It looks like mold! I discarded all the moldy parts (only 3 spots in the 2 plants) How did this happen, what caused it to mold? Humidity is only 61%, these were the only plants affected! Could it be where it was lying up against the mylar on the wall? I have flowered 3 times, and this is the first time I have ever seen mold! What do you guys think? How can I prevent this next time?
eww That's definitely mold. You're probably in hydro or if you're in soil you folier fed with spray at some point. In hydro the plant is always at a peak level of hydration. Add to that 60% humidity and you get mold. Also if you don't have constant air exchange you get mold.
Well what can I do different? This is the first time I have ever had a problem with mold. Could it be where the buds were leaning up against the mylar? I mean I have flowered 3 times in this exact same spot, the exact same way, but never had it happen before.
Spores are everywhere. There is no way to avoid them. They can even travel thru space since they're technically not alive. Sounds like that specific plant was suceptible to mold and 60% with summer temps coming in addition to oily resin for food is perfect for mold. You can only do two things and that's keep humidity and temps down. My humidity is close to 0% in thw desert and have no issues with growth.
Ideally you want 30%-50% R/H during flowering, I typically try to keep it at 50% R/H. I had a lot of mold issues with my first grow, I'm sure Serenades profit for that quarter increased due to my mold issues alone Mold can happen when R/H is above 60% the higher the more likely it is to happen and a temp swing of I think 14 degree's in the same high R/H will cause mold to happen even around the 50% R/H range. I used a small DE-humidifier that was good for 3 plant after that it couldn't keep up,I use it for drying & curing now, I bought a full size room one off C/L for $100.00, beware the large one puts out a constant 84^ air & can contribute to heating up your grow area, I use it in the winter and a window mount a/c in the summer which DE-humidifies well enough on its own. Some of the portable A/C units marketed towards growing have a DE-humid option, something to think about. I recently had a mold issue during curing, that sucked for about 15 minutes. S.S.