Dr. Who
Well-Known Member
I continue to see lots of PM (Powdery Mildew) questions and problems.
I feel it is time for a complete guide on how to not just control PM but, how to finally defeat it and how to keep it from coming back....as best we can.
You should all understand that PM is not an "IF", It's a "when"......
Lets start with what PM is.
Thanks Wiki
Powdery mildew is a fungal disease that affects a wide range of plants. Powdery mildew diseases are caused by many different species of fungi in the order Erysiphales, with Podosphaera xanthii (a.k.a. Sphaerotheca fuliginea) being the most commonly reported cause. Erysiphe cichoracearum was formerly reported to be the primary causal organism throughout most of the world. Powdery mildew is one of the easier plant diseases to identify, as its symptoms are quite distinctive. Infected plants display white powdery spots on the leaves and stems. The lower leaves are the most affected, but the mildew can appear on any above-ground part of the plant. As the disease progresses, the spots get larger and denser as large numbers of asexual spores are formed, and the mildew may spread up and down the length of the plant.
Powdery mildew grows well in environments with high humidity and moderate temperatures. In an agricultural setting, the pathogen can be controlled using chemical methods, genetic resistance, and careful farming methods. It is important to be aware of powdery mildew and its management as the resulting disease can significantly reduce crop yields. Greenhouses provide an ideal moist, temperate environment for the spread of the disease.
Now then lets start with simple things first.
PM is brought into your op by the spores coming in on air, your clothes or pets you allow outside and into your op.....It can be spread into your op in a house room by any ventilation such as heating and cold air return vents. Anyway air gets into your op! Once the house born op has PM. It has deposited spores through out the ventilation system and the rest of the house. You are now going to have a real pain in the ass cleaning job because the best course will be to clean the whole house! We will cover these things later.
You NEED to understand that once you "see" it on a plant. You now have it through out your grow, by way of the spores the PM puts out to colonize other plants. If you have 2 separate area's that are connected and have any form of air flow between them, including a doorway. That area is now infected with spores also!
You will need to treat the plants in that area - even if you don't "see" PM growing on the plants. It's there. It's just waiting to have the right conditions to attack.
In veg it is far easier to control and kill then in any week over 4 in bloom. Once you have PM in bloom. It is going to be next to impossible to completely kill off due to the nooks and crannies in your buds that this nasty shit LOVES to hide in! You can "see" it on many places but, at this point in bloom. It is in many places in the bud that you will not "see".
Lets start with simple ways to prevent PM.
For operation (grow area) exposure.
Do not come in from working outside on gardens or plants and then work in your op.
Do not allow anyone else in the op!!! (You should know better anyway)
Do not allow any pets in the op. (I know this one can be hard.)
Do not bring into your op, outside sourced clones NO MATTER WHERE OR WHO THEY CAME FROM! Until they have been properly treated for molds and pests!
Make up some HTG or GREEN CURE (more on just what these are later) and dip EVERY single outsourced clone you get in it up to the media surface. Spray the media and the pot with the solution.
Do the same with a pyrethrin concentrate for killing off any pests on the plant and water with a BT product to get any Fungus gnats in the soil.
Do your working in the op after taking a shower and putting on clean clothes IF AT ALL POSSIBLE!
USE AN INCOMING AIR FILTER!!!!!! This is the single most important factor in any stand alone building grow!!!
The use of Silica as a supplement (or built into the soil for water only organic runs) will help the plant repel PM!
NEW AREA SET UP:
If you are setting up a new area or even a new stand alone building. No matter if the equipment is used or new. SANITIZE the WHOLE thing and EVERY SURFACE with a bleach sanitizing solution, BEFORE you bring in your plants! This means EVERY SURFACE, including tables, nutrient bottles, simply EVERYTHING, fans, AC units - EVERYTHING YOU SEE = SPRAY IT and let it dry!
If you are in a room in a house be SURE to block off any air flow into the room from vents, as in heating and cold air returns! You will need to heat and cool this room by it's self for the best results in avoiding PM!
AIRFLOW ,, maintain space between plants and have fans that are moving the air lights on AND off!
Humidity ,,, Keep you RH at or slightly below 50%....very low RH of less then 40% really doesn't help that much. It's a balancing act.
Temps.....Keep temps from swings over 10F lights on to off.....Once PM is eliminated you may have that swing on to off swing increase if your a manipulator of coloring through temps swings. But as a rule. the bigger the swing, the better the chance of PM taking off.
