Development of a NanoBio Herbicide (Phytotoxic Plant Extract) for controlling Setaria verticillata

Abstract

Modern agricultural systems in the Souf Valley region face increasing challenges due to the spread of weeds, primarily Setaria verticillata, which possesses a remarkable physiological ability to compete with strategic crops and deplete water resources. Despite the historical reliance on manufactured chemical herbicides, field data and farmer surveys have demonstrated their declining effectiveness. The weed exhibits severe cellular resistance to common commercial herbicides (such as Select), particularly in advanced phenological stages (flowering and seed formation), in addition to the environmental risks resulting from their toxic accumulation in permeable desert soils. This study aims to develop a sustainable bio-herbicide alternative by synthesizing a complete plant extract combining Mentha piperite, Rosmarinus officinalis , and Artemisia herb-alba . Chemical analysis revealed a strong synergistic effect of flavonoids, alkaloids, and surfactants in necrosing and killing the weed. To enhance stability and adhesion, the active mixture was loaded onto cellulose nanocrystals (CNCs). The developed bio-nano-herbicide demonstrated superior and sustained field control efficacy with reduced active ingredient dosages. Biological tests have also confirmed the complete safety of the compound and its lack of negative impact on the soil microbiome (bacteria and fungi), thus providing a smart applied model that integrates nanotechnology with agricultural sustainability in arid regions.