GROWTH RESPONSE OF Eucalyptus Camaldulensis DHENH. AND Melia Azedarach L. SEEDLINGS TO PRIMARY TREATED WASTEWATER OF AVROCITY IN DUHOK GOVERNORATE

Abstract

An experiment was conducted during April to the beginning of November ,2018, in the lath house of the University of Duhok, College of Agricultural Engineering Sciences, Duhok city. This research was carried out to study the effect of primary treated wastewater (PTWW) of Avro city in Duhok governorate ,Iraq, on Eucalyptus camaldulensis and Melia azedarach one- and two-years old seedlings, and some growth parameters (seedlings biomass, diameter and height) were investigated at the beginning and at the end of the study, the total chlorophyll content measured, ,concentration of (Cd and Cu) and some chemical and physical properties of soil and water were determined. Chlorophyll content show significant effect for PTWW applied on Melia seedlings for both ages and the highest value was 49.90 (SPAD) in Melia seedling of one year irrigated with PTWW. Irrigation with PTWW increased significantly the growth parameters (seedlings height, diameter, and biomass) in Melia. The obtained results show that PTWW effects on the biomass of 1-year old Melia seedlings followed by 2-years old Melia seedlings, while for Eucalyptus, comparable results shown for the 2-years old seedling treated with the both types of water, while for the smaller seedlings (in age) the tap water (TW) was more effective. Concerning the heavy metals, surprisingly, Cu was higher in plants parts irrigated with TW compared with that of PTWW. The highest Cu concentration found in the roots of 2-years old Melia seedlings (23.93 mg.kg-1 d.wt), with the lowest concentration in 1-year old Eucalyptus seedlings (12.02 mg.kg-1 d.wt). In general, highest Cd concentration detected in roots and shoots treated with PTWW, whereas the uppermost (mean) Cd concentration was found in two-years old roots of Eucalyptus seedlings (1.16 mg.kg-1 d.wt) besides the lowest results noted in two- years old shoots of Melia seedlings that stands on (0.20 mg.kg-1 d.wt). As a result, Melia was more resistance to PTWW than Eucalyptus