Anyone with vast knowledge of powder mildew please?

xtsho

xtsho

Well-Known Member
I have great success outside on the roses and the Squash and pumpkin leaves in the garden using neem oil a few times during the growing season. I've never had PM on cannabis but I always spray with neem a couple weeks after germination and then weekly until they go in the flower room.


"Fungicides
Powdery mildew on fruits & berries
Several least-toxic fungicides are available for backyard trees and vines, including horticultural oils, neem oil, jojoba oil, sulfur, and the biological fungicide Serenade. With the exception of the oils, these materials are primarily preventive. Oils work best as eradicants but also work as good protectants. The fungicides listed here are registered for home use. Commercial growers should consult the UC IPM Pest Management Guidelines for fungicides for commercial use.

Oils
To eradicate powdery mildew infections, use a horticultural oil such as Saf-T-Side Spray Oil, Sunspray Ultra-Fine Spray Oil or one of the plant-based oils such as neem oil (such as Green Light Neem Concentrate) or jojoba oil (such as E-rase). Be careful, however, never to apply an oil spray within 2 weeks of a sulfur spray or plants may be injured. Some plants may be more sensitive than others, however, and the interval required between sulfur and oil sprays may be even longer; always consult the fungicide label for any special precautions. Also, oils should never be applied when temperatures are above 90°F or to drought-stressed plants. Horticultural oils and neem and jojoba oils are registered on a wide variety of crops."
 
Dr. Who

Dr. Who

Well-Known Member
Mr Westmont said:
Do you generally see powdery in general in healthy gardens? PM only attacks weak plants, just like spider mites, and lions on the african savannah. Right? I mean they chase after the young and the weak. I can tell my plants are healthy, based on the color, smell, growth, and especially big, thick, fat, greasy fan leaves.
Click to expand...
Greasy? Waxy shine all over? To much N

PM will attack any garden! It simply needs the right environmental conditions to start.
 
Dr. Who

Dr. Who

Well-Known Member
Proper use of Sulfur burners is the best way to knock down a strong persistent problem!

Once you have it under control....and I mean not appearing. You MUST sanitize the entire grow!
EVERY where, and Everything in it must be hit.
I use a sanitizing bleach mix and spray on the walls, ceiling, floors and on every exposed surface - INCLUDING the bottoms of anything in the grow area. Fricking EVERYTHING must be sprayed or wiped down with the sanitizing mix..

I use Green cure in a minor amount and home brewed Horsetail grass tea... The Green Cure is used to break surface tension only.
Horse Tail Grass tea is a fine fungicide!

Eagle 20: It works but, the problems with it's use outweigh it's benefits.
I get asked a lot why PM comes back after a few weeks-even after E-20 use. "it's systemic,,right?"
Well, as with any thing that treats a plant systemically.
There comes a point when the compound within the plant gets diluted so much it's not effective anymore....
 
dwood8165

dwood8165

Well-Known Member
I use a sulfur burner. I turn it on during lights out. Let it run 4 to 6 hours with one fan coming on every 15 minutes. The plants liked it alot. Then I would apply a spraying of neem oil or Green cure. But I washed the walls and everything just to make sure it was gone. Also I got the humidity in check. At the time i was pulling cold air (winter time) from outside getting heated up by the lamps. corrected that and it has been over a year and know signs. Knock on wood
 
manfredo

manfredo

Well-Known Member
Dr. Who said:
PM will attack any garden! It simply needs the right environmental conditions to start.
Click to expand...
That's the absolute fact!! It doesn't matter how healthy your plants are, they can still get pm or anything else if the conditions are right (or wrong). Of course healthier plants have a better chance of surviving, and young plants are even more vulnerable.
 
Renfro

Renfro

Well-Known Member
Actinovate. Hear me now and thank me later. For active PM issues use 2 teaspoons per gallon, preventative use 1 teaspoon per gallon. pH the foliar application to 10.0 as well.
 
R

RangiSTaxi

Well-Known Member
Can People please post your PM photos, Ive never had it in over 15-20 years of growing! , and would like to see the environmental conditions it arises in, Ive seen it in pumpkins in the field and a few times in strawberry plants, in dry stress conditions/low humidity. but never in cannabis.

Now for Prevention, as its better than cure, Potassium silicate in veg, water it on and foliar feed it (Spray the leaves till run off, top and bottoms of leaves, half a hour before dark or lights out.) and water it on at double dosages (totally safe)in flower and veg, it mixes fine with other nutrients, it hardens the cell walls of plants, the leaves will take on a reflective sheen.

SilikaMajic - FlairForm Potassium Silicate | Silica & Plant Growth - Flairform

flairform.com

If you use Potassium silicate in veg, you will never have a PM issue again, as long as your plant soil doesn't get too dry, for too long.

