I recommend You to check applications of anodic titania (papers of Damian Kowalski, Patrik Schmuki) and anodic alumina (check papers about dental implants by Marco Salerno and Sanjay Thorat).
Im need information about nanotechnology applications in planting, harvesting, extraction and processing of medicinal plants (Special pre-processing procedures)
you can get more recent papers on formulating medicinal plants as nanoparticles from journals like filoterapia, journal of ethnopharmacology, journal of natural products etc.. you can get loads of information and recent advancements in your interested area.
If you are concerned with cultivation of medicinal plants, the nanotech science is in nascent stage except a few applications like nanofertiliers to avoid nutrient losses from fields.