This study was carried out in the shed house of department of Horticulture and Landscape design in College of Agriculture -University of Kirkuk at Shoraw zone, to investigate the effect of two levels of Paclobutrazol ( 0 and 50 ) mg.l-1 by soaking bulbs in the solution of it for (15 minutes) and three levels of P2O5 ( 0 , 100 and 200) kg.h-1 which applied to the soil of the pots, an growth and productivity of two cultivars of (Narcissus spp. ); Tahiti and Salome, which it was grown throw the period of ( October 2013 to April 2014 ).
Results obtained indicated that the bulb’s soaking in 50 mg.l-1 of Paclobutrazol reduce the plant height (33.47) cm, flower’s stalk height (25.58) cm, and reduce from the thickness of flower’s stalk to (1.01) cm compared to control, while Phosphorus levels had no effects on the above characteristics.
Cultivars showed a significant effects, Salome showed greater number of leaves (10.77) leaf per plant than Tahiti, and more height of plant (36. 32) cm, and height of the flower’s stalk (30.86) cm above Tahiti’s variety, while Tahiti gave longer time in vase life (9.57) day than Salome’s variety.
The interaction between cultivars and Paclobutrazol, showed that Salome’s soak in Paclobutrazol gave the higher average for leaves number (10.81) leaf than control’s treatment, the control’s treatment gave the higher average for thickness of the flower’s stalk (1.06) cm, than soak’s treatment, while Tahiti without soaking of Paclobutrazol gave longer time in vase life (9.66) day, the minimum values of height plant (31.27) cm, flower’s stalk height (25.97) cm was determined with Paclobutrazol and Tahiti’s variety. Phosphorus with cultivar gave a significant effect on number of leaves per plant and plant height, at levels of 200 kg P2O5.h-1 gave a higher number of leaves with Salome which reached (11.21) leaf, while control of Phosphorus gave a higher plant height (36.32) cm, while the Tahiti’s flowers remain longer time (9.71) day in 100 kg P2O5.h-1. The interaction between Paclobutrazol and Phosphorus , showed that at bulb soaking at Paclobutrazol and 200 kg P2O5.h-1 gave higher average of leaf’s number reached (11.21) leaf per plant compared with control of Paclobutrazol and Phosphorus, which the control of Paclobutrazol and Phosphorus reduce the height of the plant to (38.30) cm compared with the soaking with Paclobutrazol and control of Phosphorus, also soaking with Paclobutrazol and 100 kg P2O5.h-1led to reduce the height of flower’s stalk to (22.12) cm.The triple interaction between Paclobutrazol, Phosphorus and Cultivar had a significant effects on most characteristics that include in this study, Salome treated with 200 kg P2O5.h-1 and 50 mg.l-1 of Paclobutrazol gave a higher average of leaves number which reached (11.33) leaf per plant, while Tahiti plant height reduced by soaking in Paclobutrazol without Phosphorus application to (29.25) cm, the application of 100 kg P2O5.h-1 without soaking with Paclobutrazol led to reducing the height of flower’s stalk of Tahiti plants (21.48) cm.