Dataset: The effects of water deficiency and the fungus <em>Beauveria bassiana</em> on the bioactivity of <em>Allium cepa</em> (onion) extracts against grapevine mealybug (<em>Planococcus ficus</em>).

This dataset is based on a study that focuses on the singular and interactive effects of <em>Beauveria bassiana</em> inoculum and water stress on plant growth, secondary metabolite contents, and antioxidant and repellent activities of <em>Allium cepa</em> extracts. Plant growth parameters, including weights and bulb circumference, were assessed. Data on secondary metabolites, including volatile constituents and antioxidant and insect-repellent activities of plant extracts, were collected. <br> The study received ethical approval from the Faculty Research Ethics Committee (Reference no. 213119196/06/2019)