Help with diagnosis

[Glookies1]

Leaf pic attached.

This is occurring in veg.
What it’s not: temps, light burn, nutrient burn, or PH.

it also didn’t appear to be a fungus (at least I can’t see anything under a scope)

It’s an organic soil grow (M3 water only soil) I’ve had great luck with the soil for a couple years, but I’m not ruling out a bad batch, ergo some type of deficiency.

PH in and PH out are both good. Temps good, airflow good, lighting good. All the same parameters I’ve used for years.

the only environmental issue I’ve had is extremely low humidity. Like 30%.

For the most part that’s been corrected with humidifiers and misting,

I have some in flower that exhibited this issue in veg, although they look horrible and most of the fans have crisped up, the buds are actually doing ok.

anyone seen this pattern?

 

[RichieRich6988]

It looks to me like it could be what ever nutes you are adding may be contaminated or old. Like you said look at the pattern, which to me shows that its coming from the plant itself. Do all the leaves look like this one? or is it only the top or lower part of the plant. Or it could possibly be since you are doing a scrog grow the netting or rope that you are using. I always wash my netting before using for scrog grows.

 

[Glookies1]

It looks to me like it could be what ever nutes you are adding may be contaminated or old. Like you said look at the pattern, which to me shows that its coming from the plant itself. Do all the leaves look like this one? or is it only the top or lower part of the plant. Or it could possibly be since you are doing a scrog grow the netting or rope that you are using. I always wash my netting before using for scrog grows.

I'm adding zero nutes. It’s a water only pre mix soil.

it’s not a scrog this go around either.

it appears on older fan leaves first.

 

[Bill284]

I'm adding zero nutes. It’s a water only pre mix soil.

it’s not a scrog this go around either.

it appears on older fan leaves first.

I've seen phosphorus and potassium deficiencies cause black spots like that.
She isn't eating properly imo. I'd flush the pot with ph,d water and then try and feed her see if that helps. As long as your sure that no pests have invaded your grow room.

 

[Emilya Green]

looks like a phosphorus deficiency to me. Phosphorus uptake is greatly assisted by the myco fungi that grow around the roots. Did you add any when you built that container? A couple of tablespoons of triple phosphate on the top of the soil should supplement what is missing, but your chore is to figure out why it is missing in this plant on this grow.

 

[Glookies1]

I've seen phosphorus and potassium deficiencies cause black spots like that.
She isn't eating properly imo. I'd flush the pot with ph,d water and then try and feed her see if that helps. As long as your sure that no pests have invaded your grow room.

It’s not pests. Zero evidence of that under a microscope.

phosphorus and or potassium crossed my mind too. It’s why I’m thinking the
screwed up mixing a batch of soil.

I’ve checked ph in and out, both good. It’s not a Ph problem.

I’m also thinking that abnormally low humidity is playing In somehow.

I’m running humidifiers and still struggling to hit 40%.

increasing humidity and misting the plants does seem to be helping in veg.

the plants in flower have basically lost all their fan leaves, but surprisingly bud developed isn’t to bad at all.

The plants in flower only have 2 weeks to go. It’ll be a slightly smaller yield than normal, but not a total loss.


I’ll be up potting in the next week or so from 3 gal pots to the final 10 gal flowering pots and using a new batch of soil.

lm kinda hoping that cures the problem.

 

[Glookies1]

looks like a phosphorus deficiency to me. Phosphorus uptake is greatly assisted by the myco fungi that grow around the roots. Did you add any when you built that container? A couple of tablespoons of triple phosphate on the top of the soil should supplement what is missing, but your chore is to figure out why it is missing in this plant on this grow.

I do tend to agree it’s a nutrient uptake problem more than a fungus or disease.

it’s a premix water only soil. M3 is the brand. I’ve had good luck with the stuff for years. So I don’t add anything. Other than a little molasses to feed the bio mass. I’m just at a loss as to why. Ph in and run off PH are both good.

it’s entire possible I just got a bad batch of soil.

really low humidity (which I’ve been fighting) will cause a plant to stop moving water. They just sit there and not grow, and eventually the fans will crisp up.

