The price of vegetables is expected to jump by up to 50 per cent as catastrophic bushfires destroy crops and shut down highways while growers remain under pressure from ongoing hot and dry conditions.

Key points: James Whiteside, chief of the vegetable industry's peak body, says the prices of "pretty well anything" will go up

James Whiteside, chief of the vegetable industry's peak body, says the prices of "pretty well anything" will go up The price rise will depend on the product and where that fresh food has come from

The price rise will depend on the product and where that fresh food has come from The AUSVEG chief says Queenslanders, in particular, will cop the higher prices

The vegetable industry's peak body, AUSVEG, made the forecast, with chief executive James Whiteside warning that Queenslanders, in particular, would cop the higher prices because so much of the state's produce came from, or through, Victoria and New South Wales.

He said with the Princes Highway shut by the fires, the produce was having to take the long way round to the supermarket shelves — and that added time and cost money.

"That product has to be rerouted through Melbourne and up the Hume Highway, which adds significantly to the time, cost and duration of moving product around," he said.

"That's certainly having an impact on what you're seeing on the supermarket shelves in the northern half of Australia."

Which vegetables will be worst affected?

Mr Whiteside said the prices of "pretty well anything" will go up, including cauliflower, broccoli, green leafy vegetables including rocket and spinaches, and root vegetables such as potatoes and pumpkins.

Australian Country Choice is carting 700,000 litres of water a week to its feedlot in the Lockyer Valley as the region grapples with drought conditions ( Supplied )

"A lot of those products where growers in Queensland have been sourcing out of southern states, which they typically do at this time of year, have been severely impacted," he said.

He said the size of the price rise would depend on the product and where that fresh food had come from.

"I wouldn't be surprised to see prices moving up between 20 per cent and 50 per cent," he said.

"Those sort of larger increases are unlikely to be sustainable, but consumers will see a range of higher prices across pretty well everything."

Who will feel the pinch?

The closure of a critical arterial between Queensland and southern states has been mirrored on the other side of the continent.

The only sealed road connecting Western Australia and South Australia — the Eyre Highway — was closed for 12 days over the New Year period, trapping trucks and travellers on either side of the Nullarbor Plain.

At the time, Adelaide truck driver Glenn Freestone said the closures had "crippled" the transport industry.

"Out of the past month, I've been stuck for 22 days," he said.

Some of the stranded truck drivers had not been home since Boxing Day. ( Supplied: Norseman Police )

The AUSVEG boss said that had to have had an impact.

"There's been some significant disruption there," Mr Whiteside said.

"The Bass and East Gippsland regions (in Victoria) are the ones that have been substantially impacted by interruptions to the supply chains."

And for those relying on Queensland produce, the drought means less produce being sent interstate, so the price of those products is also likely to go up.

"Just this ongoing drought meant that the prospects for the next couple of months to put a product out of the Lockyer Valley and up the Queensland coast — it's likely the volumes will be down if we don't get substantial rainfall for the next six or 12 weeks," Mr Whiteside said.

What can buyers do?

Mr Whiteside said it was important for buyers to understand and appreciate why prices were higher.

The drought in Queensland's Lockyer Valley is also affecting the price of fresh produce ( ABC Rural: Lydia Burton )

He said buyers and sellers both had a role to play in supporting the growers hit by fire and drought.

"Our message to the supermarkets is to try, wherever possible, to shield consumers from higher costs they might be paying, but also to consumers — if you want to help growers, be prepared to pay a slightly higher price because many growers are going through a pretty tough time at the moment," he said.

"It's one way we can all support those growers, to pay a slightly higher price and perhaps accept a quality that isn't quite as fantastic as we're used to."