Residue trials to obtain permanent maximum residue limits for crops (Residues)

Crop residue trials are required for estimating the maximum residue level likely to occur in a commodity or crop when a product is used according to good agricultural practice.

Residues remaining on or in a crop commodity from a given method, timing and rate of pesticide application may vary with trial site and climate, and the limits of such variation are important to the establishment of maximum residue limits (MRLs). Other interacting factors of varying importance include growth dilution, ratio of crop surface to mass, volatility of the product, and degree of absorption onto and into the surface of the treated commodity. All of these must be taken into account when designing residue trials that represent a range of agricultural and climatic conditions.

The recommendations for use of the chemical included on the approved label must reflect good agricultural practice. MRLs are based on good agricultural practice and will never, under any circumstances, be higher than can be justified on toxicological grounds. MRLs are legal limits that are used for enforcement purposes to monitor misuse of a chemical. Hence, accuracy in their estimation is important.

1. Objectives

The objectives of crop residue trials are:

  • to establish, in accordance with good agricultural practice, the likely residue levels in crops at the time of grazing or harvest
  • to determine the rate of decline of residues
  • to provide the data to establish a new MRL or amend an existing one
  • to provide data to support the proposal of a withholding period that is compatible with good agricultural practice.

This guideline gives general information about the minimum requirements for crop residue trials and assumes that all trials will be conducted in Australia. However, in many cases, considerable residue information may be available from other countries that can be used to reduce the number of residue trials that need to be conducted in Australia. Inclusion of residue data from other countries is discussed in the relevant sections of this guideline.

It is not possible to cover every situation and it is stressed that this guideline is not a mandatory requirement to be rigidly implemented. If your intended residue trial program is atypical, you should consult with the APVMA before commencing work.

Residue guidelines that expand on specific situations or give general information about pesticide residues are published in the regulatory guidelines and are available on the APVMA website.

These include the following guidelines:

You should consult the guidelines listed above when planning a residue trial. For a situation that is not covered by this, or one of the above, guidelines, you should consult the APVMA.

You can find further information on residue trials in the Food and Agriculture Organization’s Guidelines for conducting pesticide residue trials to provide data for the registration of pesticides and the establishment of maximum residue limits and Manual on the submission and evaluation of pesticide residues data for the estimation of maximum residue levels in food and feed (1997), OECD guidance documents and test guidelines and the APVMA regulatory guidelines.

2. General principles of trial design

Supervised residue trials form the basis for the estimation of MRLs for plant protection products on commodities of plant and animal origin. The trials should be conducted under maximum treatment regime conditions as proposed for the label. The chosen test conditions should predict the highest residues that may reasonably arise and be representative of conditions encountered under normal farming practices. Some of the factors that must be considered when designing a residues trial are described below.

2.1. Trial layout

2.1.1. Selection of sites

Trials should be conducted in major areas of cultivation or production of the crop and should be sited to cover a range of representative conditions in which the pesticide is to be used. Such conditions include climatic variation, seasonal variation, differing soil types and different cropping systems. Areas or sites with conditions that are atypical and not representative should be avoided, unless it is anticipated that normal usage of the pesticide under those conditions will result in higher residues in the crop.

2.1.2. Number of sites

The number of sites in the study depends on the range of conditions to be covered, the uniformity of the crop and the variation in agricultural practices.

Trials should preferably be conducted in different geographic locations rather than establishing multiple trials at a single trial site. Under special circumstances, however, it may also be appropriate to carry out trials under controlled conditions, such as in climate-controlled chambers or greenhouses, so that all the factors that influence residue behaviour can be controlled.

In general, trials should be carried out over a minimum of two growing seasons for crops with a single, relatively narrow harvest period (such as cereals, tree crops and vines). Separate residue trials should be conducted for cereals and other crops that are grown in more than one season in any one year (for example, wheat grown in winter and spring). For products used in an extended growing and harvesting season, such as vegetables, glasshouse crops and citrus fruit, sufficient data from two different growing seasons may be acceptable, provided the use pattern is the same for each season.

In some circumstances, trials from one growing season may be adequate—for example:

  • when negligible residues are present and therefore the MRL may be set ‘at or about the limit of quantitation’
  • for post-harvest treatments when there is no expected variation in residues
  • when extensive data from overseas uses show a trend that is consistent with one season’s use in Australia
  • if sufficient trials are provided from different climatic zones in Australia for a widely grown crop.

2.1.3. Replication

Since variations in residue levels between replicate samples at individual sites are small compared to those from a group of sites, it is usually not necessary to replicate treatments at individual sites. However, it may be useful to have three or four replicates at one individual site to study experimental variation within a site. If an efficacy trial with replicated plots is sampled, residue samples taken from plots receiving ‘identical’ treatments should be analysed separately to provide an indication of within-site variation.

2.1.4. Plots

In general, residue data should not be generated from plots that are too small to be representative. The size of the individual plot will vary from crop to crop, but should be large enough to:

  • apply the pesticide under conditions that reflect normal commercial practices
  • provide sufficient quantities of representative crop samples for analysis.

A control plot for untreated samples is necessary to determine the limit of quantitation of the method for the crop (see Rates of application). The control plot should be close enough to the treated plot to have identical growing and climatic conditions. However, it has to be sufficiently far away to exclude any contamination from the treated crop (for example, from spray drift, volatilisation or leaching). A sufficient buffer zone (lanes or guard rows) should be left to prevent cross-contamination. In general, the control plot should be placed upwind from the treated plot.

