Grower trials unusual frost protector

Spraying olive trees with a natural product from sugar beet has successfully stopped some varieties of olive trees in the South Island being knocked by frosts.
Alex Houliston, head of science at Christchurch Girls' High School, took a year off teaching high school to study the frost problem in his own orchard.
Some olive orchards have suffered severe damage when trees four or five years old have been hit by a series of 13degC frosts in recent years.
Mr Houliston sprayed some of his trees with glycine betaine, which is extracted from sugar beet as a by-product of sugar production.
He had heard it could protect plants from metabolic inactivation during environmental stresses -- water deficit, high soil salinity and extreme temperatures such as frost, by changing the speed at which water passed throught the plant's cells.
"We were delighted to find that this product significantly reduced frost damage to my trees," said Mr Houliston who was awarded a technology teaching fellowship at Lincoln University and worked with researchers, Leo Vanhanen and Associate Professor Geoffrey Savage.
It was the first time glycine betaine had been scientifically trialled on New Zealand olives, and was sprayed on trees six times while the olives were ripening.
Both the cultivars used (barnea and manzillo) were protected by the spray, barnea most successfully.