees with different yellowing grades, so that the yellowing grade of the yellowed plum fruit trees can be quickly determined by the performance characteristics of the leaves. This does not require all yellowed plum fruit trees to be analyzed for mineral elements, and the yellowing grades of the yellowed plum fruit trees can be quickly divided, so that a targeted correction plan can be formulated for a single yellowed plum fruit tree, so that the prevention and control efficiency of the yellowed plum fruit trees and the utilization rate of the fertilizer are significantly improved.

[0059] 3. The present invention uniformly mixes organic fertilizer, domestic EDDHA chelated iron fertilizer and mineral-source potassium humate as a mixed organic iron fertilizer, and adopts dry fertilization to perform topdressing on a single yellow plum fruit tree after correction. By controlling the content of organic matter and water in the organic fertilizer and its pH value, on the one hand, it is beneficial to improve the pH value of the soil and increase the content of soil organic matter; on the other hand, the organic fertilizer can wrap the domestic EDDHA chelated iron fertilizer and mineral-source potassium humate. After being buried in the soil by dry fertilization, it can not only avoid the loss of domestic EDDHA chelated iron fertilizer and mineral-source potassium humate, but also slowly release the effective iron in the domestic EDDHA chelated iron fertilizer, thereby significantly improving the soil nutritional status and providing favorable soil conditions for maintaining the control effect of yellow plum fruit trees.

[0060] 4. After the soil around the roots of the prunes thaws and before the prunes sprout, adopt Correction Plan B. Irrigate the roots 1-2 times to prevent chlorosis in the prunes that year and the next. This is because, although iron deficiency is an important factor leading to chlorosis in prunes, it is not the only factor. After the soil thaws, it means that the prunes have finished their dormancy period, and the roots begin to grow rapidly and absorb nutrients, accumulating energy for flowering and germination. At this time, root pests and diseases also begin to germinate, affecting root growth and nutrient absorption. In addition, the organic matter, microbial colonies, and other trace elements in the soil also restrict root growth and nutrient absorption. Correction Plan B uses soil root irrigation to apply EDDHA chelated iron fertilizer and mineral potassium humate. On the one hand, it can supplement the soil with iron sources that can be absorbed by the prune roots, and on the other hand, The combined application of EDDHA chelated iron fertilizer and mineral-derived potassium humate for root irrigation improves soil permeability, facilitating the extended growth of plum roots, enriching soil microbial flora and replenishing trace elements. It also kills or inhibits root pests and diseases. This supplements the roots with absorbable iron during the root growth, nutrient absorption, and energy accumulation phase after the soil around the roots thaws and before the plums germinate. More importantly, it provides a favorable growth environment for the root system during its pre-germination period, thus preventing the root system from becoming weak and sickly during the post-dormant period, which can lead to chlorosis in the plums that same year. Replacing EDDHA chelated iron fertilizer with other iron fertilizers or replacing mineral-derived potassium humate with organic potassium humate cannot achieve these technical benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 Actual photos of the application of domestic EDDHA chelated iron fertilizer and mineral-derived potassium humate to soil in Example 1 of the present invention;

[0062] Figure 2 Actual photo of spraying domestic EDDHA chelated iron fertilizer on the leaves of yellowing plum trees in Example 2 of the present invention;

[0063] Figure 3Actual photos of the use of the trunk hanging bag infusion method to deliver domestically produced EDDHA chelated iron fertilizer to yellow plum trees in Example 3 of the present invention. DETAILED DESCRIPTION

[0064] Part I: Screening of Effective Iron Fertilizers for Plum Iron Deficiency Chlorosis and Analysis of the Effects of Different Correction Schemes In this embodiment, a rapid correction method for plum iron deficiency chlorosis includes the following steps:

[0065] Step (1) diagnoses the disease in the early stages of yellowing of new plum leaves. Leaves and soil from yellowing plum trees and normal trees are collected, and mineral elements are determined for the collected leaves and soil. Soil samples are collected using a five-point sampling method within the vertical projection of the plum tree canopy, with a sampling depth of 20 cm.

[0066] Step (2): Based on the comparative analysis results of the nutrient elements in the leaves and soil of the yellowed plum trees and normal fruit trees, the yellowing degree of the yellowed plum trees is divided into different levels (see Table 1 and Table 2), and corresponding fertilization correction plans are formulated for different levels to conduct experiments.

[0067] Table 1 Grading standards for yellowing degree of plum trees and available iron content in leaves

[0068]

[0069] Table 2 Classification standard of available iron content in plum soil

[0070] Classification of soil available iron content Available iron content in soil (mg / kg) lack ＜2.5 Low 2.5～4.5 normal 4.5～20 excess 20～60

[0071] In this example, soil composition analysis was performed on the Ximei orchard in Yingmaili Town, Jiashi County, Huanghua Orchard, and soil from a normal orchard was selected for comparative analysis. The results of the two analyses are shown in Table 3.

