Efficacy of Zinc Acetate, Silicon Dioxide, and Their Trichoderma harzianum-Biosynthesized Nanoparticles Against Drechslera teres

This study assessed the antifungal efficacy of zinc acetate, silicon dioxide, and their Trichoderma harzianum-biosynthesized nanoparticles (ZnONPs and SiNPs) against Drechslera teres, the causative agent of net blotch in barley (Hordeum vulgare L.). Transmission electron microscopy (TEM) revealed spherical ZnONPs (1.72–8.64 nm) and SiNPs (9.94–18.24 nm). Energy-dispersive X-ray (EDX) analysis confirmed high purity, with ZnONPs comprising 72.41% Zn and 19.22% O, and SiNPs containing 71.55% Si and 28.45% O. Fourier-transform infrared (FTIR) spectroscopy identified functional groups (Zn-O, Si-O-Si, Si-OH) indicative of fungal biomolecule stabilization. In vitro tests showed zinc acetate completely inhibited mycelial growth at 4000 mg/L, while silicon dioxide achieved 66.27% inhibition at 20,000 mg/L. Field trials (2023–2024 seasons) demonstrated ZnONPs at 800 mg/L reduced disease severity to 8.33–10.42% (86.36% efficacy) and AUDPC to 356.6–743.3, compared to the control (86.71% severity). SiNPs, zinc acetate, and silicon dioxide reduced severity to 15.07–26.73%. Yield parameters improved significantly, with ZnONPs yielding the highest thousand kernel weight (52.27–53.37 g) and grain yield per plot (1.13–1.16 kg) compared to the control (38.64–40.59 g; 0.78–0.80 kg).