Effect of Wastewater Irrigation on Tagetes Plants

Field and experimental studies were conducted to determine the effect of some contaminants which reached the water stream from a variety of sources near Ras El-Soda area (Alexandria) on some ornamental crops and on marigold plants. The combined industrial and animal wastes lead to large increase in micro element level in nursery surface soils. Roses, carnations and bird of paradise plants suffered from chlorosis and necrosis. Water samples indicated significant increases in BOD, calcium, sodium, bicarbonate, chloride and COD. Soil samples taken from the area irrigated for 3 years with wastewater contained a higher concentration of K, Fe and Cu. The E.c. value of the soil was increased from 1.7 to 7.0 mmhos/cm. Growth of marigold plants was stimulated by irrigation with water mixture consisting of 35% wastewater +65% tap-water but did not tolerate 100% wastewater treatment and with 100% mortality. Leaves of tagetes plants irrigated with wastewater have similar concentrations of heavy metals as did plants irrigated with wastewater. Heavy metal content of the soil irrigated with wastewater was generally close to that ofthe control (tap water). The E.c. was markedly increased when the soil was irrigated with 100% waste water