Hormonal modulation of growth and metabolite dynamics in Saffron (Crocus sativus) under innovative cultivation system

Saffron (Crocus sativus L.) production is limited by land availability and climatic conditions, highlighting the need for innovative cultivation systems. The effects of three plant growth regulators, i.e., kinetin (1 ppm), gibberellic acid (GA₃, 50 ppm), and abscisic acid (ABA, 1.5 ppm), were assessed in controlled cultivation systems over two seasons (2022–2023) at Sher-e-Kashmir University of Agricultural Sciences and Technology, Jammu, India, with field-grown controls from Pampore (Kashmir) and Kishtwar. Key parameters were grouped into vegetative growth (leaf number and plant height), floral yield (flower fresh weight and dry stigma yield per 100 corms), and quality indices. Secondary metabolites were evaluated both qualitatively and quantitatively: crocin and picrocrocin contents were determined using UV–visible spectrophotometry at their respective absorption maxima, while antioxidant activity was estimated by the DPPH radical scavenging assay (IC₅₀ values). Kinetin performed comparably to or better than field controls in leaf production (21.0 vs. 22.2–23.0), stigma yield (7.65 g vs. 6.63–6.67 g), and crocin content (17.4 % vs. 14.7–16.5 %), while GA₃ enhanced shoot length (23.7 cm vs. 24.9–27.1 cm) and flower weight (404.6 mg vs. 391.7–427.5 mg). ABA was ineffective or inhibitory for most parameters. Principal component analysis grouped kinetin and GA₃ treatments with high-performing field controls, confirming their effectiveness in promoting both growth and quality. These results indicate that kinetin (1 ppm) enhances saffron quality through improved metabolite accumulation, while GA₃ (50 ppm) optimizes growth and yield. This study demonstrates that hormonal modulation in innovative cultivation systems can enable high-value, year-round saffron production in non-traditional areas, contributing to climate-resilient crop production.