A potato shortage is rippling through the nation, putting pressure on chip supplies in some supermarkets.

Foodstuffs has confirmed it is "having challenges meeting demand" for potato chips, after recent wet weather dealt a blow to crops.

However, a statement from the company said the shortage would likely last only a few weeks.

"It is anticipated new season crops will be harvested in the next few weeks so supply is likely to settle down then."

SUPPLIED A scene from the movie Mt Zion, starring Australian Idol winner and New Zealand X-Factor judge Stan Walker, right, portraying hard-working potato workers.

The comments come after notices appeared in some Pak'nSave supermarkets, warning customers of "trouble stocking potato chips" due to a nationwide potato shortage.

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The notice said the shortage was likely to last until the new year.

Double Denim marketing co-founder Angela Meyer was "shocked" when she saw the notice in Pak'nSave in Gisborne while on a bevvy and chips run.

She said the shortage could lead to a lot of very disappointed people over the Christmas and New Year period, but there were plenty of chips on the shelves at the moment.

"There did seem to be quite a lot; it was very helpful that they had put the reduced cream there as well, so you could do a quick chip and dip mission."

Potatoes New Zealand chief executive Chris Claridge said there was a shortage of crisping potatoes.

"Potato crisps use a particular cultivar of potatoes and they predominantly are grown in the Horowhenua, Matamata and Pukekohe areas.

"About 15 per cent of the total crop goes into crisping and we've got some shortfalls until the new season crisping potatoes become available to the processors – they should start to get supply around about January [or] February," Claridge said.

Potatoes were grown from Northland to Bluff to ensure year-round supply.

"We're about 20 per cent behind on planting across the country because of the wet weather," Claridge said.

Potatoes New Zealand was exploring ways to mitigate the impacts of climate change.

"You can do that in a number of ways, which is the breeding of the potatoes, the way the potatoes are planted and stored and you have to just be a little bit more careful about the whole thing," Claridge said.

Some brands had "reasonable supply", while others were "struggling", he said.

The availability of potato chips in the lead up to Christmas was dependant on "the rate at which people eat them".

"There may be intermittent shortages as the processors align their supply chains," Claridge said.

Table potatoes were also in short supply.

"There's a difference in the three different crops – processing potatoes for chips, processing potatoes for crisps and then what we call table potatoes," Claridge said.

Pukekohe Vegetable Growers Association president Brent Wilcox said the wet winter had a double-barrelled effect on growers.

"It's been a long wet winter, so it has certainly taken its toll on the crops that have been in the ground but planting the new season's crops has also been held up because it has been so wet.

"I suggest that is going to mean the supply position is going to be quite lean for a few months yet."

Wilcox estimated the loss to growers over the last six months to be in the millions of dollars.

The weather had also taken its toll on growers' morale, he said.

"It puts the stress on financially but also just trying to get things done has been almost impossible.

"There hasn't been a lot of dry breaks where people can actually catch-up. It has been quite demoralising in a lot of ways when you just can't get out and do things, and when you do them, it's not to the standard to get a good job done."

The country suffered a similar shortage in 2014, which was blamed on bad weather affecting crops.

Chips are a popular snack for kiwis, with Potatoes New Zealand reporting New Zealanders spent $157 million on potato chips in 2015 – over $30 per person.

When coupled with the $16m in exports, potato chips made one-fifth of the revenue for New Zealand's potato industry, worth $814m.