The Australian Wine Research Institute

7 October 2025

Are you aiming to ‘rest’ your vineyard block this season by removing yield and reducing water, nutrition and spray inputs? Find out how, when and where you can apply Ethephon for best results and permit compliance.

What is ethephon and how does it work

Ethephon is a plant growth regulator. It can be sprayed on to grapevines in spring to significantly reduce grape yield. It does this by causing undeveloped berries to detach from the rachis.

Application details

Ethephon for bunch removal must be applied in strict accordance with APVMA Permit PER94008.

Timing
	Apply between E-L 25 (80% capfall) and E-L 27 (fruit set: young berries enlarging (>2 mm diameter), bunch at right angles to stem). The most effective fruit removal has been seen from application at E-L 27a. DO NOT apply unless the wind speed is between 3 and 20 kilometres per hour at the application site during the time of application. DO NOT apply in a manner that may cause contamination outside the application site from spray drift. DO NOT apply if heavy rains or storms are forecast within 3 days.
Number of applications
	Up to 2 applications permitted between E-L 25 and E-L 27, at least 7 days apart. It is unlikely that 2 applications will be needed in most circumstances.
Water rate
	Apply at a dilute spray rate to the point of run-off with a non-ionic wetting agent at label rate.
Product label rate
	According to the permit – for 900 g/L Ethephon products, apply at a label rate between 32-104 mL/100 L for 720 g/L Ethephon products, apply at a label rate between 40-130 mL/100 L for 480 g/L Ethephon products, apply at a label rate between 63-190 mL/100 L
Target zone
	Apply to the full canopy unless there is a defined bunch zone where spray application can be targeted to saturate the bunches.
Equipment
	Apply using an air-blast sprayer. Thoroughly clean spray unit after applying Ethephon to ensure all residue is removed before use on non-target vines.
Jurisdiction
	Under the permit, Ethephon may be applied in all Australian states and territories.
Grazing restriction
	Do not graze any vineyard block treated with Ethephon.
Carryover
	Minimal carryover effects on yield were found in the year following that in which one or two Ethephon applications were applied. Effects on other varieties were not measured a.

^a Results of research trials completed across the 2023 and 2025 vintages by the South Australian Research and Development Institute (SARDI) on one block of Shiraz in the Riverland.

More information

• APVMA Permit PER94008 is in force from 21 July 2025 to 31 July 2030.
• SARDI Fact sheet: ‘Resting Vineyards using Ethephon: A Cost-Saving Strategy when Grapes are in Oversupply’.
• AWRI Webinar delivered by Paul Petrie (SARDI): Vineyard Resting – Webinar 
• AWRI helpdesk – call 08 8313 6600, or email helpdesk@awri.com.au.

Acknowledgements
This eBulletin is supported by Wine Australia with levies from Australia’s grapegrowers and winemakers and matching funds from the Australian Government. AWRI is a member of the Wine Innovation Cluster in Adelaide, SA.

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