The following ethylene sampling protocols have been devised for growers, so that growers can collect and send ethylene samples for each cultivar to the DEDJTR laboratory for analysis. This will greatly reduce the collection and analysis costs for producers and organisations and allow for systematic identification and database building of cultivar maturity classes for use with the DA meter. 'The DA Meter, from theory to practice'.

The following description and videos provide growers with background and clear steps to sampling ethylene.  There are also data sheets for recording important information (see below).

Video: Jason Size, stonefruit producer, discusses the DA meter

Jason Size discusses the DA Meter at Renmark 26 July 2016

Jason Size, manager of Bookpurnomg Fruits, and member of Summerfruits Australia Ltd board, discusses the DA meter use for Stonefruit at a Summerfruit SA meeting in Renmark.

The DA-Meter, from theory to practice

Christine Frisina and Dario Stefanelli.

Introduction to Ethylene Sampling for Optimal Ripening Prediction
DA-Meter technology will increase consumer satisfaction as a result of consistent fruit maturity.
The DA-Meter is a new technology that provides a rapid non-destructive method for assessing fruit maturity from orchard to market. Being non-destructive, the DA-Meter can monitor fruit maturity as it develops in the orchard to predict the optimum harvest date.

It will also be possible to identify different maturity classes to optimize harvest timing to supply local and export markets of choice. Through the maturity classes it will also be possible to optimise the selection of fruit for appropriate markets in the packhouse – that is, the ability to select fruit according to its shelf life potential. Overall, the DA-Meter technology creates increased consumer satisfaction resulting from the supply of fruit with consistent maturity.

The DA technology is based on the measurement of chlorophyll a in the mesocarp of the fruit, just below the skin and correlating this value with the fruit ethylene production rate. The correlation between the IAD and ethylene is variety dependent, but once the correlation is performed correctly, the resulting maturity classes should be independent of factors such as location, agronomical practices and growing season. These factors will influence the date in the growing season at which the fruit will reach a certain value but the relative ethylene production at the specific IADvalue will not change.

Ethylene Sampling Protocol

How to sample ethylene from stonefruit
Equipment

Fruit respiration chambers

Video: Jar Volume determination

Jar Volume determination

Download Worksheet: Jar Volume Determination

Download Datasheet: Ethylene sampling