Root and Shoot Development in Winter Wheat¹

Abstract

abstract Better characterizations of cereal root systems are needed for water extraction models, for relating root and shoot development, and for describing the root systems of individual tillers. This paper presents a naming system for root axes of wheat ( Triticum aestivum L . em. Thell). Each axis is described by the number of the node with which it is associated and by the direction of its growth with respect to the leaf borne at the node. Plants were grown in the field on a Walla Walla silt loam (coarse‐silty, mixed, mesic family of Typic Haploxerolls). Examination of the upper 10 cm of roots indicated that root axes were produced at predictable times with respect to shoot development. The number of roots on any culm (Y) could be calculated from the number of leaves on the culm (X) (Y = 1.95 X –3.06, r 2 = 0.9). The presence of lateral roots could be predicted if data were plotted to relate root axis development to a phyllochron or degreeday scale.