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How to kill powdery mildew?

Tall Grower

New member
Hi,

I am a newbie on this forum.
Since a short time I am growing some veggies in a greenhouse.
A few days ago I found some white stuff on the crops. After using google I find out that it's called powdery mildew.

Does anyone know how I can fight against powdery mildew?

Thanks in advance!
 
R

Robrites

Actinovate works good for me.

A one-stop fungus fighter for gardens, lawns & hydroponics! Actinovate works from root to leaf with a concentrated beneficial microorganism (Streptomyces lydicus) that establishes itself on plants’ roots and leaves. This water-soluble organic fungicide knocks back diseases that attack your lawn, ornamentals and even edibles yet is proven to be safe around pets, people and the environment. OMRI Listed for use in organic production.
 

Aksala

Member
Actinovate works good for me.

A one-stop fungus fighter for gardens, lawns & hydroponics! Actinovate works from root to leaf with a concentrated beneficial microorganism (Streptomyces lydicus) that establishes itself on plants’ roots and leaves. This water-soluble organic fungicide knocks back diseases that attack your lawn, ornamentals and even edibles yet is proven to be safe around pets, people and the environment. OMRI Listed for use in organic production.

Actinovate is by far the best non chemical imo.
 
R

Robrites

It works best if you use it before you have a big problem.

It works in the soil and if you spray it on your plants. I usually spray twice - 1 week apart. If it rains, you might want to spray it more.
 

Donald Mallard

el duck
Moderator
Veteran
Hi,

I am a newbie on this forum.
Since a short time I am growing some veggies in a greenhouse.
A few days ago I found some white stuff on the crops. After using google I find out that it's called powdery mildew.

Does anyone know how I can fight against powdery mildew?

Thanks in advance!

you need to incorporate preventative measures also ,,
find out why you have the problem and treat it ,,

restricted airflow etc ,, the problem will continue unless you remedy ..
 

justanotherbozo

Active member
Veteran
...milk worked for me. ...here's some info that may help you decide whether or not to try it yourself.

peace, bozo

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Milk is a useful fungicide in the garden, and is more effective than standard chemical brands.


Researchers believe the potassium phosphate in milk boosts a plant's immune system to fight the fungi.

Where most organic gardeners use a baking soda, soap and oil solution, milk may be substituted to combat the unwanted fungus.

Preparing a Milk Solution and Spraying Schedule

The correct dilution and spraying schedule for garden plants depends on the situation and takes some trial and error.

A milk fungicide solution can range from 1 part milk to 9 parts water, to a strong, milk-only solution. A 1:1 dilution may work for a week, but a 1:8 solution requires spraying every 3 or 4 days.

Skim milk may work better than whole milk, as the higher fat milk may clog a sprayer; even reconstituted powdered milk works.

Uses for Milk Fungicide

Milk was originally used in the garden to treat powdery mildew on squash plants. It is now also commonly used on flowers such as rudebekia (Black-eyed Susans) and Begonias to cure powdery mildew.

Milk has also been used to cure Botrytis on a Cyclamen houseplant. This was applied full strength every morning (leftover breakfast milk). Rotten leaves were picked away and the plant pulled through with no more Botrytis.

Black spots and rust on roses can be controlled but not cured with milk. Fortunately, milk can prevent the spread of these fungi to other plants and new leaves. This can be very useful when bringing home a plant from the nursery and finding a black spot.


The copyright of the article Milk as a Garden Fungicide for Powdery Mildew, Botrytis, and Black Spots in Organic Gardening is owned by Deborah Turton. Permission to republish Milk as a Garden Fungicide for Powdery Mildew, Botrytis, and Black Spots in print or online must be granted by the author in writing.


-------------------------------------------------------------------------------


by Arzeena Hamir
Powdery Mildew

Less than 3 years ago, researchers in South America discovered a new alternative to controlling powdery mildew. Wagner Bettiol, a scientist from Brazil, found that weekly sprays of milk controlled powdery mildew in zucchini just as effectively as synthetic fungicides such as fenarimol or benomyl. Not only was milk found to be effective at controlling the disease, it also acted as a foliar fertilizer, boosting the plant's immune system.

Powdery mildew in the cucurbit family is caused by the organism Sphaerotheca Fuliginea. It is a serious disease that occurs worldwide. For decades, organic gardeners had to rely on making a spray from baking soda to control the disease. Now, instead of measuring out the baking soda and combining it with a surfactant (a "sticking" substance) of either oil or soap, gardeners need only head for their refrigerators.

In his experiments with zucchini plants, Bettiol found that a weekly spray of milk at a concentration of at least 10% (1 part milk to 9 parts water) significantly reduced the severity of powdery mildew infection on the plants by 90%. While some gardeners may be tempted to increase the concentration of milk for more control, Bettiol found that once concentrations rose above 30%, an innoccuous fungus began to grow on the plants. How does milk control powdery mildew?

