Vineyard equipment developed in France has found an annual place in Blenheim, Marlborough, at Stuart Smith’s Torea Wines.

The Collard pulsed-air system for vine leaf removal was originally designed to defoliate grape vines before harvest.

Stuart Smith says most often, leaf removal is done to allow air to flow around bunches and to expose them to sunlight.

This lowers the risk of botrytis (bunch rot) as the exposed bunches dry out quickly after rain.

“Hand removal of leaves is the traditional method used and works well as the leaves inside the canopy can be targeted.

“Machines have been developed to pluck the leaves off by sucking the leaves into the path of a cutter.

This works well with leaves on the outside of the canopy,” he says, “but doesn’t get the leaves that are in the middle of the canopy and often around or over bunches.”

He says the Collard leaf blower works by delivering a large volume of low pressure air pulses which shatter the leaves while doing little or no damage to the bunches.

“We find it works really well as it takes a lot of the internal leaves out. We use it at the end of flowering to ensure that bunches dry out quickly if we get any rain and this greatly lowers our botrytis risk.”

Stuart Smith says he’s not in the habit of promoting particular brands of vineyard equipment, but says the Collard leaf blower has reduced Torea’s harvesting costs.

“We don’t even own one, we hire one from a contractor,” he says.

“But it is doing the job in a way that’s more like plucking by hand. Most plucking machines tend to take leaves from the outside of the vines but this system gets to the inside as well.”

He says with sauvignon blanc and chardonnay grapes, hand-harvesting the light green-coloured bunches among dense foliage can mean some bunches of grapes can be left on the vine by mistake. This either means sending pickers back to check rows already harvested, or having the grapes rot on the vine.

“And so when it comes to hand-harvesting, having fewer leaves on the vines means its much more likely the entire crop will be taken off first-time.”