Phyto-nanotechnology, employing smart nanomaterials with precise target specificity, has revolutionized agroforestry by enhancing crop yield and quality. It offers applications in Citrus tree cultivation for disease detection, stress tolerance, and growth enhancement. Citrus plants contribute significantly to agro-economy in terms of provision of fruits and pharmaceutically and industrially important metabolites that can also be elicited using nanomaterials. While a substantial body of literature explores the nexus between nanomaterials and Citrus trees, the understanding of the intricate transport mechanisms underlying nanomaterials within plants and their consequential physiological responses remains relatively limited. The literature reviewed in this chapter is on the nanomaterial administration techniques, the routes of their uptake by the plant, the subsequent transport mechanisms and processes involved in nanoparticle delivery in plants and their physiological and environmental responses. It also sheds light on the potential risks of nanomaterials and the strategies and regulations established to cope with them. Conclusively, the future research aspects in the systematic study of nanomaterials in plants are also discussed.