White cloudy blotches on a mother plant.

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chrisv

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Hi all,

Newbie here. I was given a good mother plant from a friend (In Holland) The plant is developing white blotches (1cm diameter) on the darkest leaves. Is this something to be afraid of?

Thanks in advance,

Chris.
 
There's a white powdery residue on the top side of the leaves - I can't see anything underneath the leaves..
 
chrisv said:
There's a white powdery residue on the top side of the leaves - I can't see anything underneath the leaves..

i cant really tell what it is but try wiping it off
 
Can you post pics? Is is just on one plant or has it spread?


Sounds like powdery mildew to me....
 
Right on Biffdoggie, was just on the hunt for those very pics :D
 
Sounds like the problem to me, man I hate that stuff. No problem with it down here, up north though, all the time.
 
yeah.....that stuff is nasty....and man it can spread fast :mad:
 
for sure, hard to kill if you live where it's dank at all.
 
If it is indeed powdery mildew you can safely combat it by mixing a spray of 1 tsp baking soda and 1/2 tsp of epsom salts per quart of water.

Or if you prefer, you could hit your local garden center and pick up some Safer's Defender ... Both of these can be used during bloom cycle, however you must make sure you don't spray either directly onto your buds....

Once you've got it, powdery mildews quite the pain in the ass to rid yourself of.
 
ZenLunatic said:
If it is indeed powdery mildew you can safely combat it by mixing a spray of 1 tsp baking soda and 1/2 tsp of epsom salts per quart of water.

Or if you prefer, you could hit your local garden center and pick up some Safer's Defender ... Both of these can be used during bloom cycle, however you must make sure you don't spray either directly onto your buds....

Once you've got it, powdery mildews quite the pain in the ass to rid yourself of.

Sorry I missed your reply.. I will try it tomorrow. The plant is veg-ing at the moment, so no worries with the buds.

Thanks again. :)
 
Powdery mildew spores float in the air and are everywhere. They need the proper conditions to germinate: a surface that contains nutrients on which they can grow, temperatures over 60°F (16-20 C), high humidity and a slightly acidic environment. Once the spore senses these conditions , it germinates, sending out a hyhae which seeks out a stomata. It enters the tissue and lives off its nutrients, eventually killing the tissue. The downy mildew powder you see on the leaf is the reproductive organ of the plant, which is releasing spores into the air.

Once the spore germinates, it survives in a wider range of conditions. Lowering humidity does not eliminate the infection. There are several things you can do to eliminate it:

Plant Shield is a foliar spray which kills many types of foliar and root fungus. It is not a chemical but a microbe, trichoderma harzianum strain T-22, which feasts on the fungus. It is totally harmless to non-fungal organisms so it is safe to use. It takes 2-10 days to control the disease. It is available from ITS: 800-375-1684 or 303-661-9546.

Neem Oil is available in many formulations. It is quite effective on powdery mildew, with results noticeable in a couple of days. It is available in garden shops, nurseries and the net.

Armicarb or Kali-Carb are made from potassium bicarbonate. Potassium is a plant nutrient and the bicarbonate makes it soluble and alkaline. Powdery mildew cannot grow in an alkaline environment. The mold dies.

Baking Soda, bicarbonate of soda, is a home remedy. It contains sodium so using it too often will be harmful to the plant. Use one tablespoon per gallon and spray the leaves thoroughly.

Alkaline water controls powdery mildew. Use a water with a pH of close to eight. Some western waters have higher pH. The pH should be lowered to the low eights. The pH of acidic water can be raised using pH Up, available at garden shops.

To prevent recurrences, lower the humidity in the space. The humidity goes up in the evening because as the air cools the air's water-carrying capacity goes down. The same amount of water in the air results in higher relative humidity at lower temperatures. This occurs when the lights are off, a favorite time for spores to germinate. To prevent this, use a dehumidifier, which pulls moisture from the air resulting in a lower humidity.
 
Damn Biffdoggie, you know your mold.

Kudo's for an excellent informative post.

You know what MarP needs? A FAQ section, for informative posts like this one.
 
As I would like to claim I wrote that, I did not, But I will say I'm glad I don't have to know it that well!
Thank you all the same. I agree about the FAQ section, I was surprised when I found MP that there wasn't more posts/questions about powdery and spider-mites as we were ravaged down here for some time (mites). Finally had to go chemical with it to much dismay.
 

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