An integrated method for reducing damage by citrus leafminer

Abstract

The present application relates to the field of pest control of fruit trees, and particularly relates to an integrated method for reducing citrus leaf roller damage, which is divided into citrus tree fertilization management, water management and citrus tree control management, the spring citrus tree sprouting period is applied with a shoot promoting fertilizer, the summer dormancy period is applied with a fruit promoting fertilizer, the autumn is applied with a tree vigor restoring fertilizer, the soil humidity is kept at 60% to 80% of the maximum field water holding capacity during the spring sprouting, flowering period and fruit swelling period, the citrus fertilizer and water management, citrus fruit thinning treatment, chemical pesticide control and shaping pruning control are carried out according to the summer and autumn fertilization nodes of the citrus tree, the chemical pesticide control is leaf spraying of the citrus tree, and the shaping pruning control is after the citrus sprouting, which achieves precise and controllable and unified and neat citrus sprouting time, is the key basis for the later comprehensive prevention and control of citrus leaf roller, achieves the purpose of labor saving and cost reduction for the prevention and control of citrus leaf roller, and promotes the healthy and sustainable development of the citrus industry.

Description

Technical Field

[0001] This invention relates to the field of pest control for fruit trees, specifically to an integrated method for reducing damage from the citrus leafminer. Background Technology

[0002] The citrus leafminer, belonging to the family Citrus leafmineridae in the order Lepidoptera, is a serious pest of citrus plants, including citrus, kumquat, lemon, honesty, tangerine, mandarin orange, and sweet orange. The larvae damage young buds and leaves, and in some cases, fruit. The larvae burrow under the leaf epidermis to feed on the leaf tissue, creating winding tunnels and leaving frass trails, hence their common names "ghostly scribbles" or "drawing crickets." Damaged leaves curl up, providing overwintering sites for pests such as the citrus spider mite (red spider) and leafrollers; they also reduce photosynthetic efficiency, causing leaves to fall off easily and potentially leading to infectious diseases such as canker.

[0003] Spring shoots are usually less affected, while damage is more severe during the summer and autumn shoot emergence periods, especially on autumn shoots. The larvae burrow into the tender stems, leaves, and young fruit of citrus trees, creating winding white tunnels that cause leaves to curl. In severe cases, some leaves may die or even fall off, affecting the tree's vigor and reducing flowering and fruit production the following year. Furthermore, the damaged leaves serve as refuge and overwintering sites for citrus mites, spider mites, and leafrollers, and the wounds caused by the larvae are one of the entry points for citrus canker pathogens.

[0004] Currently, the control of citrus leafminer mainly falls into two categories: horticultural control and chemical control. Horticultural control primarily focuses on eliminating the source of the pest and preventing its introduction; this is combined with winter pruning, removing and burning infested branches and leaves. Common methods for chemical control are as follows: the optimal periods for control are during adult emergence and early larval stages. Adult control can be carried out in the evening; larval control is best done on sunny afternoons. Suitable pesticides include 10% deltamethrin at a dilution of 2000–3000 times, or 2.5% deltamethrin at a dilution of 2500 times, or 25% cartap hydrochloride at a dilution of 500 times (effective for both insecticidal and ovicidal purposes), or 25% emamectin benzoate wettable powder at a dilution of 500–1000 times, or 5% imidacloprid emulsifiable concentrate at a dilution of 1500 times. Spray once every 7–10 days, for 3–4 consecutive applications.

[0005] In addition to the two main prevention and control methods mentioned above, agricultural measures such as biological control, physical control, and agricultural control are used as supplementary methods.

[0006] However, various prevention and control measures have resulted in high costs and low efficiency. The main reasons for this are as follows:

[0007] 1. At present, there is a shortage of rural labor, resulting in a large number of labor shortages and difficulties in finding workers, which makes it impossible to carry out timely unified prevention and control and scientific prevention and control.

[0008] 2. Lack of systematic and scientific fertilizer and water management leads to uneven shoot growth in citrus trees, especially in autumn, which increases the frequency and difficulty of prevention and control.

[0009] 3. The autumn shoot emergence period is from August to October. This stage is characterized by abundant rainfall. If the shoot emergence is uneven, or even occurs 3-4 times, it greatly increases the difficulty of controlling the citrus leafminer. The critical period for citrus leafminer control is when the new shoots are 1-2 cm long. Rainy weather during this period, coupled with improper fertilization, especially high-nitrogen fertilizers, will accelerate shoot growth. As the new shoots grow rapidly, particularly after the tender leaves unfold, the leafminer larvae burrow into the tender stems, leaves, and young fruit of the citrus tree to feed. Uneven shoot emergence further increases the difficulty and cost of control.

