THE INFLUENCE OF AL-MADINAH AL-MUNAWWARA TREATED AND UNTREATED DOMESTIC WASTEWATER ON GROWTH AND PHYSIOLOGY OF THREE TOMATO (LYCOPERSICON ESCULENTUM MILL.) GENOTYPES

摘要

The impact of irrigation with Al-Madinah Al-Munawwara domestic wastewater on three tomato genotypes (AL, P and VF) was investigated. Five treatments including Tap water, untreated (TN), primary (T1), secondary (T2) and tertiary (T3) treated wastewaters were used for irrigation. The physico-chemical characteristics of wastewater were determined. Leaves were analysed for N, P, K and heavy metals (Copper, Cadmium, Lead and Nickel). The growth parameters assessed were % germination, plant height, shoot and root dry weights, and total leaf dry weight. Some physiological parameters such as photosynthetic light response curve, maximum gross photosynthesis ( A max ), dark respiration ( DR ), chlorophyll fluorescence parameters ( Fo , Fm and Fv / Fm ), chlorophyll content index and stomatal conductance were detected. % germination was decreased in both A1 and P genotype, with no effect on VF genotype. Most growth parameters were increased in genotype A1, followed by VF then P genotype which had a sensitive leaf dry weight to T2 and T3. Photosynthesis was mainly increased in A1 genotype with a decrease in VF genotype. DR was negatively affected in VF genotype with no response of A1 genotype. Chlorophyll fluorescence showed an increase in Fo in VF genotype but a decrease in Fv / Fm in both A1 and VF genotypes. Chlorophyll content index was decreased but only in A1 and VF genotypes under TN. Treatment with TN and / or T1 decreased stomatal conductance in all genotypes. The levels of heavy metals in wastewaters used were lower than the standard limits; however, plant chemical analysis showed that the leaves of the three tomato genotypes accumulated heavy metals but differently with higher levels at TN and lower levels at T3.