Control measures for Cercospora beticola Sacco in the past usually have been limited to the application of fungicides either as a dust or spray. The use of fungicides for the control of leaf spot on a commercial basis has not always proved effective, practical and economical in the Upper Mississippi Valley. Because of this fact the problem was approached recently from another angle, namely, the development of leaf spot in relation to modified cultural practices. The modification employed in these studies consists of spacing the plants a greater distance apart within and between' the rows, thereby inducing a change in environmental conditions, which may directly influence the development of the pathogen. This method is in contrast to the standard method of drill-planting and hand-spacing in which the sugar beet plants are thinned 10 to 12 inches apart in drilled rows.