Analysing Opportunities and Risks in Utilizing Reverse Osmosis Reject Water for Tomato Cultivation

ABSTRACT Rising global soil salinity has increased freshwater scarcity, driving widespread use of reverse osmosis (RO) systems that generate high total dissolved solids (TDS) wastewater. This study investigated impact of RO reject water (ROR) at 100 mM of NaCl (ROR100) and 150 mM of NaCl (ROR150) treatments on tomato ( Solanum lycopersicum L) growth and yield. ROR treatments significantly reduced shoot (34.83 g) and root (1.65 g) fresh weights, plant moisture (55.85%) and leaf number (9.28) compared to control. However, plant height and stem thickness remained unaffected. Chlorophyll content increased significantly under salinity. ROR100 enhanced fruit minerals including magnesium (19.36%), phosphorus (107.21%), potassium (28.67%), calcium (23.35%), zinc (24.25%) and lycopene (208.18%). ROR150 treatment increased fruit number but reduced fruit weight and significantly decreased in essential nutrients, indicating ionic imbalance and stress. Overall, the ROR100 improved nutrient enrichment and fruit quality, whereas ROR150 impairs nutrient uptake and may induce stress‐related deficiencies. The integration of moderate ROR generated from water purifiers can be used for tomato cultivation if managed well.