CONTROLLING THE SURFACE RETENTION AND PENETRATION OF AGRO-NANOMATERIALS: DESIGNING A BROADLY APPLICABLE STRATEGY

Nanoparticles (NPs) of nutrients demonstrate strong promise in plant growth promotion andsuppression of environmental stresses, leading to higher productivity. However, inefficient use due to run-off and the risk of the NP residuals in plant edible tissues restrict the broader application of nano-enabled agriculture, but both can be modulated by rational NP modifications that alter their leaf surface retention and plant interior penetration. We are proposing to reduce the agrochemical run-off, thus reducing the input ratewith two objectives that will enable controlled penetration and improved leaf retention. We aim to develop modified NPs with surface coatings and morphology optimization to1)keep them tightly adhered to the leaf surface with less run-off, and2)controlpenetration into the plant tissue as needed for different application scenarios. More specifically, with longer retention time and better contact angle on the leaves,formulations that allow NPs to adhere tightly to the leaf surface, but with less penetration into the plant tissue, will be used to supply dissolved nutrients for plant growth enhancement and postharvest fruit protection; In the meantime, those formulations that induced greater intact NP penetration will be used as nano-carriers to deliver pesticides or genetic materials. We are also aiming to establish a useful database to provide information on the design, synthesis, and modification of various agro-NPs for researchers, and rational choice of NP formulations, when needed for specific crop production systems. Specifically, our objectives are:Objective 1: Evaluate the effect of surface coating on the fate of NPson/in representative model plants (having different content of leaf wax).Objective 2: Evaluate the effect of particle morphology on NP fate on/inrepresentative model plants.