Crop grouping

The internationalization of the crop grouping concept was addressed by the CODEX Committee on Pesticide Residues (CCPR) at their 38 Meeting in Brazil in April 2006. This meeting led to CCPR proposing an extended revision proposal of the CODEX Classification of Foods and Animal Feeds. The CODEX Alimentarius Commission at its 29 meeting in July 2006 approved the CCPR proposal. The 

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The extent of validation of confirmatory techniques is currently under consideration. Qne approach is that the extent of validation may be smaller than for the enforcement method. In principle, validation in triplicate at the relevant concentration level (LOQ or MRL) is sufficient. In the case where an MRL is set for multiple crops, a single validation in all representative crop groups is sufficient. A confirmatory method for residues in air is not required if a corresponding method was submitted for the other sample matrices. This approach is realized in Germany. ... 

The enforcement method must be suitable for the determination of all compounds included in the residue definition in order to enable Member States to determine compliance with MRLs. It is not feasible to validate a method for all commodities if a wide range of MRLs are set. Therefore, a concept of crop groups was developed in SANCO/825/00. The following crop groups with representative crops are presented ... 

For each group, one representative sample matrix has to be used for method validation. If the intended use is restricted to one of the crop groups, the method must be validated only for this group. On the other hand, the method has to be validated for all groups if the use is intended for a variety of crops that belong to two or more different groups. In addition, specific crops which are difficult to analyze due to matrix interference require individual method validation (e.g., hops, brassica varieties, bulb vegetables, herbs, tea). 

The second requirement is that enforcement methods for food must be validated by an independent laboratory [independent laboratory validation (ILV)]. The sample set is identical with the general sample set (see Section 4.1). If the method is identical for all four crop groups (mentioned at the beginning of the section), it may be sufficient to perform the ILV for plant materials with a minimum of two matrices, one of them with a high water content. In the case of food of animal origin, the ILV should be performed with at least two of the matrices milk, egg, meat, and, if appropriate, fat. 

In contrast to the requirements for enforcement methods and to ensure sufficient quality of the generated data, validation data should be submitted for all types of crop samples to be analyzed. However, matrix comparability and a reduced validation data set may be considered where two or more very similar matrices are to be analyzed (e.g., cereal grain). A reduced sample set may also be acceptable (two levels, at least three determinations and an assessment of matrix interference) provided that the investigated samples belong to the same crop group as described in SANCO/825/00 (see also Section 4.2.1). 

In this context, the list of commonly available techniques and the list of obsolete dangerous reagents must be revised regularly. Furthermore, questions which are asked frequently by applicants should be responded to, e.g., lists of commodities for the four crop groups and extent of data for confirmation techniques. 

Plant metabolism studies will provide information on the absorption, translocation, dissipation and degradation of the agrochemical. This information defines the residual analytes of regulatory concern that could include either the parent compound or metabolites in the field crops. Plant metabolism studies should be conducted with at least three crop representatives of three different crop groups listed in Table 1. One of the major objectives is to determine the comparative metabolism of the agrochemicals between animals and plants among different plant species. MAFF approves metabolism studies that are conducted in foreign countries, which should be operated under the certified GLP system. 

Crop and crop grouping. Residue studies have to be conducted with each target crop proposed for registration one variety of the target crop is acceptable. 

The citrus and cereal crop groups can be represented by any crop within that group (below), with the exception of Unshu orange for citrus, and rice, corn and buckwheat for cereals. Data from Chinese orange can cover grapefruit, navel orange, etc., and wheat and barley can cover oat and rye. 

In order to select the fresh fruits and vegetables for the OPMBS, each task force member company provided a list of commodities that the company considered to be the most important for its organophosphate products. A matrix was developed based upon a crop group strategy and the importance of commodities in the diet of infants and children. Thirteen fresh fruits and vegetables were eventually selected for inclusion in this study. 

Pruning of pome fruit crops will lead to DFR levels comparable to those for stone fruit crops therefore, a common database for both crop groups (for tree fruits) should be compiled. Further generic sets may be developed for fruit vegetables, grapes, and ornamentals. 

Table 1 Examples of Crop Groupings to Reduee Diseases ...

Table 3.3 Examples for proportions (%) of typical crop groups (Freyer 2003)...

Crop Group Acres (Millions) Metric Tons Produced (Millions)... 

New projects continue to help facilitate drug development and approved use for minor species and minor uses. To reduce the expense of drug development in aquatic species, efforts are underway to define species groups (crop grouping) for studies such as TAS, HFS and effectiveness. " A searchable aquaculture database of residues and pharmacokinetic parameters was recently published to make such data more widely available and easily used. 

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