Effect of the Growth Regulator Gibberellins and Nano Iron Spraying on the Content of Oils, Phenolic Compounds and Flavonoids in the Roots of Fennel Plant

A field experiment was carried out for the autumn season 2021 in Al-Watifia area - Al-Musauib project / Babylon province, with coordinates (longitude (44°22′ and 44°31′ east) and latitudes (32°32′ and 32°36′ north) and in a loamy soil to study gibberellin and spray Nano iron fertilizer in the roots of the local cultivar Foeniculum vulgare Mill. it used 4 levels of gibberellin growth regulator (0, 50, 100, 150 mgm L -1 ) with four levels of nano-iron (0, 25, 50, 75 mgm L -1 ). A factorial experiment was conducted by Randomized Completely Block Design (RCBD) with three replicates, and the averages of parameters compared with the LSD test of 5%. The results indicated that: The treatment of gibberellin growth regulator at a level of 100 mgm L -1 significantly increasing value of root content of the volatile oil Estagole, Carene and - Pinene α gave highest averages amounted to 318.10, 66.16 and 56.50 mg L -1 , respectively. While the treatment of spraying nano iron with a level of (75 mgm L -1 ) was increased and gave the highest averages of 319.67, 65.26 and 47,53 mgm L -1 . In terms of the best interaction treatment between them, the interaction between the two factors (gibberellin at a level of 100 mgm L -1 ) + Iron sprayed at level of 75 mgm L -1 ) was increased and it gave the highest averages of the above oily compounds, which were 488.08, 110.25 and 81.60 mgm L -1 , respectively.As for the roots’ content of phenolic and flavonoid compounds, the concentration of gibberellin (100 mgm L -1 ) was significantly increase in the roots’ content of phenolic and flavonoid compounds Rutin, Eriocitin, and Quercetin, by giving them the highest averages amounted to 74,68, 64,24, 359,35 mgm L -1 , respectively. As for the phenolic compound Ellage acid, it did not differ significantly from the 150 level of gibberellin, as it gave average of 41.97, and the level of 100 mgm L -1 had an average of 41.70, As for iron spray, the level (75 mgm L -1 ) was increasing the roots’ content of phenolic compounds and flavonoids Rutin, Ellage acid, Eriocitin and Quercetin by giving them the highest averages of 74.24, 44.31, 62.67 and 365.60 mgm L -1 , respectively. While the interaction between the two factors (gibberellin at a level of 100 mgm L -1 + iron spray at a level of 75 mgm L -1 ) gave the highest averages of the above phenolic compounds amounting to 89.17, 52.13, 65.32 and 449.33 mgm L -1 , respectively.