[0010] Therefore, how to integrate and precisely regulate the timing and uniformity of citrus shoot emergence, especially the climate during the autumn shoot emergence period that is conducive to prevention and control, has become a key technology for the efficient control of citrus leafminer. Summary of the Invention

[0011] To address the aforementioned technical problems, the present invention aims to provide an integrated method for reducing damage from the citrus leafminer, achieving both precise and uniform shoot placement. Through large-scale demonstration and promotion, this method will greatly improve the identification and control capabilities of citrus growers and fruit farmers, thereby promoting the green, high-quality, and sustainable development of the citrus industry.

[0012] To achieve the above objectives, the technical solution of the present invention is as follows:

[0013] An integrated method for reducing damage from the citrus leafminer moth, comprising:

[0014] Fertilization management for citrus trees involves applying a shoot-promoting and flowering fertilizer during the spring's budding period, a fruit-promoting fertilizer during the summer dormancy period, and a tree-restoring fertilizer in autumn. Specifically, in spring, a N:P:K ratio of 2:1:1 (NPK) compound fertilizer is used, accounting for 30% of the total annual fertilizer application; in summer, a N:P:K ratio of 2:1:2 (NPK) compound fertilizer is used, accounting for 40% of the total annual fertilizer application; and in autumn, a N:P:K ratio of 2:1:2 (NPK) compound fertilizer plus 5 kg / tree of organic fertilizer is used, accounting for 30% of the total annual fertilizer application. Fertilization methods include applying fertilizer on a tree-by-tree basis and using one of the following methods based on tree row spacing.

[0015] Water management involves maintaining soil moisture at 60%–80% of field capacity during spring shoot emergence, flowering, and fruit enlargement, and keeping the soil dry during fruit ripening.

[0016] Citrus tree shoot control management involves managing citrus fertilizer and water according to the fertilization schedule in summer and autumn, thinning citrus fruits, controlling shoot growth with chemical agents, and controlling shoot growth through shaping and pruning. Chemical shoot control involves spraying the leaves of citrus trees, while shaping and pruning involves pruning two or three types of branches, including miscellaneous branches on the main trunk, vigorous shoots in the canopy, and branches around the tree base, according to the summer and autumn schedules.

[0017] Furthermore, for every 1000 kg of citrus fruit produced, 6 kg of nitrogen, 1.1 kg of phosphorus, 4 kg of potassium, 0.8 kg of calcium, and 0.27 kg of magnesium are required, with a nitrogen-phosphorus-potassium ratio of 1:0.2:0.7.

[0018] Furthermore, tree-based fertilization methods mainly include ring fertilization, radial fertilization, and hole fertilization. Ring fertilization involves digging a ring-shaped trench around the trunk, radial fertilization involves digging 3 to 5 radial trenches around the tree base, and hole fertilization involves digging fertilization holes outside the drip line of the tree canopy.

[0019] Furthermore, fertilization based on tree row spacing involves digging strip trenches between rows and between individual trees.

[0020] Furthermore, the fertilization depth should be based on the depth of the densely rooted area, generally 25-40 cm, and the fertilization depth should be deeper on slopes than on flat land.

[0021] Furthermore, chemical pesticide control is divided into summer pesticide control and autumn pesticide control.

[0022] The summer foliar spraying for controlling shoot growth is divided into one step. After the spring shoot leaves turn green and the branches lignify, and before the summer shoots emerge, mix 1000 times high potassium solution I and 2500 times 0.004% 28-homobrassinolide soluble solution with water. After mixing, spray the mixture evenly on the leaves and stems to control summer shoot growth.

[0023] The autumn foliar spraying for shoot control involves two steps.

[0024] The first step is to control the growth of autumn shoots by mixing a 1000-fold dilution of high-potassium potassium solution II and a 2500-fold dilution of 0.004% 28-homobrassinolide soluble concentrate with water, and then spraying the mixture evenly onto the leaves and stems.

[0025] Step two involves mixing 98% potassium dihydrogen phosphate powder (800x dilution), 10% tebuconazole suspension (1000x dilution), and 0.004% 28-homobrassinolide soluble concentrate (2500x dilution) with water before the leaves turn green and the branches lignify. The mixture is then sprayed evenly onto the leaves and stems to control the growth of the autumn shoots.

