I’m almost 3 weeks into flowering, never had any problems, been lucky for my first grow. I inspected the plant today and noticed about 3 leaves with this burnt look to them, where they were brown and dry and black. Just on part of the leaf not the whole thing. Leaves were lower down in the shaded part of the grow, and farthest from the fan. What could be the cause? First time ever seeing something like this. It can’t be a fert issue because the rest of the plant is looking normal and growth is fantastic. Well, there are a couple other leaves that are turning inside, like the spikey ridge of the leaves are turning downward. Just a couple.
Watching all those little white spots and the tissue damage I suspect bug activity or some kind of fungus. Any deficiency or nutrient burn would affect the whole plant. Away from fan means poor ventilation, stagnant air and shade, conditions that would help. I would inspect with a scope the back side of that leaf …
Well I’m without a scope but I didn’t see anything on the underside, it looked just fine, and those white specks do not rub off when I try. I’m leaning toward fungus though. But doesn’t appear to be PM from what I’ve seen. I’ll up the air movement and see if that helps
The necrotic leaf tissue is because of botrytis.
More air flow, control your lights-off humidity and remove some of those lower leaves to open up the lower structure. Any tissue that goes necrotic - remove from the grow area.
Man you’re so scientific! Ya I had my main fan with my light timer so it’s been going off with the lights and left the intake fans running. Apparently that’s a big no no and need all fans running at all times!
I always run my fans. Even if they dry my leafs out a bit. Don’t want bugs or mold. If it’s stuffy to you it’s more than that to your plants. They need the air moving around. Tops and your containers. Those holes aren’t just for drainage. Keeps those 🪰 away. Oil your girls for the sun. Neem is on of my favorites. They love it. Keep lights down low.
. I would say it is mildiu 
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