Kirkuk University Journal for Agricultural Sciences (KUJAS)

The Physiological impact of some plant growth regulators and spraying dates on the vegetative and root characteristics of myrtle (Myrtus communis L.)

https://doi.org/10.58928/ku26.17121
Volume 17, Issue 1
Winter 2026
Page 183-192
Kirkuk University Journal for Agricultural Sciences (KUJAS)

Document Type : Research Paper

Authors

Birgul Hussein AL-Moussawi 1
Kefaia Ghazi AL-saad 2
Mohsin Omer AL-Shwany 3

1 University of Kirkuk / College of agriculture / department of horticulture and landscape design / Iraq / Kirkuk.

2 University of Kirkuk / college of agriculture / department horticulture and landscape design / Iraq/ Kirkuk.

3 University of Kirkuk / College of science / department of chemistry / Iraq / Kirkuk.

Abstract
This study was conducted in the lathhouse of the Department of Horticulture and Landscape Design,College of Agriculture,University of Kirkuk,Agricultural Research and Experiment Station at Al-Sayyada,during the period from Sept ,2024,to July 2025.The aim was to investigate the physiological effects of foliar application of different plant growth regulators,namely benzyl adenine(BA),gibberellic acid(GA₃),and indole-3-butyric acid (IBA),each applied at three concentrations(0,100,and 150mg L⁻¹),at two spraying dates:October1(first date)and November1(second date),with two applications for each date, on selected vegetative and floral traits of myrtle(Myrtus communis L.).The experiment was arranged in a Randomized Complete Block Design(R.C.B.D.)using a split-plot arrangement, with three replications and three plants per experimental unit. Data were analyzed using the SAS statistical software, and mean comparisons were performed using Duncan’s Multiple Range Test at the 5%probability level. The results showed that The growth regulators exhibited differential physiological effects. Foliar spraying with IBA at100 mg L⁻¹ significantly increased the number of roots(34.50 roots)and the length of the primary root(35.50 cm).IBA at150mg L⁻¹ significantly enhanced branch length(21.83 cm)and root dry matter percentage(45.83%).GA₃ at100mg L⁻¹ significantly increased total chlorophyll content(134.35 mg g⁻¹),while GA₃at150mg L⁻¹ significantly enhanced leaf number(604.67 leaves plant⁻¹)compared with the control.Spraying dates had a clear impact,with the first date(October1)being significantly superior for all studied traits.At this date,leaf number reached604.81leaves,branch length 21.57cm,total chlorophyll content141.87mg g⁻¹,root number25.04,primary root length31.19cm,and root dry matter percentage74.36%,compared with the second date(November1).The interaction between growth regulators and spraying dates revealed significant effects. Spraying BA at150mg L⁻¹ on the first date significantly increased branch length(27.50 cm).GA₃at150mg L⁻¹ on the first date significantly enhanced leaf number(682.67 leaves plant⁻¹).IBA at100mg L⁻¹ led to a significant increase in root number(36.00roots at the second date and primary root length(36.33 cm at the first date).Moreover, IBA at150mg L⁻¹ significantly increased total chlorophyll content(158.94 mg g⁻¹)and root dry matter percentage(47%).Overall, these treatments outperformed the control in most measured traits.