[0026] Furthermore, the high potassium 1000x solution I includes 5 parts nitrogen, 10 parts phosphorus, 40 parts potassium, 1.2 parts magnesium, 0.02 parts boron, 0.1 parts manganese, 0.2 parts zinc, 0.1 parts copper, and 0.1 parts iron.

[0027] Furthermore, the high potassium 1000x solution II includes 40 parts potassium oxide, 10 parts phosphorus pentoxide, 1.2 parts magnesium, 0.05 parts molybdenum, 0.002 parts boron, 0.1 parts manganese, 0.2 parts zinc, 0.1 parts copper, and 0.1 parts iron.

[0028] Furthermore, summer pruning and shoot control involves pruning the main trunk branches, vigorous shoots in the crown, and branches around the base of the citrus tree when the summer shoots have grown to 15-20cm.

[0029] Furthermore, autumn pruning and shoot control involves pruning the overgrown branches and basal branches of the citrus tree crown when the autumn shoots have grown to 20-25cm.

[0030] The beneficial effects of this invention compared to existing technologies are: precise, on-demand, and timely application of fertilizer and water formulas for citrus management, along with the use of highly efficient and low-toxicity pesticides to precisely control the timing of citrus shoot emergence and to promote uniform shoot emergence. This achieves precise and controllable shoot emergence time and uniformity, which is a key foundation for the integrated control of citrus leafminer moths in the later stages. It enables citrus leafminer control to achieve the goals of labor saving and cost reduction, and promotes the healthy and sustainable development of the citrus industry.

[0031] Controlling the timing, length, lignification degree, and number of new shoots in citrus through integrated technology is an important measure to reduce the occurrence of pests and diseases, reduce nutrient waste, coordinate the ratio of vegetative and reproductive growth in citrus, and improve the quality and yield of citrus.

[0032] Throughout the entire growth process of citrus, field fertilizer and water management should be strictly carried out in accordance with the scientific fertilizer and water management techniques described in this invention. This will prevent uneven distribution of nutrients, which can lead to unsatisfactory shoot control and increase the difficulty of shoot control. The key to citrus shoot control technology is controlling the autumn shoots. Controlling the early summer shoots is an important foundation and a crucial link in achieving effective autumn shoot control. Effective autumn shoot control is a key measure for controlling citrus leafminer and other pests and diseases, as well as increasing yield and income. Detailed Implementation

[0033] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific embodiments.

[0034] An integrated method for reducing citrus leafminer damage is divided into citrus tree fertilization management, water management, and citrus tree shoot control management, specifically:

[0035] I. Fertilization Management of Citrus Trees: Apply fertilizer to promote shoot growth and flowering during the spring shoot growth period, apply fertilizer to promote fruit growth during the summer dormancy period, and apply fertilizer to restore tree vigor in autumn. Among them, apply a ternary compound fertilizer (20-10-10 compound fertilizer) with nitrogen: phosphorus: potassium = 2:1:1 in spring, accounting for 30% of the total annual fertilizer application, with nitrogen fertilizer as the main component and phosphorus and potassium fertilizer as the supplement (to promote spring shoots).

[0036] In summer, use a ternary compound fertilizer with a nitrogen:phosphorus:potassium ratio of 2:1:2 (16-8-16 compound fertilizer), accounting for 40% of the total annual fertilizer application. Potassium fertilizer should be the main component, with nitrogen and phosphorus used as supplementary components (to promote summer shoot growth and fruit development).

[0037] In autumn, use a ternary compound fertilizer (16-8-16 compound fertilizer) with a nitrogen:phosphorus:potassium ratio of 2:1:2 plus 5 kg of organic fertilizer per plant, accounting for 30% of the total annual fertilizer application. Organic fertilizer should be the main component, with chemical fertilizer used as a supplement (to promote the ripening of autumn shoots and fruits).

[0038] Nutrient requirements during citrus fertilization periods and stages: January-February, citrus dormancy period, no fertilizer application; March-April, spring shoot emergence period, apply fertilizer to promote shoot growth and flowering; May, summer shoot emergence period, no fertilizer application; June-July, apply fertilizer to promote fruit growth, peak demand for nitrogen, phosphorus, and potassium; August-September, summer shoot emergence period, no fertilizer application; October-November, apply fertilizer to restore tree vigor.

[0039] To produce 1000 kg of citrus fruit, 6 kg of nitrogen, 1.1 kg of phosphorus, 4 kg of potassium, 0.8 kg of calcium, and 0.27 kg of magnesium are required, with a nitrogen-phosphorus-potassium ratio of 1:0.2:0.7. The requirement for nitrogen and potassium is relatively high.

