Powdery Mildew?

Hi there Yes it’s powdery mildew.. Dr Zymes eliminator is great for pests, mold and Mildew issues.. Look it up its highly recommend Best of luck 🌱

Yes. Progress -- leaf -> petiole -> stems in that order, typically. gently remove the infected area. You cannot see the mycelium network forming inside the plant. Like other microbial infections, i'd remove a bit more than what you think is necessary to be safe. If you can see it, it's been there for a while already.. in your room... on your plant. Limited options in flower. Most options do not kill it and will only slow it down. Sometimes you get lucky and that one little spot is the end of it. "cornell formula", milk, and such mostly just inmpact the pH. Oils/surfactants will help prevent hyphae from digging into leaves. UV light has shown promise, but not sure if the handheld ones you can buy are strong enough. Some big-pants fungicides might work, but also may make the weed poisonous or taste like shit. fight it... if you don't see any signs, continue whatever process you chose long after... up until that product recommends stopping before harvest for your own health concerns. Do not think that your eyes can detect it. If you stop, it;ll very likely pop back up and all that time it was spreading even faster.

You don't have to cut the branch! I've never tried milk, usually i mix 1gr baking soda in 1L water, making a pH8, that kill the oidium(PM) because he needs an acido surface, like the leaves (5.5pH) :) spray It 2 times on the flower, 1 time all over the whole plant, and cut only this leaf if It expands, repearing the treatment:) don't spray on last 2 weeks because , It can release some sediment (not harmful, only wash the flowers in case) And down Rh at 40% :)