2.1.5. Type or variety of crop and cropping system

The type or variety of crop and the way in which it is grown may influence the residue pattern. Data should be generated on the most commonly used type or variety and cropping system and on the factor or combination of factors most likely to result in the highest residue levels. If more than one variety of crop is commonly grown, then more than one variety should be used in the trials.

2.2. Application of the pesticide

2.2.1. Formulation

The residue trials should use the formulation of the pesticide to be marketed. Before you submit other formulations for registration, you should obtain a limited amount of data from comparative trials (bridging data) to check that residue levels resulting from the formulation change will not be significantly different. Details of formulations used in the trials should be reported. If in doubt, you should discuss the proposed formulation change with the APVMA.

2.2.2. Growth stages of crop

The stages of crop growth at which the pesticide is applied should be clearly identified (using terms such as pre-emergent, post-emergent, mid-season, flowering, fruit set, post-harvest, etc.; or accepted growth stage codes such as the BBCH scale).

Persistence of residues is dependent on the timing of the application, both plant growth stage and season. This is especially true in moderate climate zones, where it has been observed that the residue decline in autumn is generally less than in high summer due to the lower ultraviolet light intensity and lower temperatures.

2.2.3. Method of application

The method of application should reflect the recommendations and directions on the product label. Applications should be made with equipment similar to that used in normal commercial practice. Spray equipment should be calibrated. Other forms of applicators may be used, provided they are readily calibrated and are compatible with normal practice. Care should be taken to ensure uniformity of application and to avoid contamination in neighbouring plots.

2.2.4. Rates of application

Trials must include the maximum rate that is likely to be recommended or 1× and preferably some trials at double the maximum rate or 2× (if phytotoxicity is not a consideration). Trials at the double rate may be substituted for more trials at the maximum label rate. There may be circumstances when trial data may not be required at the double rate, such as with vines or fruit trees.

The double-rate data will give the study future value if there is ever a need to increase the use rate. It is therefore prudent to consider the need for conducting trials at the double rate.

The maximum application rate is usually specified as grams or kilograms of active ingredient per hectare, although other units are appropriate depending on the label instructions and type of crop treated (for example, grams or kilograms per tree, or grams or kilograms per meter of canopy diameter). It should also be specify whether the application rate changes during the growing season. Spray concentrations should be specified in grams or kilograms of active ingredient per 100 litres of spray volume for fruit trees, vines and orchard situations in general. If a rate is specified in an orchard situation, an appropriate conversion factor should be provided such as the spray volume per hectare or number of trees per hectare.

If two or more rates of application are included in the trial, care should be taken to avoid cross-contamination.

2.2.5. Number and timing of applications

The number of treatments and the intervals between applications should reflect the closest use to harvest and the maximum use of the product. Generally, it is the final application that has the greatest influence on the magnitude of residues at harvest. The growth stages at each application spray should be specified. If multiple applications of a product are recommended, the maximum number and the minimum interval between treatments should be studied. In some cases, the use pattern may recommend different doses for different situations (for example, ‘for control of Alternaria spp. apply 300 g/ha at 7–8 day intervals; for preventative treatment apply 500 g/ha with an interval of 10–14 days’).

2.2.6. Additional pesticides

No pesticides other than the one being analysed should be applied to the control or test plots before or during the sampling period. However, the use of other products may be necessary to maintain the health of the treated and untreated plants. In that case, only those pesticides that do not interfere with the residue analysis may be used. The additional products used should be noted and, where possible, advice from the analyst should be sought before use.

2.3. Residue decline studies

A number of the supervised residue trials submitted for registration of a product should be residue decline studies, which show how the residue levels change with time. The APVMA recommends that at least 50 per cent of the trials be decline studies. Residue decline studies are important when:

  • a systemic pesticide or slow-acting formulation is applied and maximum residues occur over an extended period after application
  • the chemical is applied when the edible portion of the crop has formed, especially if it is applied close to harvest
  • residues may occur at the earliest possible harvest or grazing period and harvesting or grazing may take place over an extended period.

The degradation or decline of residue levels may be due to one or more of the following factors:

  • physical removal (for example, by washing or volatilisation)
  • chemical degradation or metabolism in or on the plant
  • apparent disappearance due to growth dilution.

Samples to establish the residue decline should be taken as soon as the spray has dried and at regular intervals thereafter. The choice of sampling intervals will depend on the persistence of the chemical and the anticipated period between treatment and harvest or grazing. If multiple applications are recommended, a sample taken before the final application may be of value in determining the rate of degradation or decline between sprays. Sampling on at least four occasions, up to and including harvest, is recommended and it is important that the plot size is large enough to allow sampling at each interval. The proposed withholding period should be one of the sampling points (for further information, refer to the Withholding periods guideline).

The weather conditions during the period of the study should be recorded and the age and growth of the crop at each sampling interval should also be noted (for further information, refer to the Reporting of residue trials guideline).

In a normal decline trial, samples are taken from a single treated plot at appropriate intervals after application, up to and including harvest. Alternatively, it is possible to carry out a ‘reverse decline trial’, in which the product is applied to several plots at intervals corresponding to the sampling points and samples are taken from all the plots at the same time (at maturity or normal crop harvest). A reverse decline trial is recommended when the withholding period is uncertain and the crop is growing or maturing rapidly over the proposed treatment period. Under such circumstances, the residues present may be affected by the growth stage of the crop at treatment.

In cases where the product is applied at a particular stage of crop growth and harvest does not occur for several weeks or months after application, residue decline studies are required to address a failed crop situation (for further information, refer to the Failed crops guideline).

