OPTIMAL HANDLING OF BAREROOT PERENNIALS AFTER HARVEST

Abstract

The objective of this research was to investigate factors affecting the survival and regrowth vigor after storage of bareroot perennials. The first experiment was to determine the optimal storage temperature for bareroot regrowth and survival. The treatments were done by collaborators in Holland, where the plants were harvested in November 2004, washed, dried, packed and stored at –0.5, 0, or 2 °C for 6 months. Phlox paniculata `Rowie', Echinacea purpurea `Magnus', Eelleborus orientalis `Tricastin' and Papaver orientalis `Forncett Summer' were evaluated using three replicates per treatment with 18 bareroots per replicate. In Phlox, height, the number of shoots and survival increased as storage temperature decreased from 2 to –0.5 °C. In Papaver, survival decreased as the storage temperature decreased. In the other species the variables were not affected by these temperatures. The second experiment was to evaluate the effect of drying and rehydration on regrowth of bareroot perennials. Bareroots were dried for 0, 2, 4, 8, or 24 hours at 9 °C and 85% RH before storage for 6 months. In each treatment, nine bareroots were planted per replication without preplant soaking and eight bare-roots were pre-plant soaked in water for ten minutes before planting. In Phlox, the pre-plant soaking increased regrowth and survival, but had no effect on Echinacea, Helleborus, and Papaver. For all species, with the limits imposed in these experiments, desiccation had no consistent effect on survival.