Farscape - Season 1 Episode 6 -

D'Argo goes into a hyper rage and seeks out Crichton, thinking he left the ship for a nearby planet, he pursues his quarry. The crew then searches for D'Argo. When they find him, they find he has changed. He and the inhabitants work in the fields every day. But the crew soon discovers there's more to the harvested plant than they first thought. The crew has to figure a way to save themselves and the planet.