[0040] The amount of fertilizer applied is determined based on the measurement of soil nutrient status. Citrus fertilization should be carried out in accordance with the principles of "fertilizing according to the weather", "fertilizing according to the soil", "fertilizing according to the citrus tree", "fertilizing according to the phenological stage of citrus", "fertilizing according to the fertilizer", and "fertilizing according to economic benefits".

[0041] The following is a table showing the soil nutrient status of citrus orchards in some local areas:

[0042]

[0043] The effects of applying a certain element on the mineral element composition of citrus fruits are shown in the table below:

[0044]

[0045] The dosage can be adjusted according to factors such as tree vigor and soil fertility. It is recommended to use well-rotted organic fertilizer or commercial organic fertilizer. Fertilization methods for citrus orchards:

[0046] ① Ring fertilization: Dig a ring-shaped trench with the tree trunk as the center;

[0047] ②Radial fertilization: Dig 3-5 radial trenches around the tree base;

[0048] ③ Hole fertilization method: Dig fertilization holes on the outside of the drip line of the tree canopy;

[0049] ④ Strip fertilization: Dig strip trenches between rows and between plants;

[0050] ⑤ Broadcasting throughout the orchard: First, broadcast the fertilizer throughout the orchard. After harvesting and pruning, deeply cultivate the soil to incorporate the fertilizer as base fertilizer. Suitable for mature citrus orchards, once every 3-5 years;

[0051] ⑥ Fertilization depth: The depth should be based on the depth of the dense root zone, generally 25-40 cm, deeper on slopes and shallower on flat land.

[0052] II. Water Management: Water is crucial during the spring shoot emergence and flowering periods (March to May) and the fruit enlargement period (July to October). Soil moisture should be maintained at 60%–80% of field capacity. However, irrigation during droughts in the flowering and early fruit development stages will cause more severe flower and fruit drop. Therefore, irrigation should be done in winter or before early spring budding. This will simultaneously promote uniform and robust spring shoot development, improve flower quality and quantity, and reduce flower and fruit drop.

[0053] Keeping the soil dry from September to November can increase the sugar content of the fruit and also help promote flower bud differentiation. In production areas prone to drought during winter and spring, irrigation should be carried out as early as possible, ensuring thorough and complete irrigation in one go; otherwise, the fruit is prone to "waterlogging" and loses its marketability. Water should be controlled as much as possible 15-20 days before harvest to avoid excessive moisture, which can lead to a decline in quality. At other times, irrigation is generally not necessary unless there is a severe drought.

[0054] III. Citrus Tree Shoot Control Management: Based on the summer and autumn fertilization schedules for citrus trees, this includes fertilization and water management, fruit thinning, chemical shoot control, and pruning to control shoot growth.

[0055] Citrus summer shoot control techniques:

[0056] (1) Citrus fertilizer and water management

[0057] The fertilizer and water management technology of this invention is applied to summer field fertilizer and water management in combination with different citrus tree ages, varieties, soil fertility, and climates. Reasonable and appropriate fertilizer and water management is a key factor in citrus tree vigor, pest and disease control, new shoot development, fruit yield and quality.

[0058] (2) Perform fruit thinning treatment on citrus fruits in a timely and appropriate manner.

[0059] Depending on the tree's age, vigor, and variety, remove diseased, insect-infested, upturned, and sun-exposed fruits. The goal is to retain citrus fruits of uniform size, evenly distributed throughout the canopy, and in appropriate quantity. Too many or too few fruits on a citrus tree will affect the timing and uniformity of summer shoot emergence.

[0060] (3) Adopt green prevention and control technologies to comprehensively control diseases and pests in citrus orchards

[0061] Based on the citrus management situation in different ecological zones, green pest control technology is used to control major citrus pests and diseases such as aphids, mites, flies, anthracnose, scab, and brown spot, thereby ensuring the vigor of citrus trees, avoiding impact on citrus yield and variety, and also avoiding impact on the development of summer shoots.

[0062] (4) Drug-based shoot control program

[0063] a) Foliar spraying

[0064] After the spring shoots turn green and the branches lignify, and before the summer shoots emerge, use a mixture of 1000 times diluted high-potassium (nitrogen 5%, phosphorus 10%, potassium 40%, magnesium 1.2%, boron 0.02%, manganese 0.1%, zinc 0.2%, copper 0.1%, iron 0.1%) and 2500 times diluted 0.004% 28-homobrassinolide soluble concentrate, diluted with water, and then spray the mixture evenly on the leaves and stems to control summer shoot growth.

