The Central Otago Winegrowers Association (COWA) has launched a campaign urging farmers and orchardists to consider their neighbours before spraying chemicals.
A serious spray drift, like the incident in Hawkes Bay in October, would be the final straw, COWA committee member James Dicey said.
''The industry is going through a tough time and it would be enough to put a few people under.
''If a serious spray incident occurred, it could bankrupt a number of growers here.''
The crop on 6ha of Hawkes Bay vineyards, worth $200,000, was destroyed in October by a drift of herbicide spray containing 2,4-D. There are no restrictions on the use of the weedkiller.
If the vines do not recover and have to be pulled out, losses are estimated at millions of dollars.
''Our campaign is aimed at preventing something similar happening here. We've already had a close call,'' Mr Dicey said.
Cromwell basin grapegrowers narrowly escaped disaster when vines on 18 properties were affected by chemical spray drift last January.
It is believed a hormone-based spray commonly used to kill weeds such as gorse and broom drifted over the vineyards.
The damage was minimal, but grapevines were particularly sensitive to hormone-based sprays and such an incident had the potential to cripple the area's multimillion-dollar wine industry, Mr Dicey said.
''That was a hugely close call and we were very lucky not to have sustained significant damage.
''However, it did put vines about half a year behind and if we had found the person responsible for the spray drift, we would have sued them, '' he said.
Vines were most vulnerable when in leaf, so the campaign focused on the period from September through to May.
The association was asking rural property owners to consider whether it was necessary to use any chemical sprays during those months and if it was, then to take all possible precautions to prevent spray drift.
''Grapes are particularly sensitive to three types of herbicide - glyphosate, sulfonylurea and growth regulators - so we'd like people to use another chemical, if there are valid alternatives.
''If they can't do that, we'd like them to choose something that's less likely to damage the environment we're in.
If they do not have a choice, we'd like them to avoid using chemicals anywhere near grapevines and abide by the exclusion zones,'' Mr Dicey said.
''We support people's right to farm and use agrichemicals, but we're asking for it to be done responsibly, remembering the consequences for their neighbours can be highly significant.''
Spray drift could travel a long way from its source, he said.
