Effect of certain essential oils and biocides on controlling marjoram root rot and wilt diseases


  • Abdallah A. M. Ali Plant Pathology Department, Faculty of Agriculture and Natural Resources, Aswan University, Aswan, Egypt https://orcid.org/0000-0002-7200-8795
  • Yosra Z. Abo-Shosha Central laboratory of Organic Agriculture, Agricultural Research Centre, Giza, Egypt
  • Mahmoud M. H. Hassanin Ornamental, Medicinal and Aromatic Plant Diseases Research Department, Plant Pathology Research Institute, Agricultural Research Centre, Giza, Egypt




Majorana hortensis, Fusarium oxysporum, Fusarium semitectum, Rhizoctonia solani, Plant Guard, Actamyl 70% wp, thyme oil


The aim of this study was to determine the impact of certain essential oils (eucalyptus and thyme essential oils) and biocides (Plant Guard and Rhizo-N) as fungicidal alternatives for the control of root rot and wilt diseases of marjoram (Majorana hortensis L.) caused by several fungi. Marjoram plants with root rot and wilt symptoms were obtained from Giza, Beni-Suief, and Minia governorates, Egypt. Pathogenicity tests showed that all isolated fungi (Fusarium semitectum, F. solani, F. oxysporum, F. roseum, Rhizoctonia solani, and Macrophomina phaseolina) had the ability to infect plants and seedlings. Fusarium oxysporum, followed by R. solani, was the most pathogenic fungus on the marjoram seedlings, resulting in pre- and post-emergence damping-off. Additionally, the most significant disease incidence percentages on marjoram plants after transplanting were caused by F. oxysporum and F. semitectum. In vitro investigations were performed utilizing eucalyptus and thyme essential oils indicated that the growth of the investigated fungi (F. oxysporum, F. semitectum, and R. solani) was significantly inhibited. However, thyme was the most efficient treatment, especially at a concentration of 6000 ppm, which completely inhibited mycelial growth of R. solani and F. oxysporum. The effectiveness of eucalyptus and thyme essential oils, Plant Guard, Rhizo-N, and Actamyl 70% wp was determined for the control of target diseases under greenhouse conditions. The results showed that all tested treatments significantly reduced the disease incidence caused by the investigated fungi. Actamyl was the most efficient treatment. Thyme oil was an effective treatment against R. solani and F. oxysporum in the second order following Actamyl, whereas Plant Guard was effective against F. semitectum and F. oxysporum. Generally, Plant Guard was the most successful treatment for enhancing plant growth of marjoram plants. These findings demonstrate the potential of applying Plant Guard as an alternate fungicide against wilt and root rot diseases of marjoram plants.


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How to Cite

Ali, A., Abo-Shosha, Y., & Hassanin, M. (2020). Effect of certain essential oils and biocides on controlling marjoram root rot and wilt diseases. Journal of Phytopathology and Disease Management, 7(1), 109–120. https://doi.org/10.5281/zenodo.8422299



Research Articles