Efficacy of Dodonaea viscosa Extract and Its Chitosan-Based Nanoparticle Formulation on the Growth of Fusarium Strains and the Production of Deoxynivalenol and Moniliformin in Stored Wheat

<i>Fusarium</i> is considered one of the most important fungi that attack plants and cause serious diseases resulting in huge losses to crops, especially wheat. Fungicides have been used to control it, but they have drawbacks, including residues and toxicity to mammals, which encouraged researchers to find alternatives to these methods and materials. This study was conducted to find natural alternatives to the chemicals used as fungicides. The <i>Dodonaea viscosa</i> plant extract was evaluated as an extract (DVE) and nanoparticles (chitosan NPs loaded with DVE) to inhibit the growth of <i>Fusarium</i> spp. strains and production ability of Deoxynivalenol (DON) and Moniliformin (MON) mycotoxins. The wheat samples were taken from storage in eighteen different governorates in Iraq. <i>Fusarium</i> spp. strains were detected phenotypically, and seven strains were identified by using the polymerase chain reaction technique (PCR) as <i>F. oxysporum</i>, <i>F. pseudograminearum</i> and <i>F. chlamydosporum</i>. DVE effectively inhibited the growth of <i>Fusarium</i> spp. strains at three different concentrations (0.5, 1.0, and 1.5%) on PDA. The highest percentage was 68.94% for <i>F. oxysporum</i> strain 5, and the lowest percentage was 22.58% for <i>F. pseudograminearum</i> strain 6 at a concentration of 1.5%. However, applying chitosan NPs loaded with DVE at a concentration of 0.75% effectively increased the inhibition rate. The treatment of chitosan NPs loaded with DVE played a role in inhibiting the percentage of mycotoxins produced. The highest percentage of inhibition of the DON toxin was recorded as 73.75% in <i>Fusarium pseudograminearum</i> strain 2, and the highest percentage of inhibition of the production of the (MON) toxin was 73.62% in isolate <i>Fusarium chlamydosporum</i> strain 8. Overall, this study highlights for the first time the potential of <i>Dodonaea viscosa</i> nano-formulation to suppress both fungal growth and mycotoxin biosynthesis, providing a sustainable and safe strategy for protecting stored grains.