It was south of Blythe a few years ago as I was returning to AZ from Barona that l learned that they spray the fields at night. Now mind you at 2am after being up way to many hours those bright lights really mess with you in the distance luckily they were working a field right along the road I was on so I got to slow down and observe. Two pickups spotted at each end of the field with bright blue LED whips. Contacted a pilot friend the next day and he stated that was the best time and the visibility was actually quite good. No breeze at night and no bees.