Customers will be temporarily limited to two items.

"This will help to maintain availability for all customers," the supermarket said in a statement on Friday.

"Thank you for your patience, we apologise for any inconvenience caused."

Potato farmer Rod Guthrie, from Clarkes Hill in central Victoria, said wet summers had taken a massive toll.

"It all started back in January when we got the floods, it wiped a lot of potato crops out and the tonnage was heavily down for this year," he told 3AW radio.

"It's been an extremely hard year, the tonnages were down and it's been a cold and wet winter too, which doesn't help."

Mr Guthrie said potato farmers in Victoria, NSW and Queensland had yielded about half their usual crops.

He warned the shortages could impact cafes and restaurants as well as supermarkets.

"The supply is not there, it's not going to be on the shelves and at restaurants and I'd say by January there will be no supply around, hardly.

"The crops are down and we're back to about half of the usual tonnage."

Woolworths has not imposed any product limits.

Australian Associated Press