Pesticides guidelines for laboratory bioactivity tests Part 4: Potted plant test for fungicide control of powdery mildew on wheat

NY/T 1156.4-2006 Guidelines for Indoor Bioassay Tests for Pesticides Fungicides Part 4: Test Method for Control of Wheat Powdery Mildew Pot Method NY/T1156.4-2006 Standard Download Decompression Password: www.bzxz.net

ICS65.100
Agricultural Industry Standard of the People's Republic of China
NY/T1156.4-2006
Guidelines for laboratory bioactivity tests for pesticides
Fungicides
Part 4: Test for control of powdery mildew on wheat
Pot method
Pesticides guidelines for laboratory bioactivity testsPart 4 :Potted plant test for fungicide controlof powdery mildew on wheat
Published on July 10, 2006
Implemented on October 1, 2006
Ministry of Agriculture of the People's Republic of China
"Guidelines for laboratory bioactivity tests for pesticides, fungicides" is a series of standards. This part is the 4th part of "Guidelines for laboratory bioactivity tests for pesticides, fungicides". This standard is proposed and managed by the Ministry of Agriculture of the People's Republic of China. Drafting unit of this standard: Pesticide Control Institute of the Ministry of Agriculture. The main drafters of this standard are: Xu Wenping, Zhu Chunyu, Wu Xinping, Zhang Hong, Qiu Jianping. The Ministry of Agriculture's Pesticide Testing Institute is responsible for the interpretation of this standard. NY/T1156.4—2006wwW.bzxz.Net
1 Scope
Guidelines for Indoor Bioassay Tests for Pesticides Fungicides NY/T1156.42006
Part 4: Pot Method for Testing the Control of Wheat Powdery Mildew This part specifies the basic requirements and methods for testing fungicides for the control of wheat powdery mildew using the pot method. This part is applicable to indoor tests for pesticide registration to determine the activity of fungicides against wheat powdery mildew fungi. Other tests shall be carried out in accordance with this part. 2 Test conditions
2.1 Target
Wheat powdery mildew fungi (Erysiphegraminis). Record the source of the fungus. 2.2 Instruments and Equipment
2.2.1 Electronic balance (sensitivity 0.1mg); 2.2.2 Sprayer;
2.2.3 Microscope;
2.2.4 Conical flask:
2.2.5 Pipette or pipette;
2.2.6 Measuring cylinder;
2.2.7 Blood cell counting plate;
2.2.8 Counter, etc.
3 Experimental Design
3.1 Test Material Preparation
Select susceptible wheat varieties and plant them in pots. Wait until the seedlings grow to 2-3 leaves for use. 3.2 Chemicals
3.2.1 Test Chemicals
The test chemical uses the original drug (mother drug), and indicates the generic name, trade name or code, content and manufacturer. 3.2.2 Control Agents
Control agents use registered and commonly used technical drugs in production. The chemical structure type or mode of action of the control agent should be the same or similar to that of the test agent.
3.3 Test Steps
3.3.1 Agent Preparation
Water-soluble agents are directly dissolved and diluted with water. Other agents are dissolved in suitable solvents (such as methanol, acetone, dimethylformamide or dimethyl sulfoxide, etc.) and diluted with 0.1% Tween 80 aqueous solution. According to the activity of the agent, 5 to 7 series of mass concentrations are set, and the final content of organic solvents does not exceed 1%.
3.3.2 Agent Treatment
Use the spray method to evenly spray the agent on the spare wheat seedlings and dry them naturally. The test sets the treatment without agent as a blank control. 3.3.3 Inoculation and culture
NY/T1156.4—2006
The fresh spores of powdery mildew produced on the diseased wheat leaves within 24 hours were evenly shaken off and inoculated on the 2-3 leaf stage potted wheat seedlings. Each treatment should be no less than 3 pots, with 10 plants in each pot. In the protective test, the seedlings were inoculated 24 hours after the treatment with the pesticide; in the curative test, the seedlings were inoculated 24 hours before the treatment with the pesticide, and then cultured under appropriate conditions. 4 Investigation
Investigate according to the incidence of the blank control. The following classification method is used: Grade 0: No disease:
Grade 1: The area of ​​lesions accounts for less than 5% of the entire leaf area: Grade 3: The area of ​​lesions accounts for 6% to 15% of the entire leaf area; Grade 5: The area of ​​lesions accounts for 16% to 25% of the entire leaf area; Grade 7: The area of ​​lesions accounts for 26% to 50% of the entire leaf area; Grade 9: The area of ​​lesions accounts for more than 50% of the entire leaf area. 5 Statistical analysis of data
5.1 Calculation method
Based on the survey data, calculate the disease index and control effect of each treatment. The disease index is calculated according to formula (1), and the calculation result is retained to two decimal places: X
Where:
Disease index;
Number of diseased leaves at each level:
Relative level value;
Total number of leaves investigated.
Control effect is calculated according to formula (2):
Where:
E(N,xi)
P=CK-PT,
Control effect, the unit is percentage (%); CK—blank control disease index;
PT—disease index of drug treatment.
5.2 Statistical analysis
According to the logarithmic values ​​of each agent concentration and the corresponding probability value of protection, regression analysis was performed to calculate the ECso, ECo and other values ​​of each agent and their 95% confidence limits
When conducting the combined toxicity test of agents, the synergistic coefficient (SR) or co-toxicity coefficient (CTC) of the mixture was calculated according to the Wadley method or Sun Yunpei method to evaluate the combined action type of the mixture. Wadley method: The synergistic effect of the mixed use of agents was evaluated based on the synergistic coefficient (SR), that is, SR<0.5 is antagonistic, 0.5≤SR<1.5 is additive, and SR>1.5 is synergistic. The synergistic coefficient (SR) is calculated according to formula (3) and formula (4): PA+PB
XI=PA/A+PB/B
Wherein:
X is the theoretical value of ECso of the mixture, in milligrams per liter (mg/L); the percentage of A in the mixture, in percentage (%): PA
Pe is the percentage of B in the mixture, in percentage (%); A
Wherein:
ECso value of A in the mixture, in milligrams per liter (mg/L): ECo value of B in the mixture, in milligrams per liter (mg). X
is the synergistic coefficient of the mixture:
Xi is the theoretical value of ECsn of the mixture, in milligrams per liter (mg/L); X2 is the measured value of ECso of the mixture, in milligrams per liter (mg/L). NY/T1156.4—2006
Sun Yun method: The synergistic effect of mixed drugs is evaluated based on the co-toxicity coefficient (CTC), that is, CTC80 is antagonistic, 80
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