Demeter is the goddess of fertility, and grain

Ceres

The Romans didn't have a Demeter per say, however they did have the Goddess of Grain and Agriculture, in the same manner as Demeter was for the Greeks.

Demeter is the Greek goddess of agriculture (particularly grain), fertility, the seasons, and the harvest. She is daughter of Kronos and Rhea, and mother of Persephone. Her symbols are a torch, a sheaf of wheat, or barley.

ceres

Demeter is the great Olympian goddess of agriculture, grain, and bread, the prime sustenance of mankind. She also presided over the foremost of the Mystery Cults which promised its initiates the path to a blessed afterlife.