Labour unrest affecting farms in the Western Cape was a political problem rather than a wage dispute, the Transvaal Agricultural Union (Tau-SA) said on Thursday.
"We have evidence that people are bused to the violence-stricken areas, where they go on a rampage," Tau-SA president Louis Meintjes wrote in a letter to President Jacob Zuma.
"We believe this is for political purposes, to destabilise the province, because the ANC is not the ruling party in that province.
"However, all these people are dissatisfied because you and your government, as part of the ruling party, made promises of housing, service delivery and job creation."
Tau-SA demanded compensation for property damaged during the strike.
It also wanted the government to protect farmers, farmworkers, and farm property from violence, including farm murders, to exclude farmers from toll fees, and to stop water pollution.
"We demand a lowering of Eskom electricity tariffs. We demand roads without potholes. We demand an end to BEE [Black Economic Empowerment]," the union said.
The Federation of Unions of SA (Fedusa) condemned the violence linked to the farmworkers' strike.
"We condemn in the strongest terms these acts of violence," said Fedusa general secretary Dennis George.
"While we support the right to strike as an important tool in the hands of workers, Fedusa firmly believes in positive labour relations and constructive engagements."
A farmworker was killed in Wolseley in the Western Cape, and looting and gunfire was been reported.
George said violence and killing was deplorable, and was ineffective and unnecessary.
Employers and the government needed to use dispute resolution processes provided for in labour legislation, such as the Commission for Conciliation, Mediation and Arbitration (CCMA), bargaining councils and the Labour Court.
"The levels of violence that seem to have become a standard in wage talks during the past months are totally unacceptable," said George.
Fedusa and other trade unions met President Jacob Zuma last month to commit to a constructive industrial relations environment, he said.