I tried that way also and it helped, but I seemed to think and someone correct me if I’m wrong but once you get it you never really get rid of it, you control it. I actually went to town on a lot of the damaged leaves and trimmed away and sprayed and all products seemed to worked but unfortunately weather out here didn’t help my problem.
2 Likes
I’m wondering about compost/worm tea applications? Get the good biology working on them before the bad guys setup shop ! Thoughts?
1 Like
That works but it is hard on sprayers. @lotus710 is a good source for ideas and recommendations for those methods. Aloe is very good also.
2 Likes
has anyone tried milk? i’ve heard it’s pretty effective against powdery mildew
2 Likes
Just wanted to point out that Powdery Mildew is actually mildew that prefers opposite condititions than other ordinary mildew . PM likes warm and dry environment.
But you are right, that sweat usually promotes Botrytis (which likes wet conditions)…
2 Likes
I think I found a new found love for a great cleaner for sprayers! Havent tied it yet but I picked up a gallon of 30% h2o2 for like 15 $ at the grow shop! Diluted down to 3% this makes about 10 gallons of normal otc hydrogen peroxide, but be VERY careful with this stuff and wear your PPE very CAUSTIC! Hydrogen peroxide is recommended for cleaning your compost/worm tea brewers! great around the house for pet stains/ shower/tub cleaner grout, toilet, laundry, and a overall great sanitizer, the list goes on!
1 Like
LAB is all you need for PM. Also if you have a good soil life youll probably have good life on your leaves. These micro organisms will beat PM no prob as long as they can establish first. Compost tea foliars are an amazing way to establishh that community on your leaves. Like ryasco said they can be hard on sprayers so either make sure you have a good sprayer like a chapin concrete sprayer or make sure you strain the tea really good.
2 Likes
How do you apply it bro? I mean, foliar LAB? I can make a batch really good and spray it…
1 Like
Dilute 1:1000 and spray. Much much better then milk.
2 Likes
We are both right Mr. Joe.
High relative humidity is favorable for infection and conidial survival; however, infection can take place as low as 50% RH. Dryness is favorable for colonization, sporulation, and dispersal. Rain and free moisture on the plant surface are unfavorable. However, disease development occurs in the presence or absence of dew. Mean temperature of 68-80°F is favorable; infection can occur at 50-90°F. Powdery mildew development is arrested when daytime temperatures are at least 100°F. Plants in the field often do not become affected until after fruit initiation. Susceptibility of leaves is greatest 16 to 23 days after unfolding.
5 Likes
5 posts were merged into an existing topic: Relative Humidity vs dew point?
Condolences @whatrock …it is heartrending to be so impotent in protecting your plants from the nasty dynamic duo of PM and bud rot.
When I grew outdoors in the NE US, I tried
milk, vinegar, potassium bicarbonate, and h2o2…for me the most effective was h2o2.
I would use it at full strength 3%(some plants or strains are more tolerant than others…but damaged leaves or buds are far preferable to PM or botrytis.)
Anyway, by default, I found the most productive strategy to stave off PM and mold to be the use of containers. This way I could move the afflicted plants to an indoor climate controlled environment. This greatly enhances the odds of successful eradication of the PM and bud rot. I moved them in and out as needed.
Smaller plants vs.the in-ground plants , but much higher certainty of harvesting nice buds.
4 Likes
What are the Organic Treatments for Killing Powdery Mildew?
When treating your plants, make sure the leaves are coated with the solution. Reapply weekly unless otherwise specified on a products label.
Milk
Numerous studies have shown milk and/or whey to be an effective anti-fungicide. The milk and whey are believed to produce free radicals which are toxic to the fungus.
Mix 60 parts water with 40 parts milk or whey and spray onto the affected plants bi-weekly.
or
Mix one oz powdered milk to 2 liters of water.
Baking soda
Baking soda changes the pH of the fungus and kills it.