[0072] Table 3 Soil nutrient content in different plum gardens

[0073]

[0074] Table 3 shows that the main reason for the low content of available Fe in the soil, low pH value and low HCO3 - The soil is alkaline, which inhibits the absorption of trace iron elements, causing yellowing, slow absorption and conversion of trees, weak metabolism, small, few, yellow leaves, poor photosynthesis, and insufficient absorption and synthesis of nutrients.

[0075] Step (3): correcting the yellowed plum trees according to the established correction plan for plum iron deficiency chlorosis.

[0076] The correction scheme formulated in this embodiment includes primary correction and secondary correction. Specifically, in early May 2022, the first correction experiment was carried out in the Plum Garden in Yingmaili Town, Kashgar County (the trees in the Plum Garden are 10 years old and the row spacing is 2.5M×4M). The method of the first correction experiment is: uniformly apply organic fertilizer in the yellowing orchard, select Plum trees with consistent growth, and for the three kinds of iron fertilizers tested, according to the standard dosage instructions of each iron fertilizer, 4 concentrations are formulated for each iron fertilizer for treatment. Each concentration treatment is repeated 5 times. The iron fertilizer is dissolved in water for root irrigation and clear water treatment is used as a control. The treatments of each concentration are shown in Table 4; leaves are collected 15 days after treatment to perform leaf-related indicators.

[0077] Table 4 Different treatment concentrations of different iron fertilizers

[0078] Treatment CK Concentration 1 Concentration 2 Concentration 3 Concentration 4 Root irrigation EDDHA-Fe clear water 500 times solution 1000 times solution 2000 times solution 3000 times solution Root irrigation EDTA-Fe clear water 500 times solution 1000 times solution 2000 times solution 3000 times solution <![CDATA[灌根FeSO4]]> clear water 500 times solution 1000 times solution 2000 times solution 3000 times solution

[0079] Table 5 Available iron content in leaves of yellow plum trees after treatment (mg / g)

[0080] Treatment CK Concentration 1 Concentration 2 Concentration 3 Concentration 4 Root irrigation EDDHA-Fe 34 105 93 89 57 Root irrigation EDTA-Fe 34 87 65 58 49 FeSO4 drench 34 47 43 41 38

[0081] Based on the measured indicators from the initial treatment and the regreening of the plum orchard, it was found that EDDHA-chelated iron fertilizer was the most effective in correcting yellowing fruit trees. Therefore, in the subsequent secondary treatment plan, domestic EDDHA-chelated iron fertilizer (EDDHA-Fe) was selected to further correct yellowing of plum trees.

[0082] In this embodiment, the iron content in the domestic EDDHA chelated iron fertilizer is greater than or equal to 6wt%, and the proximal value is 4.8; the fulvic acid content in the mineral source potassium fulvate is greater than or equal to 52wt%, and the potassium oxide content is greater than or equal to 12wt%.

[0083] In this example, a secondary treatment was conducted in May 2023. This secondary treatment targeted the chlorotic 'France' plums using the domestically produced EDDHA chelated iron fertilizer, which had shown excellent results in the primary treatment, using different application methods. Four groups of chlorotic plums of the same age, similar growth, and the same chlorosis level were selected for treatment. Leaves were collected 15 days after treatment and relevant indicators measured. A comprehensive analysis of the measured indicators and input costs was used to determine the final method for correcting iron deficiency chlorosis in the plum orchard.

[0084] In this embodiment, the secondary correction plan for prune iron deficiency chlorosis includes:

[0085] (1) Correction Plan A: Use foliar spraying to apply domestically produced EDDHA chelated iron fertilizer to the leaves of yellow plum trees;

[0086] (A-1) Spraying time: spray in the morning or evening during the early development and flowering period of plum trees;

[0087] (A-2) Spraying amount: The total amount of spraying for a single yellow plum tree is 50g, which is sprayed in 4 times of 50g, once every 7 days, 12.5g each time;

[0088] (A-3) Spraying method: dilute the domestic EDDHA chelated iron fertilizer 1000 times with water, i.e., dilute 1g of domestic EDDHA chelated iron fertilizer with 1000mL of water to prepare a foliar spray; use a plant protection drone, handheld sprayer or mechanical sprayer to spray the foliar spray on the leaves of the prune trees; spray once a week for 4 consecutive times.

[0089] (2) Correction Plan B: Use root irrigation to apply domestic EDDHA chelated iron fertilizer and mineral potassium humate to the roots of yellow plum trees. Root irrigation not only directly replenishes the reserve nutrients of the fruit trees, but also promotes the growth of new roots and transfers its effective iron content to the leaves to improve photosynthesis.

