Tobacco seeds are often pelleted to facilitate precision seeding into float trays. Pelleting consists of the application of solid particles, such as clay, to seeds with a binder in a coating pan or tumbling drum to form spherically shaped dispersal units. One of the several advantages of pelleting is to provide seeds with a vastly enlarged bulk size to ensure proper placement of the seed at the surface of the growing medium.
Caruso, L. V.; Pearce, Robert C.; Gilkinson, B.; and Bush, Lowell P., "Effect of Seed Pellet Modification on Spiral Root Formation of Tobacco Seedlings" (2001). Agronomy Notes. 9.