IF, you have a power outage and it lasts for even an hr....if spores are present....your going to be hit and hit HARD with PM!
Spray with a preventive or killing spray right after the power comes back on and get the whole plant and the media surface......LOOK for emerging PM at 2 and especially 3 days after the outage! You should have done a prevent spraying already - but you might have missed some! LOOK carefully!
BLEACH SANITIZING SOLUTION:
1 part bleach to 9 parts water
PREVENTION METHODS FOR PLANTS THEM SELVES:
Serenade "organic" garden disease control - This will not only kill PM and many other "molds". It also acts as a pretty fair PM prevention spray.....This stuff works by putting live Bacillus subtilis on the leaves that as it lives it creates a pH environment that the PM spores can not live on.
This effect lasts about 2 weeks at a time.
I have a personal problem with Serenade = It stinks like old gym socks! The smell returns anytime the plant is wet down for weeks!
AACT tea - Home made! When you run a simple AACT tea. Remove enough to fill your spaying needs at 18hrs of brew time.....This works EXACTLY the same way as Serenade for far less the cost and for far LESS SMELL. In fact, I don't really smell anything from this when done properly.
AACT TEA FORMULA simple bio tea:
2.38% by volume compost or vermicompost (EWC) per gallon = .38 cups or around half a cup max or about 2 cups in 5 gallons max.
0.5 to 0.75% molasses by volume per gallon = 1.28 to 1.92 tablespoons per gallon. 0.75% is the maximum I use. It is a good bacterial and fungal food.
0.25% (max) Alfalfameal by volume per gallon = 0.64 tablespoon or half a tablespoon.
PLEASE NOTE: I have given you a formula to be able to prepare any amount appropriate for you, down to 1 gallon.....this is for 1 gallon.
You may take a 1 1/2 or 2 gallon container and an aquarium pump with air stone and place the stone into the container (try to have a small diameter container)...Pour in the ingr. and fire up the air pump. Best results will be with the temp of the liquid at 68-70F. Bubble this for 18hrs.
STRAIN through something to remove the solids (use this as a top dress for soil run plants - synthetic or organic) and the liquid be able to run through your sprayer.
Spray down the entire plant with these above spray's.
The next post/section will go on to killing PM on plants
I feel it is time for a complete guide on how to not just control PM but, how to finally defeat it and how to keep it from coming back....as best we can.
You should all understand that PM is not an "IF", It's a "when"......
Lets start with what PM is.
Thanks Wiki
Powdery mildew is a fungal disease that affects a wide range of plants. Powdery mildew diseases are caused by many different species of fungi in the order Erysiphales, with Podosphaera xanthii (a.k.a. Sphaerotheca fuliginea) being the most commonly reported cause. Erysiphe cichoracearum was formerly reported to be the primary causal organism throughout most of the world. Powdery mildew is one of the easier plant diseases to identify, as its symptoms are quite distinctive. Infected plants display white powdery spots on the leaves and stems. The lower leaves are the most affected, but the mildew can appear on any above-ground part of the plant. As the disease progresses, the spots get larger and denser as large numbers of asexual spores are formed, and the mildew may spread up and down the length of the plant.
Powdery mildew grows well in environments with high humidity and moderate temperatures. In an agricultural setting, the pathogen can be controlled using chemical methods, genetic resistance, and careful farming methods. It is important to be aware of powdery mildew and its management as the resulting disease can significantly reduce crop yields. Greenhouses provide an ideal moist, temperate environment for the spread of the disease.
Now then lets start with simple things first.
PM is brought into your op by the spores coming in on air, your clothes or pets you allow outside and into your op.....It can be spread into your op in a house room by any ventilation such as heating and cold air return vents. Anyway air gets into your op! Once the house born op has PM. It has deposited spores through out the ventilation system and the rest of the house. You are now going to have a real pain in the ass cleaning job because the best course will be to clean the whole house! We will cover these things later.
You NEED to understand that once you "see" it on a plant. You now have it through out your grow, by way of the spores the PM puts out to colonize other plants. If you have 2 separate area's that are connected and have any form of air flow between them, including a doorway. That area is now infected with spores also!
You will need to treat the plants in that area - even if you don't "see" PM growing on the plants. It's there. It's just waiting to have the right conditions to attack.
