Effect of Nano-Iron and Some Growth Regulators on the Volatile Oil Content of Dill Plants and Its Active Compounds

The experiment was conducted in the field of the Department of Horticulture and Landscape Engineering, College of Agriculture at the University of Babylon, during the 2022-2023 season to study the effect of combinations of growth regulators and nano-iron in the volatile essential oil and its content of active compounds of the dill plant. The experiment was conducted according to the split plate system, with three replicates in each replicate five. Ten treatments. The results were as follows: The treatment (gibberellin 50 and benzyl adenine 25 mg.L -1 ) was significantly excelled in oil density and specific gravity of the oil, and the treatment (gibberellin 50 and benzyl adenine 50 mg.l -1 ) was significantly excelled in the percentage of active compounds in the essential oil (a-phellandrene, p- cymene, limonene, myricetin) compared to the control treatment. The spraying treatment with nano-iron at a concentration of 100 mg.L -1 was significantly excelled in the density of the volatile oil, the specific gravity of the oil, and the active compounds in the oil (a-phellandrene, myricetin) compared to the control treatment. As for the results of the interaction coefficients between the combinations of growth regulators and nano-iron, the treatment (gibberellin 50 mg.L -1 , benzyl adenine 50 mg.L -1 , and nano-iron at a concentration of 50 mg.L -1 ) was significantly excelled and achieved the highest rate of flavonoids (36.304 mg.kg -1 ).), and the amount of active compounds in the volatile oil under study: carvone (63.66%), a-phellandrene (5.71%), p-cymene (3.85%), limonene (21.60%) and myricetin (2.59%). As for the treatment (gibberellin 100 mg L -1 , benzyl adenine 50 mg.L -1 , and nano-iron at a concentration of 100 mg.L -1 ) were significantly excelled in the rate of phenols (0.969 mg.kg -1 ) compared to the control treatment.