Growing Green Ash and Red Oak in CuCO3-treated Containers Increases Root Regeneration and Shoot Growth Following Transplant

Abstract

Control of green ash ( Fraxinus pennsylvanica Marsh.) and red oak ( Quercus rubra L.) root growth in containers treated with CuCO 3 and its effects on root regeneration following transplant were studied. Root elongation was controlled by applying 100 g CuCO 3 /liter of flat-white exterior acrylic latex paint to the interior surfaces of plastic containers. Plants grown in CuCO 3 -treated containers did not require root-pruning, whereas root-pruning was required to correct root deformations of plants grown in untreated containers. Root pruning removed up to 37% of root dry weight. When plants grown in CuCO 3 -treated containers were transplanted to 45.6-liter containers, root dry weight beyond the original root ball was greater than that of root-pruned seedlings transplanted from untreated containers. Seedlings transplanted from CuCO 3 -treated containers to field plots in July, August, or September showed enhanced shoot growth for two growing seasons compared with root-pruned control seedlings. Seedlings transplanted from CuCO 3 -treated containers appeared to suffer less stress than root-pruned control seedlings transplanted on the same date. Green ash seedlings transplanted in July had greater shoot growth than those transplanted in August and September over two growing seasons.