Impact of irrigation water sources on growth and physiological traits in tomato (Solanum lycopersicum)

Abstract

<p>This study examined the effects of tap water (TW), treated wastewater (TWW), and raw wastewater (RWW) on <em>Solanum lycopersicum</em>. Raw wastewater showed high nitrite (42.57 ± 1.78 mg·L⁻¹) and BOD₅ (170 ± 12 mg·L⁻¹) levels. These values were lower in TWW (12.41 ± 0.56 mg·L⁻¹ and 20 ± 4.5 mg·L⁻¹), which met Moroccan irrigation standards. Germination tests revealed higher α-amylase activity and germination index in RWW. This may reflect nutrient enrichment<strong>. </strong>After 90 days, plants irrigated with TWW showed the strongest vegetative growth, with taller stems (57.5 cm) and larger leaves. Microbiological analysis of tomato fruits showed minimal contamination across treatments. Succinate dehydrogenase activity was highest in TW-irrigated plants. This indicated optimal mitochondrial function<strong>. </strong>TWW produced moderate reductions in activity<strong>. </strong>RWW caused marked declines in both leaves and fruits<strong>, </strong>suggesting metabolic inhibition under stress. These findings show that TWW provides a useful balance between nutrient supply and plant health<strong>, </strong>supporting its suitability for sustainable irrigation.</p>