An "exorbitant" increase in the minimum wage for farmworkers will bring about job losses and mechanisation in the sector, Deputy Agriculture Minister Pieter Mulder said.

He said farmers were ready to limit their reliance on farmworkers, following the recent violent strikes in various farming towns in the Western Cape.

"The current agricultural strikes will change agriculture in South Africa forever," he said at an agriculture day in Willowmore in the Eastern Cape.

Mulder said a reduction in the number of farmworkers over the past seven years was part of an international trend, but the situation in South Africa was compounded by a range of controversial decisions.

Farmworker numbers had decreased from over one million in 2004 to 624,000 in 2011.

"Factors such as land reform, government interference on farms and the general insecurity about the future of agriculture has made this figure in South Africa much higher than the decrease in other countries," Mulder said.

He said the number of jobs lost will speed up as farmers move to mechanisation following the strikes.

"In developed countries such as the USA and Australia, where there are few farmworkers available, farm implements are already so developed that it assists farm owners to manage without hundreds of farmworkers."

Mulder said more than half of commercial farmers in the country had a turnover of less than R300,000.

"With the increasing prices in electricity, water and fuel, farmers cannot afford the sudden increase in labour costs."

Mulder said farmers will be left with two choices: bankruptcy or staff cuts.