Control method for jacobiasca formosana

Abstract

The present invention relates to the technical field of tea pest control, and provides a control method for Jacobiasca formosana, comprising: pruning a tea tree, and retaining a plurality of branches on two sides of the tea tree in the pruning process as trapping branches (S1); acquiring maximum usage data of tolfenpyrad in a tea garden, and on the basis of the maximum usage data, spraying the tolfenpyrad on the trapping branches by means of an electrostatic spraying method on the basis of different pesticide application dosages (S2); and using a chessboard sampling method to investigate the pest density of Jacobiasca formosana, obtaining corresponding pesticide effect data of different pesticide application dosages and residual data of the tolfenpyrad, and calculating the minimum effective dosage of the tolfenpyrad on the trapping branches on the basis of the corresponding pesticide effect data and the residual data of the tolfenpyrad (S3). The electrostatic spraying position and the pesticide application dosage of the tolfenpyrad can be determined, thereby ensuring the pesticide effect and the safety.

Description

A method for preventing and controlling tea green leafhopper Technical Field

[0001] The invention belongs to the technical field of tea pest control, and particularly relates to a method for controlling tea green leafhoppers. Background Art

[0002] The main pest in tea gardens is the tea green leafhopper, which is difficult to control. Currently, there are no established pesticide application limits to regulate its use. Currently, the registered pesticides for tea leafhopper control are mainly tolfenpyrad, indoxacarb, and bifenthrin. Indoxacarb is relatively ineffective, and bifenthrin is a relatively old pesticide.

[0003] In addition to traditional manual or electric spraying, electrostatic spraying is also currently available for the application of tolfenpyrad. Using tolfenpyrad with an electrostatic sprayer can reduce pesticide use by 20%, improve pesticide utilization, and reduce pesticide residues in tea leaves. However, determining the optimal spray location and safe, effective application rate for tolfenpyrad electrostatic spraying remains a technical challenge in the control of tea green leafhoppers.

[0004] Summary of the Invention

[0005] The purpose of the present invention is to provide a method for preventing and controlling tea green leafhoppers to solve the problems existing in the above-mentioned prior art.

[0006] To achieve the above object, the present invention provides a method for controlling tea green leafhopper, comprising:

[0007] Step 1: Prune the tea tree, and keep several branches on both sides of the tea tree as trapping branches during the pruning process;

[0008] Step 2: obtaining the maximum usage data of tolfenpyrad in the tea garden, and spraying tolfenpyrad on the trapping branches by electrostatic spraying according to different application doses based on the maximum usage data;

[0009] Step 3: using a checkerboard sampling method to investigate the population density of tea green leafhoppers, obtaining corresponding efficacy data and tolfenpyrad residue data of different application doses, and calculating the minimum effective dose of tolfenpyrad on the trapping branch based on the corresponding efficacy data and the tolfenpyrad residue data;

[0010] Step 4: spraying the green leafhoppers in the tea garden based on the minimum effective dose of the tolfenpyrad on the trapping branches;

[0011] Step 5: Check the control effect three days after spraying to ensure the control effect.

[0012] Optionally, during pruning, several branches are retained on both sides of the tea tree as trapping branches, including:

[0013] Retain one bud and three leaves on each of the trapping branches, and remove all leaves and side branches except the one bud and three leaves on each of the trapping branches.

[0014] Optionally, obtain the maximum usage data of tolfenpyrad in tea gardens, including:

[0015] Based on NY / T2882 "Guidelines for Environmental Risk Assessment of Pesticide Registration", the environmental safety threshold data of tolfenpyrad is obtained; further the pesticide application safety threshold data is obtained, and the maximum usage of tolfenpyrad on the trapping branch is determined based on the environmental safety threshold data and the pesticide application safety threshold data and combined with the maximum residue limit value of tolfenpyrad registered in tea.

