Assessing the planting material size and light intensity levels for maximization of quality flower production in Heliconia cv. Golden Torch

The cut-flower industry is witnessing rapid growth, with tropical ornamentals such as Heliconia commanding premium value for their vivid inflorescences and long vase life. Among production factors, light environment and propagule size critically influence growth and floral quality, yet their interactive effects remain poorly understood under Indian conditions. This two-year pot experiment (2022-2024) was conducted on the terrace garden of the Department of Floriculture and Landscaping, Faculty of Agricultural Sciences, Siksha ‘O’ Anusandhan University, Bhubaneswar, to evaluate the response of Heliconia psittacorum ‘Golden Torch’ to two light intensities (open sun, 100 %; 50 % shade net) and three rhizome sizes (single-, double- and triple-node cuttings) in a factorial completely randomised design with four replications. Results revealed that full sun accelerated sprouting (17.15 days vs 19.47 days), enhanced vegetative-to-flowering shoot conversion (136.8 % vs 105.1 %) and produced more spikes per clump (3.68 vs 3.30) as compared to 50 % shade net. In contrast, 50 % shade significantly improved floral quality, with longer inflorescences (24.23 vs 19.03 inch), longer stalks (18.30 vs 14.94 inch), higher chlorophyll content (6.82 vs 5.09 mg cm-2) and prolonged spike longevity (16.2 vs 10.3 days) than open sun (100 %). Propagule size strongly influenced performance: triple-node rhizomes (P₃) produced the tallest plants, the largest leaf area (1009 cm²), the maximum spikes (4.66 clump-1) and superior physiological efficiency. Notably, the P₃ rhizome under protected conditions yielded the highest-quality spikes, while double-node rhizome under open conditions promoted earliness and higher spike numbers. The study concluded that growers targeting export markets should adopt 50 % shade with P₃ rhizomes for premium floral quality, whereas full-sun culture with double-node cuttings is better suited for rapid turnover in domestic markets. These findings provide the first evidence-based recommendations for optimizing Heliconia production under coastal Odisha conditions and can guide future commercial scale-up.