Evaluation of the efficacy of β-glucanase and the biopharmaceutical Novo-Treat in the integrated control of Verticillium wilt disease caused by Verticillium dahliae on olive seedlings

• Shifa Ahmed Delf1 and Abdullah Abdulkareem Hassan2

  Author

This study was conducted in the laboratories of the College of Agriculture and the research station of the Plant Protection Department - Tikrit University, which aimed to evaluate the effectiveness of the beta-glucanase and the biopharmaceutical Novo-treat in the integrated control against Verticillium wilt disease on olive seedlings for the 1/10/2025-1/5/2026 season. The initial diagnosis results of the fungi isolated from olive seedlings that showed symptoms of wilt and yellowing infection in Salah Al-Din province showed that the causative agent of the disease is the fungus Verticillium dahlia, which was molecularly identified with 100% conformity to the fungal strains registered in the NCBI gene bank, and the isolate was deposited under accession number PX682723.1. Field application results showed that the treatment (β-glucanase + Novo-treat + Beltanol) for the Nabali olive variety resulted in the highest peroxidase activity, reaching 2.71 units/ml, compared to the lowest activity of 0.12 units/ml in the control treatment for the Ashrasi and Ba'ashiqi varieties. The Nabali olive variety also recorded the highest polyphenol oxidase activity, reaching 2.45 units/ml, compared to the lowest activity of 2.37 units/ml in the Ba'ashiqi control treatment. Interaction results showed that the treatment (β-glucanase + Novo-treat + Beltanol) for the Nabali olive variety resulted in the lowest infection severity of 0.11, compared to the highest infection severity of 0.95 in the pathogen treatment for the Ba'ashiqi variety. The same treatment also showed the highest plant height, number of branches and leaves, leaf area, chlorophyll, and total dry weight for the Nabali olive variety, reaching 72.84 cm, 13.96 branches, 131.05 leaves, 7.45 cm², 33.27 spad., and 24.46 g, respectively. This contrasts with the lowest indicators in the pathogenic fungus-only treatment for the Ba'ashiqi variety, which reached 37.97 cm, 4.74 branches, 3.22 leaves, 3.3 cm², 15.58 spad., and 7.5 g, respectively.

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