[0065] (5) Shaping, pruning and shoot control techniques

[0066] Pruning time: When the summer shoots of citrus trees have grown to 15-20cm.

[0067] Main stem miscellaneous branches: Use scissors to cut off the miscellaneous branches close to the main stem, without leaving any "handles" to prevent the rapid growth of new miscellaneous branches.

[0068] Overgrown branches in the canopy: Prune overgrown branches in the entire citrus canopy, cutting off branches that are higher than the canopy surface, with the cut ends at an angle to reduce the amount of pathogens introduced by rainwater through the cut.

[0069] Tree basin branches: Inspect and sort the branches in the five directions of the citrus tree crown: east, south, west, north and center. Prune excessive and dense branches, remove diseased, drooping, and vigorous branches. When pruning, try not to remove fruit-bearing branches. Remove weak branches from newly emerging summer shoots in the crown according to the method of "remove two out of five, or one out of three".

[0070] Citrus autumn shoot control techniques:

[0071] (1) Citrus fertilizer and water management

[0072] The fertilizer and water management technology of this invention is applied to autumn field fertilizer and water management in combination with different citrus tree ages, varieties, soil fertility, and climates. Reasonable and appropriate fertilizer and water management is a key factor in citrus tree vigor, pest and disease control, new shoot development, fruit yield and quality.

[0073] (2) Perform fruit thinning treatment on citrus fruits in a timely and appropriate manner.

[0074] During this period, the main focus is on thinning out small, diseased, insect-infested, and cracked fruits from the citrus trees. The goal is to ensure that the remaining citrus fruits are of uniform size and evenly distributed throughout the canopy. Too many or too few fruits on a citrus tree will affect the timing and uniformity of the autumn shoot emergence.

[0075] (3) Adopt green prevention and control technologies to comprehensively control diseases and pests in citrus orchards

[0076] Based on the citrus management situation in different ecological zones, green pest control technology is used to control major citrus pests and diseases such as aphids, mites, flies, anthracnose, scab, and brown spot. In particular, efficient control of citrus mites, aphids, and anthracnose is required to protect the vigor of citrus trees, avoid affecting citrus yield and variety, and also avoid affecting the development of autumn shoots.

[0077] (4) Drug-based shoot control program

[0078] a. Foliar spray 1

[0079] After the summer shoots turn green and the branches lignify, but before the autumn shoots emerge, use a mixture of 1000 times diluted high-potassium (40% potassium oxide, 10% phosphorus pentoxide, 1.2% magnesium, 0.05% molybdenum, 0.002% boron, 0.1% manganese, 0.2% zinc, 0.1% copper, and 0.1% iron) and 2500 times diluted 0.004% 28-homobrassinolide soluble concentrate, and spray the mixture evenly on the leaves and stems to control the autumn shoots.

[0080] b. Foliar spray 2

[0081] Before the leaves of the autumn shoots turn green and the branches lignify, spray the leaves and stems evenly with a mixture of 800 times diluted 98% potassium dihydrogen phosphate powder, 1000 times diluted 10% tebuconazole suspension, and 2500 times diluted 0.004% 28-homobrassinolide soluble concentrate. This treatment aims to suppress the emergence of late autumn shoots in citrus and promote lignification of these shoots, thereby reducing damage from citrus leafminers and increasing the flowering and fruit setting rates of citrus in the following year.

[0082] (5) Shaping and pruning

[0083] Pruning time: When the autumn shoots of citrus trees have grown to 20-25cm.

[0084] Overgrown branches in the canopy: Prune overgrown branches in the entire citrus canopy, cutting off branches that are higher than the canopy surface, with the cut ends at an angle to reduce the amount of pathogens introduced by rainwater through the cut.

[0085] Tree basin branches: Inspect and sort the branches in the five directions of the citrus tree crown: east, south, west, north and center. Prune excessive and dense branches, remove diseased, drooping, and vigorous branches. When pruning, try not to remove fruit-bearing branches. Remove weak branches from newly emerging autumn shoots in the crown according to the method of "remove two out of five, or one out of three".

