Shahid Bahonar University of Kerman and Iranian Biotechnology Society Agricultural Biotechnology Journal 2228-6705 18 4 2026 12 22 Contributing to reducing the damage caused by Fusarium solani that causes rot of wheat seeds and roots using Trichoderma harzianum and gibberellic acid Contributing to reducing the damage caused by Fusarium solani that causes rot of wheat seeds and roots using Trichoderma harzianum and gibberellic acid 511 524 5637 10.22103/jab.2026.27134.1890 FA Mohammed Naithel Radhi Department of Field Crops, College of Agriculture and Marshes, University of Thi-Qar, Thi-Qar, 64001, Iraq. 0000-0002-0681-9610 Journal Article 2026 05 09 ObjectiveThis study evaluated the efficacy of Trichoderma harzianum and gibberellic acid (GA₃) in mitigating the adverse effects of Fusarium solani on growth and yield attributes of wheat (Triticum aestivum L.). The research also examined whether integrating biological control with GA₃ could improve wheat performance under pathogen stress.Materials and methodsThe experiment was carried out in the winter season and the treatments were arranged in a factorial experiment as the presence or absence of T. harzianum and F. solani and four concentrations of gibberellic acid (0, 100, 200, and 300 mg L⁻¹). Parameters related to growth and yield were measured. This included plant height, length of roots, area of leaves, length of spikes, number of tillers per plant, number of grains per spike, and weight of 1000 grains. All data were analyzed statistically using the ANOVA technique. Mean comparisons were made at the 0.05 probability level.ResultsData for most of the traits studied differed significantly (P ≤ 0.05) among treatments. The combined treatment with T. harzianum and gibberellic acid significantly enhanced all the parameters of wheat growth and productivity compared to the untreated plants. Integrated application significantly improved growth and yield traits compared with pathogen-inoculated plants. On the other hand, most of the parameters of growth and yield were significantly reduced when plants were grown in soil infested with F. solani as compared with plants grown in pathogen-free soil, which confirms the deleterious effect of this pathogen. Besides, the T. harzianum treatments ameliorated the adverse effects of pathogen infection and enhanced plant vigor and productivity. The improvement observed reveals an effective interaction between biological control and plant growth regulation in alleviating disease-induced stress.ConclusionThe results prove that the application of T. harzianum with gibberellic acid is effective in reducing the adverse effects of F. solani on wheat. In fact, this treatment improved growth, yield components, and overall plant performance. Therefore, use of T. harzianum in combination with gibberellic acid may be considered a sustainable and environmentally friendly approach to increase wheat productivity under pathogen stress. ObjectiveThis study evaluated the efficacy of Trichoderma harzianum and gibberellic acid (GA₃) in mitigating the adverse effects of Fusarium solani on growth and yield attributes of wheat (Triticum aestivum L.). The research also examined whether integrating biological control with GA₃ could improve wheat performance under pathogen stress.Materials and methodsThe experiment was carried out in the winter season and the treatments were arranged in a factorial experiment as the presence or absence of T. harzianum and F. solani and four concentrations of gibberellic acid (0, 100, 200, and 300 mg L⁻¹). Parameters related to growth and yield were measured. This included plant height, length of roots, area of leaves, length of spikes, number of tillers per plant, number of grains per spike, and weight of 1000 grains. All data were analyzed statistically using the ANOVA technique. Mean comparisons were made at the 0.05 probability level.ResultsData for most of the traits studied differed significantly (P ≤ 0.05) among treatments. The combined treatment with T. harzianum and gibberellic acid significantly enhanced all the parameters of wheat growth and productivity compared to the untreated plants. Integrated application significantly improved growth and yield traits compared with pathogen-inoculated plants. On the other hand, most of the parameters of growth and yield were significantly reduced when plants were grown in soil infested with F. solani as compared with plants grown in pathogen-free soil, which confirms the deleterious effect of this pathogen. Besides, the T. harzianum treatments ameliorated the adverse effects of pathogen infection and enhanced plant vigor and productivity. The improvement observed reveals an effective interaction between biological control and plant growth regulation in alleviating disease-induced stress.ConclusionThe results prove that the application of T. harzianum with gibberellic acid is effective in reducing the adverse effects of F. solani on wheat. In fact, this treatment improved growth, yield components, and overall plant performance. Therefore, use of T. harzianum in combination with gibberellic acid may be considered a sustainable and environmentally friendly approach to increase wheat productivity under pathogen stress. https://jab.uk.ac.ir/article_5637_71d2d6ccac82f8a334937ff0fcdc0d8a.pdf