Hi! Public Lab recently put out a publication on Odor you can explores the articles here.
I'm not sure what people are usually spraying when they do this or if there are any regulations around this, so I've posted a couple other questions about it hopefully others can help with. You can find them all here. To get email updates when people post to those you can "like" the questions, or follow the related tags (crop-dusting, pesticides, agriculture, etc.)
Also, are you available to join one of the Tuesday Open Call? It can be a good place to brainstorm with others- www.publiclab.org/open-call.