Chopper to help fight frost threat

AGrampians helicopter business has joined forces with one of Australia’s most historic wineries in an effort to protect fragile vines and grape crops from frost this spring.

Grampians Helicopters is working with Best’s Wines at Great Western in a concerted and integrated 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 a helicopter’s downwash to dramatically change air temperature above crops and at ground level.

Winegrowers have used helicopters for frost mitigation in other parts of Australia and around the world but this is the first time it will occur as part of a comprehensive plan in the Grampians.

Best’s Wines managing director and vineyard manager Ben Thomson said the dramatic move, which has involved installing a temperature-sensitive lighting system throughout about 12 hectares of vineyard, had been a necessity.

He revealed last November’s freakish frost that crippled a variety of crops across the region had cost Best’s Wines more than $1-million based on the loss of productivity and potential of premium and speciality wines. He said it was an impact the winery was set to experience for several years.

“There’s not much else we can try. We don’t have the water to use sprinklers to battle the effects of frost and this is the next best thing. It would be pretty devastating to be wiped out two years in a row,” he said.

“It’s an expensive exercise but if in doing this you can save your crop it’s worth it.

“We’re on tenterhooks from now until into November. Because last year’s frost was so late, we didn’t get as much wood growth on the canes and canopy so our pruning material is thin and spindly, which is far from ideal. The reality is that at this stage, with vines only starting to bud now, we’re unsure how well they are going to come back and how much damage is going to carry over.

“Hopefully this works.”

Ravaged vines

All new growth on grape vines is vulnerable to frost and growers usually plan for some seasonal loss due to weather conditions. But last year’s event ravaged vines and crops.

The concept of using a helicopter involves raising air temperature by dragging warm air from an inversion layer above crops and preventing cold air from ‘ponding’ by keeping it moving.

The pilot, in this case Grampians Helicopters pilot Justin Neofitou, after getting airborne, will hover above the vines, and guide his craft under direction from temperature-sensitive lights on the ground. The process also involves Mr Neofitou using an outside temperature gauge on the aircraft to find the inversion layer and establish a suitable hover height to drag down warm air.

Circumstances required Civil Aviation Safety Authority certification and Grampians Helicopters had the final sign-off last week.

Mr Neofitou said the helicopter would be on standby to quickly respond to indications of a heavy frost at the vineyard.

“When the situation arises I’ll wait for Ben to give me a call and we’ll zoom out and fire up the helicopter,” he said.

“Then it will be a case of chasing lights on the ground.”

Mr Neofitou said the helicopter would also be heavily weighted to maximise the amount of air it pushed to the ground.

Mr Thomson said the problem with last year’s frost was that the inversion layer was too high for frost fans installed among the vines to be effective.

“We’re hoping the helicopter will push the warmer air down to the frost fans and out to the extremities. It is all going to be trial and error,” he said.

“When the temperature is one to three degrees the lights are green. From zero to one they are white and from minus one to zero they are red. When it gets below minus one they are red and start to flash.”

The helicopter pilot then follows the lights accordingly, rounding up cold areas similar to a sheepdog responding to a moving mob of sheep.

Mr Neofitou said the procedure had been successful around the world and in Australia for other produce as well as grapes and suggested it might also work on frost-sensitive broadacre crops such as lentils and peas.

He added that he was glad to be involved considering his tour and joy-flight business also relied on the health of Grampians wines.