The Comparative Root Development of Regional Types of Corn 1

T HE root systems of regional types of corn (Zea Mays L.) differing materially aboveground were studied to discover any inherent morphological differences. Investigations during the last four decades by Hays (1), 3 Ten Eyck (6), and Weaver (8) have added much to general knowledge of the root system of corn but did not concern the comparative development of divergent vegetative types. In other species definite differences in root systems have been shown by Mohammad and Deshpande (5) with chillies, by Venkatraman and Vittal (7) with sugar cane seedlings, and by Jean (2) with peas. suggests their possible existence among divergent types of corn. Accordingly, varieties differing materially in mature plant height, number and area of leaves, earliness of maturity, etc., when grown at Lincoln, Nebr., were assembled from various regions. A natural classification grouped the varieties representative of corn adapted to northern, central, and southern areas of the United States into small, medium, and large vegetative types, respectively. The gross morphology of the root systems was studied under normal field conditions, while root weight and volume were determined under pot culture.