Influence of Compost Fertilizer and Gibberellic Acid Priming of Bulbs on the Growth and Flowering of Daffodil (Narcissus tazetta L.) Plants

Supplementing horticultural crops with non-synthetic fertilizers such as compost and plant growth promotors such as gibberellic acid is a promising environment-friendly strategies to enhance the vegetative growth and flowering characteristics of horticultural crops including cut-flowers. This study aimed to find out the effect of soil application of compost fertilizer and bulb priming with gibberellic acid on different plant growth parameters and flowering age of Narcissus daffodil plants. Three levels of compost (0, 15 and 30% of the soil mix) and gibberellic acid (0, 50 and 100 mg L-1) were applied to bulbs of Narcissus tazetta in a pot experiment. Results of the study showed a significant effect of adding compost fertilizer and soaking bulbs with gibberellic acid on all the plant growth parameters and flowering age of daffodil plants. Particularly, 30% compost application and soaking bulbs in 100 mg L-1 gibberellic acid solution exhibited maximum plant height (38.19 and 36.83 cm, respectively), per plant leaf numbers (4.82 and 4.89 leaves, respectively), emergence duration (9.18 and 9.38 days, respectively), leaf length (52.74 and 54.68 cm, respectively) and width (2.31 and 2.35 cm, respectively) and flowering age (15.04 and 13.03 days, respectively) of plants as compared to control and other treatments. Moreover, the binary application of both treatments (30% compost plus 100 mg L-1 gibberellic acid) showed a synergistic effect on all plant growth traits suggesting the incorporation of these non-synthetic fertilizer and plant growth promotors for enhancing the production of N. Tazetta daffodils and other cut-flowers.