Environmentally friendly weed control in tomato using amine-grafted silica microparticles for strigolactone adsorption

The root holoparasitic plant Phelipanche aegyptiaca (broomrape) severely reduces crop productivity by attaching to host roots and diverting nutrients. Broomrape seed germination is triggered by root-exuded strigolactones, making early control challenging. Conventional management relies on sulfonylurea herbicides, which pose environmental risks due to leaching and non-target toxicity. Here, we developed eco-friendly silica particles (Si-μL) grafted with 3-aminopropyltriethoxysilane (APTES) (Si-μL@APTES) to adsorb strigolactones in the rhizosphere, disrupting host-parasite signaling, while the selected large particles showed no detectable negative effect on tomato growth or CO₂-based microbial respiration under the tested conditions. Si-μL@APTES formed stable suspensions and achieved high strigolactone adsorption, leading to significant reductions in broomrape seed germination in petri-dish assays and decreased tuber attachment in hydroponic bioassays. In a 90-day greenhouse trial, Si-μL@APTES reduced broomrape infection and increased tomato biomass at 60 DAP, whereas final fresh and dry biomass at 90 DAP did not differ significantly among treatments, indicating that additional applications of the particles may be necessary. These results support the potential of functionalized silica particles as a promising herbicide-free approach for broomrape management. Our findings highlight the potential of soil-applied, functionalized mineral particles to improve crop productivity and food security, offering a practical solution for parasitic weed control in tomato and potentially other vegetable crops.