Japan, New Zealand's fourth-biggest trading partner, accounted for almost 8 per cent of this country's total exports in the year to June 2011. Exports - mostly aluminium, dairy and forestry products, meat, seafood and vegetables - reached $3.4 billion last year.
Eion Garden, chairman of Silver Fern Farms, said Japan and other Asian countries had been consistently strong markets for the company.
"The exchange rate strengthening in any of our Asian markets is absolutely significant," Gardner said.
Meanwhile, the New Zealand dollar, which was trading at US84.40c against the greenback at 5pm last night, is expected to breach US85c this week.
New Zealand Manufacturers and Exporters Association chief executive John Walley said the kiwi's strength against the US dollar was "clearly a worry".
"The longer it's up there and the longer it stays there, the more difficult it becomes and [exporters] are left with the options of quit, move or hang in there."
Rosewarne said the Government should take action, such as lowering the official cash rate, to weaken the kiwi and give exporters a helping hand.
"There's certainly levers they can pull that would be helpful."