2.4. Guide to sampling

Generally, the ‘portions’ that make up the field sample are selected randomly, systematically or from pre-determined parts of the plot, depending on the situation. In sampling, the factors that control the residue distribution over the entire plot need to be considered. In certain circumstances—for example, when there is likely to be some within-plot variation such as orchards or vines—samples from each plot should be selected at random from the high, middle and lower parts of the tree or vine and bulked for analysis. The field sample should be representative of the treated plot and the individual ‘units’ must be typical of those taken at harvest—immature or unripe samples, for example, are not representative of a commercially viable commodity. The samples should also be as close as possible to the normal harvested crop in relation to trimming or cleaning (outer or wrapper leaves removed, or adhering soil removed). It is useful if the number of units per composite sample is recorded by the analytical laboratory together with the residues analyses.

Table 1 shows the commodity to be analysed and sampling procedure outlining the quantity of sample to be taken, the edible portion of the commodity for particular crop groups and the portion of the commodity to which the MRL applies.

Information on residues in the edible portion of the commodity is also necessary for chronic intake estimates for crops for which the MRL does not necessarily reflect the residues in the edible part of the crop (bananas, pineapples, mangoes, etc.). Residue analyses of the edible portion of the crop should be conducted on representative samples.

Similar principles apply when collecting single units to determine a variability factor for acute intake estimation. Single-unit analyses should be conducted if the applicant wishes to determine a variability factor from trial data, rather than use default factors that have been determined by the Joint FAO/WHO Meeting on Pesticide Residues. A minimum of 100 single units should be analysed to be statistically valid.

In summary, the following points should be considered:

  • When taking a sample at harvest, avoid taking undersized or diseased commodities or crop parts at a stage when they would not normally be harvested.
  • Sample the parts of the crop that normally constitute the commercial commodity.
  • Take samples in a way that is representative of the normal harvesting practice.
  • Take care not to remove surface residues during handling, packing or preparation.
  • Take and weigh the required weight of samples in the field and do not subsample.
  • Store samples under freezer conditions to avoid any deterioration of the residues.
  • Record the number of units per composite sample together with the analysis.

Control or untreated samples should be taken before the treated samples, to avoid contamination from handling. The control samples should be of a similar quality to the treated samples. For further detail, refer to the Food and Agriculture Organization’s Manual on the submission and evaluation of pesticide residues data for the estimation of maximum residue levels in food and feed.

3. Number of trials required for registration

It is impossible, and could be misleading, to indicate precisely the number of trials that need to be conducted to establish an MRL. However, experience indicates that a minimum number of datasets (trials) are required. The minimum number of datasets is provided in the Suggested number of crop trials (Australian and overseas data section. The datasets should be spread across representative cropping areas or geographic locations in Australia and may also include trials conducted in other countries, if the use pattern and good agricultural practice in those countries are considered to be similar to Australia’s. In the Suggested number of crop trials (Australian and overseas data) section, the representative states for particular crops are indicated by crop yield. The basic requirements for the number of trials are determined partly by whether the crop is a major or minor crop, is a significant export commodity or forms a significant proportion of the diet, and also by the degree of risk involved in extrapolating data from trials to commercial practice. The numbers indicated are the minimum numbers required for normal situations. In situations that are considered unusual, more or fewer trials may be appropriate, and the APVMA should be consulted prior to developing a trial program.

4. Negligible residues

Residues are considered to be negligible if the levels in the harvested produce are below the limit of analytical quantitation (see the Maximum residue limit proposals ‘at or about the limit of quantitation’ guideline). This is often the case with pre-emergent and early post-emergent applications of herbicides, applications of non-systemic insecticides and fungicides to fruits prior to flowering, and some seed treatments.

When no detectable residues are found, it is often due to the properties of the chemical, the type and timing of application and the rate of application. This result can be confirmed by considering studies of the plant’s uptake, metabolism and distribution of the compound.

In situations where metabolism studies and method of treatment indicate that negligible residues are expected, all the trials may be carried out within one growing season. However, if, contrary to expectations, detectable residues are found in preliminary trials, then trials over a second growing season may be requested.

If no quantifiable residues occur under maximum treatment regime conditions, no further trial results are required if conditions of use are changed to be more favourable (that is, the chances of residues remaining in the commodity are reduced by a modification in the use pattern).

5. Multiple formulations

Applicants seeking to register more than one formulation type of the same active constituent may need to generate residue data for the additional formulation types. The number of trials required to register additional formulations of a chemical will depend on the use pattern and the relative risks involved. The factors to consider include mode of application, timing of application and crop growth stage, and formulation type.

Slow-release formulations (microencapsulated, controlled release) normally require a full set of residue trials. As these formulations are designed for controlled release of the pesticide, the residues incurred cannot be compared to those resulting from a single treatment with ‘normal’ fast-acting formulations.

The data required for other types of formulations will be determined on a case-by-case basis. In general, applications made prior to crop emergence will require less residue data than formulations applied directly to growing plants. In some cases, the number of trials required may be reduced by conducting side-by-side or equivalence residue trials in which the two formulations are applied using the same rates and pre-harvest intervals. If the residues from the new formulation are less than or equal to those from the registered formulation, no additional studies will be required. However, if the new formulation results in greater residues, a full set of residue trials will be required, unless existing studies already characterise the fate of higher residues.

6. Changes to existing use patterns

In the following discussion, it is assumed that the original residue data used to set the existing MRL were of a quality to meet contemporary standards and are well documented.

