I want to do an experiment with nano particles on plants in both pot and field as well. But till now there is no proper guidelines available or suggested by any government organization to conduct in filed level.
In Switzerland, there is a guideline available, see attached document. It is in German only. But as the government regulations are the same as in the EU, there might be some other guidelines.
I am not aware of any guidelines existing in India, however, the type of nanoparticles will provide some ideas, what kind of nanoparticles are you trying to use? If they are biodegradable or biologically derived (such as plant or animal based such as chitosan, cellulose) they may be easier to get approved.
My purpose of interest is ZnO nano particles. Some researchers in India, using metal nano particles on plants to see their efficacy on plant metabolism, content and uptake.