Bay of Plenty kiwifruit growers that have not harvested are on a weather watch after the recent cold snap.
New Zealand Kiwifruit Growers chairman Doug Brown said two consecutive frosts on Sunday and Monday had sparked concern - with some orchardists using windmills, frost fans and overhead irrigation to combat a freeze.
Frost could shut down the vine, raising the brix levels that could bring on maturity.
A severe frost could burn the leaves off and freeze the kiwifruit, Mr Brown said.
''It's worrying for growers, and I think they will be knocking down the doors of post-harvest companies to get their fruit picked now.''
Welcome Bay kiwifruit grower Mike Smith said his crop was not affected because his orchard was sheltered on an elevated site.
He was trying to get 2.5ha of green kiwifruit picked later this week which could take one to three days depending on the number of kiwifruit pickers and equipment available, he said.
Mr Smith had thought the industry had enough pickers ''but now that everyone wants to pick at once, it remains to be seen''.
Zespri grower and external relations general manager Dave Courtney said the industry was more than halfway through harvest and with full canopies on the vines, there was protection for the fruit.
Zespri had not received reports yet of any substantial damage to crops from the recent frost, he said.
''The colder weather and frost will likely encourage growers who haven't already picked their crop to harvest as soon as possible.''
MetService meteorologist April Clark said that overnight on Sunday the temperature recorded at Tauranga Airport was 3.2C compared with 2.4 C the night before.
But because the reading was taken 1.3m off the ground it was possible temperatures were three degrees cooler at ground level, she said.
Niwa climate scientist Nava Fedaeff said the coldest May temperature of -1.5C was recorded at Tauranga Airport on May 31 in 1941.