Treating PM/mold in flower

[Loc Dog]

I am not sure how to change the title. I wouldn't say I am convinced I don't have to deal with PM in flower, it just seems as though that is not my only issue.



That is a really good idea! Thanks.



I will do some reading on this slurry method.



They are still kicking along, the main issue apart from the gnarly leaves is that the bud sites are developing really poorly, things are shaping up for a very sub par yield. I am hoping that things will improve in this respect once I get the medium/nutes sorted out.

It is not possible for anyone to edit the title.

They are obviously in need of flushing, heavily. Just do not go below 300 PPM.

That is why I hate it when people say that coco is hydro. It is not. Hydro does not get salt buildup. You can check the solution at anytime and get exact results. If PPM goes down feed more. If it goes up feed less. I only use coco for mothers, and plants to make seeds.

One very interesting system i am considering is PPK, which is confusing, and most threads were poorly written, so need to read for days to figure it out. The one guys method i like uses Turface, which is inert. It is a combination of multiple top feeds a day (automated), and a central reservoir with wick effect, in case top feed fails. With the reservoir, you know how plants are doing easily.

 

[Sam_Skunkman]

I did not read the whole thread but next crop use varieties that are resistant to PM.
PM mostly comes for varieties that have WLD as a parent or poly hybrids that have WLD varieties in them.
Unfortunately almost all varieties sold today are poly hybrids with WLD (Indicas) in them.
Why fight the flow? If you try tropical, equatorial varieties PM is seldom seen, they have natural resistance or they would be useless at the equator or in jungle humid weather.
You can try cultural controls, higher light levels, dry low humidity levels, good air movement, I see UVB being used in the greenhouse industry here, just a short exposure seems to zap PM, but why fight the tide? Use resistant varieties is where I would start with your next crop.
-SamS

 

[Loc Dog]

I did not read the whole thread but next crop use varieties that are resistant to PM.
PM mostly comes for varieties that have WLD as a parent or poly hybrids that have WLD varieties in them.
Unfortunately almost all varieties sold today are poly hybrids with WLD (Indicas) in them.
Why fight the flow? If you try tropical, equatorial varieties PM is seldom seen, they have natural resistance or they would be useless at the equator or in jungle humid weather.
You can try cultural controls, higher light levels, dry low humidity levels, good air movement, I see UVB being used in the greenhouse industry here, just a short exposure seems to zap PM, but why fight the tide? Use resistant varieties is where I would start with your next crop.
-SamS

How many watts of UVB for how long??? I have not had PM in awhile, but like to be prepared.

I think consensus is that the plants were very sick from overfeeding/salt buildup, and that was main problem.

 

[Eager2Grow]

It is not possible for anyone to edit the title.

They are obviously in need of flushing, heavily. Just do not go below 300 PPM.

I flushed the medium with about 25 litres per plant/container last night until the run off was reading just under 400 ppm. Now do I just go back to feeding the plants, but starting with half strength nutes?

Someone mentioned that the ph I had been using was a little too low. I can't get to the store to get more ph calibration liquid for my pen, but I plan to get some ASAP and start adjusting the ph of my water to 6.0 before feeding.

That is why I hate it when people say that coco is hydro. It is not. Hydro does not get salt buildup. You can check the solution at anytime and get exact results. If PPM goes down feed more. If it goes up feed less. I only use coco for mothers, and plants to make seeds.

This is my seventh indoor run, all in coco/perlite mixed 70/30 and I have never had this problem before. I have looked into hydro before but handwatering in coco just seemed so much more simple. Between this issue and the frequent annoyance of fungus gnats I am starting to question that conclusion. What method are you currently using?

 

[ChaosCatalunya]

I did not read the whole thread but next crop use varieties that are resistant to PM.
PM mostly comes for varieties that have WLD as a parent or poly hybrids that have WLD varieties in them.
Unfortunately almost all varieties sold today are poly hybrids with WLD (Indicas) in them.
Why fight the flow? If you try tropical, equatorial varieties PM is seldom seen, they have natural resistance or they would be useless at the equator or in jungle humid weather.
You can try cultural controls, higher light levels, dry low humidity levels, good air movement, I see UVB being used in the greenhouse industry here, just a short exposure seems to zap PM, but why fight the tide? Use resistant varieties is where I would start with your next crop.
-SamS

I get PM on pure sativas outside on sunny windy balconies, I now believe that it is endemic in the Oak forest around here.

To answer OP, Peroxide is good for washing it off, not "curing it" Bicarb washes seem to work and Milk, @30% spray certainly does.

 

[Loc Dog]

I flushed the medium with about 25 litres per plant/container last night until the run off was reading just under 400 ppm. Now do I just go back to feeding the plants, but starting with half strength nutes?

