Abstract
SUMMARY: Azospirillum brasilense Cd, when inoculated onto wheat roots, multiplied and formed aggregates on the root surfaces and established an internal root population. Washing the roots removed most of the external but not the internal bacterial population. Killing the bacteria before or after their interaction with the roots eliminated the adsorbed bacteria from the root surface. The external adsorption of A. brasilense to wheat roots can be categorized as a weak active process.