GRAPE prices and yield-per-hectare have a greater effect on the financial performance of vineyards than other factors such as mechanisation, according to a new report.

A comparison of production costs in Australia's main inland wine regions - the Murray Valley, Riverina and Riverland - with similar regions in six other countries found, at $5750 a hectare, they were the second highest.

In her report, Davidson Viticulture Consulting Services managing director Di Davidson said the highest-cost region was France ($7562/ha), while the lowest-cost regions were South Africa ($2051-$2251/ha), Argentina ($2354/ha) and Chile ($2480/ha).

Calculated as costs per tonne, Australia's inland growers can grow red wine grapes at $319/tonne, which is cheaper than their peers in France ($1260/t) and California ($339/t) and white varieties at $250/t, which is less than France ($890/t), California ($270/t) and Spain ($268/t).

On a positive note, Ms Davidson said the average quality of fruit from warm irrigated regions of Australia was "consistently higher than from some other countries".

Australian yields varied from 15 tonnes a hectare to 25t/ha, compared to 15-20t/ha in California and South Africa, 10-15t/ha in Chile and Argentina and 12t/ha or less in Spain and France.

But she said technical advances in irrigation and trellising, mechanisation, management efficiency and relatively higher yields, gave Australian growers "no real advantage" over the world's other warm climate regions.

"Indeed, despite differences in labour costs and some differences in vineyard management practices, the same influence on financial performance of vineyards in all countries is grape pricing and the yield per hectare," she said.

"It is apparent that the winegrape industries, particularly in Australia, South Africa and California, are facing major challenges, despite any particular localised strengths, due to low and apparently declining grape prices."

The survey included direct costs such as labour, fertiliser, chemicals, electricity, fuel, repairs and maintenance, but not debt, water purchases, rates or general overheads.

Murray Valley Winegrowers chief executive officer Mike Stone said the report contained no surprises, confirming what most in the industry had long suspected.

The report will be released at the annual What's Going On conference in Mildura this week.