S14 - Session O4 - Designing nanoparticles to block root parasite-host communication - environmental friendly weed control

Authors: Chen Dayan *, Hammam Ziadne, Hanan Eizenberg, Yael Mishael

Problem : The root holoparasitic plant, Orobanche and Phelipanche spp. (Broomrape), causes severe damage to crops worldwide. Its control is complex and currently treated by applying herbicides. Broomrape seed germination is elicited by host-derived stimulants, strigolactones, produced by the host plant roots. Main goal is protecting tomato and sunflower crops from broomrape weeds by designing environmental-friendly nano-silica particles which adsorb the strigolactones in the root zone, blocking the communication between the host and the parasite and therefore preventing germination of the broomrape seeds. The nano-particles will be applied by immersing seedlings in the particle solution or via the irrigation system. Methodology: We have successfully grafted silica particles with amino silanes consisting relevant functional groups. The particles were characterized 1. the loading of the substitute group was determined by TGA (10%), 2. the chemical bonding between the particles and the substitute group confirmed by FTIR, and 3. the surface charge reversal, from slightly negative to positive charge, was indicated by ZETA potential measurement. The particles which were grafted with 3-Aminopropyltriethoxysilane (APTES), had the highest zeta potential, and as a consequence created the most stable suspension. Results : The adsorption of the strigolactones to the APTES particles was higher compared to the others. A significant decay in germination was achieved, in a petri dish bioassay, upon applying APTES particles. A reduction in the number of broomrape tubers was also found in several treatments in an experiment performed with tomato and sunflower plants, cultivated in a hydroponic system, in which the grafted particles were applied in the root zone. This research shows that the unique approach of adsorbing the strigolactones, using environmental-friendly materials, has a high potential for sustainable broomrape control without using herbicides.