Several pathogens were known to attack the roots of maize, but their effect was not well understood. These organisms seemed to attack not only singly but in combination with one another and in a certain succession, influenced by environmental conditions.

The present study was undertaken to investigate the relative importance of (a) various pathogens attacking seeds and seedlings in their early stages of development, (b) symptoms manifested by each pathogen singly and in combination, (c) the injuries produced by each pathogen under laboratory, greenhouse and field conditions, and (d) the influence of environmental factors upon the succession of pathogens on the seeds and seedlings.