After surviving years of drought and destructive floods Australian potato growers are now battling a crop price cut by McCain foods, reported the Herald Sun.

Ballarat potato growers drove 50 tractors to the McCain factory in Wendouree, Victoria, yesterday to protest a reduction of almost 20 per cent in the price they would receive for their crop.

The picket line blocked loads of potatoes heading to the factory and the growers are said to have convinced 17 South Australian suppliers to boycott McCain.

McCain has cut contracts by $26.50 a tonne in Victoria which will reduce growers pay from $300 to $273.50 per tonne.

Grower representative, Ross Dimond, said although it was an "ugly" way to do business there were no negotiations and a reduction would threaten their livelihood.

"McCain just delivered its price, which for many of us will be a death sentence for our businesses," Mr Dimond said.

"It is a travesty and comes at a time when Simplot in Tasmania has increased its potato payments to growers," he said.

The Ballarat potato industry is worth about $20 million, most of which is poured back into the local community.