Scientist aren't 100% sure how milk works to control this disease. It seems that milk is a natural germicide. In addition, it contains several naturally occurring salts and amino acids that are taken up by the plant. From previous experiments using sodium bicarbonate, potassium phosphate, and other salts, researchers have found that the disease is sensitive to these salts. It is possible then, that milk boosts the plant's immune system to prevent the disease.

Milk used around the world
The benefits of using milk to control powdery mildew haven't been isolated to Brazil. Melon growers in New Zealand are saving thousands of dollars every year by spraying their crops with milk instead of synthetic fungicides. The melon growers in New Zealand have been so successful that the wine industry is taking notice and beginning experiments using milk to control powdery mildew in grapes.

What kind of milk should be used?
In Bettiol's original experiment, fresh milk was used, straight from the cow. However, this is obviously not feasible to most home gardeners. The research work in New Zealand actually found that using skim milk was just as effective. Not only was it cheaper, but the fact that the milk had no fat content meant that there was less chance of any odours.

Wagner Bettiol's original article was published in the journal Crop Science (Vol. 18, 1999, pp. 489-92).
 

Tall Grower

New member
Thanks for the information. I really appreciate it!
I am really looking for some organic stuff. During my search this morning I also found the website www.stoppowderymildew.com. They sell UV-Lights to kill diseases like mildew.

Is there anyone who have some experiences with UV-Light or either with the website?
 
I would use the products listed above to try and make it vthrough the rest of this grow unless it's very early on in the grow,after you finish,I would take and clean your greenhouse and saturate everything in it with Pysan20 walls,floor,ceiling everything then id let that dry and thrn follow up with a fungaflor fungicide bomb possibly 2 depending on the size of your greenhouse then I'd let that sit for a cpl days and drop a cpl more fungicide bombs and again let it air out..then I'd start with all new cuts. I know it seems like drastic measures and it alot but that's really the only way to eradicate the pm as if you dnt break the cycle it will be a continuous problem that will be continuous and more trouble in the long run..I had it once in my indoor grow and it cost me alot and I mean alot if time,down time,money and work but I had to do it to break the cycle..hope this helps even though it's probably not what u wanted to hear..hope you get your pm problem eradicated .I dnt wish pm on my worst gardening enemy's.
 

Tall Grower

New member
Thanks for the response! First I'll try it with the products from above. When It's still there I am afraid that I have to clean my greenhouse..
 

Mikell

Dipshit Know-Nothing
ICMag Donor
Veteran
Arzeena Hamir has a farm not too far from here. Always enjoy hearing her speak.

As mentioned, prevention is the key. Until you alter the conditions that allowed PM spores to germinate on your foliage you will continue to fight the problem.

Actinovate, milk, conventional fungicides, etc, are bandaids. Closely monitor environmental conditions to determine deficiencies in environmental control.

Most greenhouses lack proper air exchange and circulation, combine that with humidity swings and dense foliage and you're fighting an up hill battle.
 

Tall Grower

New member
The past two weeks I have used the Actinovate from Monsanto (http://www.monsanto.com/products/Pages/actinovate-us.aspx) on the half of my crops. On the other half I've used the CleanLight Hobby Unit from (http://stoppowderymildew.com). As far as I can see is the PM at the side where i use the Hobby Unit gone or almost gone. This comparing with the Actinovate where I still can see the PM. For me the Hobby Unit proves that it works.

It's more expensive to buy but it works. I can recommend it to everyone!
 

justanotherbozo

Active member
Veteran
protein synthesis over protein breakdown... soluble ions, sugars and unchained aminos in the plant sap are the root causes of PM.

yeah, i'd say that ubiquitous mildew spores and poor environmental control is the actual cause, ...as was said above by both Mikell and Donald Mallard before that.

...you can't hide from the spores, but you CAN control your air flow and exchange and your humidity levels, both of which, left unattended, can create conditions ideal to mildew spore germination.

so your statement on the inner chemistry is of little use to a new grower struggling with a problem, ...help is what he needs.

oh, and Mikell, while the milk may be a bandaid, it WILL control the mildew in an organic way that is safe to use right up to the day of harvest, ...if the mildew is caught early enough the milk will even eradicate the mildew through multiple applications assuming the environmental conditions are corrected.

peace, bozo

btw, Jorge' Cervantes has a video on YouTube detailing how to wash powdery mildew from a harvested cannabis crop using hydrogen peroxide that looks interesting although i have no personal experience with the method.
 

dimebag_

Active member
The past two weeks I have used the Actinovate from Monsanto (http://www.monsanto.com/products/Pages/actinovate-us.aspx) on the half of my crops. On the other half I've used the CleanLight Hobby Unit from (http://stoppowderymildew.com). As far as I can see is the PM at the side where i use the Hobby Unit gone or almost gone. This comparing with the Actinovate where I still can see the PM. For me the Hobby Unit proves that it works.

It's more expensive to buy but it works. I can recommend it to everyone!
way to support Monsanto big guy! no worries on what they do to the planet, our food, and people's lives. Don't be so ignorant-

db
 

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