The objectives of this study were to compare the growth of prairie forb seedlings inoculated with vesicular-arbuscular mycorrhizal (VAM) fungi to noninoculated seedlings transplanted to a highway right-of-way and to evaluate the effect of different VAM fungal species or combinations on posttransplant seedling growth. Four species of prairie forbs: pale-purple coneflower (Echinacea pallida Nutt.), prairie blazingstar (Liatris pycnostachya Michx.), prairie phlox (Phlox pilosa L.), and gray-headed coneflower [Ratibida pinnata (Venten.) Barnh.], were grown in greenhouse mix and inoculated with Gigaspora margarita Becker and Hall, or Glomus interadicies Schenk and Smith, or with a native Indiana prairie soil inoculum, or with a mix of all three. They were transplanted to a highway site in June, 1994. Only gray-headed coneflower exhibited a positive growth response to VAM inoculation. Inoculation of gray-headed coneflower with G. margarita produced the largest growth response by the end of the experiment.
The objective of this study was to determine whether container size or incorporation of water-holding hydrogels in the container medium would affect growth of prairie perennials transplanted on a steep slope. Seedlings of pale-purple coneflower (Echinacea pallida Nutt.), rough blazingstar (Liatris aspera Michx.), gray-headed coneflower [Ratibida pinnata (Venten.) Barnh.], and little bluestem grass [Schizachyrium scoparium (Michx.) Nash.], were grown in 3.7-cm (1.46-inch) diameter tubes that were either 13 cm (5.1 inches) or 18 cm (7.1 inches) long containing either standard greenhouse mix or the mix amended with hydrogels Terra-sorb AG or Liqua-Gel, or a nonhydrogel experimental compound, GLK-8924. The seedlings were transplanted to the slope in May 1994, and harvested in June 1995. After two growing seasons, plants of pale-purple cone-flower and gray-headed coneflower from the longer containers were larger (dry weight) than those from the shorter containers. The blazingstar and little bluestem were unafffected by container size. Terra-sorb AG and Liqua-Gel did not significantly affect height growth of the prairie perennials. GLK-8924-amended medium resulted in smaller or similar height plants.