Can’t rid white powdery mildew.

xtsho

Well-Known Member
There are several natural Thymol (essential oil from thyme herb) anti-fungal products on the market now that have shown great efficacy in treating PM. Here is one study, I think it was done by the manufacturer, that compares it to Serenade (which works better as a preventive anyway). https://www.agroresearchinternational.com/2018/02/28/thyme-guard-vs-cucumber-powdery-mildew-2017-study...Anyway, it's worth trying but I'd only use it prior to any significant bud formation unless you want your buds to taste like Italian food.
Thymol is in mouthwash like Listerine. Listerine is also a PM remedy used by gardeners.


"5. Mouthwash – Because of its ability to kill germs, mouthwash can be used to destroy mildew spores

Mouthwash is very powerful and therefore, it’s important to test a small area on squash leaves to make sure plants do not suffer any damage.

Dilute mouthwash with water in the ratio of 1 part mouthwash to 3 parts water

Use a generic, ethanol based mouthwash. Jeff Gillman, Ph.D and Associate Professor at the University of Minnesota, Department of Horticulture had very effective control.

His tests used one part mouthwash to three parts water. Be careful when mixing and applying mouthwash as new foliage can be damaged."

 

trambles

Well-Known Member
Agreed at least a week before flower. How much did you use? I spray 5ml/gal, that's preventative. In the past I hosed down an outdoor plant already displaying PM and it took a couple weeks to clear it
 

Apalchen

Well-Known Member
Agreed at least a week before flower. How much did you use? I spray 5ml/gal, that's preventative. In the past I hosed down an outdoor plant already displaying PM and it took a couple weeks to clear it
Yeah I hope it's like you said and it's just taking a lil longer. Has me kinda stressed cause if this doesn't work I don't have a clue what will.
 

SnidleyBluntash

Well-Known Member
1) change strains
2) change environments.
What is your humidity and temp. I Imagine if you were transported to the arid desert, would you still have this problem?
 

SnoopyDoo

Well-Known Member
I had a mix of three different stains in the tent last time and they all caught it.
Once it gets in the tent, it's going to get all of the plants. The plant that can't defend itself against PM will get it and pass it along to the other plants. Try identifying which one gets it worse or first and take that strain out of the mix. Light can be a great defense against PM. Prune off lower fan leaves that aren't getting light and try brighter lighting. As others mentioned, airflow is your ally and low RH. Keep the plants spaced apart as much as possible - try reducing plant count until you have it under control.

It could also be outside and you're tracking it in. Roses often get hit with PM going into the winter. If it's your yard, then you should be treating it as well. If not, then be careful about the path you take back to your apartment. Avoid roses, avoid piles of dead rotting leaves, etc. You can try Activonate (sp?) to battle PM. Activonate is a natural bacteria that crowds out the PM preventing it from gaining a foothold. Good luck, rest assured PM can be defeated. If the extreme measures you're taking aren't doing the trick, then I'd suspect you're bringing it into the grow from outside and/or you have PM prone strain.
 

WordzCatz

Member
are your plants from seed or clone? is the 30% humidity constant or only while the lights are on. Have you plants wilted from drought before?
 
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