[0090] (B-1) Application time: Apply after the plum trees bloom and during the fruit growth period, on sunny days;

[0091] (B-2) Application Amount: Root fertilization was performed based on the soil mineral nutrient element test results. In this embodiment, the test results showed that the available iron content of the yellowed plum garden soil was less than 4.5 mg / kg (the soil available iron content was classified as low), and the soil was alkaline (pH>8). 50 g of domestic EDDHA chelated iron fertilizer and 25 g of mineral-derived potassium humate were added to 25 kg of clean water and thoroughly mixed to obtain a root fertilization solution. The solution was applied once per plant.

[0092] (B-3) Application Method: Dig trenches 30-40 cm wide and 15-45 cm deep along both sides of the prune tree (or dig a circular trench around the outer periphery of the prune tree canopy projection), pour the prepared root irrigation solution into the trench and immediately cover the trench with soil to fill it. Maintaining the soil moisture content within 60-70% for 72 hours (measured with a soil moisture meter) can promote the absorption of nutrients from domestically produced EDDHA chelated iron fertilizer and mineral-derived potassium humate by the etiolated prune trees.

[0093] Treatment Plan B, a rapid treatment method for yellow plums, is effective quickly (greening is achieved in one week) and lasts for a long time (the control effect lasts for six months), saving time and effort. This is because root fertilization utilizes root absorption and trunk conduction to quickly and effectively distribute the nutrients in domestically produced EDDHA-chelated iron fertilizer to the leaves, stems, branches, flowers, and fruit of the tree. By selecting trees or areas requiring root fertilization, the fertilizer is protected from wind, rain, and sunlight, resulting in a 60-80% lower utilization rate than conventional fertilization methods.

[0094] Chelated iron is more effective than inorganic iron fertilizers, but simply applying domestically produced EDDHA chelated iron fertilizer doesn't significantly increase the rate at which yellowing plum trees absorb nutrients, and the regreening effect isn't very noticeable after a week. Adding mineral-derived potassium humate to fertilization not only boosts root growth but also activates the soil, promoting iron fertilizer absorption and utilization, boosting chlorophyll formation and enhancing photosynthesis, allowing weakened trees to quickly recover and their leaves to turn green. Maintaining soil moisture at 60-70% after fertilization is a simple and practical way to regreen fruit trees.

[0095] In early May, correction plan B was adopted, which involved applying domestic EDDHA chelated iron fertilizer through root irrigation in the soil, assisted by the addition of mineral source potassium humate. One week after completion, statistics were observed on the greening of 100 yellowed plum trees, and the prevention and control rate reached more than 98%. The chlorosis was effectively corrected, and the effect lasted for more than 6 months.

[0096] (3) Corrective Plan C: Use the trunk hanging bag infusion method to deliver domestically produced EDDHA chelated iron fertilizer to yellowing plum trees. This method is suitable for seedlings with a trunk diameter of more than 5 cm. Thin trunks are more likely to damage the tree. This method uses the fruit tree's conductive tissue to dilute the concentrated chelated iron solution and deliver it directly to various organs of the plant to prevent and control yellowing.

[0097] (C-1) Application time: between May and June;

[0098] (C-2) Application rate: 5g per plant in 5 applications, 1g each time, with an interval of 3 days between each application;

[0099] (C-3) Application method: dilute domestic EDDHA chelated iron fertilizer 1000 times with water, that is, 1g of domestic EDDHA chelated iron fertilizer is diluted with 1000mL of water to prepare a chelated iron solution; then fill the chelated iron solution into infusion bags, and fill each infusion bag with 1.0L of chelated iron solution; this method relies on the weight of the solution itself and the transpiration pull of the tree for infusion, and the infusion volume can be 1.0L each time, does not require special sealing, and the infusion speed is adjustable, which is easy to operate; the trunk hanging bag infusion method is used to infuse all 1.0L of the filled chelated iron solution into the yellow plum tree each time, and 5g of domestic EDDHA chelated iron fertilizer is applied through continuous infusion for 15 days.

[0100] The method of applying domestic EDDHA chelated iron fertilizer using the trunk hanging bag infusion method is as follows:

[0101] Drill 1 to 2 slightly downward-sloping holes on the trunk of the fruit tree 0.5 to 1 meter above the ground. The hole diameter should be 4 to 6 mm and the depth should be 4 to 5 cm, depending on the age and growth of the tree. Screw or insert the needle of the trunk syringe into the infusion hole; hang the liquid storage bag upside down at a high place, straighten the infusion tube, turn on the switch, adjust the flow rate of the liquid, and inject the medicine. When there is no more liquid to be injected, turn off the switch, pull out the needle, and seal the hole with tape or cotton (for next use).