Silica must be used throughout both vegetative and flowering phases. Electron microscopy and x-ray analysis both confirm that existing silica within the plant is not mobile and cannot benefit new growth. To benefit new growth therefore, silica must be present at all times in the nutrient solution. Various research projects have shown that the presence of silica in plant tissue produces several beneficial side effects:
● Silica produces healthier and stronger plant growth. When silica is taken up by the roots, it is deposited in the cell walls of the plant as a solid, rigid 'quartz-like' matrix. This produces a ‘mechanically’ stronger plant which enables superior leaf orientation and therefore greater rates of photosynthesis and growth.
● Increases the weight and shelf-life of fruit due to the physical accumulation of silica in plant cells.
● Increases plant tolerance to heat stress or “wilting”.
● Increases resistance to fungal diseases, particularly mildews and botrytis. It resists fungal ingress by accumulating around the points of fungal attack.
● Improves the healing rate and neatness of pruning wounds. This property is especially beneficial in commercial cropping of plants such as tomato and cucumber. Regular pruning of these species threatens the plant's survival due to the risk of disease penetration through the site of the pruning wound.

Plus Potassium Silicate increases dry matter, increases cannabis yields massively and makes your buds dense and rock solid.
 
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Ogchieff

Ogchieff

Member
Can someone help me from going crazy. My plants look healthy and my temps and humidity have been very well controlled 78f 40%rh. I’m in week 1 of flower and examining my plants extremely close. Is what I’m seeing EARLY stages of powder mildew or is this normal. Notice I’m zoomed in extremely close so I don’t know if this is something I’m just overthinking. My intake fan does allow dust in my environment Help please
 

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randallb

randallb

Well-Known Member
You can get pm if the leaves overlay one another even if temp/humidity are good. In pic 1 , go look at some of the lower most buds/growth, you should see it heavier there....if it's there. Can only commit to "could be/not sure" on the other pics.
 
Gemtree

Gemtree

Well-Known Member
RangiSTaxi said:
Can People please post your PM photos, Ive never had it in over 15-20 years of growing! , and would like to see the environmental conditions it arises in, Ive seen it in pumpkins in the field and a few times in strawberry plants, in dry stress conditions/low humidity. but never in cannabis.

Now for Prevention, as its better than cure, Potassium silicate in veg, water it on and foliar feed it (Spray the leaves till run off, top and bottoms of leaves, half a hour before dark or lights out.) and water it on at double dosages (totally safe)in flower and veg, it mixes fine with other nutrients, it hardens the cell walls of plants, the leaves will take on a reflective sheen.

SilikaMajic - FlairForm Potassium Silicate | Silica & Plant Growth - Flairform

flairform.com

If you use Potassium silicate in veg, you will never have a PM issue again, as long as your plant soil doesn't get too dry, for too long.

Silica must be used throughout both vegetative and flowering phases. Electron microscopy and x-ray analysis both confirm that existing silica within the plant is not mobile and cannot benefit new growth. To benefit new growth therefore, silica must be present at all times in the nutrient solution. Various research projects have shown that the presence of silica in plant tissue produces several beneficial side effects:
● Silica produces healthier and stronger plant growth. When silica is taken up by the roots, it is deposited in the cell walls of the plant as a solid, rigid 'quartz-like' matrix. This produces a ‘mechanically’ stronger plant which enables superior leaf orientation and therefore greater rates of photosynthesis and growth.
● Increases the weight and shelf-life of fruit due to the physical accumulation of silica in plant cells.
● Increases plant tolerance to heat stress or “wilting”.
● Increases resistance to fungal diseases, particularly mildews and botrytis. It resists fungal ingress by accumulating around the points of fungal attack.
● Improves the healing rate and neatness of pruning wounds. This property is especially beneficial in commercial cropping of plants such as tomato and cucumber. Regular pruning of these species threatens the plant's survival due to the risk of disease penetration through the site of the pruning wound.

Plus Potassium Silicate increases dry matter, increases cannabis yields massively and makes your buds dense and rock solid.
Click to expand...
Seems to be working for me I had pm last grow and have been spraying and watering my clones with AgsilH16 that had a couple spots and no sign. The eighth teaspoon per quart of ro comes out right at 10 ph.
 
Renfro

Renfro

Well-Known Member
An expensive way to keep a room sterile:

www.airrosbysage.com

Home - AirROS Agriculture

AirROS is an industrial surface and air purification system that kills mold, bacteria, viruses including e-coli, salmonella, norovirus, ethylene gas plus odor control.
www.airrosbysage.com www.airrosbysage.com

It will not only sterilize anything in the air but surfaces too (like your leaves).
 
Gemtree

Gemtree

Well-Known Member
Renfro said:
An expensive way to keep a room sterile:

www.airrosbysage.com

Home - AirROS Agriculture

AirROS is an industrial surface and air purification system that kills mold, bacteria, viruses including e-coli, salmonella, norovirus, ethylene gas plus odor control.
www.airrosbysage.com www.airrosbysage.com

It will not only sterilize anything in the air but surfaces too (like your leaves).
Click to expand...
I put my true hepa filter in there hope it helps.
 
Chuckle_berry

Chuckle_berry

Member
I had this i used everything.. milk, acidic water, vinegar water, cx PM washed every leave with a toothbrush... spent about 2 hours every couple of days from week 6 to 8.. cut away all the badly affected leaves. It didnt work it was game over and for the chop. I wouldnt like it again . I think that late in flower my chances would be slim of eradicating it.
Other than sulphur
 
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