“The farmers are finished,” said Josef Schlaghecken from the service centre for the rural areas of Rhineland-Palatinate where the offending package of rocket salad came from.

Schlaghecken estimates that the farmers have already lost €500,000 in orders. According to state data, the rocket salad industry is worth €10 million.

“The market broke down completely and for the last eight days, there has been no demand for the supply,” Schlaghecken told news agency AFP.

Many farmers had started to specialize in rocket salad, growing with the green’s increasing popularity over the years. But now that farmers are not finding customers for the salad, the harvest is going home with the farmhands. Others are leaving the fields untouched and sending their harvest helpers home.

A week ago, a customer at discount market Plus in Hannover found leaves of senecio, commonly known as ragwort, within a package of rocket salad. The leaves of the plant look similar to the leaves of the rocket plant, but can cause life-threatening liver damage. The customer was fortunate enough to be able to distinguish between the two plants before ingesting it.

After the discovery, Plus and its sister store Netto pulled some 9,000 packages of rocket salad from their shelves and cancelled all further orders from the Rhineland-Palatinate supplier.

The 150-gramme box contained 2,500 microgrammes of ragwort. A University of Bonn botanist told German news magazine Der Spiegel that one microgramme is the maximum amount a person can consume.

Ragwort is a yellow-flowering plant related to the daisy and is commonly found across Germany.