[0086] Fertilization of young trees: Apply fertilizer frequently but in small amounts. Use nitrogen and phosphorus fertilizer as the main components, supplemented with potassium fertilizer. The N:P:K ratio is 2:1:0.5. The annual nitrogen fertilizer application per tree is 150-250g, applied in 4-5 applications: late March, early May, early July, and early September. Each application can use well-rotted human and animal manure mixed with 0.25kg urea and 0.5kg compound fertilizer per dan (a unit of weight). Afterward, apply fertilizer once before new shoots sprout and once after the new shoots turn green. The amount of fertilizer should be gradually increased as the young trees grow. In November, apply organic fertilizer mixed with 500-1000g of superphosphate per tree. Young trees have shallow and sparse root systems, so timely irrigation is necessary during droughts, with small amounts applied frequently, 5-10kg per tree each time. During waterlogging, drain water promptly to keep the soil moist, which is beneficial for normal tree growth.

[0087] Fertilization of fruit-bearing trees: From April to October in spring and autumn, citrus trees absorb the most fertilizer throughout the year. These characteristics should be considered when fertilizing, as improper fertilization can cause harm. Excess nitrogen during spring shoot emergence often leads to excessive shoot growth, reducing fruit set. Later nitrogen excess results in continuous late autumn shoots, affecting the citrus's overwintering ability. Nitrogen deficiency during fruit enlargement leads to severe physiological fruit drop, small fruit size, and low yield. Excessive potassium application can also increase peel thickness, affecting quality.

[0088] Note: Fertilization should be tailored to local conditions, timing, and location, and should adhere to the following principles: do not fertilize trees with strong vigor, fertilize trees with weak vigor; fertilize more trees in a bumper year, fertilize less trees in a lean year; fertilize more trees with many flowers, fertilize less trees with few flowers; mainly use fast-acting fertilizers, and use organic fertilizers in appropriate amounts.

[0089] To verify the effectiveness of an integrated method for reducing citrus leafminer damage and to provide a basis for its promotion, the company's technical center conducted a large-scale field demonstration trial of the integrated method. The experimental process and data are as follows:

[0090] Subject of the experiment: Citrus leafminer (Phyllocnistis citrella)

[0091] Experimental crop: Citrus variety, Chun Jian

[0092] Experimental Sites: As per experimental requirements, the experiment was conducted in the citrus-producing areas of Daxing Town and Shou'an Town, Pujiang County, Sichuan Province. Demonstration sites were located in Daxing Town's town center community, Jiujian Village, and Wangdian Village, and Shou'an Town's Weizhen Village and Qixing Village. The demonstration area is a major citrus production base in Chengdu. The terrain of the demonstration area is flat, the soil is yellow loam, the pH is 6.1 (slightly acidic), and the organic matter content is 3.4%. The experimental citrus trees were 8 years old, vigorous, and planted at a density of over 80 trees per mu (approximately 667 square meters). Citrus leafminer is a perennial and serious pest. Before the experiment, the infestation was moderate. Aphids, spider mites, and other pests also occurred in the citrus trees.

[0093] Control method: Integrated control method for citrus leafminer

[0094] Traditional methods for controlling citrus leafminer (provided by citrus growers)

[0095] Dosage and labeling of medicines:

[0096]

[0097] The total demonstration area is 30,010 mu, including 10,000 mu of an integrated method to reduce citrus leafminer damage, 10,000 mu of a control method for multiple integrated control of citrus leafminer, 10,000 mu of traditional methods for controlling citrus leafminer, and 10 mu of water control.

[0098] Application equipment: HD-400 manual sprayer (pressure 45Pa, spray rate 710ml / min).

[0099] Usage capacity: 50L of liquid solution per mu (unit of land area).

[0100] During the demonstration period, normal prevention and control measures were implemented for other citrus diseases and pests.

[0101] Meteorological data: During the demonstration period, it did not rain on the day of the first application of pesticide and the second and third applications.

[0102] Soil data: The soil texture of the demonstration site is yellow loam, with a pH value of 6.1, slightly acidic, and an organic matter content of 3.4%.

[0103] Investigation time and number of times: In accordance with the requirements of the "Guidelines for Field Efficacy Trials of Pesticides (I)", the control effect of citrus autumn shoot leafminer was investigated three times, at 3 days, 7 days and 14 days after the application of the control agent.

[0104] Survey Methods: A five-point sampling method (W sampling) was used. Five sampling points were selected in each demonstration plot, with 50 trees surveyed at each point, for a total of 250 trees surveyed. The distance between sampling points depended on the size of the plot, and the sampling points were at least 1 meter away from the field edge. The number of live insects was recorded, and the entire tree was surveyed. Simultaneously, the effects of pesticides (natural enemies) on other citrus pests, beneficial insects, and the crop were observed.