Maybe I’ll try mixing up a PK foliar feeding and see if it helps.

 

[Glookies1]

I’ve grown for years and seen lots of stuff. I’m usually pretty good at diagnosis.

Just goes to show ya that there’s always more to learn

 

[Glookies1]

Update:

I’ve up potted from 3 gal to their final 10 gal smart pots.

gave them a good soaking and foliage mist with the repot, and raised the lights a bit to let them settle in.

It’s been about 36 hours since the up pot, snd they seem to be doing much better.

Older growth still has some ugly spots, but it seems to not be spreading and new growth is more green/ less purple.

(some purple is normal for this strain)

hence, at the moment, I’m leaning towards it was a deficiency.

I’ll know more in a few days of growth.

 

[Glookies1]

Whatever it was, getting them into their 10 gallon pots seems to have fixed it. There about 4 weeks after light change now

 

[Glookies1]

looks like a phosphorus deficiency to me. Phosphorus uptake is greatly assisted by the myco fungi that grow around the roots. Did you add any when you built that container? A couple of tablespoons of triple phosphate on the top of the soil should supplement what is missing, but your chore is to figure out why it is missing in this plant on this grow.

I’m pretty sure you’re diagnosis was correct. I’m chalking it up to the soil company mixed a bad batch.

They've recovered really well.
still have 5 or 6 weeks to go.

 

[Glookies1]

Starting to sugar up

 

[013]

A late spring snow storm, hello Frosty!!! Well done

 

[Glookies1]

A late spring snow storm, hello Frosty!!! Well done

They’ve got at least 4 weeks to go too. They’re getting 3, 15 minute bursts of UVB lighting right now. I’ll increase that in a week or so.

if you’ve never tried UVB, it does really kick up the “sticky”

 

[Bill284]

They’ve got at least 4 weeks to go too. They’re getting 3, 15 minute bursts of UVB lighting right now. I’ll increase that in a week or so.

if you’ve never tried UVB, it does really kick up the “sticky”

I herd it gives them a sun burn and making bigger stickier trichomes is their reaction. Since they don't have sun screen.
So its working?
I herd you don't do it till your ready to harvest.

 

[Glookies1]

I herd it gives them a sun burn and making bigger stickier trichomes is their reaction. Since they don't have sun screen.
So its working?
I herd you don't do it till your ready to harvest.

Oh, it CAN give them sunburn, which is why you introduce it slowly.

It’s the sunburn that causes the plant to make more trichs as a way to protect itself. It absolutely works.

Too much will burn up the top of the canopy. Looks like any other light burn.

I start giving uvb as soon as the flowers pop pistils. Small busts through the day.

As it matures I’ll increase the expose to a max of 30 min early day, 45 min mid day, and 30 min and hour before lights out.

 

[Bill284]

Oh, it CAN give them sunburn, which is why you introduce it slowly.

It’s the sunburn that causes the plant to make more trichs as a way to protect itself. It absolutely works.

Too much will burn up the top of the canopy. Looks like any other light burn.

I start giving uvb as soon as the flowers pop pistils. Small busts through the day.

As it matures I’ll increase the expose to a max of 30 min early day, 45 min mid day, and 30 min and hour before lights out.

Sounds great, got any pics of the improvement?

 

[Glookies1]

Starting to sugar up

Sounds great, got any pics of the improvement?

Not really. I mean, the last pics I posted a week ago were when I started UVB, but they were taken with lights on and no flash.

Lights off and a flash shows the sugar better

I’ve used UVB for years.

 

[Glookies1]

I herd it gives them a sun burn and making bigger stickier trichomes is their reaction. Since they don't have sun screen.
So its working?
I herd you don't do it till your ready to harvest.

You can see some leaf burn and curl starting from the UVB.

 

[Glookies1]

They also got a one time feeding of Pk13/14 yesterday.

I’d expect to see a bit of nute burn on leaf tips in a couple days, followed by a second round of new pistil growth.

The buds in this strain don’t get huge. They do however have great density.