[0102] However, because iron transport in fruit trees is directional, a single hole often requires only half or most of the tree's crown to turn green. Therefore, drilling two holes in opposite directions and at staggered heights is preferable. This method not only delivers iron to the leaves but also increases iron content throughout the tree, resulting in a longer-lasting effect. With prompt irrigation after injection, this method can be effective within a week.

[0103] The trunk hanging bag infusion method is used to directly inject domestic EDDHA chelated iron fertilizer into fruit trees to quickly correct the iron deficiency chlorosis of plums. The trees can return to green in 3-5 days, and the prevention and control effect of iron deficiency chlorosis of plums can be maintained for more than 6 months.

[0104] (4) Correction Plan D: Apply domestic EDDHA chelated iron fertilizer and mineral potassium humate to yellow plum trees by spraying on the leaves and irrigating the roots simultaneously;

[0105] (D-1) Time for foliar spraying: During the early development and flowering period of plum trees, spray in the morning or evening, avoiding the high temperature period at noon;

[0106] Root irrigation application time: During the growing season of plum trees, avoid high temperature and drought periods, and choose sunny weather for application;

[0107] (D-2) Foliar spraying amount: The total amount of domestic EDDHA chelated iron fertilizer sprayed is 50g / plant, sprayed twice, once every 7 days;

[0108] Root irrigation dosage: The application amount of domestic EDDHA chelated iron fertilizer is 50g / plant, and the application amount of mineral potassium fulvic acid fertilizer is 25g / plant;

[0109] (D-3) Foliar spraying method: dilute domestic EDDHA chelated iron fertilizer 3000 times with water, that is, 1g of domestic EDDHA chelated iron fertilizer is diluted with 3000mL of water to prepare a foliar spray agent; use a plant protection drone, handheld sprayer or mechanical sprayer to evenly spray the foliar spray agent on the front and back of the leaves of the prune fruit tree; spray once a week.

[0110] Irrigation method: 50g of domestic EDDHA chelated iron fertilizer and 25g of potassium fulvic acid were added to 25kg of water and mixed evenly, and then irrigated once for each plant. A ring-shaped trench was dug outside the tree crown projection, and the prepared irrigation liquid was poured into the trench and immediately covered with soil to fill the trench.

[0111] Generally, foliar fertilization is an auxiliary and supplement to soil fertilization, and foliar fertilization is only used to supplement the nutrient requirements of yellowing apricot trees at a certain growth stage, but cannot replace soil fertilization. Soil fertilization should still be the main method of fertilization for fruit trees. If trace elements are severely deficient in the soil, they can be supplemented by multiple foliar applications, but must be combined with soil fertilization.

[0112] Treatment scheme D is a rapid correction method for iron deficiency chlorosis of apricot trees by combining soil root irrigation with foliar spraying of domestic EDDHA chelated iron fertilizer, which can maintain the prevention and treatment effect of apricot iron deficiency chlorosis for 12 months.

[0113] The apricot trees treated by the above four correction schemes in this example were divided into test group A, test group B, test group C, and test group D, respectively. Yellowing apricot trees treated with water were used as a control group. After 15 days, the comparison results of the effective iron content in the leaves of each treatment group before and after the test are shown in Table 6.

[0114] In this example, the relative utilization rate of iron fertilizer was calculated using the following formula:

[0115] Iron fertilizer utilization rate (%) = [(absorption of iron elements in the leaves of the test group - absorption of iron elements in the leaves of the control group) / total amount of iron elements in the domestic EDDHA chelated iron fertilizer] x 100%.

[0116] Table 6

[0117]

[0118] From the results of the effective iron content in the leaves of each treatment group in Table 5, it can be seen that the effective iron content in the leaves of the yellowing apricot trees treated by correction scheme D is the highest, and the yellowing apricot trees recover quickly, but the most domestic EDDHA chelated iron fertilizer is used in correction scheme D. According to the data in Table 6, the iron fertilizer utilization rates of the test groups from high to low are: correction scheme C, correction scheme A, correction scheme B, and correction scheme D, and the difference between correction scheme D and correction scheme B is not large. Therefore, although correction scheme D can quickly and effectively solve the problem of yellowing of apricot trees, the fertilizer utilization rate is not high. Therefore, it is necessary to further improve the correction method for iron deficiency chlorosis of apricot trees.

[0119] Second part: Improvement of correction schemes for apricot orchards with different yellowing levels

[0120] After multiple experiments and explorations, it was found that the utilization rate of domestic EDDHA chelated iron fertilizer is not only related to its application method (i.e., the utilization rate of domestic EDDHA chelated iron fertilizer varies with different correction schemes), but also to the degree of yellowing of the yellowing plum trees. That is, the utilization rate of iron is different when domestic EDDHA chelated iron fertilizer is applied in the same application method to yellowing plum trees with different yellowing levels. To this end, in May 2024, this example continued to conduct correction experiments on "French" plums with different yellowing levels using domestic EDDHA chelated iron fertilizer with different correction schemes in the plum garden of Jiashi County.

