Windmills protect trees from frost
Two ten-metre high windmills are combatting this month’s frost problems at Mr John Paynter’s Hastings orchard.
The windmills were bought by Mr Paynter in the United States and they were installed just in time for the seven heavy frosts which have hit orchardists this month.
The war against frosts has been waged on the Paynter orchards with oil burners.
Mr Paynter’s family owns land on the west side of St Georges Rd and many of the apple trees are planted in ground that was once a swamp.
“Apples from parts of the orchard have never been exportable quality and this was losing a lot of revenue for us,” Mr Paynter said.
He said the ever-increasing cost of oil, plus the hassle of getting out of bed at an early hour to light smoke pots, prompted investigations into other methods.
Overhead sprinklers were considered but because the land is moist extra water could create problems, such as disease, he said.
A trip to the western seaboard of the United States, particularly the California and Washington States, showed how successful windmills can be.
Orcharding areas in both States have hundreds of windmills. They were first used in the United States in the early 1950’s and have been developed since then.
The propellers on top of the windmill tilt slightly upward and suck warm air from the atmosphere’s inversion layer which is about 15 metres off the ground down in around the trees.
The temperature is then lifted by up to six degrees, making frost damage impossible.
The movement of warm air also creates a temperature balance around the tree, Mr Paynter said.
Power for Mr Paynter‘s wind machines are provided by a 100 hp electric motor but six-litre V8 petrol motors can also be used.
The motor spins at about 600 rpm turning the five-metre-long blades at a fair speed.
The blades are connected to a gearbox which makes a 360-degree turn every four-and-a-half minutes.
Each machine protects a four-hectare block.
The windmills will soon be available from the New Zealand Fruitgrowers’ Federation at a cost of about $12,000.
This might seem a big price but costs are only $8.20 a hectare a night compared with $250 a hectare a night with oil protection.
Interest in Mr Paynter’s machines has been high with several other Hawke’s Bay orchardists contemplating buying a windmill.
Photo caption – Mr John Paynter, St Georges Rd, Hastings, in his orchard. In the background is one of the two ten-metre high windmills which provide frost protection for the trees.