When applying for a change in use pattern or registration, the effect of the changes on the residue behaviour may be based on argument, although thorough justification for the argument must be submitted. A justification could be that existing trial data show that relevant residues do not occur, or are unlikely to occur, under the new use pattern. The following sections discuss some of the common changes to use pattern or registration.

6.1. Changes in formulation

The discussion in the multiple formulations section also applies here. In principle, if there is a significant change in formulation new residue trials are necessary. If the formulation change does not involve a change in application method, it may be sufficient to carry out a comparative trial on one crop for each of the major crop groups listed on the label. If the label claims cover a wide range of crops, data should be generated for representatives of the major crop groups (leafy crops, root crops, soft fruits, tree fruits, cereal grains, etc.). The trials should be carried out on the crops expected to show the highest levels of residue or the greatest variation in residues. Representative crops in the major crop groupings are summarised in Table 3. If the residues found in a crop are not comparable for each type of formulation, trials for each crop listed on the label may be required.

6.2. Changes in application rate

In order to achieve maximum treatment regime conditions, the trials must be carried out using the highest rate of application. An increase or reduction in the rate of application of up to 25 per cent is accepted as comparable, provided all other conditions of use remain identical.

6.3. Changes in number of applications

In order to encompass the maximum treatment regime, the trials must be carried out using the maximum number of applications, or the maximum number of consecutive applications, that may be made to the crop. It is generally the last application before harvest that contributes most significantly to the level of residue in the harvested commodity. Applications prior to flowering are generally of lesser importance. In the case of relatively stable active ingredients, the residue results can be assumed to be comparable if the number of applications after flowering is increased by not more than 25 per cent (for example, 4 + 1 or 8 + 2 applications), provided there is no change in the interval between applications.

If an increase of more than 25 per cent is proposed, data may be required. Existing residue data may be used to support proposed reductions in the number of applications recommended on the label, unless a reduction in the MRL is requested.

6.4. Changes in application method

Different application methods, such as spraying, dipping, flooding, dusting, misting and granule spreading, will not, as a rule, produce comparable residue results and must therefore be tested separately. In some situations, however, there may be some comparability (for example, low volume application and dilute spraying).

6.5. Changes of timing of application; changes in withholding period

The stage of development of the crop and the intervals between applications are important factors influencing the level of residues. When setting an MRL, the maximum treatment conditions are the determining factors. An application at a later stage of crop growth may encompass residues from treatment at an earlier stage of crop development. Similarly, an application at a shorter interval before harvest may encompass residues from treatment at an application at a longer interval before harvest.

With proposed changes in the withholding period, a change of 25 per cent or less can be assumed to be comparable. This depends, however, on the interval between the last treatment and the withholding period. If the withholding period is to be extended, comparative data would not be required unless a change in the MRL is requested.

6.6. Use situation (outdoor, under glass, in store, under plastic)

The results of outdoor trials are not normally comparable with the results of trials carried out in other situations. In non-outdoor situations such as under glass, under plastic, in climate-controlled chambers or in stores, the difference in climatic conditions generally results in higher residues than those found in outdoor testing. Therefore, a full testing program is necessary for each of these situations. However, if an MRL is already set for indoor use, data for outdoor use will not be required.

6.7. Simultaneous changes in several trial parameters

The 25 per cent rule for purposes of comparability applies only when one of the parameters of the use pattern is changed. If more than one parameter is changed at the same time, the effects may be cumulative, or may cancel each other out. If more than two trial parameters are changed at the same time, it is not possible to assume comparable residue behaviour with any sufficient degree of certainty. Residue trials will therefore be required.

7. Comparable residue behaviour in different crops

In some cases, the morphology or growth habit, growing season and agronomic practices applied to one crop may be similar to other crops. For such crops, it is possible to extrapolate the MRLs based on the same use pattern from crop to crop. Guidance for possible crop groupings within which an extrapolation might be possible is given by the Codex Classification of foods and animal feeds, a summary of which has been reproduced in Table 3.

7.1. Inference of group or subgroup maximum residue limits

A group MRL applies to all the individual crops in the group, so the maximum use pattern used to generate the residue data for the major crops must be similar. Group MRLs will therefore only be established if good agricultural practice for the crops in the group is comparable. Minimum data requirements apply only if comparability can be established between production areas (similar climate, methods of growing, seasons of production, etc.). Some groups are further classified into subgroups, which are primarily indicative of form and growth habit. The subgroups are based on differences such as the size of the commodity, the surface of the crop (curly leaf versus straight leaf, or hairy surface versus smooth surface versus wrinkled surface) and the edible portion of the crop.

If a group contains crops that are considered animal feed commodities, additional data may be required for that portion of the commodity used as an animal feed (for example, fodder, forage or stubble).

7.2. Residue situations

The comparability of residue behaviour in different crops is dependent on a series of influencing factors that can affect the residues and can vary under a different set of conditions. In situations when data cannot be transferred from one crop to another, a full trial program will be required for each individual crop, in the same manner as for establishing a new MRL. For example, a group MRL will not normally be considered if the individual crop residue levels vary by more than a factor of 5.

The factors that affect the residue data requirements for an extrapolation include:

  • similarity of use pattern (number and timing of applications)
  • similarity of growth habit, form of crop and size of edible commodity
  • range of residue levels in different crops from a proposed use pattern.

We will consider extrapolations on a case-by-case basis. Residue data from other countries may be used to assist in setting a group MRL and for extrapolation from one crop to another. Possible extrapolations are given in Table 3. For more information, you can contact the APVMA.