[0105] Methods for calculating drug efficacy:

[0106]

[0107]

[0108]

[0109] Direct impact on crops: Visual inspection showed that the demonstration method caused no damage to the citrus trees, and the citrus trees grew normally.

[0110] Product quality and output: According to the demonstration requirements, it is not necessary to measure output and quality.

[0111] Impact on other pests and diseases: An integrated method for reducing damage from citrus leafminer has a population-reducing effect on pests such as citrus red spider mite, aphid, and leafroller.

[0112] Impact on other non-target organisms: An integrated approach to reduce citrus leafminer damage has no impact on natural enemy populations of citrus pests.

[0113] The results and analysis are as follows:

[0114] The results of a large-scale demonstration project to control citrus leafminer are shown in the table below:

[0115]

[0116]

[0117] Regarding the control of citrus leafminer:

[0118] 1. Three days after application, the average control efficacy of an integrated method for reducing citrus leafminer damage, a multi-integrated control method for citrus leafminer, and traditional methods for controlling citrus leafminer in Daxing Town's town center, Jiujian Village, Wangdian Village, and Shouan Town's Weizhen Village, Qixing Village were 92.68%-96.43%, 90.82%-92.80%, and 64.09%-69.24%, respectively. The average control efficacy of the integrated method for reducing citrus leafminer damage in Daxing Town's town center, Jiujian Village, Wangdian Village, and Shouan Town's Weizhen Village, Qixing Village was significantly higher than that of the traditional methods, with significant and highly significant differences. The efficacy was comparable to that of the multi-integrated control method for citrus leafminer, with no significant difference.

[0119] 2. Seven days after application, the average control efficacy of an integrated method for reducing citrus leafminer damage, a multi-integrated control method for citrus leafminer, and traditional methods for controlling citrus leafminer in Daxing Town's town center, Jiujian Village, Wangdian Village, and Shouan Town's Weizhen Village, Qixing Village was 92.31%-95.89%, 89.64%-93.80%, and 78.10%-87.33%, respectively. The average control efficacy of the integrated method for reducing citrus leafminer damage in Daxing Town's town center, Jiujian Village, Wangdian Village, and Shouan Town's Weizhen Village, Qixing Village was significantly higher than that of the multi-integrated control method compared to the traditional methods.

[0120] 3. Fourteen days after application, the average control efficacy of an integrated method for reducing citrus leafminer damage, a multi-integrated control method for citrus leafminer, and a traditional method for controlling citrus leafminer in Daxing Town's town center, Jiujian Village, Wangdian Village, and Shouan Town's Weizhen Village, Qixing Village was 90.48%-92.93%, 87.61%-90.51%, and 85.75%-88.76%, respectively. The average control efficacy of the integrated method for reducing citrus leafminer damage in Daxing Town's town center, Jiujian Village, Wangdian Village, and Shouan Town's Weizhen Village, Qixing Village was significantly higher than that of the multi-integrated control method and the traditional method, although the difference was not highly significant.

[0121] Efficacy Evaluation: An integrated method for reducing citrus leafminer damage achieved a control rate of 90.98%-96.43%. During the application of this technology, scientific fertilizer and water management techniques and shoot control techniques effectively controlled the timing and uniformity of new shoot emergence in citrus trees, thus achieving sustained and effective control. Comparing the control efficacy of this integrated method, multiple integrated control methods for citrus leafminer damage, and traditional methods, the integrated method for reducing citrus leafminer damage is significantly superior to both the multiple integrated control methods and traditional methods.

[0122] The demonstration shows that an integrated method for reducing citrus leafminer damage has a good control effect on large-scale citrus leafminer control. At the same time, it is safe for citrus and has no significant impact on beneficial organisms such as natural enemies of citrus pests. It also has a good concurrent control effect on other pests such as citrus spider mites, aphids, and leafrollers. Furthermore, this integrated method for reducing citrus leafminer damage can promote the lignification of autumn citrus shoots, which is beneficial for increasing flowering and fruit setting rates in the following year, thus increasing yield. It is recommended for use in large-scale citrus leafminer control.

[0123] The above provides a detailed description of an integrated method for reducing damage from the citrus leafminer provided by this invention. The specific embodiments described are merely illustrative of the method and its core principles. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims of this invention.

