Phenolic foam rooting matrices allows faster transfer and more rapid growth of Echinacea plants in greenhouse

Abstract

Shoot cultures of Echinacea × Sombrero® “Salsa Red” were rooted in vitro in rigid and flexible film vented vessels, in agar-gelled medium, and in phenolic foam plugs (Oasis® InVitro Express [IVE]). Rooted plants were acclimatized to greenhouse conditions in a peat-based, soilless medium or in a larger cellular plug (Oasis® Rootcubes® Wedge®). The size of the plants leaving the laboratory, the speed of planting in greenhouse medium, and plant growth in greenhouse medium were influenced by both the laboratory and greenhouse media in which they were grown. The largest plants leaving the laboratory were from agar medium. The speed of deflasking and medium removal was greatly improved with IVE replacing agar in laboratory vessels. Planting in the Oasis® Rootcubes® Wedge® allowed a further reduction in planting time compared to planting in peat-based medium. In the greenhouse, plants in IVE/Oasis® Rootcubes® Wedge® grew more quickly and had more leaves of better quality than those from agar, planted in peat-based medium. However, the best plants (based on number of leaves, leaf length, and plug quality) in the greenhouse were from IVE, planted in peat-based medium, a treatment that still required less planting time than agar-based medium. Pre-hardening of in vitro-rooted plantlets using vessel systems that allow for ventilation and easily transferred root systems showed superior greenhouse growth simultaneous with improvements in the efficiency of workers that handled the plants. This is the direct impact of vessel systems and matrix purposefully designed to facilitate this stage of growth.