Valorizing treated sludge for sustainable growing media to improve rooting and growth of Co. 1- Gundumalli (Jasminum sambac (L.) Aiton) stem cuttings

The suitability of treated sewage sludge for vegetative propagation of ornamental crops has received little rigorous evaluation. The present study evaluated the physicochemical characteristics of treated sludge (TS) and its potential as a component of growing media for the propagation of Jasminum sambac (L.) Aiton through stem cuttings. Different combinations of organic and inorganic substrates were prepared and compared with TS to assess their effects on rooting and growth of J. sambac semi hardwood stem cuttings. The best results for all growth parameters including earlier sprouting (12.46 days), highest rooting % (86.66 %), number of roots (9.12), root length (12.74 cm), shoot length (21.50 cm) and vigour index (2967.24) were recorded in the combination of vermicompost (VC) + cocopeat (CP) + TS in a 2:1:1 ratio. The highest root fresh weight (11.34 g) and root dry weight (2.32 g) was also detected in this medium, suggesting an optimal nutrient and moisture balance. Based on correlation analysis, nitrogen and phosphorus had strong positive relationship, whereas potassium had weaker but positive relationship with all the physical parameters recorded. This study shows TS as a sustainable and efficient rooting media component when combined with VC and CP, enhancing nutrient utilization, rooting efficiency and seedling vigour in J. sambac cuttings.