Powdery mildew

What do I do about mold?

My plants are in flowering on a 12/12 schedule. The problem is a light dusting of whitish-grey mold. I have a very good exhaust system. Will this affect the THC? Is it harmful to human consumption? How can I stop it?
Shellie, Bobbins and Battie,
White City, Oregon

It sounds as if your plants have been attacked by powdery mildew. This is a mildew closely related to fungus. The powder is the mildew's reproductive spores. It thrives in an acid environment in a temperature range of 60-70?F (15-21?C) with a humidity above 50%. The spores are floating in the air and there is no practical way to screen them out. Instead, try to change the environment so that conditions don't match the mildew's needs. This may require raising the temperature or lowering humidity.

There are also several safe and effective ways of controlling powdery mildew using minerals or organisms.

Most of the mildicides listed here are fairly new and they are all much less harmful than the old chemical formulations. You won't find most of them at your local store or garden shop, but they are available on the Internet. Many companies sell them there. All of these mildicides are used on edibles or herbs. Some are naturally occurring organisms and are exempt from registration. Others are registered for use on vegetable crops and are considered in the "caution" category, the category for the least dangerous registered mildicides.

AQ10: AQ10 uses a totally new method of fighting powdery mildew, a biofungicide. The active ingredient, Ampelomyces quisqualis, is a fungus that parasitizes the powdery mildew organism. It offers control over a long period of time.

Cinnamite: Cinnamite is an extract of cinnamon used as a miticide which is also effective as a fungicide. It is very easy to use, is effective and has a pleasant cinnamon odor. Studies show it is not harmful to marijuana plants.

Copper: Copper ions inactivate some fungal enzyme systems, killing the mycellium. Copper has been used for over 100 years, and is effective. A few brands of copper based fungicides are Phyton 27, Dexol Copper Bordeaux Mix and Kocide DF. There are many other brands available.

Neem Oil: Neem oil is pressed from the nut of the Indian Neem Tree. It protects against and kills mildew by interfering with respiration and collapsing the cell wall. Some growers claim that plants grow more vigorously when sprayed with dilute neem oil twice a month. There are many brands of neem oil available. Many of them are listed as organic.

Plant Shield: Plant Shield contains the organism Trichoderma harzianum strain T-22. This organism attacks fungi and mildews. It is used as a spray or dip. The organism seeks its food and forms a symbiotic relationship with plant roots, which it also protects.

Potassium Bicarbonate: Potassium bicarbonate collapses and desiccates the mildew hyphae. This is a very safe, very effective contact fungicide. Mildew do not develop resistance to it. The potassium in the formula is absorbed by the plant. Two brands are Kaligreen (registered in California) and Armicarb100.

Serenade: Is the fermentation product of a bacterium, bacillus subtillis, that inhibits cell growth of fungi and bacteria. It is very effective and easy to spray on or to use as a dip. It is a contact fungicide that kills only areas that it contacts. A wetting agent or spreader increases total contact.

Sodium Bicarbonate (baking soda): Baking soda leaves an alkaline residue on the leaves. The sodium collapses the powdery mildew cell wall and the alkaline environment discourages growth. Plants have a limited tolerance to sodium, so the residue should be washed off before more is applied. Used at the rate of 1/2 teaspoon per quart of water with a wetting agent.

Sulfur: Elememtal sulfur interferes with mildew cellular respiration. It has been used as a fungicide for more than 100 years. There are small packages available in the baking sections of supermarkets.

These new remedies make it much easier to deal with powdery mildew. They are all non-toxic and eliminate the problem fairly easily.

Readers with grow questions (or answers) should send them to Ed at: Ask Ed, PMB 147, 530 Divisadero St., San Francisco, California 94117, USA
You can also email Ed at AskEd@quicktrading.com, and send queries via his website at www.quicktrading.com.
All featured questions will be rewarded with a copy of Ed's The Big Book of Buds from Quick Trading.
Sorry, Ed cannot send personal replies to your questions.

Comments

powdery mildew ion collard greens

I HAVE TRIED UNSUCCESSFULLY TO FIND OUT IF COLLAR GREENS WITH POWDERY MILDEW ON THEM ARE SAFE TO EAT........

Gross......you want to try

Gross......you want to try to eat mildew?????
you will get the craps.

Oiwdery Mildew on Collards

I am asking the same question. Are they safe to eat?

Powder mildew

I have a small amount of powder mildew and am on my fith week of flowering and have treated them all with sm-90 they seem to smell better and look realy good. I didn't spray the buds because I only could see the pm on a couple of leafs and stems . I'm ok I hope?

powdery mildew

hi guys i've got a problem with mildew... dodgy cuttings from some where... grrr.

it has migrated to all me plants. I'm in 4th week of 12hr stage all healthy . in the 3years i've been indoor gardening i've never had Mildew indoors. my temp is around 28 when light on and 20 with light off. humidity is never higher than 38%. I decided to use the same stuff i use in the garden on roses... its not for use with edible crops but hey i'm gonna smoke it not eat it.lol. the stuff i used is Scotts Natural pest & disease control. i got it from B&Q about £3. if it works i'll comment later.

powdery mildew/not going to eat it!

wow dude do you know how many people eat pot and cook w/it
not to mention its only going in my lungs isn't it the biggest organ in us
you should really think about the big picture.
Educate knowledge is power

powder mildew

Really need an answer about the safety of smoking plants that have or have had powder mildew. We have been controlling it fairly well with only a few leaves still showing signs. Are about 3-5 days from wanting to harvest. What's your best advice.
P.S. This is the second crop we've had this problem with and we tossed the whole lot last time. It was a lot more severe and had gotten out of control.

AQ-10

Where can aq-10 be purchased. I can't find it anywhere. The one place that looked promising had a message stating it was no longer available from ecogen, the manufacturer. Ideas?

powdery mildew treatment timing

How late in the flowering cycle can powdery mildew be treated safely, with Serenade?
Cervantes says "avoid sprays that leave a residual during the weeks before harvest." How many weeks?
The infection is not severe - can I get by with trimming all affected elaves and avoid the spray?

I read a 10-15% skim

I read a 10-15% skim milk/water solution is a great way to get rid of and control the stuff. A recent remedy discovered in Brazil, nobody knows why it works, but it apparently works amazingly well and also foliar feeds your plants, and increases its immunity to disease.

Skim Milk

5-10% skim milk mixed at a 9 parts water to 1 part milk is what is use. Use only skim milk as it has little to no fats in it. and won decompose you leaves and buds. milk has atibodys and other things to fight mold. It will not only treat but help with future breakouts. H/E this is only a temporary fix. There is an underlying problem with your airflow or humidity or both

Milk on powdery mildew

I had a sudden bad mildew and powder fungus break out in my entire outdoor garden. It hit the pumkins really bad, and the cucumbers a bit. The powdery mildew got to the adult garden as well. I think I was overwatering, and I let things overgrow and get thick so they weren't getting proper air, so I took care of that. I have also read quite a bit about the nonfat milk mixture as a reliable fix for the pumkins and cucumbers as well. Spraying them down regularly now. I will post back how it works out for me, so scroll down!

Guardo

ED

So this is called ask Ed correct? When is Ed going to answer the question on everyones mind. PM??????

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