Relation of Root and Shoot Morphology of Grass Seedlings

7-49 ABSTRACT Grass seedling establishment is dependent on adventitious root development. However, evaluating the establishment status of a seeding by excavating a population of seedlings and determining root morphology is difficult and generally will not be undertaken. Based on both field and greenhouse studies we have found that root and shoot morphological development is closely related within species, for intermediate wheatgrass, [Thinopyrum intermedium (Host) Barkw. and D.R. Dewey], smooth bromegrass (Bromus inermis Leyss.), switchgrass (Panicum virgatum L.), and big bluestem (Andropogon gerardii Vitman) seedling populations. Easily observable developmental stages of seedling shoots were related to adventitious root development. When the average stage of the population of shoots of these grasses reaches three to four collared leaves for intermediate wheatgrass and smooth bromegrass, first secondary tiller for switchgrass and the four to six collared leaf stage for big bluestem, there was an average of two to three adventitious roots which indicates the onset of seedling establishment.