Table 1: Commodity to be analysed and sampling procedure

Codex group

Commodity

Sample

Portion of commodity to which MRL applies (and is analysed)

Comment

001 Citrus fruit

Orange, mandarin, lemon, lime, etc.

12 fruits from several places on 4 individual trees (more fruit may have to be collected to obtain 2 kg fruit)

Whole commodity

Citrus fruits are produced by trees of the Rutaceae family and are characterised by aromatic oily peel, globular form and interior segments of juice-filled vesicles. The fruit is fully exposed during the growing season. The fruit pulp may be consumed in succulent form and as a beverage. The entire fruit may be used for preserving

002 Pome fruit

Apples, pears, quinces, etc.

12 fruits from several places on 4 individual trees (more fruit may have to be collected to obtain 2 kg fruit)

Whole commodity after removal of stems

Pome fruits are produced by trees related to the genus Pyrnus of the rose family (Rosaceae) characterised by fleshy tissue surrounding a core consisting of parchment-like carpels enclosing the seed. The entire fruit, except the core, may be consumed in the succulent form or after processing

003 Stone fruit

Large stone fruit: peaches, nectarines, plums/prunes, apricots

12 fruits from several places on 4 individual trees (more fruit may have to be collected to obtain 2 kg fruit)

Whole commodity after removal of stems and stones but the residue calculated and expressed on the whole commodity without stem

Stone fruits are produced by trees related to the genus Prunus of the rose family (Rosaceae) characterised by fleshy tissue surrounding a single hard-shelled seed. The entire fruit, except the seed, may be consumed in the succulent form or after processing

Small stone fruit: cherries

1 kg from several places on 4 trees

004 Berries and other small fruit

Grapes

12 bunches, or parts of 12 bunches from separate vines to give at least 1 kg

Whole commodity after removal of caps and stems

Currants: fruit with stems

Small fruits and berries are derived from a variety of plants whose fruit is characterised by a high surface–weight ratio. The entire fruit, often including seeds, may be consumed in succulent or processed form

Currants, raspberries and other small berries

0.5 kg from 12 separate areas or bushes

Strawberries, gooseberries

1 kg from 12 separate areas or bushes

005 Assorted tropical and sub-tropical fruit (edible peel)

Dates, olives, figs

1 kg from several places on 4 trees

Dates and olives: whole commodity after removal of stems and stones but residue calculated and expressed on the whole fruit

Figs: whole commodity

Assorted fruits with an edible peel are derived from immature or mature fruits of a variety of plants, usually shrubs or trees from tropical or subtropical regions. The whole fruit may be consumed in succulent or processed form

006 Assorted tropical and sub-tropical fruit (inedible peel)

Bananas, mangoes, pineapples, avocados, litchi

Bananas: 24 fruit (take 2 fingers each from top, middle and lowest hand of 4 harvestable bunches)

Pineapple: 12 fruit

Whole commodity unless qualified

Pineapples: after removal of crown

Avocados and mangoes: whole commodity after removal of stone but calculated on whole fruit

Bananas: after removal of crown tissue and stalks

Assorted fruits with an inedible peel are derived from immature or mature fruits of a variety of plants, usually shrubs or trees from tropical or subtropical regions. Edible portion is protected by skin, peel or husk. Fruit may be consumed in a fresh or processed form

009 Bulb vegetable

Onion, leeks, spring onions, garlic, shallots

Leeks, bulb onions: 12 plants

Spring onions: 24 plants (the sample should weigh at least 2 kg)

Garlic, shallots: 12 bulbs from 12 plants (the sample should weigh at least 2 kg)

Remove adhering soil (eg by rinsing in running water or by gentle brushing of the dry commodity)

Bulb/dry onions and garlic: whole commodity after removal of roots and whatever parchment skin is easily detached

Leeks and spring onions: whole vegetable after removal of roots and adhering soil

Bulb vegetables are pungent, flavourful foods derived from the fleshy scale bulbs or growth buds of alliums of the lily family (Liliaceae). The entire bulb may be consumed following the removal of the parchment-like skin

010 Brassica vegetables

Broccoli, brussels sprouts, cabbage, cauliflower, etc.

Large brassica crops: 12 plants

Broccoli: 1 kg from 12 plants

Brussels sprouts: 1 kg from 12 plants. Buttons to be taken from at least 2 levels on each plant

Whole commodity after removal of obviously decomposed or withered leaves. For cauliflower and headed broccoli, analyse flower head and stems, discarding leaves; for brussels sprouts, analyse ‘buttons’ only.

Brassica (cole) leafy vegetables are foods derived from the leafy parts, stems and immature infloresences of plants commonly known and botanically classified as brassicas and also known as cole vegetables. The entire vegetable may be consumed.

011 Fruiting vegetables—cucurbits

Rockmelon (cantaloupe), pumpkin, watermelon, cucumber, zucchini, etc.

Cucumbers: 12 fruits from separate plants

Gherkins, courgettes, squash: 12 or more fruits from 12 plants to make 2 kg

Melons, gourds, pumpkins, watermelons: 12 fruits from 12 separate plants

Whole commodity after removal of stems

Cucurbits are derived from the immature or mature fruits of various plants belonging to the botanical family Cucurbitaceae: usually these are annual vines or bushes.

The entire fruiting vegetable or the edible portion after discarding the inedible peel may be consumed in the fresh form or after processing

012 Fruiting vegetables other than cucurbits

Tomatoes, mushrooms, capsicums, sweet corn, etc.