[0121] (1) Select 5 different chlorosis grades of prune trees with the same age and similar growth as shown in Table 1, with 100 chlorosis trees of each grade; adopt correction scheme A to spray domestic EDDHA chelated iron fertilizer on the leaves to quickly correct prune iron deficiency chlorosis.

[0122] After fertilization, the regreening time of each fruit tree was monitored and counted, and leaves of yellowed fruit trees were collected 15 days after fertilization to determine the utilization rate of domestic EDDHA chelated iron fertilizer; the results are shown in Table 7.

[0123] Table 7 Experimental results of using treatment plan A to correct different grades of yellow plums

[0124] Yellowing level Level 1 Level 2 Level 3 Level 4 Level 5 Average regreening time / d 2.5 5 7 10 20 Iron fertilizer utilization rate / % 95 90 91 93 92

[0125] (2) Select 5 different chlorosis grades of prune trees as shown in Table 1 with the same age and similar growth, with 100 prune trees of each grade; use the soil root irrigation method of correction plan B to apply domestic EDDHA chelated iron fertilizer and auxiliary addition of mineral source potassium humate; after the prune trees bloom (in this example, in May 2024), choose sunny weather to carry out soil root irrigation fertilization;

[0126] After the fertilization was completed, the regreening time of each fruit tree was monitored and counted, and leaves of the yellowed fruit trees were collected 15 days after the fertilization to determine the utilization rate of the domestic EDDHA chelated iron fertilizer; the results are shown in Table 8.

[0127] Table 8 Experimental results of using treatment plan B to correct different grades of yellow plums

[0128] Yellowing level Level 1 Level 2 Level 3 Level 4 Level 5 Average regreening time / d 3 6 6.5 15 21 Iron fertilizer utilization rate / % 87 88 93 90 91

[0129] (3) Select 5 different chlorosis grades of prune trees with the same age and similar growth as shown in Table 1, with 100 prune trees of each grade; adopt the trunk hanging bag infusion method of correction plan C to directly inject domestic EDDHA chelated iron fertilizer into the fruit trees to quickly correct prune iron deficiency chlorosis.

[0130] After the fertilization was completed, the regreening time of each fruit tree was monitored and counted, and leaves of the yellowed fruit trees were collected 15 days after the fertilization to determine the utilization rate of the domestic EDDHA chelated iron fertilizer; the results are shown in Table 9.

[0131] Table 9 Experimental results of using treatment plan C to correct different grades of yellow plums

[0132] Yellowing level Level 1 Level 2 Level 3 Level 4 Level 5 Average regreening time / d 3 4 8 14 27 Iron fertilizer utilization rate / % 92 97 94 91 93

[0133] (4) Select 5 different chlorosis grades of prune trees with the same age and similar growth as shown in Table 1, with 100 chlorosis trees of each grade; use the correction scheme D of foliar spraying combined with root irrigation to quickly correct prune iron deficiency chlorosis.

[0134] After the fertilization was completed, the regreening time of each fruit tree was monitored and counted, and leaves of the yellowed fruit trees were collected 15 days after the fertilization to determine the utilization rate of the domestic EDDHA chelated iron fertilizer; the results are shown in Table 10.

[0135] Table 10 Experimental results of using treatment plan D to correct different grades of yellow plums

[0136] Yellowing level Level 1 Level 2 Level 3 Level 4 Level 5 Average regreening time / d 2 4 6 8.5 14 Iron fertilizer utilization rate / % 89 87 91 94 90

[0137] (4) Select 5 different chlorosis grades of prune trees with the same age and similar growth as shown in Table 1, with 100 prune trees of each grade; adopt Correction Plan E to correct prune chlorosis. Correction Plan E is a combination of Correction Plan C and Correction Plan B, that is, the trunk hanging bag method combined with root irrigation of domestic EDDHA chelated iron fertilizer to quickly correct prune iron deficiency chlorosis.

[0138] After the fertilization was completed, the regreening time of each fruit tree was monitored and counted, and leaves of the yellowed fruit trees were collected 15 days after the fertilization to determine the utilization rate of the domestic EDDHA chelated iron fertilizer; the results are shown in Table 11.