[0016] Optionally, obtain pesticide application safety threshold data, including:

[0017] Based on the use of tolfenpyrad tags, the behavioral patterns of tolfenpyrad under the electrostatic spray application method on the trapping branch are obtained. Based on the behavioral patterns, the deposition patterns, digestion patterns, metabolic patterns and the relationship between dosage and safe transfer of tolfenpyrad in the trapping branch are obtained, and the safety threshold data for the application of tolfenpyrad is determined.

[0018] Optionally, the deposition pattern of tolfenpyram in each trapping branch is an inverted pyramid distribution, the deposition amount decreases from top to bottom, and the deposition concentration on leaves is much greater than that in soil;

[0019] The degradation pattern of tolfenpyrad in the trapping branches is the half-life of tolfenpyrad in the tea tree system;

[0020] The metabolic pattern of tolfenpyrad in the trapping branches showed that no highly toxic metabolites were produced;

[0021] According to the relationship between the dosage of tolfenpyrad and the quantity transfer of food safety, the maximum allowable dosage of tolfenpyrad for food safety is 112.5 g ai / hm2. 2 ;

[0022] The safety threshold data for the application of tolfenpyrad was determined based on the deposition, digestion, metabolism and dose-safety transfer relationships of tolfenpyrad in the trapping branches.

[0023] Optionally, the calculation process of the minimum effective dose of tolfenpyrad on the trapping branch includes:

[0024] According to different application doses, tolfenpyrad was sprayed on the trapping branches by electrostatic spraying to control tea green leafhoppers. The insect population density of tea green leafhoppers was investigated by chessboard sampling method to obtain the application rate of tolfenpyrad and the corresponding efficacy data. The half-life of tolfenpyrad in the tea tree system was calculated by pesticide residue data and kinetic equations. The LD50 of tolfenpyrad against tea green leafhoppers was further calculated by tea leaf immersion method test. 50 and LD 99 .

[0025] Optionally, after checking the control effect, if there is a small amount of tea green leafhoppers, spray a second time to ensure the control effect.

[0026] The technical effects of the present invention are:

[0027] The present invention targets the tea green leafhopper, a major pest in tea gardens at present. By comprehensively screening candidate pesticides such as tolfenpyrad and electrostatic spraying equipment based on the aspects of prevention efficacy and pesticide residue, the present invention sets trapping branches by utilizing the tea green leafhopper's tendency to attract tender leaves. The tea green leafhoppers in pruned tea gardens and adult tea green leafhoppers during the tea season are attracted by using tender shoots (one bud and three leaves) on the trapping branches, and are killed by combining physical or biological control techniques to achieve the purpose of trapping and killing the tea green leafhoppers. The present invention is simple to operate, reduces costs, and can quickly and accurately prevent and control the tea green leafhoppers.

[0028] After the electrostatic spraying of tolfenpyrad, the present invention deduces the application limit value range of tolfenpyrad to be 72-112.5 g.i. / hm based on comprehensive factors such as the application safety threshold of tolfenpyrad, the minimum effective dose of tolfenpyrad, and environmental safety. 2 Under the conditions of reducing the use of tolfenpyrad by 20% and increasing it by 12 percentage points, the limit standard range of electrostatic spray application of tolfenpyrad in tea leaves is established as 72-112.5 g a.i. / hm 2 , providing important technical support for reducing the use of tolfenpyrad in tea planting systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] FIG1 is a flow chart of an embodiment of the present invention. DETAILED DESCRIPTION

[0030] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0031] Example 1

[0032] As shown in FIG1 , this embodiment provides a method for controlling tea green leafhoppers, comprising:

[0033] The tea trees are pruned, and several branches are retained on both sides of the tea trees as trapping branches during the pruning process. In production, tea trees are planted in strips to form tea bushes. Tea trees are crops for harvesting buds. In order to facilitate management and picking, pruning and other measures are generally used to make the upper part of the tea bushes relatively flat, that is, to form a crown surface. Mature tea gardens are generally pruned more than twice a year. During pruning, all protruding branches are cut off to ensure that the crown surface is flat. In this embodiment, some branches are selectively retained as trapping branches, namely flag branches. Due to the wide width of the tea bush, the flag branches do not cause inconvenience to tea garden work.