Someone mentioned that the ph I had been using was a little too low. I can't get to the store to get more ph calibration liquid for my pen, but I plan to get some ASAP and start adjusting the ph of my water to 6.0 before feeding.



This is my seventh indoor run, all in coco/perlite mixed 70/30 and I have never had this problem before. I have looked into hydro before but handwatering in coco just seemed so much more simple. Between this issue and the frequent annoyance of fungus gnats I am starting to question that conclusion. What method are you currently using?

i would go by what your pen says till you can get calibration solution. I use those cheap yellow and black ones, rinsing in distilled water before and after calibration, and only check every few weeks. It is only off by .1, when it is.

For fungus gnats, stockpile your water for 3 days before use, and put a mosquito dunk in it (BTI).

I use RDWC, but have been doing various hydro methods for years, and have had all the problems, so have all the solutions. DWC might be a better first attempt. With either, the water needs to be below 70F and above 65F or you will have problems. A chiller is expensive. I am in basement so not an issue. Some throw a frozen soda bottle filled with water once a day. Here is the method I use, but have made a few improvements -

https://www.icmag.com/ic/showthread.php?t=267918

I am going to PPK with Turface to replace coco, for mother and breeding plants. Basically a bucket on top of another bucket with lid. Top bucket has tailpipe from home depot plumbing (straight drain for sink) attached to bottom of top bucket, going through lid of bottom bucket. Tailpipe has screen on bottom end to keep wicking media in it. Top bucket and tailpipe filled with Turface. Bottom bucket connected together with tubing close to bottom, connected to central bucket with float valve (optional but could go away for weeks and takes care of itself). Then a top feed system connected to pump and timer, fed a number of times a day. If for any reason the pump fails, they will still wick from bottom.

 

[Eager2Grow]

I have found neem/azadirachtin drenches pretty effective for fungus gnats.

I grow in a garage and don't have a lot of control over the temps. That is part of the reason hydro seemed more difficult, or at least a fair bit more expensive. I should look into this further though.

 

[Loc Dog]

I have found neem/azadirachtin drenches pretty effective for fungus gnats.

I grow in a garage and don't have a lot of control over the temps. That is part of the reason hydro seemed more difficult, or at least a fair bit more expensive. I should look into this further though.

Azadirachtin should not be used in flower. They recently found that when heated (smoked or vaped) it produces poison.

 

[Eager2Grow]

I won't use it past mid flower, and try not to use it beyond the first couple weeks of flower. I should clarify that by drenches I meant watering it into the coco, not spraying it on the plant. I don't spray neem/azadirachtin in flower at all.

 

[Sam_Skunkman]

I get PM on pure sativas outside on sunny windy balconies, I now believe that it is endemic in the Oak forest around here.

To answer OP, Peroxide is good for washing it off, not "curing it" Bicarb washes seem to work and Milk, @30% spray certainly does.

Odd, I would grow several large batches of seeds I imported from Afghanistan and 3/4 of them got PM to some degree in my greenhouse 5-10 foot tall plants. They would be growing right next to equatorial tropical NLD varieties that seldom if ever got PM even if the plant next to it was covered with PM so it was white all over. I would just kill them normally if they had PM. I really did not want to control the PM my goal was to find or breed resistant varieties to PM, same with Botrytis, you should prefer resistance to treatment, to be honest.
-SamS

 

[brown_thumb]

Odd, I would grow several large batches of seeds I imported from Afghanistan and 3/4 of them got PM to some degree in my greenhouse 5-10 foot tall plants. They would be growing right next to equatorial tropical NLD varieties that seldom if ever got PM even if the plant next to it was covered with PM so it was white all over. I would just kill them normally if they had PM. I really did not want to control the PM my goal was to find or breed resistant varieties to PM, same with Botrytis, you should prefer resistance to treatment, to be honest.
-SamS

That certainly makes sense to me... but couldn't nutrition be a factor as well?

 

[rjrom90]

That certainly makes sense to me... but couldn't nutrition be a factor as well?

Yes. Since indica varieties prefer higher nutrient dosage and low humidity climates, this can easily allow fungal diseases to take advantage of these factors.

 

[The Hermit]

How much did you dilute the H202? I have a few bottles of 3% H202 lying around.

I am also curious about the specifics of the aloe vera and epsom salt mix.

Sorry for the delay, took me a while to find my notes:

Initially I diluted 3% H202 1:1 with plain water but in the end i was spraying it undiluted with no adverse effects

as for the aloe/epsom mix it was 1 teaspoon (5ml) of Epsom Salts and 1/4 cup of Aloe Juice in a gallon of water. I'm making my own aloe juice here so I probably ended up chucking a bit more in.

Hope that helps!

 

[gtg341w]

DocTim420 thanks for the tip, I have a few minor spots showing up on my thickest plant, and I have been snipping the leaves that have PM, but I need to give them a good milk treatment.

 

[DocTim420]

It will work in most cases.