Migrant farm workers are taking on one of Australia's richest families, the Smorgons, in what could be the first major strike in the farm sector for many decades.

The workers and a union are seeking better pay and conditions at giant glasshouses north of Adelaide at a company majority owned by a Smorgon-family investment company.

Ejaz Ali, who gave evidence in the Fair Work Commission asking to be allowed to go on strike over conditions at Perfection Fresh in Adelaide Credit:James Elsby

Strikes are almost non-existent in the farm sector, which is overwhelmingly non-union. On Friday, three migrant workers appeared in the Fair Work Commission to argue that they were genuinely representing their co-workers and wanted to strike.

One worker, Ejaz Ali, speaking through a Hazaragi interpreter, said he was representing up to 50 workers and that they were prepared to strike so they "could demand our rights". He said workers "had a lot of differences" with their employer, Perfection Fresh.