Mix 1 tbs of baking soda and 1/2 tsp liquid hand soap with one gallon of water.
Spray solution on affected leaves, and dispose of any remaining solution. Do not apply during daylight hours. It may be best to test one or two leaves to see if the solution will cause the plant to suffer sunburn.
Potassium bicarbonate
Potassium bicarbonate is a safe, effective fungicide. It is used as a leavening agent, and is used in wines and bottled waters.
Mix 3 tbs potassium bicarbonate, 3 tbs vegetable oil and a half teaspoon soap iinto a gallon of water.
Sulfur
Sulfur is a natural product that is very effective at preventing and controlling powdery mildew. Sulfur can be bought as a dust, or as a liquid which can be added to sulfur vaporizers.
Follow the dosing instructions closely and wear gloves, eye protection, and a face mask. Avoid inhaling or coming into contact with the sulfur .
Neem oil
Neem oil is made from the seeds and fruit of the evergreen neem tree. Neem oil works by disrupting the plants metabolism and stopping spore production.
Mix 3 tbs of neem oil to one gallon of water.
Take precautions to avoid sunburn of leaves, and avoid spraying the plant’s buds and flowers.
Copper fungicides
Copper is a very effective fungicide, but it is very important to follow label directions closely. Too much copper will be detrimental to the plant and the soil.
Powdery mildew on pumpkin leaves,
Powdery mildew on pumpkin leaves, | Source
Vinegar
Vinegar is very acidic. When sprayed on powdery mildew it changes the fungi’s pH, effectively killing it.
Mix 4 tbs of vinegar with 1 gallon of water. Reapply every three days.
Garlic
Garlic has a high sulfur content and is an effective anti-fungicide. Garlic oil can be bought commercially if you do not wish to make the solution at home. Garlic works best when added to organic oil mixtures.
Crush six cloves and add to one ounce of an organic oil such as neem oil and one ounce of rubbing alcohol. Let set for two days, then strain and retain the liquid and crushed garlic. Again soak the garlic, this time in one cup of water for a day. Strain out and dispose of the crushed garlic. Add the oil and alcohol mixture and garlic water to one gallon of water. Spray your plants, coating only the leaves.
4 Likes
Thank You to all that have gave their insight and suggestions to what happen to my 1st attempted grow outside albeit unsuccessful. I know one thing for sure unlike an indoor grow where you can control the environment mother nature will have her way and I do believe the conditions were prime as ryasco stated for what happen to me. I won’t even consider this a mistake, I rather look at this like a learning experience and hope it will help others, again the community came thru and to the rescue.
Semper Fi
Whatrock
3 Likes
also make sure you pick a strain that is mold resistant. while looking for shishkaberry seeds i read one description that said very resistant to mold, even being surrounded by infected plants and not catching any PM … so that might be a good option
2 Likes
FWIW, I grew some Skunk#1XBurmese which was virtually impervious to PM or bud blight in the NE US. It was unscathed while all of the other strains in the same plot were woefully afflicted.
The only problem with finishing the SkunkXBurmese was the threat of a hard freeze or frost…it needed to go until the 1st week or so of November to ripen properly …didn’t always make it.
Some strains can be seemingly oblivious to PM and botrytis.
Conversely, some strains are like magnets for PM!!
3 Likes
Well gang, i started to see PM problems but the milk spray worked wonderful, on top of that the fan running 24/7 helped too. So glad to have caught it early. I did 40% milk / 60% water and sprayed it once, and it stopped completely, that was close.
2 Likes
in which tent? i thought you had good environmental controls etc
1 Like
Right but my costume was to turn off the power of both the lamp and the fan while the plants sleep, at the same time i was giving them foliar just as they went to sleep, therefore replicating conditions for spores to propagate, but it´s been solved now. Damn! Mother nature deserves our respect and gratitude!
3 Likes
yes i keep my exhaust/intake going all night but not my circulation fans maybe i should keep those going
2 Likes