ROOT-GROWTH OF ECHINOCHLOA-COLONA - EFFECTS OF HEAVY-METALS IN SOLUTION CULTURE

The rate of retardation in the root growth of the germinating seedling s of Echinochloa colona in solution culture was taken as an index to m easure the level of toxicity of copper, nickel, lead, chromium, mercur y, silver, manganese, iron and molybdenum; effective dosage (ED(50)) f or root growth in Echinochloa colona was determined. Phytotoxicity sym ptoms were observed in the plants sowing at high concentrations of met al ions; the toxicity in terms of root growth inhibition was in order of Copper > Nickel > Lead > Chromium > Mercury > Zinc > Silver > Manga nese > Iron; Molybdenum. Effective dosage (ED(50)) for root growth in Echinochloa colona was determined.