[0034] Obtaining maximum usage data of tolfenpyrad in the tea garden, and using the maximum usage data as a limit, spraying tolfenpyrad on the trapping branches by electrostatic spraying according to different application doses;

[0035] Safety threshold for application of tolfenpyrad: follow the tolfenpyrad usage label (67.5-112.5g ai / hm 2 ), study the behavior of tolfenpyrad under electrostatic spraying on tea trees, and clarify the deposition, degradation, metabolism and dosage and safe delivery relationship of tolfenpyrad in tea trees.

[0036] Deposition law of tolfenpyrad in tea trees: In terms of the deposition behavior of tolfenpyrad, when the application rate of tolfenpyrad by electrostatic sprayer is 72g a.i. / hm 2 When the pesticide was applied for 2 hours, tolfenpyram was mainly deposited in leaves and soil. The distribution of tolfenpyram was inverted pyramid, and the deposition amount decreased from top to bottom. The deposition concentration on leaves was much greater than that in soil.

[0037] The degradation pattern of tolfenpyrad in tea plants: According to the different dosages of tolfenpyrad (36, 72, 108, 112.5 g ai / hm 2 ), the pesticide residue values ​​at different time periods (2h, 1d, 3d, 5d, 7d) were measured, and the half-life of tolfenpyrad in the Chinese tea system was calculated to be 1.96-3.67d through the kinetic equation, which was mainly related to the application rate and the growth environment of the tea trees;

[0038] Metabolic patterns of tolfenpyrad in tea plants: The hydrolysis half-life DT of tolfenpyrad in pure form 50 All are more than 1 year; photolysis half-life in water at 25℃, 765W / m 2 , 300~800nm, DT in distilled water 50 35.2h, DT in natural water 50 The metabolic pathway of tolfenpyrad is photolysis and hydrolysis, and the metabolite is 4-[4-[(4-chloro-3-ethyl-1-methylpyrazole)carbonylaminomethyl]phenoxy]benzoic acid, with no highly toxic metabolites produced.

[0039] The quantitative transfer relationship between the dosage of tolfenpyrad and food safety: Based on the safe interval period, degradation constant and other parameters of tolfenpyrad, the application scenario of tea tree sprayer in my country was adopted, the application crop was the trapping branch of tea tree, the application period was the summer and autumn tea season, the number of applications was 1, the application equipment was electrostatic sprayer, the application interval was 7 days, the application safety interval was 7 days, and the degradation half-life was 3 days. Combined with the national food safety standard of tolfenpyrad registered in tea is 50 mg / kg (GB 2763-2019), it was verified through field trials that at the maximum allowable application dose (112.5 g a.i. / hm 2 ), the final residues of tolfenpyrad after 2 hours and 7 days were 25.6 and 4.01 mg / kg, indicating that the field test values ​​of tolfenpyrad (25.6 and 4.01 mg / kg) were within the MRL value of tolfenpyrad registered for tea (China: 50 mg / kg; CAC: 30 mg / kg). Therefore, the maximum allowable application rate of tolfenpyrad for food safety in China and the Codex Alimentarius Commission (CAC) is determined to be 112.5 g ai / hm 2 .

[0040] Effect of tolfenpyrad dosage on crop safety: According to different tolfenpyrad dosages (36, 72, 108, 112.5 g ai / hm 2 ), electrostatic sprayer was used to spray tolfenpyrad to control tea green leafhoppers. The damage of tea leaves in different time periods (2h, 1d, 3d, 5d, 7d) was investigated and no damage was found. Therefore, when the application rate was 36, 72, 108, 112.5 g ai / hm 2 At the same time, tolfenpyrad did not affect the normal growth of tea trees and was safe for tea trees.

