Strawberry Growers NZ said although the affected berries were from Australia, farmers here were becoming concerned.
Some of those growers were now looking at adding metal detectors to their production line in a bid to reassure consumers.
Executive manager Michael Ahern said: "Some of our guys, like a week or so ago, have already been hunting for metal detectors.
"But we've got to appreciate this is all from a standing start. You can't go down to The Warehouse and buy one of these things.
"We're not accustomed to this type of challenge to our fruit safety systems.''
About 80 growers were associated with the volunteer industry group but it was estimated there were about 150 strawberry farmers nationwide, not include many smaller businesses.
Ahern said it was important to understand that a lot of strawberry sales in New Zealand were on a personal and intimate level - with sales being carried out at farmers' markets and local areas within communities.
With the season and crop ready in a matter of about two weeks, he said growers were hoping the public would continue to buy the much-loved fruit.
"What really is the question is would consumers be put off by what they're hearing, I guess. And so far not. It's early days, but so far not.
"I'm not too casual about it either," he said.
"We're very worried. There's a lot of money on the line, it's a seasonal business and I guess we're just trying to manage the unknown."
The Ministry for Primary Industries is now also involved in investigations.
EARLIER
Countdown is warning customers to cut up strawberries before eating them after needles were found in fruit bought in an Auckland supermarket.
The supermarket chain has withdrawn the Choice brand strawberries - in which the needles were found - from the shelves at Countdown, SuperValue and FreshChoice outlets.
The Choice brand of strawberries, sourced from Western Australia, were sold nationwide last week.
"Customers can return any Choice brand of strawberries they may have at home to Countdown for peace of mind and a full refund," the supermarket said.
"As an extra precaution and following similar advice from public health authorities in Australia, customers should cut up any Australian strawberries before eating them," it said.
"Countdown is in contact with both New Zealand and Australian authorities as they investigate this matter."
Asked specifically about which Countdown supermarket store the affected strawberries were found at, a spokeswoman would not say.
It is not known either whether the affected punnet was discovered by a member of the public or a staffer.
The spokeswoman told the Herald that apart from this discovery, no other strawberries with needles had been reported across the Countdown store network in New Zealand.
Foodstuffs said last week that it would halt the distribution of Australian strawberries in New Zealand.
