Minor spray damage to two Waitaki Valley vineyards has prompted a plea from growers for neighbours to take care when spraying hormone chemicals.
The hormone spray damage has been found in scattered shoots throughout the two vineyards and is not major enough to affect their crops.
However, the Waitaki Valley Wine Growers' Association wants to highlight "the incredible potential for disaster" from a major spray mishap.
Its chairman, Jim Jerram, said yesterday viticulture was relatively new to the Waitaki Valley and had been established alongside traditional irrigated and dryland farming.
"We are here to stay and it's the responsibility of everyone to know the risks from spray," he said.
Neighbours might not be aware of how sensitive vineyards were to spray drift or spray in irrigation water reaching vines, or realise the implications.
"It only takes a few molecules to damage vines from spray that could be five or 10km away," he said.
Dr Jerram said there were "very good" helicopter and ground-based spray contractors within the area, but individuals might underestimate how sensitive vines were to hormone spray damage.
It appeared the spray damage may have occurred about Christmas, but was only discovered recently, when shoots started to show the tell-tale signs in otherwise healthy vineyards.
The potential for damage from sprays was only when vines were growing, from spring to autumn.
When dormant in winter, they were not affected, he said.
Waitaki Valley growers' concerns follow an incident in Cromwell in January, when more than 90ha of vines were affected by chemical spray drifting over 18 properties.
A hormone-based spray, commonly used to kill weeds such as gorse and broom, was thought to have drifted from a nearby rural property.
Members of the Central Otago Winegrowers' Association said damage was minimal, although they warned the incident could have crippled the area's multimillion-dollar wine industry.
