white powder on the leaves, is this mold or what the hell? I've never seen this before..

Straightforward White Powdery Mildew (WPM). WPM forms when you have sustained humidity over 60% and poor airflow. Unfortunately, it's a pernicious beast, and your best bet is to kill anything in the tent (as it spreads via microscopic spores), and sterilize your tent with something like bleach/Microban (scrub walls with bleach, dry, spray with Microban, wipe down), and improve your air intake, outflow, and tent humidity. You may even need a dehumidifier for your grow area. Unfortunately, though, that plant is dead.

Pourcentage d'humidité ? Humidité de la terre ? Fait vraiment laisser sécher la terre de temp à autre et surtout bien aéré !! Pour éviter se genre de soucis

Si tu a d autre plant pas atteind encore je conseil de très vite mettre 1 sav poubelle sur la plante et une fois en place tu coupe (le sac tu le tien fermé pour pas que des spores contamine le reste de ton grow si se n est pas déjà trop tard ..srry mais le mieux serais de tous jeter et tous nettoyer avec de la javel histoire d être sur que le prochain grow ne tourne pas pareil

WHITE POWDERY MILDEW

High bobo, No it does not matter what milk you use. Look at my comment earlier in this question. Happy Growing! 😋

@Organoman does it matter what kind of milk I use and in what proportion do I mix it with water? does it not harm the flowers?

Oh, and spray the milk solution when the lights are on, the light activates an enzyme in the milk which kills the mildew.

Oil, neem or others won't fix it, you need a fungicide containing sulfur (which I wouldn't use) or a milk solution.... one part full cream milk to four parts water. Removal of affected parts and keeping the humidity low after that is your best treatment option. Once present, it is always waiting to go again, so there is no real cure while still growing, only control. The spores are EVERYWHERE and just wait for the right conditions to sprout. After harvest, cleaning forensically will need to be done and this may be the best option to prevent it in future crops. One or two sprays with the milk solution should halt its progress, there is no need to do both the milk and a fungicide as well.

There's a product you might want to investigate... Trifecta Crop Control - it's organic and can be used/sprayed during flower with no ill effects to your buds... When your grow is over, you're going to have to SUPER sanitize your tent and all equipment with bleach to eradicate any spores that may be lingering.... it's a shitty fungus and I wish you luck... btw, I've just read that it doesn't need sustained periods of high humidity to occur... just one instance will be enough if the spores are present... so don't beat yourself up. Good luck mate....

preventative -- horticultural oil or neem oil will function the same way... coats leaves with film that athe hyphea cannot easily penetrate to latch into the plant material underneath.. reapply ever 7-14 days as preventative. the biggest problem with wpm is when it occurs in flower... this severely limits what you can do.. others mentioned sodium bicarbonate (baking soda) -- can also use potassium carbonate.. again this stuff only works by changing pH on leave... add a surfactant and it will spread better... plain water has too high of surface tension.. it'll just bead up on the leaves, otherwise. can good "cornell" formula for instructions.. fwiw, it has nothign to do with the university.. it's not research backed by any means.. will be hit or miss how much it helps an ongoing infection. sulfur bombs can kill it. copper soap sprays h2o2 + surfactant -- changes pH and oxidizing effect which will kill some of it. again, gotta worry about what you'll be smoking later... make sure it is biodegradable in a short period of time, i guess? when pruning be very careful or you just spread it around... if anywhere near a bud site, i take it off completely below the node of infection. if lucky to get rid of it by removing chunks and simple things, that's great... but... expect to continue to fight this.. if applying a foliar spray, jsut keep doing it whether you see anything or not...

WPM is a bitch and a half to deal with. pluck all leaves that have it and burn/bin them. do not add into compost pile. You can make a milk spray easy enough and it works for a bit. needs reapplication. The spore can come from bag soil, to the air from a neighbour or they may have been present on the seed before you got it. The stuff is pure evil. It breads in high humidity and sheds spores in low humidity. it does not like PH swings and that's why milk helps. the ph is high then the lactic acid bacteria make the ph low. other options are a baking soda spray as well but I don't like that one as much and it only worked for a bit when I used it outdoors. need to be reapplied every time they get wet. I make a LAB serum that can be sprayed on plants to help WPM. Its in my one journal call m0use's Haus Of Projects. I also make a cheese out of the leftovers :D growdiaries.com/diaries/143769-grow-journal-by-m0use Good Luck!

I read it and yes, unfortunately, it's mold.(Wpm) I'm in the 4th week of flowering, should I buy a fungicide spray at the farm store? I also read about the milk spray, I can get to the garden store after two days, should I use the milk spray until then? I don't have much humidity! I have never encountered this, the fresh air comes into the tent from outside, I don't understand what caused it. what is the fastest way to stop all this crap? I'm starting to get sad that in recent times only crap comes one after another, please someone give me advice to stop this fucking mold!