Living next door to orchid

I’ve lived in my home for approx 10 years, I live next to 45 acres of orchids. A few years ago it was sold & what used to be a whole lot of hay, has now been converted into pomegranate orchid. Other than a much nicer view, and a nicer neighbour. I have noticed they spray the trees, I close all of the windows when I see them spraying as the trees come very close to my fence. Would anyone know what they are spraying and if it is harmful?