Abstract
Root branching in maize (Zea mays L. cv. Pioneer 3558) at harvest stage was examined, with the "branching index" defined as the product of the 'length factor' and 'density factor'. "Branching index" was very effective to characterize the remarkable differences in branching degree of primary roots from different nodes. It was also shown that "branching index" seemed to depend on 'length factor' much rather than 'density factor'. The analysis on the branching degree with reference to primary root diameter suggested a possible relation of 'density factor' to the surface area of primary roots where 1st-order branch roots emerged and that 'length factor' might depend on other factors. And methods for measuring root length were compared with one another. Root length measurements by the root length scanner were quite reliable, based on the assumption that the intersection method would be a standard. The image analyzing system was also useful to measure root length as classified by its diameter.
