I can’t say with certainty that it’s the reason, but I did not need any sort of spray on my plants last year! No bad bugs, no PM at all.
it’s not just a preventative, it also has nutrient value.
I was gonna start a thread about this and found this one, I've always had this idea that anything above a 12 hour light cycle would keep the photoperiod ladies in VEG. And I know two growers in my area that started their grows near the beginning of June and now with the daylight cycle here at 13 hours of daylight and extending...they are flowering. What are the chances they just go back to Veg?
My comments still apply but definitely geared more for indoor since light schedules are constant, unlike outside in most places other than around the equator.
If you're worried about early outdoor plants jumping into flower, consider using a clamp light with a timer in backyard grows to keep things vegging.
I leave a light on a handful of suspected "semi-autos" at night to keep them vegging and then around the 1st of July the light goes off and the plants start to flower. The light / timer can easily be adjusted to keep early outdoor photo period plants from flowering too.