Eggplants: 12 fruits from 12 separate plants

Sweet corn: 12 or more ears weighing 2 kg

Mushrooms: 12 or more items to make 0.5 kg

Tomatoes, peppers: >24 fruits for small or >12 from large fruiting varieties from 12 plants to make 2 kg

Whole commodity after removal of stems

Fruiting vegetables, other than Cucurbits are derived from the immature and mature fruits of various plants, usually annual vines or bushes. The group includes edible fungi and mushrooms, being comparable organs of lower plants. Many plants of this group belong to the botanical family Solanaceae.

The entire fruiting vegetable or the edible portion after discarding husks or peels may be consumed in a fresh form or after processing.

013 Leafy vegetables (including brassica leafy vegetables)

Lettuce (head and leaf), spinach, kale, etc.

Endive, lettuce: 12 plants

Spinach, chicory: 1 kg from >12 plants

Kale: 2 kg from 12 plants sampled from 2 levels per plant

Small leafed salad crops: 0.5 kg from 12 plants or sites in plot

Whole commodity after removal of obviously decomposed or withered leaves

Leafy vegetables are derived from the leaves of a wide variety of edible plants including leafy plants. The entire leaf may be consumed.

014 Legume vegetables (succulent seeds and immature pods)

Green beans, green peas, etc.

Peas, Phaseolus spp.: 1 kg fresh green or dry seed as appropriate

Whole commodity

Legume vegetables are derived from the succulent seeds and immature pods of leguminous plants commonly known as beans and peas. Succulent forms may be consumed as whole pods or as the shelled product

015 Pulses (dry)

Lupins, field peas, soybeans, chickpeas, faba beans, etc.

Pulses (dried broad beans, field peas, lentils, etc.): 1 kg

Whole commodity

Dry pulses are derived from the dried seeds of leguminous plants commonly known as beans and peas

016 Root and tuber vegetables

Potatoes, carrots, etc.

Fodder/sugar beet: 12 plants

Potatoes: 12 tubers to give >2 kg

Other root crops: 12 roots to give > 2 kg

Whole commodity after removing tops. Wash roots or tubers in cold running water, brushing gently with a soft brush to remove loose soil and debris, if necessary, and then dab lightly with clean tissue paper to dry. For carrots, after drying cut the tops off carefully with a knife by cutting through the bottom of the stem at the lowest point of attachment of the outer petioles. If an annulus of root tissue is thereby severed from hollow-crown roots, the material should be recombined with the roots

Root and tuber vegetables are starchy foods derived from the enlarged solid roots, tubers and corms or rhizomes, mostly subterranean, of various species of plants. The entire vegetable may be consumed

017 Stalk and stem vegetables

Asparagus, celery, rhubarb, chicory, artichokes

Celery: 12 plants

Asparagus, rhubarb: 12 sticks from 12 separate plants to give >2 kg

Globe artichokes: 12 heads

Whole commodity after removal of obviously decomposed or withered leaves

Rhubarb and asparagus: stems only

Celery and asparagus: remove adhering soil (eg by rinsing in running water or by gentle brushing of the dry commodity)

Stem vegetables are foods derived from the edible stems or shoots of a variety of plants

020 Cereal grains

Wheat, barley, oats, rice, sorghum, triticale, etc.

1 kg

Whole commodity

Fresh corn and sweet corn: kernels plus cob without husk (see fruiting vegetables, other)

Cereal grains are derived from the clusters of starchy seeds produced by a variety of plants primarily of the grass family (Gramineae). Husks are removed before consumption

021 Grasses for sugar or syrup production

Sugarcane

Min 2 kg. Select whole canes from 12 areas of the plot and take short (eg 20 cm) sections from all parts of the length of the canes.

Whole commodity (cane)

Grasses for sugar or syrup production, includes species of grasses with a high sugar content especially in the stem. The stems are mainly used for sugar or syrup production, and to a small extent as vegetables or sweets.

022 Tree nuts

Macadamias, almonds, pecans, chestnuts, etc.

1 kg

Coconut: 12 nuts

Whole commodity after removal of the shell

Chestnuts: whole in skin

Tree nuts are the seeds of a variety of trees and shrubs which are characterised by a hard, inedible shell enclosing an oil seed. The edible portion of the nut is consumed in succulent, dried or processed form

023 Oilseeds

Cottonseed, sunflower, peanut, rapeseed (canola), etc.

2 kg from 12 separate areas of plot (crops harvested mechanically can be sampled from the harvester as it proceeds through the crop)

Cottonseed: 1 kg with or without fibre

Peanuts, sunflower, safflower: 1 kg

Sesame, rapeseed: 0.5 kg

Whole commodity

Peanut: whole kernel after removal of shell

Oilseed consists of the seed from a variety of plants used in the production of edible vegetable oils. Some important vegetable oilseeds are by-products of fibre or fruit crops

024 Seed for beverages and sweets

Coffee, cacao beans

Seed/ bean

Whole commodity

Seed for beverages and sweets consist of the seeds from several tropical and sub-tropical trees and shrubs mostly used in the production of beverages and confections. Tropical seeds are consumed after processing

027 Herbs

Parsley, etc.

0.5 kg fresh

0.2 kg dry

Whole commodity

Herbs consist of leaves, stems and roots from a variety of herbaceous plants used in relatively small amounts to flavour other foods. They are consumed in succulent or dried form as components of other foods

028 Spices

Coriander seed, etc.

