This study was conducted from February 1 to July 1, 2024, in the Nursery of Dohuk University to evaluate the response of two cultivars (Red and Pink) to three concentrations of 2,4-D (0, 200, 400 mg L-1) and NPK fertilizer (0, 150, 300 mg L-1) under the agro-climatic conditions of Kurdistan.
The results indicated that the Pink cultivar showed significantly better responses than the Red cultivar in most of the studied parameters. Spraying the plants with 400 mg L-1 of 2,4-D significantly increased plant height (31.14 cm), growth index (923.8 cm³), vase life (7.14 days), bulb number per plant (6.33), bulb weight per plant (11.76 g), and bulb size per plant (13.78). Meanwhile, spraying with 200 mg L-1 of 2,4-D increased the bulblet size per plant to 7.22. Increasing NPK fertilizer from 0 to 300 mg L-1 significantly increased plant height from 25.65 to 32.75 cm, growth index from 576.7 to 1057.2 cm³, vase life from 6.64 to 7.47 days, bulb number per plant from 5.28 to 6.22, bulblet number per plant from 6.72 to 9.33, bulb weight per plant from 9.15 to 14.34 g, bulblet weight per plant from 4.09 to 6.40 g, bulb size per plant from 10.81 to 14.17, and bulblet size per plant from 5.58 to 8.22. The treatment that resulted in the highest significant values for most of the studied parameters was the combination of the Pink cultivar with 400 mg L-1 of 2,4-D and 300 mg L-1 of NPK, producing the highest bulb number per plant (7.67), bulb weight per plant (17.43 g), bulblet weight per plant (7.99 g), and bulb size per plant (15.67). Moreover, the treatment involving the Red cultivar with the same concentrations of 2,4-D and NPK yielded the highest plant height (35.26 cm) and growth index (1547.1 cm³).
However, the vase life was increased to 8.05 days with the treatment of the Pink cultivar with 400 mg L-1 of 2,4-D and 150 mg L-1 of NPK.
Sadeeq, Janan. (2025). Effect of 2,4-Dichlorophenoxyacetic Acid and NPK fertilizer on the growth and bulb production two cultivars of freesia (Freesia hybrid L.) under-Kurdistan climate. 54. 6110-6116. 10.48047/z9tcmw03.
Source: Research Gate