[0139] Table 11 Experimental results of using treatment plan E to correct different levels of yellow plums

[0140]

[0141]

[0142] According to the above test results, it can be seen that: for chlorotic plum trees with mild symptoms (chlorosis level 1), correction plan A is used for correction. Iron is absorbed directly through the leaves, which can quickly relieve the symptoms of iron deficiency and make the yellow leaves green again within 3 days, and the utilization rate of iron fertilizer is the highest; for chlorotic plum trees with mild symptoms (chlorosis level 2), correction plan C is used for correction. The chelated iron infused into the tree body is transported quickly in the plant body, which can make the yellow leaves green again within 5 days, and the utilization rate of iron fertilizer is the highest; for chlorotic plum trees with moderate symptoms (chlorosis level 3), correction plan B is used to irrigate the roots with chelated iron in the soil. Iron can be released continuously for long-term absorption by plants, and can make yellowed leaves green again within a week. Although the utilization rate of iron fertilizer is lower than that of correction plan C, the difference is not much; for more severe (chlorosis level 4) yellowed plum trees, correction plan D of spraying chelated iron fertilizer on leaves combined with soil root irrigation is a fast and effective way to supplement plant iron, which can make the leaves green again within ten days, and the utilization rate of iron fertilizer is high; for severely (chlorosis level 5) yellowed plum trees, correction plan E of hanging bags of chelated iron fertilizer on the trunk combined with soil root irrigation can make the yellow plums green again within two weeks and make the iron fertilizer effectively utilized.

[0143] After targeted correction treatment with the best correction plan, yellow plums with different yellowing grades can achieve rapid greening in a relatively short period of time. After greening, the entire plum orchard is top-dressed by dry soil fertilization; the topdressing fertilizer is a mixed organic iron fertilizer composed of organic fertilizer, domestic EDDHA chelated iron fertilizer and mineral potassium humate. In the present embodiment, the test results show that the effective iron content of the yellowed plum garden soil is lower than 4.5 mg / kg (the effective iron content of the soil is classified as low), and the soil alkalinity is high (pH>8). Therefore, when the soil is dry fertilized in this embodiment, the topdressing amount of the mixed organic iron fertilizer is 100 kg / mu, and the mass ratio of domestic EDDHA chelated iron fertilizer to mineral potassium humate is 2:1.5. In the mixed organic iron fertilizer, the mass fraction of domestic EDDHA chelated iron fertilizer is 5wt%. Specific fertilization method: Dig trenches 30-40 cm wide and 15-45 cm deep along both sides of the plum trees, bury the mixed organic iron fertilizer obtained by mixing organic fertilizer, domestic EDDHA chelated iron fertilizer and mineral potassium humate in the above proportions into the trenches and immediately cover the trenches with soil to fill them.

[0144] Applying the above-mentioned mixed organic iron fertilizer after the yellowing symptoms of individual plum trees are corrected can, on the one hand, significantly improve the pH value of the soil and increase the content of soil organic matter; on the other hand, the organic fertilizer can wrap up the domestic EDDHA chelated iron fertilizer and mineral potassium humate. After burying them in the soil by dry fertilization, it can not only avoid the loss of domestic EDDHA chelated iron fertilizer and mineral potassium humate, but also slowly release the effective iron in the domestic EDDHA chelated iron fertilizer, thereby significantly improving the soil nutritional status and providing favorable soil conditions for maintaining the prevention and control effect of yellowing plum trees.

[0145] After the yellowing plums of different yellowing levels are treated with the best correction plan and restored to green, the prevention and control effect of plum yellowing can be maintained for 12 months by applying mixed organic iron fertilizer.

[0146] In summary, choosing targeted correction plans for plum trees with different chlorosis levels, adjusting soil pH and quickly supplementing soil iron can effectively correct iron deficiency chlorosis in plums and ensure long-term iron supply for plums, which will last for at least 10 months without recurrence. The lack of any link will make the correction effect worse.

[0147] In addition, the study unexpectedly discovered that not only the method of application but also the timing of application affected the effectiveness of the treatment. In 2022, treatment plan B was used to administer two preventive root irrigation treatments to plum trees with chlorosis level 5 (one week apart). The irrigations were administered after the soil around the plum roots thawed and before the plums sprouted. The results showed that these trees essentially avoided chlorosis in 2022 and 2023. Compared to foliar spraying, root irrigation, or trunk bag infusion after chlorosis appears, root irrigation after the soil around the plum roots thaws and before the plums sprout is a combination of prevention and treatment. While root irrigation requires individual tree irrigation when uncertainty about chlorosis is present, this method incurs higher costs, including iron fertilizer and labor. However, it avoids the impact of the regreening waiting period required for corrective treatment after chlorosis appears on plum growth. Furthermore, the duration of action is longer, and the application method is simpler than foliar spraying and trunk bag infusion.

[0148] This paper proposes a set of diagnostic criteria for high-yield and high-quality fertilization of plums adapted to local ecological and soil conditions for research on plums in Jiashi County, Xinjiang, a major commercial plum production area nationwide. Furthermore, by studying balanced fertilization techniques, the paper identifies the optimal fertilizer dosage for high-yield and high-quality plums. This provides a scientific basis for guiding the rational fertilization of plum plants, improving fertilizer utilization, increasing yield, improving quality, and enhancing the economic benefits of fruit farmers. Furthermore, the paper offers feasible suggestions for the causes and corrective measures for leaf yellowing during plum cultivation.

