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Plant Science Today (PST)

Research Articles

Early Access

Eco-friendly control of zucchini leaf blight disease in the greenhouse

DOI
https://doi.org/10.14719/pst.11831
Submitted
17 September 2025
Published
28-01-2026

Abstract

Leaf blight is one of the diseases prevalent in zucchini fields in Iraq. This study investigated the etiological agent of zucchini leaf blight in agricultural fields across the Erbil, Diyala and Salah Al-Din governorates of Iraq. The fungus Alternaria cucumerina was found to be the predominant cause, with a percentage of appearance reaching 70.7 % in the samples and a frequency rate of 55 %. The Eac-12 strain showed the highest virulence among the 44 fungal isolates, with disease severity reaching 80.5 % under greenhouse conditions. Copper sulphate and neem oil showed 100 % efficacy in inhibiting pathogenic fungal growth in vitro, followed by plant growth-promoting bacteria (PGB), Azotobacter vinelandii and Azospirillum brasilense. In the greenhouse, the dual inoculum treatment of A. brasilense and A. vinelandii isolates significantly reduced disease incidence and severity. The quadruple combination treatment (copper sulphate, neem oil, A. brasilense and A. vinelandii) achieved the highest disease control rate, with disease incidence and severity recorded at 9 % and 4.3 % respectively. This study demonstrated that the rhizobacterial isolates of A. brasilense and A. vinelandii induced disease resistance in zucchini plants through elevated peroxidase levels, as well as the effectiveness of neem oil and copper sulphate in controlling the pathogenic fungus A. cucumerina.

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