Evaluation of seed and seedling response to aid revegetation of hazardous chemical waste sites

The response of several plant species to heavy metal contaminated soils was evaluated using plant bioassays with a soil substrate. A natural soil was collected from Dinwiddie County, Virginia and soil analysis was performed. The plant species, Lolium multiflorum, setaria italica and Trifolium rep ens latum, Robinia pseudoacacia, Andropogon gerardi, Asclepias syriaca, Echinacea purpurea, Rudbeckia hirta and Festuca rubra were grown in to determine the response to cupric and cadmium chloride in soils (mg Cu/kg soil). A few plant species were grown in small pots in a plant growth chamber for 28 days using control, 10, 30, 100 and 300mg Cu or Cd/kg soil. Germination proved to be less sensitive than root length. S. italica had highest ECSOs. In eu 20.7 and 15.3 in Cd. All plant species were grown for 7 days in 0.3, 1.0, 3.0 10.0, and 30.0mg Cu/kg soil and in control. Germination was not effected by metal concentrations in most species (p=0.07-0.6), except T.repens latum, R. hirta and F. rubra at 30mg/kg (p=0.0007). Root length was significantly effected by Cu concentrations for almost all species (p=0.0001-0.0112). Setaria italica had the highest EC50 at 10.86mg/kg. Robinia pseudoacacia root length was not significantly affected by CU concentrations. The other species had EC50s ranging from 3.74-7.51mg/kg. Both inhibition and stimulation of root growth were observed.

Preliminary studies regarding germination rates, fungicides and rangefinding are included.