0.5 kg fresh

0.2 kg dry

Whole commodity

Spices consist of aromatic seeds, roots, fruits and berries from a variety of plants used in relatively small amounts to flavour other foods. They are consumed primarily in dried form as components of other foods

8. Suggested number of crop trials (Australian and overseas data)

Table 2 is a guide to the number of crop trials needed for registration of a pesticide. The number of trials may be reduced depending on factors, such as:

  • timing of application (how close application of the product is to harvest of the crop)
  • method of application
  • total number of applications and re-treatment intervals
  • persistency of the product applied and resulting residues in the crop
  • physicochemical characteristics of the active constituents and product formulation.

All uses will be considered on a case-by-case basis and applicants are advised to contact the APVMA before considering the generation of any residues data.

The following numbers of trials are suggested:

  • major crops: 8–12 trials
  • major-minor crops: 6 trials
  • minor-major crops: 4–6 trials
  • minor crops 2 trials.

The figures in parentheses in Table 2 indicate the numbers of trials required to set a group MRL; refer to Table 3 for the commodities that are required for a particular crop group.

Reductions in trial numbers will be considered by the APVMA for crops where experience shows that agronomic practices and growth habit lower the risk of finite residues being present in the edible part of the crop. (Note: Codex requires a minimum of 8 trials to be conducted according to good agricultural practice before an MRL can be considered.)

Table 2: Suggested number of crop trials (Australian and overseas data)

Codex group

Commodity

Trials

Ranked growing regions

NSW

NT

Qld

SA

Tas.

Vic.

WA

001 Citrus fruit

Orange

8 (6)

1

 

4

2

 

3

 

Mandarin

8 (4)

   

1

2

 

3

 

Lemon/lime

6 (4)

3

 

2

1

     

Other

4

             

002 Pome fruit

Apple

8 (6)

2

     

3

1

 

Pear

8 (4)

     

3

 

1

2

Other

4

             

003 Stone fruit

Peach

8 (6)

2

   

3

 

1

 

Nectarine

8 (4)

2

       

1

3

Plum/prunes

8 (4)

1

   

3

 

2

 

Apricot

6 (4)

3

   

1

 

2

 

Cherries

6 (4)

1

   

3

 

2

 

Other

4

             

004 Berries and other small fruit

Grapes (wine)

8 (6)

             

Grapes (table)

8 (6)

2

 

3

   

1

 

Strawberry

8 (4)

   

2

   

1

3

Blueberry

4 (2)

             

Others

4 (2)

             

005 Assorted tropical and sub-tropical fruit (edible peel)

Others

4

             

006 Assorted tropical and sub-tropical fruit (inedible peel)

Banana

8

2

 

1

     

3

Mango

8

 

2

1

     

3

Pineapple

8

   

1

       

Avocado

8

1

 

1

       

Litchi

2

2

 

1

       

Other

2 -4

             

009 Bulb vegetable

Onion

8 (6)

3

   

2

1

   

Leek

4 (4)

   

3

2

 

1

 

Spring onion

4 (4)

2

 

1

     

3

Other

2

             

010 Brassica vegetables

Broccoli

8 (4)

   

2

 

3

1

 

Cauliflower

8 (4)

3

       

1

2

Cabbage

8 (6)

3

 

2

   

1

 

Brussels sprouts

4 (2)

     

1

3

2

 

Other

2 -4

             

011 Fruiting vegetables—cucurbits

Rockmelon (cantaloupe)

8 (6)

2

 

1

     

3

Pumpkins

4

2

 

1

     

3

Watermelon

4

3

 

1

     

2

Cucumber

4 (3)

2

 

1

     

3

Zucchini

4 (3)

             

Other

2 -4

             

012 Fruiting vegetables other than cucurbits

Tomato

8 (6)

3

 

2

   

1

 

Mushrooms

6

             

Capsicum

8 (6)

   

1

   

2

3

Sweet corn

6

1

 

2

   

3

 

Other

4

             

013 Leafy vegetables (including brassica leafy vegetables)

Lettuce (head)

8 (6)

3

 

2

   

1

 

Lettuce (leaf)

8 (6)

3

 

2

   

1

 

Other

4 (2)

             

014 Legume vegetables (succulent seeds and immature pods)

Green bean

8 (4)

   

1

 

2

3

 

Green pea

6 (4)

             

Other

4

             

015 Pulses dry

Lupin

8 (4)

1

       

3

1

Field pea

8 (4)

3

   

2

 

1

 

Soybean

8 (4)

2

 

1

     

3

Chick-pea

4 (2)

             

Faba bean

4 (2)

     

3

 

1

2

Other

4

             

016 Root and tuber vegetables

Potato

8 (6)

     

3

2

1

 

Carrot

8(6)

     

3

 

1

2

Other

4(2)

             

017 Stalk and stem vegetables

Asparagus

4 (2–4)

             

Celery

4 (2–4)

2

 

3

   

1

 

Other

4

   

2

   

1

3

020 Cereal grains

Wheat

12 (8)

2

       

3

1

Barley

8 (4)

3

   

1

   

2

Oats

6 (4)

1

       

3

2

Rice

6 (4)

1

 

3

   

2

 

Sorghum

6 (4)

2

3

1

       

Triticale

4

1

       

3

2

Other

4

             

021 Grasses for sugar or syrup production

Sugarcane

8

   

1

       

022 Tree nuts

Macadamia

6 (4)

2

 

1

       

Almonds

6 (4)

3

   

2

 

1

 

Pecan

4

1

 

2

       

Chestnuts

4

2

       

1

3

Other

2

             

023 Oilseeds

Cotton seed

8 (6)

1

 

