Response of Gladiolus grandiflorus varieties to planting date: effects on growth, flowering, and vase life.

Gladiolus, a bulbous plant native to South Africa, is known for its vibrant and diverse floral colours. To enhance the growth, flowering, and corm production of gladiolus, it is crucial to identify the optimal planting time suited to the climatic conditions of Jammu and Kashmir, India. The present study investigates the response of Gladiolus grandiflorus varieties to planting date: effects on growth, flowering, and vase life. In Experiment I, early planting on October 15 significantly improved vegetative traits, with the variety 'Oscar' showing superior performance in terms of plant height (129.78 cm), number of leaves per plant (8.96), number of florets per spike (15.22), spike length (93.44 cm), and spike weight. Oscar variety planted in October gave the tallest plant, highest leaf number, and corm yield. Additionally, chlorophyll content was highest in variety 'White Prosperity' (0.92 mg g⁻¹ fresh weight) when planted in October. Experiment II focused on postharvest management, demonstrating that specific holding solutions, particularly sucrose supplemented with acetic acid, significantly increased the vase life of cut spikes, with 'Oscar' achieving a vase life of 12.30 days. The highest water uptake (135.30 mg) was observed in spikes planted in October, and a strong positive correlation was noted between water uptake, electrical conductivity (EC) of the holding solution, and chlorophyll content. In conclusion, it is recommended to plant gladiolus varieties, particularly 'Oscar', in mid-October in Jammu and Kashmir to maximize growth and flowering, and to use sucrose supplemented with acetic acid as a holding solution to extend vase life and improve postharvest quality.