PLANT CELL BIOTECHNOLOGY AND MOLECULAR BIOLOGY

The present investigation was conducted at the Experimental Orchard, Department of Horticulture, CCS Haryana Agricultural University, Hisar, Haryana, India, during 2024–25 and 2025–26 to evaluate the influence of pre- and post-planting application of plant growth regulators on bulb sprouting and plant height of tuberose (Polianthes tuberosa L.) cv. Prajwal. The experiment was laid out in a factorial randomised block design. The treatments comprised gibberellic acid (150, 250 and 350 ppm), salicylic acid (150, 250 and 350 ppm) and benzyl adenine (50, 100 and 150 ppm), along with a control. The application methods included bulb dipping, foliar spray and bulb dipping + foliar spray. Among the treatments, GA₃ at 350 ppm recorded the earliest initiation of sprouting (10.56 and 5.78 days) and complete sprouting (33.11 and 21.56 days) in the fresh and ratoon crops, respectively. The maximum bulb sprouting percentage (85.78 and 92.44%) and plant height (79.51 and 74.64 cm) were recorded with salicylic acid at 350 ppm in the fresh and ratoon crops, respectively. Among the application methods, bulb dipping + foliar spray resulted in the earliest sprouting initiation (12.47 and 6.93 days), complete sprouting (35.27 and 22.90 days), maximum bulb sprouting percentage (80.67 and 87.23%) and plant height (76.18 and 71.02 cm) during the fresh and ratoon crops, respectively. The findings indicate that the combined use of 350 ppm GA₃ for sprouting traits and 350 ppm salicylic acid for bulb sprouting percentage and plant height, applied through bulb dipping and foliar spray, improved sprouting behaviour and plant height in tuberose cv. Prajwal.