Plant growth regulators refer to a class of substances in plants that regulate growth and other functions. Plant growth regulators have a variety of uses. It can be said that they can be used to regulate the germination, rooting, leafing, flowering and fruiting of seeds, as well as the preservation and storage of fruits and vegetables after harvest. It is mainly divided into three categories: auxin, cytokinin and gibberellin.

1、 Registration of plant growth regulators in China

China promulgated and implemented the Regulations on the Administration of Pesticides in 1997 and revised it in 2001 as the basic law on pesticides, which uniformly manages plant growth regulators as pesticides. At present, there are not many varieties of plant growth regulators registered in China. However, in agricultural production, plant growth regulators are widely used, ranging from bulk food crops such as soybeans, corn, rice, wheat, potatoes, to various economic crops such as vegetables, flowers, fruit trees, etc., in rooting, shaping, defoliation, inducing resistance, improving fruit setting, controlling growth, promoting growth, ripening, preserving, and increasing yield Plant growth regulators play an important role in improving quality.

A total of 33 registered active ingredients have been obtained, including gibberellic acid, meperidate, ethephon, naphthoic acid, chlormequat, sec-butylene, thiazolone, monocyandiamide, S-inducin, chloranilide, propionyl brassinolide, brassinolide, antidepressant, butyrylhydrazide, uniconazole, paclobutrazole, enaadenine, hydroxyurea purine, silycycline, Yiyadan, indoleacetic acid, triacontanol, flubenamide, dimethoxypentyl, clopidomide 1-methylcyclopropene, hypersensitive protein, calcium cyclamate, nucleotides, potassium dinitrate, prochloraz, 24-drop sodium salt, 24-drop triethanolamine salt.

2、 Exemption list of plant regulators and pesticide residues

At the ninth meeting of the 8th National Pesticide Registration and Review Committee, in accordance with the relevant provisions of the Provisions on Pesticide Registration Data, and in reference to international practices, seven plant growth regulators were exempted from the maximum residue limits, namely: gibberellic acid, enaadenine, 6-benzylamino-purine, hydroxyenaadenine, hypersensitive protein, and S-attractant acid, Triacontanol.

3、 Key points for review of registration residue data of plant growth regulators

1. Data of residue reduction test

The application or explanation for reducing residue test data confirms that the product has been officially registered on the crop for more than six years and has complete residue test data. Whether the product registration number, pesticide name, dosage form, registered crop, dosage (not more than 1.5 times) and use method of the cited enterprise are consistent with the enterprise.

2. Conditions and 3 conditions for authorizing residue report

2.1 Conditions to be met: The authorized residue test report shall comply with the provisions of the Regulations on Pesticide Registration Data and the Guidelines for Pesticide Residue Test and other policies. According to the Regulations on Pesticide Registration Data, the applicant "must provide the authorization of the registered reporter who independently has the same effective ingredients, dosage forms, scope of use and method data", and must also provide the authorization statement and complete residue test report of the authorized enterprise, and the authorized enterprise must have obtained the registration authorization to be effective.

2.2 There are three cases of authorizing residue data: residue data can be authorized between single agent and single agent with the same effective ingredients; Residue information can be authorized between mixtures with identical active ingredients; The single-agent residue data can be authorized to the mixture containing the same active ingredient and the content is not higher than this single agent.

3. Review points of residue test report

3.1 Evaluate whether the field test design scheme is reasonable according to the Provisions on Pesticide Registration Data and Pesticide Residue Test Criteria.

3.2 Evaluate whether the residue analysis and detection method is feasible.

3.3 The safety interval is recommended according to the registered application dose and times, and the residual test results are evaluated.

Field design of residue test

1. Requirements for test points

It shall meet the requirements of Annex 2 of the Provisions on Pesticide Registration Data: more than two years and three places for bulk crops; More than one plot of small crops in two years; Other crops are planted for two years.

2. Arrangement principle of test points

The representative main planting areas and planting methods are tested; The main planting areas should have sufficient spacing; The planting area should select different climatic zones and soil types for testing; Two years and two places - select the north and south according to the main planting areas; Two years, one place - limited by climate, planting area and planting mode.

3. Area and quantity of field test plots

In principle, it should comply with the requirements of the Guidelines for Pesticide Residue Test (NY/T 788-2004). Vegetables shall not be less than 15 square meters per plot; Grain shall not be less than 30 square meters per plot; At least 2 fruit trees are required; The number of cells is set to 3; A protection line is set between the cells.

4. Dose and times of application

The final residue test dose is 1.5 times the recommended dose of the enterprise; The application times are the recommended application times and one more application times; Application period and interval

5. Collection interval setting

It shall be set according to the provisions of 5.3 of the Guidelines for Pesticide Residue Test. It should conform to the growth characteristics of crops and actual production conditions. Generally, there should be more than 2 recovery intervals. The harvest interval of cucumber, tomato, tea and other crops should be shorter, set as 1, 2, 3, 5, 7 days; The harvest interval of cotton, rice, citrus and other crops can be longer, set as 7, 14, 21, 28 or 30 days.

6. Sampling

It shall meet the requirements of Appendix A Crop Classification, Sampling Location and Recommended Sampling Amount in 7.2.1 of the Guidelines for Pesticide Residue Test, and the crop location to be tested shall include the edible part of the crop. The emergency shall be recorded and explained. (World Agrochemical Network)