The influence of al-madinah al-munawwara treated and untreated domestic wastewater on growth and physiology of three tomato (lycopersicon esculentum mill.) genotypes

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 (Amax), 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. (author)