Claims

1. An integrated method for reducing damage from the citrus leafminer, characterized in that, Divided into: Fertilization management for citrus trees involves applying a shoot-promoting and flowering fertilizer during the spring's budding period, a fruit-promoting fertilizer during the summer dormancy period, and a tree-restoring fertilizer in autumn. Specifically, in spring, a N:P:K ratio of 2:1:1 (NPK) compound fertilizer accounts for 30% of the total annual fertilizer application; in summer, a N:P:K ratio of 2:1:2 (NPK) compound fertilizer accounts for 40% of the total annual fertilizer application; and in autumn, a N:P:K ratio of 2:1:2 (NPK) compound fertilizer plus 5 kg / tree of organic fertilizer accounts for 30% of the total annual fertilizer application. Fertilization should be done on a tree-by-tree basis or according to the row spacing. Water management involves maintaining soil moisture at 60%–80% of field capacity during spring shoot emergence, flowering, and fruit enlargement, and keeping the soil dry during fruit ripening. Citrus tree shoot control management involves managing citrus fertilizer and water, thinning citrus fruits, using chemical agents to control shoot growth, and pruning to control shoot growth, based on the fertilization schedules for citrus trees in summer and autumn. Chemical shoot control involves spraying the leaves of citrus trees, while pruning to control shoot growth involves pruning two or three types of branches, including miscellaneous branches on the main trunk, vigorous shoots in the canopy, and branches around the tree base, according to the summer and autumn schedules. Chemical pesticide control is divided into summer pesticide control and autumn pesticide control. The summer foliar spraying for controlling shoot growth is divided into one step. After the spring shoot leaves turn green and the branches lignify, and before the summer shoots emerge, mix 1000 times high potassium solution I and 2500 times 0.004% 28-homobrassinolide soluble solution with water. After mixing, spray the mixture evenly on the leaves and stems to control summer shoot growth. The autumn foliar spraying for shoot control involves two steps. The first step is to control the growth of autumn shoots by mixing a 1000-fold dilution of high-potassium solution II and a 2500-fold dilution of 0.004% 28-homobrassinolide soluble concentrate with water, and then spraying the mixture evenly onto the leaves and stems. Step two involves mixing 98% potassium dihydrogen phosphate powder (800x dilution), 10% tebuconazole suspension (1000x dilution), and 0.004% 28-homobrassinolide soluble concentrate (2500x dilution) with water before the leaves turn green and the branches lignify. The mixture is then sprayed evenly onto the leaves and stems to control the growth of the autumn shoots. High-potassium 1000x solution I comprises 5 parts nitrogen, 10 parts phosphorus, 40 parts potassium, 1.2 parts magnesium, 0.02 parts boron, 0.1 parts manganese, 0.2 parts zinc, 0.1 parts copper, and 0.1 parts iron. High potassium 1000x solution II includes 40 parts potassium oxide, 10 parts phosphorus pentoxide, 1.2 parts magnesium, 0.05 parts molybdenum, 0.002 parts boron, 0.1 parts manganese, 0.2 parts zinc, 0.1 parts copper, and 0.1 parts iron. Summer pruning and shoot control involve pruning the main trunk, miscellaneous branches, overly vigorous shoots in the crown, and branches around the base of the citrus tree when the summer shoots have grown to 15-20cm. Autumn pruning and shoot control involves pruning the vigorous shoots and branches around the base of the citrus tree when the autumn shoots have grown to 20-25cm.

2. The integrated method for reducing citrus leafminer damage according to claim 1, characterized in that: To produce 1000 kg of citrus fruit, 6 kg of nitrogen, 1.1 kg of phosphorus, 4 kg of potassium, 0.8 kg of calcium, and 0.27 kg of magnesium are required, with a nitrogen-phosphorus-potassium ratio of 1:0.2:0.

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3. The integrated method for reducing citrus leafminer damage according to claim 2, characterized in that: Fertilization methods based on trees include ring fertilization, radial fertilization, and hole fertilization. Ring fertilization involves digging a ring-shaped trench around the trunk, radial fertilization involves digging 3 to 5 radial trenches around the tree base, and hole fertilization involves digging fertilization holes outside the drip line of the tree canopy.

4. The integrated method for reducing citrus leafminer damage according to claim 3, characterized in that: Fertilization based on tree row spacing involves digging strip trenches between rows and between individual trees.

5. An integrated method for reducing citrus leafminer damage according to claim 3 or 4, characterized in that: The depth of fertilization should be based on the depth of the dense root zone, generally 25-40 cm, and the fertilization depth on slopes should be deeper than on flat land.

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