Sales of some vegetables have soared by up to 300 per cent following moves by a number of New Zealand supermarkets to ditch plastic packaging.

A group of New World supermarkets have abandoned the use of plastic wrapping for virtually all of their fruit and vegetables in a project labelled 'food in the nude'. Pioneered by the New World store at Bishopdale in Christchurch, it has led to stunning sales figures.

"We monitor them year on year and after we introduced the concept we noticed sales of spring onions, for example, had increased by 300 per cent," says Bishopdale owner Nigel Bond. "There may have been other factors at play but we noticed similar increases in other vegetable varieties like silver beet and radishes.

"When we first set up the new shelving our customers were blown away," he says. "It reminded me of when I was a kid going to the fruiterer with my Dad, you could smell the fresh citrus and spring onions. By wrapping products in plastic we sanitise and deprive people of this experience; it (dispensing with plastic) was a huge driver for us."

Bond says he was initially concerned his plans could backfire: "When you take on these projects they can be a disaster and lead to customer pushback but in my 30 years in the supermarket industry this simple change has resulted in the most positive feedback from customers I have ever received."

The initiative is part of the war against plastic. In New Zealand the days of single-use plastic shopping bags are numbered – most supermarkets no longer providing them at the check-out - while the government late last year agreed to regulations for a mandatory phase-out across all retailers from July 1.

Of the 300 million tons of plastic produced worldwide every year, half is used just once and thrown away, while only nine per cent is recycled. In New Zealand about 252,000 tonnes of plastic waste goes into landfill each year, a significant amount also ending up in our waterways and ultimately the sea.

Bond says eight or nine New World supermarkets in the South Island have followed Bishopdale's example, a move which is part of a suite of sustainable practices adopted by New World owner Foodstuffs.

He says he and store manager Gary May first came up with the idea over two years ago: "At the time we noticed an increasing amount of fresh produce was being supplied in plastic wrapping. We thought this was crazy and vowed and declared to do something about it.

"I went on a study tour to the United States and saw what the Whole Foods supermarket chain is doing over there," he says. "They have a massive range of fresh food and their merchandising is almost an art form.

Bond began discussions with growers and suppliers, most of whom he says were happy to look at ways of providing produce free of plastic packaging (Foodstuffs is also continuing to work with suppliers to look at how it can be reduced across-the-board including areas other than produce).

A new refrigeration shelving system for displaying fresh fruit and vegetables was installed along with a process known as 'misting' to help keep items fresh.

"Vegetables are 90 per cent water and studies have shown that misted produce not only looks better, retains its colour and texture, but also has higher vitamin content," Bond says. "We've also installed a reverse osmosis system that treats the water by removing 99 per cent of all bacteria and chlorine, so we are confident the water we're misting with remains pure."

Bond says some produce - including berries, grapes and some tomatoes - still come in plastic containers while mushrooms are packaged in cardboard trays. Most of this packaging is, however, recyclable.

Although many suppliers are reviewing the way produce is packaged, Bond believes manufacturers don't always understand what consumers want: "We know, but we are like an intermediary, we sell what they give us. I think manufacturers have a much bigger part to play."

New World is also trialling another initiative – bring your own containers. The trial, in which customers can use BYO containers for meat and seafood, is under way in a number of stores including Howick in Auckland, Hastings, Levin and Rototuna.

"Take-up has been slow," says Brendon Jones, owner-operator at New World in Howick, "but we're committed to conducting the trial. We have limited it so far to the butchery and seafood counters, where potential food safety risks are reduced because these products are likely to be cooked after being purchased."

He says Foodstuffs is also trialling paper alternatives to foil seafood bags and fibre-based deli trays.

Foodstuffs have signed the NZ Plastic Packaging Declaration which is committed to making all store and private label packaging 100 per cent reusable, recyclable or compostable by 2025. It has also introduced recyclable food trays – a measure that gives customers the opportunity to divert more than 80 million trays from landfill every year.