The Collaborative International Dictionary of English v.0.48:

Seeder \Seed"er\, n.
   One who, or that which, sows or plants seed.
   [1913 Webster]

WordNet (r) 3.0 (2006):

seeder
    n 1: a person who seeds clouds [syn: seeder, cloud seeder]
    2: a mechanical device that sows grass seed or grain evenly over
       the ground
    3: a kitchen utensil that removes seeds from fruit