Johannesburg - Recruiting farmworkers to join unions is the only way to advance their interests, the Food and Allied Workers' Union (Fawu) said in a statement on Monday.
Speaking to farmworkers at Ramaphosa village in the Eastern Cape, Fawu general secretary Katishi Masemola said unions were vital.
They had become even more necessary since some farm owners had threatened to retrench workers, claiming they could not afford the new minimum wage.
Labour Minister Mildred Oliphant has increased the new minimum wage for farmworkers to R105 a day from March 1.
The increase followed violent protests by Western Cape farmworkers.
Masemola conceded that profit margins may be low in some sub-sectors of agriculture.
He said Fawu and the Congress of SA Trade Unions would be launching a campaign against retailers, which were profiting the most from agricultural produce and processed products.
Follow Fin24 on Twitter, Facebook, Google+ and Pinterest.