Pilot project gets frost test
The vineyard manager of one of Australia’s most historic wineries remains hopeful that the use of a helicopter to protect fragile vines and grape crops from frost will work.
But Best’s Wines’ Ben Thomson, also the winery’s managing director, said he was unlikely to know for several weeks the level of success of the mitigation efforts.
He said the process, which involved Grampians Helicopters responding to frost conditions by dragging warm air from an inversion layer down to the vines, had undergone a major test in the early hours of Saturday morning.
“It was minus-four degrees and I know pilot Justin Neofitou was working pretty hard in getting the temperature warning lights in the vines to stop flashing. But at daylight there was less frost evident in the vines than in surrounding areas. So I’m unsure,” he said.
“Because the vines are at the early woolly-bud stage, they might be okay but minus four is really low. It’s during the next few weeks as the plants come out more that they will be really susceptible.
“But I’m remaining quietly optimistic. We know this works in other areas, and it is just a matter of how well it works here. It really does depend on inversion layers.”
Grampians Helicopters is working with Best’s at Great Western in an effort to thwart the late-season conditions that devastated the winery’s crops last year.
The businesses have been working for the past five months on a frost-fighting management plan that involves using helicopter downwash to dramatically change air temperature above crops and at ground level. The project involves about 12 hectares of vines.
Helicopter response to a minus-one frost last week was a success but conditions were considerably colder on Saturday morning.
Mr Thomson said he was resigned to enduring ‘six or seven’ weeks of anxiety as the project worked to nurse the vines through an expected tough frost-prone period.
“It’s a bit of a knife-edge during the next couple of weeks – there’s not much moisture in the air. For us, it’s a case of trying to get something from the season. But we’re looking at a high-risk season,” he said.
“We obviously don’t want to lose anything, but if we lost 20 percent and got away with saving 80 percent it would have all been worthwhile. Like I said, I’m remaining optimistic.”
After receiving a weather alert, the helicopter process involves the aircraft hovering above the vines and responding to temperature-sensitive lights on the ground.
An outside temperature gauge on the chopper allows the pilot to find an inversion layer and establish a suitable hover height to drag down warm air.
Last week, with temperatures at minus one at ground level, the temperature in the inversion layer was 12 degrees. On Saturday morning, with temperatures at minus four, warm air in the inversion layer was seven.
Last November’s freakish frost that crippled a variety of crops across the region cost Best’s Wines more than $1-million based on the loss of productivity and potential of premium and speciality wines.