[0149] Obviously, the above embodiments are only examples for clearly illustrating the present application and are not intended to limit the present application. Based on the above description, one of ordinary skill in the art can make other different forms of changes or modifications. Here, it is not necessary or possible to enumerate all the embodiments. The obvious changes or modifications derived from the above should be covered in the protection scope of the present application.

Claims

1. A method for rapidly correcting prune iron deficiency chlorosis, characterized in that: Correction plans for plum chlorosis include any one of Correction Plan A, Correction Plan B and Correction Plan C, or a combination of any two or more of them; Correction Plan A is: spraying EDDHA chelated iron fertilizer on the leaves of yellow plum trees; Correction Plan B is: applying EDDHA chelated iron fertilizer and mineral potassium humate through soil root irrigation; Correction Plan C is: using the trunk hanging bag infusion method to deliver EDDHA chelated iron fertilizer to yellow plum trees.

2. The rapid correction method for prune iron deficiency chlorosis according to claim 1, characterized in that: Use Correction Plan B after the soil around the prune roots thaws and before the prunes sprout.

3. The rapid correction method for prune iron deficiency chlorosis according to claim 2, characterized in that: After yellowing of the plum leaves occurs, use Correction Plan A and Correction Plan B, or use Correction Plan A and Correction Plan C, or use Correction Plan B and Correction Plan C, or use Correction Plan A, Correction Plan B, and Correction Plan C.

4. The rapid correction method for prune iron deficiency chlorosis according to claim 3, characterized in that: The steps include: Step (1), at the early stage of yellowing of new plum leaves, collecting leaves and soil from yellowed plum trees and normal fruit trees, respectively, and performing mineral element determination on the collected leaves and soil; Step (2), determining the chlorosis grade of the individual chlorosis prune trees and the classification of the available iron content in the soil of the chlorosis prune orchard based on the comparative analysis results of the mineral elements in the leaves and soil of the chlorosis prune trees and the normal fruit trees; Step (3), determining a correction plan for the yellowed plum tree according to the yellowing grade of the yellowed plum tree; Step (4), treating the single yellowing prune tree according to the determined treatment plan for prune chlorosis; Step (5): After all the yellowed plum trees have been corrected, a mixed organic iron fertilizer is applied to the entire plum orchard by dry soil fertilization according to the classification of the effective iron content in the soil of the yellowed plum orchard; the mixed organic iron fertilizer includes organic fertilizer, chelated iron fertilizer and mineral potassium humate.

5. The rapid correction method for prune iron deficiency chlorosis according to claim 4, characterized in that: In step (2), the chlorosis grade of a single yellow plum tree is divided into the following criteria: Yellowing level 1: leaf iron content is greater than or equal to 35 mg / kg and less than 45 mg / kg; Yellowing level 2: leaf iron content is greater than or equal to 25 mg / kg and less than 35 mg / kg; Yellowing level 3: leaf iron content is greater than or equal to 15 mg / kg and less than 25 mg / kg; Yellowing level 4: leaf iron content is greater than or equal to 5 mg / kg and less than 15 mg / kg; Yellowing level 5, leaf iron content is less than 5mg / kg; Based on the yellowing symptoms of yellowing leaves at different yellowing levels, a quick judgment standard for the yellowing level of a single yellowing plum tree was developed. The specific method for judging the yellowing level of a single yellowing plum tree is as follows: When the leaf periphery or the entire leaf shows spotted chlorosis, the yellowing level is level 1; When the mesophyll of the entire leaf is light green and the veins are green, the yellowing level is level 2; When the leaf periphery or the entire leaf is pale yellow, the veins are pale green, and the third and fourth level lateral veins are visible in a network-like pattern, the yellowing level is level 3; Only the main veins and primary lateral veins are green, while the rest turn yellow or white. Sometimes the leaf margins are scorched, there are necrotic spots, growth is stagnant, and the internodes of new shoots are significantly shortened. The chlorosis level is level 4. When all leaves turn yellow or white, and sometimes large areas of necrosis occur, the yellowing level is level 5.

6. The rapid correction method for prune iron deficiency chlorosis according to claim 5, characterized in that: In step (3), the method for determining the correction scheme for iron deficiency chlorosis of prunes is as follows: when the chlorosis level of the chlorotic prune trees is level 1, correction scheme A is adopted for correction; when the chlorosis level of the chlorotic prune trees is level 2, correction scheme C is adopted for correction; when the chlorosis level of the chlorotic prune trees is level 3, correction scheme B is adopted for correction; when the chlorosis level of the chlorotic prune trees is level 4, correction scheme A and correction scheme B are adopted simultaneously for correction; when the chlorosis level of the chlorotic prune trees is level 5, correction scheme B and correction scheme C are adopted simultaneously for correction.