[0041] Environmental safety threshold: According to NY / T 2882 "Guidelines for Environmental Risk Assessment of Pesticide Registration", for the tea green leafhopper in the trapping branch scene, the allowable concentration value of pesticide residues in the environment is reversed based on the environmental risk model. According to the standard that the amount of pesticide residues in the environment at any time (the maximum value is the original deposition amount) cannot exceed the risk value for non-target organisms, the pesticide application amount is reversed. Combined with the minimum effective dose and maximum registered dose of tolfenpyrad, the degradation half-life corresponding to the application period is, the maximum recommended number of applications is 1, and the application interval is 7 days. It has been verified through field trials that at the maximum use dose (112.5g ai / hm 2 ), the original deposition of tolfenpyrad in 2 hours was measured to be 25.6 mg / kg (which does not exceed the MRL value of tolfenpyrad registered in tea in my country and CAC), thus determining that the maximum use dose of tolfenpyrad should not exceed the maximum registered dose of 112.5 g ai / hm 2It is prohibited to use during the flowering period of nectar-producing crops, near silkworm rooms and mulberry gardens, and should be kept away from aquaculture areas.

[0042] Based on the above pesticide safety thresholds and environmental safety thresholds, the maximum usage of tolfenpyrad in tea gardens is determined to be 112.5g ai / hm 2 .

[0043] The checkerboard sampling method is used to investigate the population density of tea green leafhoppers, obtain corresponding efficacy data and tolfenpyrad residue data of different application doses, and calculate the minimum effective dose of tolfenpyrad on the trapping branch based on the corresponding efficacy data and the tolfenpyrad residue data;

[0044] According to the different dosages of tolfenpyrad (36, 72, 108, 112.5 g ai / hm 2 ), spraying tolfenpyrad with an electrostatic sprayer to control tea green leafhoppers, and using a checkerboard sampling method to investigate the density of tea green leafhoppers. The results showed that when the tolfenpyrad application rate was 36g ai / hm 2 When the dosage of tolfenpyrad was 72g ai / hm 2 When the dosage of tolfenpyrad is 108g ai / hm 2 The efficacy of the pesticide against tea green leafhoppers for 7 days was 86.1-92%. The half-life of tolfenpyrad in the Chinese tea system was calculated to be 1.96 days (36 g ai / hm2) based on pesticide residue data and kinetic equations. 2 ), 2.08d(72g ai / hm 2 ), 3.09d(108g ai / hm 2 ) and 3.67d(112.5g ai / hm 2 ) The LD50 of tolfenpyrad against tea green leafhopper was calculated by the tea leaf immersion method. 50 and LD 99 Therefore, according to the control effect of tolfenpyrad on tea green leafhopper, the tolfenpyrad residue data and the resistance occurrence pattern of tea green leafhopper, when the tolfenpyrad application rate is 72g a.i. / hm 2 When the pesticide is used, the 7-day efficacy against tea green leafhoppers is 85.2-91%. When the control efficacy of the pesticide against tea green leafhoppers is greater than 85%, tea green leafhoppers can be effectively controlled. The minimum effective dose of tolfenpyrad was 72g ai / hm 2 , which is 1 to 1.5 times the registered minimum recommended dose;

[0045] The green leafhoppers in the tea garden are sprayed for prevention and control based on the minimum effective dose of the tolfenpyrad on the trapping branches; and the prevention and control effect is checked three days after the spraying to ensure the prevention and control effect.

[0046] The half-life of tolfenpyrad in the Chinese tea plant system is 1.96-3.67 days, and the maximum allowable application rate for food safety of tolfenpyrad is 112.5g ai / hm 2 The minimum effective dose of tolfenpyrad is 72g ai / hm 2 The maximum allowable environmental safety dosage of tolfenpyrad is 112.5 g a.i. / hm2 2 The application limit of tolfenpyrad was calculated to be 72-112.5 g ai / hm 2 and verified by field trials.