Keywords

Myrtus communis L
Plant growth regulators
BA
IBA
Spraying date
vegetative growth
root
Subjects
[1].   SAS Institute. 2002. The SAS system for Windos v. 9.00 SAS Institute Inc., Cary, NC. USA.
[2].   Al-Sultan, S. M., Al-Jalabi, T. M., & Al-Sawwaf, M. D. (1992). Ornamentals. Mosul: Dar Al-Kutub for Printing and Publishing, Ministry of Higher Education and Scientific Research.
[3].   Al Saad, K. G. 2024. Ornametal Plants, First Edition, Ministry of Higher Education and Scientific Research, Kirkuk University, College of Agriculture, ISBN: 978_9922_8376_0_4.
[4].   Boelense, M. H. and Jimenez, R., 1992. The chemical composition of Spanish
[5].   Akalu, N., Endale, A. and Asres, K. 2007.. Evaluation of Antimicrobial Activity of the Essential Oil of Myrtus communis L. and Its Formation into Gum Paint. Ethiopian Pharmaceutical Journal. Vol. 25, No. 1, pp. 72-76.
[6].   Akin, M., Aktumsek, A. and Nostro, A. 2010. Antibacterial activity and composition of the essential oils of Eucalyptus camaldulensis Dehn. and Myrtus communis L. growing in Northern Cyprus. African Journal of Biotechnology. Vol. 9(4), pp. 531-535.
[7].   Sumbul, S., Ahmed, M. A., Asif,  M. and Akhtar, M. 2011.. Myrtus communis Linn. - A review. Ind. J. Nat. Prod. Resources, 2(4): 395-402.Ereeş, F. S., Aközcan, S., Parlak, Y., & Cam, S. (2006). Assessment of dose rates around Manisa (Turkey). Radiation Measures, 41(5), 598-601.‏
[8].   Al-Kahfagi, Huda S. A. R. 2016. The effects of attractants and repelleants for some plants extracts to houseflies Musca domestica ( Diptera : Muscidae)
[9].   Abdel-Rahman, S. S. 2020. Influence of rooting media and indole-3- butyric acid (IBA) concentration on rooting and growth of different types of Conocarpus erectus L. stem cuttings. Scientific Journal of and Flowers Ornamental Plants, 7(3), 199-219
[10].    Mustafa, F. I. and Al-Sayed, H. M. 2021.Growth Biostimulants as Synthetic Hormone Replacements for Rooting, Vegetative Growth and Chemical Constitutions Promotion in Rose Cuttings Under Different Growing Media Assiut Journal of Agricultural Sciences 54(2) (73-90).
[11].    El-Banna, H., Haroun, S. A., Albishi, T. S., Rashed, A. A., Albadrani, M., Abdelaal, K., & Abdou, A. H. 2023. The Natural Alternatives: The Impact of Plant Extracts on Snowbush (Breynia distichForst.) Cuttings’ Morpho-Physiological and Biochemical Characteristics. Horticulturae, 9(10), 1122.
[12].    Mahdi S. M. 2024.The effect of some plant extracts and indole butyric acid on the rooting and growth of cuttings of two population varieties (Punica granatum L.). Master Thesis.University of Karbala - College of Agriculture
[13].    Hassan, E. A. and El-Quesni, F. M. 1989. Application of growth regulators in agriculture. A cytokinininduced new morphogenetic phenomenon in carnation (Dianthus caryophyllus L.). Bull. Fac. Agric, Cairo Univ., 40, 187-196.
[14].    Shudok, K. 1994. Chemistry of Phenylurea Cytokinins. In Cytokinins: Chemistry, activity and function.
[15].    Subbaraj, A. K., Funnell, K. A. & Woolley, D. J.(2010). Dormancy and Flowering are regulated by the recursive in correction between cytokines and gibberellin in Zantedeschia time for a change Trends Genet. (11): 263-268.
[16].    Eraki, M. A. 1994. Effect of benzyl adenine (BA) application on the growth, fruit yield and some chemical constants of Hibiscus sabdariffa L. plants. Minofiya J. Agric. Res., 2, 623-637.
[17].    Al-Zubaidi, M. M. O. and Al-Saad, K. G. S. 2019. Effect of Benzyl Adenine on Growth and Flowering of Some Saffron (Crocus sativus L.) Cultivars J. of Kirkuk Univ. for Agri. Sci.  Vol. (12) No. (2) 2021 Appendix.
[18].    Al-Khafaji, M. A. 2014. Plant Growth Regulators, Their Horticultural Applications and Uses. Ministry of Higher Education and Scientific Research. University of Baghdad. College of Agriculture.