In veg it is far easier to control and kill then in any week over 4 in bloom. Once you have PM in bloom. It is going to be next to impossible to completely kill off due to the nooks and crannies in your buds that this nasty shit LOVES to hide in! You can "see" it on many places but, at this point in bloom. It is in many places in the bud that you will not "see".
Lets start with simple ways to prevent PM.
For operation (grow area) exposure.
Do not come in from working outside on gardens or plants and then work in your op.
Do not allow anyone else in the op!!! (You should know better anyway)
Do not allow any pets in the op. (I know this one can be hard.)
Do not bring into your op, outside sourced clones NO MATTER WHERE OR WHO THEY CAME FROM! Until they have been properly treated for molds and pests!
Make up some HTG or GREEN CURE (more on just what these are later) and dip EVERY single outsourced clone you get in it up to the media surface. Spray the media and the pot with the solution.
Do the same with a pyrethrin concentrate for killing off any pests on the plant and water with a BT product to get any Fungus gnats in the soil.
Do your working in the op after taking a shower and putting on clean clothes IF AT ALL POSSIBLE!
USE AN INCOMING AIR FILTER!!!!!! This is the single most important factor in any stand alone building grow!!!
The use of Silica as a supplement (or built into the soil for water only organic runs) will help the plant repel PM!
NEW AREA SET UP:
If you are setting up a new area or even a new stand alone building. No matter if the equipment is used or new. SANITIZE the WHOLE thing and EVERY SURFACE with a bleach sanitizing solution, BEFORE you bring in your plants! This means EVERY SURFACE, including tables, nutrient bottles, simply EVERYTHING, fans, AC units - EVERYTHING YOU SEE = SPRAY IT and let it dry!
If you are in a room in a house be SURE to block off any air flow into the room from vents, as in heating and cold air returns! You will need to heat and cool this room by it's self for the best results in avoiding PM!
AIRFLOW ,, maintain space between plants and have fans that are moving the air lights on AND off!
Humidity ,,, Keep you RH at or slightly below 50%....very low RH of less then 40% really doesn't help that much. It's a balancing act.
Temps.....Keep temps from swings over 10F lights on to off.....Once PM is eliminated you may have that swing on to off swing increase if your a manipulator of coloring through temps swings. But as a rule. the bigger the swing, the better the chance of PM taking off.
IF, you have a power outage and it lasts for even an hr....if spores are present....your going to be hit and hit HARD with PM!
Spray with a preventive or killing spray right after the power comes back on and get the whole plant and the media surface......LOOK for emerging PM at 2 and especially 3 days after the outage! You should have done a prevent spraying already - but you might have missed some! LOOK carefully!
BLEACH SANITIZING SOLUTION:
1 part bleach to 9 parts water
PREVENTION METHODS FOR PLANTS THEM SELVES:
Serenade "organic" garden disease control - This will not only kill PM and many other "molds". It also acts as a pretty fair PM prevention spray.....This stuff works by putting live Bacillus subtilis on the leaves that as it lives it creates a pH environment that the PM spores can not live on.
This effect lasts about 2 weeks at a time.
I have a personal problem with Serenade = It stinks like old gym socks! The smell returns anytime the plant is wet down for weeks!
AACT tea - Home made! When you run a simple AACT tea. Remove enough to fill your spaying needs at 18hrs of brew time.....This works EXACTLY the same way as Serenade for far less the cost and for far LESS SMELL. In fact, I don't really smell anything from this when done properly.
AACT TEA FORMULA simple bio tea:
2.38% by volume compost or vermicompost (EWC) per gallon = .38 cups or around half a cup max or about 2 cups in 5 gallons max.
0.5 to 0.75% molasses by volume per gallon = 1.28 to 1.92 tablespoons per gallon. 0.75% is the maximum I use. It is a good bacterial and fungal food.
0.25% (max) Alfalfameal by volume per gallon = 0.64 tablespoon or half a tablespoon.
PLEASE NOTE: I have given you a formula to be able to prepare any amount appropriate for you, down to 1 gallon.....this is for 1 gallon.
You may take a 1 1/2 or 2 gallon container and an aquarium pump with air stone and place the stone into the container (try to have a small diameter container)...Pour in the ingr. and fire up the air pump. Best results will be with the temp of the liquid at 68-70F. Bubble this for 18hrs.
STRAIN through something to remove the solids (use this as a top dress for soil run plants - synthetic or organic) and the liquid be able to run through your sprayer.
Spray down the entire plant with these above spray's.
The next post/section will go on to killing PM on plants
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