Effect of water soaking and rooting substrates on the rooting development of salakhani pomegranate hardwood cuttings

Abstract

This study was carried out to evaluated the effects of soaking duration and rooting substrate on the root and shoot development of Salakhani pomegranate hardwood cuttings. The experiment was conducted at Darbandikhan Technical Institute, Sulaimani Polytechnic University, Iraq, from February to June 2025. The results showed that soaking duration had significant effect on rooting percentage, while the highest rooting percentage (60%) was obtained from the non-soaked cuttings, but prolonged soaking (48 h) resulted in the lowest rooting percentage (33.33%). Rooting substrate had a significant impact, with sand showing superior performance (75.56%) compared to the mixture (46.67%) and peat moss alone (20%). Moreover, the interactions between soaking duration and substrate revealed that soaking for 24 hours combined with sand yielded the highest rooting percentage (93.33%), while 48-hour soaking in peat moss led to complete rooting failure (0%). Root length and number were maximized in the 48 h + sand and 48 h + sand/peat moss treatments, while root biomass was highest in the 24 h + sand combination. Shoot characteristics were generally best in the control (0 h soaking), with the highest shoot length, diameter, weight, and chlorophyll content. However, the combination of 48 h soaking and sand/peat moss mixture resulted in the highest shoot length (35.44 cm) and leaf number (122), while 48 h + peat moss treatment suppressed all growth parameters. Consequently, the results suggest that immediate planting in sand or a sand/peat moss mix supports optimal rooting and shoot development.