[0047] The above description is merely a preferred embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for controlling tea green leafhopper, characterized in that: include: Step 1: Prune the tea tree, and keep several branches on both sides of the tea tree as trapping branches during the pruning process; Step 2: obtaining the maximum usage data of tolfenpyrad in the tea garden, and spraying tolfenpyrad on the trapping branches by electrostatic spraying according to different application doses based on the maximum usage data; Step 3: using a chessboard sampling method to investigate the insect population density of tea green leafhoppers, obtaining corresponding efficacy data and tolfenpyrad residue data of different application doses, and calculating the minimum effective dose of tolfenpyrad on the trapping branch based on the corresponding efficacy data and the tolfenpyrad residue data; Step 4: spraying the green leafhoppers in the tea garden based on the minimum effective dose of the tolafenamide on the trapping branches; Step 5: Check the control effect three days after spraying to ensure the control effect.

2. The method for controlling tea green leafhopper according to claim 1, characterized in that: During the pruning process, several branches are retained on both sides of the tea tree as trapping branches, including: Keep one bud and three leaves on each of the trapping branches, and remove all leaves and side branches except the one bud and three leaves on each of the trapping branches.

3. The method for controlling tea green leafhopper according to claim 1, characterized in that: Obtain the maximum usage data of tolfenpyrad in tea gardens, including: Based on NY / T2882 "Guidelines for Environmental Risk Assessment of Pesticide Registration", the environmental safety threshold data of tolfenpyrad is obtained; further the pesticide application safety threshold data is obtained, and the maximum usage of tolfenpyrad on the trapping branch is determined based on the environmental safety threshold data and the pesticide application safety threshold data and combined with the maximum residue limit value of tolfenpyrad registered in tea.

4. The method for controlling tea green leafhopper according to claim 3, characterized in that: Obtain pesticide application safety threshold data, including: Based on the use of tolfenpyrad labels, the behavioral patterns of tolfenpyrad under the electrostatic spray application method on the trapping branch are obtained. Based on the behavioral patterns, the deposition patterns, digestion patterns, metabolic patterns and the relationship between dosage and safe transfer of tolfenpyrad in the trapping branch are obtained, and the safety threshold data for the application of tolfenpyrad is determined.

5. The method for controlling tea green leafhopper according to claim 4, characterized in that: The deposition pattern of tolfenpyram in each trapping branch is an inverted pyramid distribution, with the deposition amount decreasing from top to bottom, and the deposition concentration on leaves is much greater than that in soil. The degradation law of tolfenpyrad in the trapping branches is the half-life of tolfenpyrad in the tea tree system; The metabolic pattern of tolfenpyrad in the trapping branches showed that no highly toxic metabolites were produced; According to the relationship between the dosage of tolfenpyrad and the quantity transfer of food safety, the maximum allowable dosage of tolfenpyrad for food safety is 112.5 g ai / hm 2 ; The safety threshold data for the application of tolfenpyrad was determined based on the deposition, digestion, metabolism and dose-safe transfer relationships of tolfenpyrad in the trapping branches.

6. The method for controlling tea green leafhopper according to claim 1, characterized in that: The calculation process of the minimum effective dose of tolfenpyrad on the trapping branch includes: According to different application dosages, tolfenpyrad was sprayed on the trapping branches by electrostatic spraying to control tea green leafhoppers. The insect population density of tea green leafhoppers was investigated by chessboard sampling method to obtain the application dosage and corresponding efficacy data of tolfenpyrad. The half-life of tolfenpyrad in the tea tree system was calculated by pesticide residue data and kinetic equations. The LD50 of tolfenpyrad against tea green leafhoppers was further calculated by tea leaf immersion method test. 50 and LD 99 .

7. The method for controlling tea green leafhopper according to claim 1, characterized in that: After checking the control effect, if there is a small amount of tea green leafhoppers, spray a second time to ensure the control effect.

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