The loud clatter of helicopters echoed above some Wairarapa vineyards early yesterday morning as they were used to save budding grapevines from a sharp spring frost.
A long-time Martinborough resident told the Times-Age the noise from the helicopters was so loud that it woke up their household.
“It was still pitch black outside, and it went on for a number of hours.”
Although it’s not unusual for Wairarapa vineyards to experience a cold snap in October, for several of the region’s wineries it was the first time this year the frost-fighting machines had to be deployed to prevent the frost from settling on the vines.
According to MetService, Wairarapa temperatures had plummeted to -0.1 degrees by 2am yesterday.
As a Martinborough viticulturalist explained, frost injury occurs when the plant cells are damaged by ice that can either form on the inside or outside of the cells.
It is often not immediately noticeable when frost has damaged a grapevine, with symptoms of frost injury not showing up until after a number of sunny days.
In spite of the cold snap, Tirohana Estate general manager Toby James said it is an exciting time for winemakers.
“We don’t actually have frost protection – we are very blessed in our location. We get light frosts where we are,” he said.
“The risk of loss without the helicopters and wind machines is horrendous, so everyone embraces them if you’re in the industry for sure,” James said.
More commonly, due to availability and lower cost, many vineyards use frost fans instead of helicopters to draw down the warmer air in the inversion layer to blow it onto the vineyard.
