The industry exports $1.1 billion of wine annually, making it New Zealand's ninth biggest export goods sector, but the currency is doing the sector a lot of damage, he said.
"For me the number one challenge we now face as an industry is the strength of the NZ dollar."
But Smith said that despite the currency, export sales were stronger than ever.
"If they continue at the current rate, I believe we will see some real tension in the supply [and] demand balance in coming months."
New Zealand is the world's 11th biggest wine exporter by volume and 8th by value, with the third largest share of the global super-premium wine market, behind France and Italy, he said.
NZ Winegrowers' chief executive Philip Gregan said the wine industry was in a much better position than it was three years ago, following the bumper 2008 vintage. At that time, a 285,000 tonne crop resulted in a 27-million litre oversupply - eroding wine, land and grape prices.
"We have made a lot of progress with volume and it is now time to address the value challenge," Gregan said.
"What has happened in the last few years, with our supply imbalance, is that New Zealand wine has become cheaper in the New Zealand market place, so it has displaced imported wine - that's the big change."
The wine glut led to the up-rooting of around 500ha of grape vines, out of a total of 33,000ha, over the last two or three years.
Gregan said more vines may need to be pulled out, but only on a small scale.
Gregan also said he expected there to be some consolidation in the industry through mergers and acquisitions.
"I think we will see it among some of the wineries, perhaps some second-tier wineries, with people who want to get economies of scale."
Gregan said economically priced New Zealand wines would be around for some time yet.
"It's not going to end quickly, so we would imagine that we will see a gradual increase in New Zealand wine prices over the next two or three years," he said.