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New leaf growth purple! Help Diagnose!

H

Hammer

New member
Having some issues with my plants. Plants are grown from seed. Recently transplanted from 1-3 gallon pots. Plants were well watered with 20%+ runoff with a nute soln with a 0.7 EC and a 6.7 pH.

Previous to this leaf growth had slowed to a snail's crawl and plants showed signs of leggy woody purple stems. Leaves became yellow with mottled purple/brown spots that turned necrotic.

After the upgrade flush and RE application of nutes healthy green growth seems to be re establishing itself however I'd like the community to weigh in on this purple leaf growth?

My best guess is there is a root problem caused by over watering.

Thanks for everyone's input
 

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What media are you using? I don't have enough experience to help answer your question but are you using soil or coco or mixture of both? 6.7 ph seem like soil and what soil are you using? This will help those with more experience figure out why you girl are turning purple.
 
What temps do you keep your room at? I've had new growth be discolored due to cooler night tempuratures. The slow growth you talk about can also be caused by temps not being high enough, though I'm not sure about the yellowing.
 
They have a Mg deficiency I do believe. The question is why? Is there a shortage in feeding, or is the plant not accepting it?
 
I'm to busy right now to give a proper response. For now, I'm just going to say it's a boron deficiency. To fix it, water with 3% hydrogen peroxide (the stuff you find in the 1st aid isle in a supermarket will work) and something with Fe, Zn, B, Ca,Mg, N at 1/4th the recommended rate. It's being caused by your pH being to high and/or a root rot that is starting to form. I'll type a longer response when I have some time later.

Note:
Fe + H2O2 will react and form ferrous oxide so don't mix them directly.
 
Calmag can be add to water feeding or put in a sprayer and give a plant a nice morning spring dew. Make sure if you mist the plant the light is not on so it doesn't burn the leaves unless you use CFL.

BTW, what light are you using for your plant. You leave so many information out. The lesser the info the harder to diagnose the true cause of the problem.
 
Thanks guys for responses.

Here are further details:

Medium is triple mix with added perlite
Temps are 75-82 F Hum 40-60%
Light has been HO T5 Full spectrum. Moved under Full spectrum LED two days ago with transplant to bigger pots
I have included cal-mag with last nute app and have cal mag added to a misting bottle.

I still have not been able to find any online or literature that shows cal mag deficiency producing new leaves as purple.
 
Triple mix...what is that...if it has coco in it then your ph should be 6....if there is any dirt in there than up to 6.5 ....

Brown spots looks like bad ph...

Purple color could be strain related...what is it..do you know?...or bag seed?
 
I would like to say there probably isn't anything wrong with your plants. I am surprised no one mentioned or asked, what seeds are you growing? I grow from seeds, I have had different plants with reds and purples in the stems, they turned out to be excellent plants, leaving me to believe color like this sits in the genetics.
 
I said I would give a real reply later, here it goes:
The bad news: I'm seeing a lot of problems happening with these. Boron is causing the purple color. People are getting cal mg because they use some of the same channels.
The good news: It's basically all happening because of some easy to fix problems.

This is an easy to follow chart of where different deficiencies are expressed. Link
You have mobile and immobile nutrients. Immobile nutrient deficiency's is ALWAYS expressed in the new leafs where as mobile deficiencies are ALWAYS expressed in the old leafs. That being said calcium is somewhat mobile so i'm 100% sure that purpling isn't caused by calcium or strain. Although calcium IS one of the problems. This guy sums it up better than I will be able to type it. Youtube Link
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I'm also going to link this video for those of you that are willing to spend 14min on a college level soil science explanation. Link
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First off, you can easily get your pH to 5.2 without causing this many problems. This entire thing is basically explaining why you should aim for 5.8.

Nutrient availability chart
Nutrient availability graph
You can see calcium deficiency . Some of the bigger leafs are forming those small brown spots. Link
You can see boron deficiency because of the purple in the NEW growth right next to the meristem. Link
You can see magnesium deficiency can be seen in because of the bright yellow tips along with innerveinal chlorosis Link
You can see Iron deficiency which tells me your pH is WAY to high. Link

The plant is not producing as much chlorophyll due to the pH being on the high end causing lack of Mg availability. (Chlorophyll: C[SUB]55[/SUB]H[SUB]72[/SUB]O[SUB]5[/SUB]N[SUB]4[/SUB]Mg)

I'm interested to know the process you are using to get a runoff pH of 6.5.
I should also mention, Soil pH and water pH are two entirely different things. High pH tends to mean you are lacking Fe, S, and Mg.

Add Magnesium Sulfate to your water/soil. It will help reduce the pH and make existing iron more available. It will also help with your sulfur deficiency. Link
Add Aluminium Sulfate to your water/soil. It will lower soil pH and in doing do grab some nutrients out of your soil. 'purifying' it of nutrients depending on it's oxidation state. Link

How often do you water?
If it's less than once every 1-3 days (so like once a week) you are letting them sit in standing water too long causing root rot which can attribute to that.
Generally when you see this much chlorosis you have some root rot at that point.
The common ones are Fusarium, Rhizoctonia, Phytophthora, and Pythium if you feel like googling them.
Just add more perlite in your soil to fix that, if it is a water problem.
H2O2 will kill all the fungus and bacteria in the soil if you apply it at around 3% concentration a few times. I have watered clones with it, it is safe to use.

Hope this helps clarify.
- Komatchi
 
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I appreciate your pictures, Hammer: I've never seen anything like that, and I'm very curious to know what's causing it!!!
 
Komatchi, so what you're explaining is that there are mineral deficiencies, pH issues in the soil and perhaps over-watering? You are saying that there's both chlorosis due to over-watering and discoloration due to deficiencies?

I'm a hydro grower, but I'm trying to learn as much as I can to add to my understanding of cannabis plant growth. The "college level" explanation of how deficiencies in the soil work was very interesting. First, deficiency symptoms appear in older leaves which have sent mobile elements (like nitrogen) to younger growth, but since there is some kind of nutrient deficiency in the soil, the older leaves get sapped of nutrients first. With the immobile elements (like calcium), deficiency symptons appear first in the younger leaves because the older leaves don't MOVE immobile elements to younger leaves.

So what you are recommending is to fix soil pH so roots can transport what they aren't transporting to the plant right now.
You are recommending more caution with watering and potential root rot/drowing (add perlite). Drowned or rotted roots can't transport nutrients.
You are recommending some supplemental minerals. If the pH and water problems get fixed, might that take care of the deficiency symptoms appearing on the leaves, if the nutrients Hammer is using are the correct ones? It seems you are saying that the fundamental problem is at the root level: fix that so nutrients can be supplied as necessary.
 
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