2

      <td "=""> 

3

Sunflower

8 (4)

2

 

1

   

3

 

Peanut

8 (4)

2

 

1

     

3

Rape seed (canola)

8 (6)

1

   

3

 

2

 

Other

4 (2–4)

             

024 Seed for beverages and sweets

Coffee

4

             

027 Herbs

Parsley

2

             

Other

2

             

028 Spices

Other

2

             
Table 3: Codex commodity crop groupings

Group name

Important members of group grown in Australia

Possible extrapolation

From

To

001 Citrus fruit

Subgroup 1

Lemon

Lime

Mandarin

Subgroup 2

Grapefruit

Orange

Tangelo

Orange + lemon

or

Orange + lime

or

Orange + mandarin

Whole group

002 Pome fruit

Apple

Crab-apple

Loquat

Nashi pear

Pear

Quince

Apple + pear

Whole group

003 Stone fruit

Subgroup 1

Apricot

Nectarine

Peach

Subgroup 2

Cherry

Plum

Prunes

Peach + nectarine + cherry

or

Peach + plum + cherry

 

Peach

Whole group

 

 

 

Nectarines, plums

004 Berries and other small fruit

Subgroup 1

Blackberries

Boysenberry

Cranberry

Raspberries

Subgroup 2

Blueberry

Currant

Gooseberry

Other

Grapes

Strawberry

Grape + strawberry and one other from subgroups 1 or 2

 

Raspberry

 

Currant

Whole group

 

Subgroup 1

 

Subgroup 2

010 Brassica vegetables

Subgroup 1

Cauliflower

Broccoli

Subgroup 2

Cabbage

Subgroup 3

Brussels sprouts

Cauliflower + cabbage + brussels sprouts

or

Broccoli + cabbage + brussels sprouts

Whole group

011 Fruiting vegetables—cucurbits

Subgroup 1

Cucumber

Choko

Courgette

Bitter melon

Zucchini

Subgroup 2

Melon

Marrow

Pumpkins

Squash

Subgroup 3

Gherkin

Rockmelon + cucumber + zucchini

Melon

Whole group

Subgroup 2

012 Fruiting vegetables other than cucurbits

Subgroup1

Eggplants

Tomato

Subgroup 2

Fungi

Mushrooms

Other

Peppers

Cape gooseberry

Sweet corn

Okra

Roselle

Tomato + capsicum (note it may be more appropriate to generate data as growing patterns and size vary widely)

 

Maize

Whole group

 

 

Sweet corn

013 Leafy vegetables (including brassica leafy vegetables)

Subgroup 1

Lettuce

Mustard

Cress

Subgroup 2

Spinach

Silverbeet

Subgroup 3

Fennel

Subgroup 4

Chinese cabbage

Kale

Leafy lettuce + spinach + Chinese cabbage

Spinach

Celery

Whole group

Subgroup 2

Silverbeet

014 Legume vegetables (succulent seeds and immature pods)

Beans (green)

Peas (green)

Bean (green) + pea (green)

Whole group

015 Pulses (dry)

Peas

Beans

Chick-pea

Lentil

Lupin

Soybean

Field pea (dry) + faba bean (dry) + lupins

Or

Field pea (dry) + chickpea + lupin

Or

Field pea (dry) + navy bean + lupin

Whole group

016 Root and tuber vegetables

Subgroup 1

Carrot

Parsnip

Subgroup 2

Beetroot

Swede

Turnip

Subgroup 3

Sweet potato

Potato

Yam

Subgroup 4

Radish

Horseradish

Subgroup 5

Chicory

Potato + carrot + beetroot

or

Potato + carrot + swede

or

Potato + carrot + radish

Whole group

017 Stalk and stem vegetables

Artichoke

Asparagus

Celery

Witloof

Rhubarb

Celery, asparagus, artichoke

Celery

Whole group

Rhubarb

020 Cereal grains

Subgroup 1

Wheat

Triticale

Cereal rye

Subgroup 2

Barley

Oats

Subgroup 3

Maize

Sorghum

Millet

Subgroup 4

Rice

Wheat + barley + oats

 

Maize + sorghum

 

Rice

 

Wheat or barley

 

 

Wheat

Subgroups 1 and 2

 

Subgroup 3

 

Subgroup 4

 

Oats, rye, triticale, durum wheat (treatments applied before GS32 only)

Whole group except rice for post-harvest treatment only

021 Grasses for sugar or syrup production

Sugarcane

   

022 Tree nuts

Almonds

Cashew

Chestnuts

Hazelnuts

Macadamia

Pecan

Pistachio

Walnuts

Almonds + macadamia

Whole group

023 Oilseeds

Subgroup 1

Mustard seeds

Linseed

Rapeseed (canola)

Subgroup 2

Poppy seed

Safflower seed

Sesame seed

Sunflower seed

Subgroup 3

Peanut

Subgroup 4

Soybean

Subgroup 5

Olive

Subgroup 6

Maize

Subgroup 7

Cotton seed

Canola (safflower, linseed or linola may replace canola in case of winter crops depending on use pattern), cottonseed, peanut (summer crops sunflower, soybean may replace peanuts depending on use pattern)

 

 

 

Rapeseed

Whole group

 

 

 

 

Mustard seed, poppy seed, sesame seed, linseed

024 Seed for beverages and sweets

Coffee

   

027 Herbs

Many

Parsley, mint (extrapolations to a group on a case-by-case basis)

Whole group

028 Spices

Many

Ginger (extrapolations to a group on a case-by-case basis)

Whole group

 

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