NEWS FROM AGRICULTURE AND LIFE SCIENCES DIVISION, LINCOLN UNIVERSITY
By Janette Busch
Olives: a new solution to an old problem?
People don’t like frosty mornings and neither do olives trees.
A perennial problem for New Zealand olive growers is the annual frosts that occur during the ripening season, especially
in the south of the country.
Frosts, while not occurring often, have the potential to damage olives trees; delay olive ripening and cause potential
losses to the industry, for example, in oil production and table olives.
Researchers from the Agriculture and Life Sciences Division at Lincoln University have been successfully using a new
treatment aimed at protecting olives trees from frost damage.
Alex Houliston, Leo Vanhanen and Associate Professor, Geoffrey Savage, who carried out the trial and the subsequent
analysis of the olives and olive oil, used a naturally occurring product (glycine betaine) found in many organisms,
including plants, to spray the trees.
This is done during the cooler temperatures from mid-summer to just prior to harvest in some olive growing areas of New
Zealand.
They didn’t have to look far for an olive grove in which to conduct the experiment, as Mr Houliston, owned a suitable
olive grove in Canterbury and was keen to allow it to be used for research purposes.
“We were delighted to find that this product significantly reduced frost damage to my trees,” said Mr Houliston.
“This was the first time glycine betaine has been scientifically trialled on olives in New Zealand although it has
previously been used successfully on other crops worldwide.”
The experiment was designed to include trees that were sprayed and others that were not (a control group). The olive
trees were sprayed six times while the olives were ripening.
After all the olives were hand picked and measured, the frost damaged and non damaged olives were separated.It was found
that both cultivars used (Barnea and Manzillo) were protected by the spray, Barnea more so than Manzillo.
“Glycine betaine already has a role in body metabolism so the increased levels found in the olives could actually be a
positive feature,” said Vanhanen.
The oil from one kilogram of olives, using the same ripeness and frosted (or not) proportions, and the control oil were
analysed for their fatty acid content. Whole leaves and olives from each sample and control tree were also analysed for
their glycine betaine content.
The current era of olive growing in New Zealand began with plantings of five cultivars by Dr Gideon Blumenfeld in 1986.
Mr Houliston carried out this research while a Science and Technology Teaching Fellow at Lincoln University.
The project was funded by Olives New Zealand (Canterbury Branch) with other funding and supply of glycine betaine by TCL
Marketing Ltd, Christchurch, and Feedworks, Australia.
A fuller description of the research is found in Olivae No. 108, 2007, published by the International Olive Council.
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About the Agriculture and Life Sciences Division
Agriculture and Life Sciences is Lincoln University’s second-largest division, providing teaching and research in a
number of areas including: Animal Science, Farm Management, Horticultural Management; and Food and Wine Science. It has
a number of specialised research units including the Centre for Soil and Environmental Quality; Centre for Viticulture
and Oenology; and Centre for Advanced Computational Solutions. The Division operates its own vineyard, horticultural
research area, winery and nursery, and has three research farms. www.lincoln.ac.nz
ENDS