South Africa raised the minimum wage for farm workers by up to 50 percent on Monday in response to a wave of violent strikes, but farmers said the increase would only cause job losses and more unrest in the major fruit exporter.

Labour minister Mildred Oliphant said the new salary, which has jumped to 105 rand a day ($11.85) from as little as 69 rand, would come into effect on March 1 and would rise by inflation plus 1.5 percent in subsequent years.

The wage review follows clashes in fruit-growing regions of the Western Cape province in December and January between police and striking farm workers demanding their daily pay be more than doubled to 150 rand.

Farm owners, most of whom are from South Africa's white minority, say they cannot afford to pay their mostly black workers more because of the rising costs of fuel and electricity, adding that higher wages may put jobs at risk.

"The minimum wage has been pegged above the affordable level. This is going to have serious negative social economic impact in the agriculture sector," said Johannes Moller, president of industry group Agri SA.

Louis Meintjes, president of farmers group Tau SA, also said the basic salary was too high.

"This is a collective notice by the minister of labour to farm labourers and farmers that from March 1 a lot of people will be out of jobs," he said. "Farmers have no choice but to balance their income and expenditure."

Job losses could spark a repeat of the farm violence in which police were forced to use rubber bullets and stun grenades to disperse protesters blocking highways and torching vineyards and warehouses in the farming belt east of Cape Town.

Oliphant said the relationship between farm owners and workers, which in many cases has changed little in the 19 years since apartheid, had to improve.

"The relationship between farmers and farm workers is difficult and needs to be far better to achieve agricultural expansion, higher employment and better living conditions," she told a news conference in the capital, Pretoria.

The strike in the Western Cape came at the end of a wave of labour unrest that began in South Africa's platinum mines in August and swept through the trucking and agriculture sectors, hitting growth and undermining the country's investment reputation.