Photo: Contributed

A tool that could change how and when Canadian apple growers harvest their crops is being worked on in Summerland.

Agriculture and Agri-Food Canada researchers at the Summerland Research and and Development Centre and in Kentville, N.S., are creating protocols for using the DA Meter, an instrument that takes the guesswork out of apple harvesting.

"You can't judge an apple by its looks. That's why we use an instrument like the DA Meter to help us know what's going on inside the apple," said Dr. Peter Toivonen, who is working on the apple research in Summerland.

Toivonen, whose areas of expertise include quality of fresh-cut fruits and vegetables and energy-saving approaches for storage, has been working on the meter for measuring apple maturity since 2010.

His work has focused on the measuring the maturity of ambrosia apples, but they are developing protocols for other apples as well.

The work is an advancement on traditional testing which involves cutting the apples open and spraying them with iodine.

The iodine reacts with the starch in the fruit and turns black. When an apple is ripe it has very little starch and the iodine creates only a light stain.

The method isn’t very precise and the grower loses fruit with every test, said Toivonen.

"On average, orchardists or field service people might cut five to 10 apples in an orchard to determine how ripe they are and they can lose apples that way," he said.

The DA meter on the other hand has LEDs on the outside of the sensor. When the light from the LEDs shines on the apple, it goes into the fruit and gets reflected back.

The instrument reads the light reflection to measure the chlorophyll content of the apple's peel without damaging the fruit.

This means growers can test the apples right on the tree and leave them on the tree to continue to ripen. Picking the fruit when it's at the correct maturity is important in keeping their quality high throughout the storage season.

"Because it is fast and non-destructive, you can take as many samples from an orchard as you want," said Toivonen.

The research scientist said the work is still in the early stages. They are working with field servics people and imagine it will take them a few years to get comfortable with the meter.

"I'm quite happy with the reliability of the instrument for the ambrosia apple, and I'm quite optimistic," he said.