7. The rapid correction method for prune iron deficiency chlorosis according to any one of claims 1 to 6, characterized in that: In step (3), the treatment plan A for prune iron deficiency chlorosis is: (A-1) Spraying time: spray in the morning or evening during the early development and flowering period of plum trees; (A-2) Application rate: The application rate of chelated iron fertilizer is 30-50g / plant, which should be sprayed in 2-4 times. (A-3) Spraying method: dilute the chelated iron fertilizer 1000-3000 times with water, i.e., 1g of chelated iron fertilizer is diluted with 1000-3000mL of water to prepare a foliar spray; spray the foliar spray on the leaves of the prune trees using a plant protection drone, handheld sprayer or mechanical sprayer; spray once a week for 2-4 consecutive times; Treatment plan B for prune iron deficiency chlorosis: (B-1) Application time: Apply after the plum trees bloom and during the fruit growth period, on sunny days; (B-2) Application amount: The application amount of chelated iron fertilizer is 30-50g / plant, and the application amount of mineral potassium fulvate is 20-25g / plant; (B-3) Application method: Dig a 30-40 cm wide and 15-45 cm deep trench around the plum tree. Add 30-50 g of chelated iron fertilizer and 20-25 g of mineral potassium humate to 20-25 kg of clean water, mix well, pour into the trench, and immediately cover with soil to fill the trench. Maintain the soil moisture content within 60-70% within 72 hours. Treatment plan C for iron deficiency chlorosis of prunes: (C-1) Application time: between May and June; (C-2) Application amount: The application amount of chelated iron fertilizer is 5-10g / plant; (C-3) Application method: dilute the chelated iron fertilizer 1000 to 1500 times with water, that is, 1g of domestic EDDHA chelated iron fertilizer is diluted with 1000 to 1500mL of water to prepare the chelated iron solution; then fill the chelated iron solution into infusion bags, with each infusion bag filled with 1.0 to 1.5L of chelated iron solution; use the trunk hanging bag infusion method to infuse all the filled chelated iron solution into the yellow plum fruit trees at one time, and the infusion time of a single bag of chelated iron solution is controlled at 3 to 6 days.

8. The rapid correction method for prune iron deficiency chlorosis according to claim 7, characterized in that: The chelated iron fertilizer is domestically produced EDDHA chelated iron fertilizer, and the iron content in the domestically produced EDDHA chelated iron fertilizer is greater than or equal to 6wt%, and the PH value is 4.8; the fulvic acid content in the mineral-source potassium fulvate is greater than or equal to 52wt%, and the potassium oxide content is greater than or equal to 12wt%; the organic matter content in the organic fertilizer is greater than or equal to 30wt%, the water content is 20-40wt%, and the pH value is 5.5-6.

5.

9. The rapid correction method for prune iron deficiency chlorosis according to claim 4, characterized in that: In step (2), when collecting soil, soil samples were collected using a five-point sampling method within the vertical projection range of the plum tree crown, with a sampling depth of 20 to 25 cm. The classification method for the available iron content in the etiolated plum garden soil is: When the soil available iron content is less than 2.5 mg / kg, the soil available iron content is classified as "deficient"; When the soil available iron content is greater than or equal to 2.5 mg / kg and less than 4.5 mg / kg, the soil available iron content is classified as "low"; When the soil available iron content is greater than or equal to 4.5 mg / kg and less than 20 mg / kg, the soil available iron content is classified as "normal"; When the available iron content in the soil is greater than or equal to 20 mg / kg and less than 60 mg / kg, the available iron content in the soil is classified as "excessive".

10. The rapid correction method for prune iron deficiency chlorosis according to claim 9, characterized in that: In step (5), when dry fertilizing the soil, trenches 30 to 40 cm wide and 15 to 45 cm deep are dug along both sides of the plum trees, the mixed organic iron fertilizer is buried in the trenches and immediately covered with soil to fill the trenches; the amount of the mixed organic iron fertilizer applied is 50 to 100 kg / mu, and the mass ratio of the chelated iron fertilizer to the mineral source potassium humate is 2:(1 to 1.5); When the soil available iron content is classified as "deficient", the mass fraction of domestic EDDHA chelated iron fertilizer in the mixed organic iron fertilizer is 8-10wt%; When the soil available iron content is classified as "low", the mass fraction of domestic EDDHA chelated iron fertilizer in the mixed organic iron fertilizer is 5-7wt%; When the soil available iron content is classified as "normal", the mass fraction of domestic EDDHA chelated iron fertilizer in the mixed organic iron fertilizer is 2-3wt%; When the soil available iron content is classified as "excessive", the mass fraction of the domestic EDDHA chelated iron fertilizer in the mixed organic iron fertilizer is less than or equal to 1.5wt%.

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