China National Veterinary Drug Quality Inspection Institute — Latest Responses to Frequently Asked Questions on Drug Efficacy Registration

Reply from the Pesticide Testing Institute of the Ministry of Agriculture and Rural Affairs to Common (Hot‑Topic) Questions Received via the Consultation Email—Regarding Efficacy: The questions and corresponding responses are as follows:

Question 1: When applying for registration of a new crop, if the application does not involve any new target pests or diseases, is it still necessary to submit an in‑lab bioassay report?

Reference response: In principle, for the same pest, pathogen, or weed (referring to the biological taxonomic rank) on different crops, indoor bioassay testing may be exempted. Plant growth regulators shall be evaluated on a case-by-case basis, according to their specific regulatory functions, to determine whether indoor bioassay testing is required.

Question 2: For mixed formulations with the same formulation ratio but different active ingredient concentrations, is it necessary to submit an indoor formulation screening study report when applying for registration?

Reference response: For mixed formulations that are identical to those already registered in terms of active ingredients, formulation ratios, and intended uses, an indoor formulation screening report is not required.

Question 3: Is it necessary to conduct indoor crop safety tests when applying for registration of plant growth regulators?

Reference response: For pesticide products involving new crops, a crop‑safety test report shall be submitted; however, for plant growth regulators and similar products for which indoor crop‑safety testing is impractical, field trials may be conducted.

Question 4: If a product application for registration involves a new intended use, can the submission of resistance risk assessment test data be exempted or reduced?

Reference response: If the new target pest or disease is not involved, the submission of resistance‑risk assessment data may be exempted.

Question 5: Since other products have already been registered for the control of wheat rust, can an application for registration to control corn rust be exempted from submitting resistance‑risk assessment data?

Reference response: The pathogens causing wheat rust and maize rust are different. Since the pathogen of maize rust is difficult to culture in the laboratory, the risk assessment for resistance can be waived.

Question 6: Can all crops listed in the “Catalogue of Special Small-Volume Crops with Drug Shortages” (2019 Edition) undergo field efficacy trials at three locations?

Reference response: Crops listed in the “Catalogue of Special Small-Scale Crops Facing Drug Shortages” (2019 edition) are considered to be cultivated in specific local areas and may undergo field plot efficacy trials at three locations.

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Question 7: For the registration of a new mixed formulation on minor specialty crops, is it required to conduct a one-year, three-location trial or a two-year, three-location field efficacy study?

Reference response: A two-year, three-location field plot efficacy trial is required.

Question 8: Do efficacy trials for public health insecticides need to be conducted at one site in both the northern and southern regions?

Reference response: For the registration application of outdoor-use public health insecticides, one site in each of the northern and southern regions must be selected to conduct efficacy trials; for indoor-use public health insecticides, two sites may be chosen at will to carry out efficacy trials.

Question 9: For mixed formulations involving new crops and target pests or diseases, is it necessary to include a locally conventional pesticide as a control in efficacy trials?

Reference response: According to the “Guidelines for Field Efficacy Trials,” a locally customary formulation should be included as a control. The type and mode of action of the control formulation should be identical or similar to those of the test formulation. Based on local conditions, an effective single‑component or formulated mixture should be appropriately selected as the control (for herbicides, if a single active ingredient fails to control weeds, a formulated mixture should be chosen).

Question 10: For microbial pesticides seeking registration for a new intended use on grapes, one year of field efficacy trials may be conducted across eight sites. However, the guidelines for trial locations list only seven grape-growing regions. Could two trial sites be arranged within a single growing region?

Reference response: Yes, but the two‑site trial should be conducted in different provinces within the same region.

Question 11: For a mixed formulation with identical active ingredient ratios, concentrations, formulations, registered crops, target pests or diseases, and application methods as an already‑registered product, but differing only in the timing of application—one applied before planting and the other at the onset of disease—can a one‑year field efficacy trial be conducted?

Reference response: For pesticide products that do not involve new uses or new application methods, a one-year field efficacy trial report may be submitted.

Question 12: A mixture product with the same active‑ingredient formulation, target weeds, and application method is already registered for weed control in winter wheat. If we now apply to register it for weed control in spring wheat, can we submit only a one‑year field efficacy study report conducted at three sites?

Reference response: Spring wheat fields and winter wheat fields do not fall within the same scope of use, and therefore a one-year field efficacy trial report cannot be exempted.

Question 13: When applying for registration of a plant growth regulator intended for winter wheat, is it permissible to conduct field efficacy trials at four locations?

Reference response: For plant growth regulators, there is no need to differentiate between winter wheat and spring wheat; registration for use on wheat requires submission of field efficacy trial reports from five locations.

Question 14: How many on-site efficacy test reports are required for molluscicides?

Reference response: For molluscicides used to control snails, field trial reports from two locations may be provided; for the control of apple snails in agricultural fields, efficacy trial reports from four field sites should be submitted.

Source: Pesticide Inspection Institute of the Ministry of Agriculture and Rural Affairs