Synergistic effect of gibberellic acid and salicylic acid on growth, flowering and yield of French Marigold (Tagetes patula) cv. Pusa Arpita

Abstract

The present study explores the combined effects of gibberellic acid (GA3) and salicylic acid (SA) on the growth, flowering, and yield of French marigold (Tagetes patula cv. Pusa Arpita), conducted during the winter season of 2021-22 at the Horticulture Research
Block, Janta Vedic College, Baraut, Baghpat, Uttar Pradesh. Utilizing a Randomized Block Design (RBD), the experiment included eight treatments, with a control group receiving distilled water, and each treatment was replicated three times. The treatments involved varying concentrations of GA3 (100 ppm and 150 ppm) and SA (150 ppm and 300 ppm), applied both individually and in combination. Results showed significant improvements in growth parameters when GA3 at 150 ppm was combined with SA at 300 ppm, resulting in a plant height of 67.12 cm, a plant spread of 58.14 cm, an average of 17.60 primary branches per plant, 24.45 secondary branches per plant and 310.44 leaves per plant, all significantly higher than the control group. Additionally, this treatment i.e T8 (GA3 150 ppm + SA 300 ppm) led to earlier flowering at 56.30 days to first bloom and an extended flowering duration of 50.20 days, along with improved yield metrics of 150.67 flowers per plant and a total yield of 19.40 tonnes per hectare. These findings indicate that the combined application of GA3 and SA not only enhances vegetative growth but also significantly boosts floral yield, suggesting that these plant growth regulators can greatly improve productivity in French marigold cultivation and highlighting their potential benefits.