What are Persephones responsibility?

Persephone is responsible for making the flowers in the spring grow. But, when she was abducted by Hades, she became Queen of the underworld for half the year (or 1 third of the year... not quite determined). After 1 third of the year was over, (or half year) she would rise back up above ground for the remaining 2 thirds of a year (or half year) and greet her parents, Zues and Demeter.