Growers flocked to Te Awa Winery on Tuesday for Fruitfed Supplies' Bird and Pest Control Field Day, where discouraging birds was the focus.
An arsenal was on display at 12 stations amongst the vines.
Field representative Andrew McNeil said most research in New Zealand had concluded that in order to discourage birds "anything other than a net is a waste of time".
"But you ask any grape grower that and they will emphatically deny it," he said.
An orange and-black gun on display that shot Bird Banger and Bird Screamer cartridges, costing about $2 a shot. Ear protection is a necessity.
The Mega Blaster played recorded predator and distressed-bird calls.
"There ares some vineyards in Moteo that have had them for some time.
They rate them quite heavily," Mr McNeill said.
A gas gun provided a double deterrent. As well as the sound and concussion, a Mirror Pyramid rotated and shook as it fired.
The most impressive weapon on display was the Thermal Fogger, which uses the hot exhaust from a pulse jet engine to spread a gas that only birds find irritating.
"The food-grade additive hurts the respiratory passages of the birds.
"You use it as a tool periodically to keep birds out of the vineyard. Smoke comes out initially but all it is doing is charging the air particles. Once it disappears the food-grade additive is still in the air and moves throughout the vineyard.
"The active ingredient is naturally occurring in wine grapes, amongst other food crops," Mr McNeill said.
Starlings, blackbirds, silver eyes, wax eyes and rooks were the main pests.
"Starlings are probably the biggest problem and you only tend to see rooks in Mataphero," he said.
Large birds swallowing whole grapes were preferable to small-bird damage.
"Small birds peck the fruit which induces sour rot," he said.
In answer to a grower's question, if there was scope for a contractor to travel around vineyards discouraging birdlife to save all wineries investing in the same equipment, Mr McNeill gave an emphatic no.
"Birds feed at morning at night and you have to be on site at those key times," he said.
Vineyards had different parameters when discouraging birds.
"There have been some self-imposed restrictions on shooting by a number of wineries that border cycleways and there are council regulations regarding noise close to a boundary," he said.
In his experience white was the best colour for bird netting because it acted as a deterrent.
"Birds can't see black and they tend to land on the cloth and, regardless of whether it is there or not, will peck into the bunch."
The sweeter variates such as pinot gris, chardonnay, sauvignon blanc and, especially gewurztraminer, were targeted, he said.
A vineyard close to the Bridge Pa triangle has six gewurztraminer vines accidently planted in a merlot block with no netting, he said.
"Every year just the gewurztraminer are completely stripped by birds."