The Australian Wine Research Institute

Guidelines for agrochemical registrants 

This page provides information on the data agrochemical companies are advised to provide in order for new active constituents to be considered for inclusion in the AWRI’s Agrochemicals registered for use in Australian viticulture (the ‘Dog book’) as recommended for use on grapes destined for export wine. The required data includes residue data for both grapes and wine, as well as reports on fermentation and wine quality studies completed in the same vintage.

Trial details

Locations

• Data from a minimum of six sites must be provided, covering a range of climates (cool to hot). It is preferred that results come from studies undertaken on Australian sites, but a combination of Australian and overseas data is acceptable.
• A climatic classification of some Australian regions are provided as examples:
  • Cool: Tasmania, Mornington Peninsula, Yarra Valley, Great Southern
  • Warm: Barossa, McLaren Vale, Pyrenees
  • Hot: Riverland, Hunter Valley, Swan Valley, Rutherglen

Varieties

• It is preferred that trials are undertaken on grape varieties that are common to the region where the trial is held. The variety of the grapes does not matter for residue testing but the grapes must come from a wine-grape variety (table grapes are not acceptable).
• It is recommended that one of the six sites represents grapes destined for sparkling wine that are harvested at a lower ripeness (16–19.5°Brix).

Treatments

• At each of the six test sites there should be a control (untreated) and a treated sample.
• The treatments should be applied according to the directions that will be on the label (e.g. rate, maximum number of applications).
  • The final application must be applied at the withholding period (WHP) that the registrant feels will yield the appropriate residues to satisfy export markets that do not have a maximum residue limit (MRL). In most cases, this will be a non-detectable residue. For instance, if growth stage E-L 31 (berries pea-size, 7 mm diameter) is the label WHP, the last application at each of the six sites would be E-L 31.
  • If the registrant is unsure and wants to investigate the residue levels at different withholding periods, then additional treatments will need to be applied and tested for residues.
• At two of the six test sites, an additional treatment is required. This treatment has the product applied according to label directions but at twice the label rate. Samples from these sites should be red grape varieties, as this ensures the best quality results from the study.
  • This treatment should provide samples containing higher levels of residues than typically expected. This study is used to confirm that at higher residue levels there will be no effect on wine quality.

Analysis

Agrochemical residue data

Samples from all treatments from each of the six sites should be submitted for processing studies involving residue analysis of both grapes and wine.

This is to provide wineries data about:

• a WHP that results in no quantifiable residue in wine
• degradation of the active constituent through the winemaking process (processing factor) where residues are detected in grapes.

Note: Some regulatory authorities may require residue data on samples of juice and pomace (recycled for animal feed). Consideration may need to be given to the inclusion of these commodities when establishing the study protocol.

Fermentation and wine quality studies

• Fermentation and wine quality studies are to be performed independently of residue studies, to provide the wine industry with the knowledge and assurance that the active constituent or product is not going to have a detrimental effect on fermentation or wine quality. Such an effect could include the formation of off-flavours or aromas due to the breakdown of the active constituent itself.
• The winemaking protocol followed for these studies should reflect that of processing red varieties into wine, considered the worse-case-scenario for residues due to the skin contact employed in the process. This technique is not suitable for white grape varieties and tends to make wines which are quite unpalatable and not suitable for the sensory component of the study. Hence, it is strongly recommended that these studies are conducted with red wine-grape varieties.
• Sample requirements
  1. samples should be taken from both sites where 2 x label rate applications have been implemented. If no detectable residues are present in the samples, the study can still proceed based on the possibility that the active constituent may have been converted to a secondary metabolite or broken down to another compound which may affect fermentation or wine quality.
  2. fruit condition must be sound as wine made from spoiled, mouldy or unripe fruit will not be suitable for a fermentation or wine quality assessment
  3. grapes should be harvested at commercial quality or ripeness (21–26°Brix) and it is recommended that a °Brix reading be taken prior to harvest. Ideally, the fruit should be at a similar level of maturity (based on °Brix) across the different treatments. It is strongly advised that samples be frozen as soon as possible after harvest, as these studies rely heavily on good fruit quality to ensure the best outcome.
  4. a minimum of 25 kg of grapes must be harvested per sample or treatment.
• AWRI’s commercial arm, Affinity Labs, offers fermentation and wine quality studies as a service. Companies intending to undertake a fermentation and wine quality study with a service provider other than Affinity Labs, are advised to contact AWRI prior to commencing the trial to discuss the protocol to ensure the study is sufficiently comprehensive and its conclusions can be relied upon.

Summary of trial sites and minimum required analysis

The following table summarises the minimum sample and analysis requirements to be provided to AWRI for review.

Trial site	Minimum treatments			Residue analysis		Fermentation study	Wine quality study
	Control	Label rate treatment at recommended WHP	2 x Label rate treatment at recommended WHP	Grapes	Wine
1*	Yes	Yes	Yes	Yes	Yes	Yes	Yes
2*	Yes	Yes	Yes	Yes	Yes	Yes	Yes
3	Yes	Yes	No	Yes	Yes	No	No
4	Yes	Yes	No	Yes	Yes	No	No
5	Yes	Yes	No	Yes	Yes	No	No
6	Yes	Yes	No	Yes	Yes	No	No

*It is strongly recommended that these trials are conducted with red wine-grape varieties.