[19].    Taiz, L. and E. Zeiger. 2010. Plant Physiology. Phytochem. Anal. 31(6): 778-785. https://www.sinauer.com/media/wysiwyg/tocs/PlantPhysiology5.pdf.
[20].    Colebrook, E. H., Thomas, S. G., Phillips, A. L. and Hedden, P. 2014.The role of gibberellin signing in plant responses to abiotic stress. J. Exp. Biol. 217(1): 67-75. :https://doi.org/10.1242/jeb.089938
[21].    Li, Z., Pei, X., Yin, S., et al., 2019. Plant hormone treatments to alleviate the effects of salt stress on germination of Betula platyphylla seeds. J. For.Res. 30, 779–787.
[22].    Ahmed, S. B. H., and Al-Saad, K. G. S. 2018. Effect of Thiamine and Gibberellic acid on growth and flowering of Geranium (Pelargonium sp.) College of Agriculture - University of Kirkuk, III. International Scientific Conference for Agricultural Sciences _ p. 425. Iraq.
[23].    El-Yazal, M. A., and Rady, M. M. 2019. Effect of growth regulators on plant growth and development: A review. Journal of Plant Growth Regulation, 38(2), 329-347.
[24].    Taiz, L. and Zeiger, E. 2015. Plant Physiology and Development (6th ed.). Sinauer Associates.
[25].    Davies, P. J. 2010. Plant Hormones: Biosynthesis, Signal Transduction, Action! Springer.
[26].    Al-Saad, K. G. S. 2010. The effect of planting dates, gibberellic acid, and licorice Root extract on growth and yield of ( Gladiolus hybrida ) . PhD thesis. University of Mosul. College of Agriculture and Forestry. Iraq.
[27].    Al-Zubaidi, K. M. D. and Al-Jubory, K. K. A. 2016. Design and Analysis of Genetically Experiments. Dar Al Wadah for Publishing, Jordan, Amman, Dijla Bookshop for Printing, Publishing and Distribution, Iraq – Baghdad.
[28].    Hartmann, H. T., Kester, D. E., Davies, F. T. and Geneve, R. L. 2014. Plant propagation: Principles and practices (8th ed.). Pearson.
[29].    Ali, H. H., Khalaf, J. M. and Noori, A. M. 2024. In vitro Propagation of pomegranate (Punica granatum L). Kirkuk University Journal for Agricultural Sciences. ISSN:2958-6585. https://doi.org/10.58928/ku24.15129.
[30].    Ashraf, A. M., et al. 2022. Auxin-mediated regulation of chlorophyll biosynthesis and photosynthetic performance. Frontiers in Plant Science.
[31].    Niu, Y., et al. 2016. Auxin regulates chloroplast development through gene expression control in Arabidopsis. Journal of Experimental Botany.
[32].    Sharma, N., Singh, K. and Kumar, R. 2018. Effect of auxins on rooting of hardwood cuttings in woody plants: A review. Journal of Pharmacognosy and Phytochemistry, 7(5), 323–329.
[33].    Kamal, T. F., Al-Saad, K. G. and Noori, A. M. 2024. Influence of Auxins and different growth media strength on rooting of Petunia hybrida L. In vitro Propagation. Kirkuk University Journal for Agricultural Sciences. ISSN:2958-6585. https://doi.org. 10.58928/ku24.15315.
[34].    Hartmann, H. T., Kester, D. E., Davies, F. T. and Geneve, R. L. 2011. Plant Propagation: Principles and Practices. 8th ed. Prentice Hall.
[35].    Abdel-Rahman, M., El-Sherif, M. and El-Nashar, Y. 2017. Effect of IBA on rooting and growth of ornamental plants. Journal of Horticultural Science, 89(2), 145-152.
[36].    Abdullah, R., Iqbal, M., Ahmad, I. and Hussain, S. 2020. Auxins mediated root induction and growth responses in ornamental plants. International Journal of Botany Studies, 5(3), 45–52.
[37].    Taiz, L., Zeiger, E., Møller, I. M. and Murphy, A. 2015. Plant physiology and development (6th ed.). Sunderland, MA: Sinauer Associates.

Home

Submit Manuscript

Editorial Board

Aims and Scope

Animal and Ethical Approval

Publication Ethics

Guide for Authors

Guide for Reviewer

Indexing and Abstracting

DOI Use

Generative AI (GenAI) Policy

Data Availability and Reproducibility Policy

Peer Review Process

Copyright Policies

Self Archiving Policy

The Time Period of Reviewing Process

Privacy Statement

Plagiarism Policy

Article Processing Charges (APC)

Reviewers

Contact Us