When we see these machines in the fields, we grab the animals, close all the doors and windows, and hold our collective breaths.
In the case above it was spraying the Sunflowers. I have no idea what chemicals are being used, but it's probably best not to breathe it in!
Hidden off to the left are about a dozen Beehives that were brought in firstly for the Chestnuts, and secondly for the Sunflowers. It does seem strange to spray with insecticides just when they're about to do their job.
Bring 'em in; kill 'em off.