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P def -- why for?

W

whythefnot

Member
So it looks to me like I have some minor P def.

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This is 2xFFOF, 1xFFLW soil, with some small amounts of blood meal and Peruvian seabird guano mixed in, in 5gal fabric pots. I've had some pH issues with this soil -- it was super high for a while (kind of like me! hehe) but stabilized in the mid 6 range about 3 weeks ago. I have not checked it since then because of how much water I have to put on the plants. The root systems have been saturated since getting the pH issue fixed (took a flush, followed by some compost tea) but are currently adjusting to recently-installed blumats (and drying out for the first time) providing clean tap water only, at 78ppm and ~7.0pH.

It's occurring on one or two leaves on 3 out of 8 plants. So it's not bad yet, but it's definitely got potential to get worse. I noticed it last night for the first time.

I wouldn't think that I'd be lacking any P, due to the foxfarm soil and the PSG I added. So what gives? Any thoughts?
 
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W

whythefnot

Member
I had some severe leaf curl today on just two neighboring branches of the largest plant. I pulled it out to check its pH and it was pretty low...runoff was something like 5.8. So I guess that would be my problem. I dosed the worst plant with a light pH 8.0 solution and I adjusted the res to 7.1 from 6.8 to try to bring things back up. I don't know how I have so many pH issues in soil.

P is the second of all the micros/macros to get to get locked out at a low pH, should have known.

I'm still all ears if anyone wants to chime in.
 
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W

whythefnot

Member
Nope, no sign of fungus gnats or broad mites as far as I can see. I haven't seen any fliers or crawlers this whole grow (first grow in this location) which is pleasantly surprising.
 
R

Ratzilla

Member
Veteran
While not being sure the pictures don't look like a P deficiency to me.
When I see things on a leaf edge it makes me think K.
A P deficiency shows on the bottom of the plant and the leaf tips turn bluish black.
Can you get a shot of the affective leaf, leaves while it is still on the plant?
Something to know about P uptake.
The Mycorrhizae fungi is the main player in up taking phosphorous from soils.
So maybe you done something to have hurt the microbe herd.
Liquid P and or high ratio of P fertilizer hurts the development of the mycorrhizae fungi .
A real paradox
High ratio of P ferts above a 8 and or liquid P greatly retards the fungi growth the very thing that is responsible for their up take.
Heh heh heh I don't think your showing a P deficiency.
Ratz :tiphat:
 
W

whythefnot

Member
Ratzilla said:
While not being sure the pictures don't look like a P deficiency to me.
When I see things on a leaf edge it makes me think K.
A P deficiency shows on the bottom of the plant and the leaf tips turn bluish black.
Can you get a shot of the affective leaf, leaves while it is still on the plant?
Something to know about P uptake.
The Mycorrhizae fungi is the main player in up taking phosphorous from soils.
So maybe you done something to have hurt the microbe herd.
Liquid P and or high ratio of P fertilizer hurts the development of the mycorrhizae fungi .
A real paradox
High ratio of P ferts above a 8 and or liquid P greatly retards the fungi growth the very thing that is responsible for their up take.
Heh heh heh I don't think your showing a P deficiency.
Ratz :tiphat:
Click to expand...


Thanks, I had considered K but I never saw a single spot of yellow. They went from green to gray. And yes, it's at the leaf edges, but not always. It's pretty spotted.

The photos I posted are of the leaf while it is still on the plant (I certainly didn't cut it off), not sure which one of us is confused here, could be me.

I described my soil in the first post, that's all there is in it. PSG is pretty even across the board, I think it's like 12-11-12 or something close, so I doubt it's anything like that. Maybe a dozen small pellets per 4-5gal pot. It's been about 2 weeks since I've used any compost tea on them. I'm going to be brewing another batch. I typically just do EWC @ 2.38% and BSM @ 0.05% by volume, as per microbeman. Any suggestions for it? I have some rooting myco powder, but I know it doesn't brew in a tea. Maybe I'll just put some under my blumat drippers...
 
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W

whythefnot

Member
It got much worse overnight. I guess my res adjustment wasn't nearly enough. I watered with ~ 10 pH and left the res @ ~7.2. For some reason I always have pH issues in soil when it starts to dry out.
 
W

whythefnot

Member
mkkaaaay...so here are some pics of how this has been developing.

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I'm not so sure it's a p def anymore guys...


As you might image I'm pretty eager to get this taken care of. And once that's done, I'm really interested in how I can change my behavior to prevent this in the future. Anyone?
 
W

whythefnot

Member
No nutes, no teas for 2 weeks prior to this incident. I checked runoff of one plant and it was pretty low, as per my second post. I dont really want to check the rest because it would involve me removing the blumat so I can get the plant out, but if this progresses I'm certainly willing to do that.
 
W

whythefnot

Member
I should point out that those leaves that look fried and crispy are actually soft and supple. It looks a lot like nute burn to me too, but I would expect the leaves to flake off if that were the case. I rubbed each leaf before I took a photo of it to get a better idea of what's going on. If it had been nute burn, those crispy edges would be gone now.
 
R

Ratzilla

Member
Veteran
I would think that the leaf tips curling UP would be telling?
If they were curling down I would think over feeding but they are curling up?
When at a loss I go back to figuring it out and I start with if it is a mobile or Immobile nutrient.
If it is a mobile it will show on older (bottom) leaves first.
If it is a immobile it will show on new growth first(tops).
Heh heh heh it looks like your plants are showing in the middle.
Plants will show signs if pH is too high by yellowing around the middle of the plant (middle lower) with slow growth rates, stunting, small leaves.
If the pH is too low it gets taco leaves up top with many leaves twisting away from the light
I really don't see any of this in your plants.
I often think screwing with the pH in organic gardening practices creates many confusing signs.
I usually think tips curling up to be over watering practices.
I honestly don't know what else to say.
Wish I could be of more help to you.
Ratz :tiphat:
 
W

whythefnot

Member
Ratzilla said:
I would think that the leaf tips curling UP would be telling?
If they were curling down I would think over feeding but they are curling up?
When at a loss I go back to figuring it out and I start with if it is a mobile or Immobile nutrient.
If it is a mobile it will show on older (bottom) leaves first.
If it is a immobile it will show on new growth first(tops).
Heh heh heh it looks like your plants are showing in the middle.
Plants will show signs if pH is too high by yellowing around the middle of the plant (middle lower) with slow growth rates, stunting, small leaves.
If the pH is too low it gets taco leaves up top with many leaves twisting away from the light
I really don't see any of this in your plants.
I often think screwing with the pH in organic gardening practices creates many confusing signs.
I usually think tips curling up to be over watering practices.
I honestly don't know what else to say.
Wish I could be of more help to you.
Ratz :tiphat:
Click to expand...


You're right -- it's right in the middle of the plants. It's actually on the leaves that are getting the most intense light, if that says anything. I think I pointed out in the first post that two branches of the worst plant showed some serious curl and yellowing at the tips on day 2 of this fiasco. The subsequent dosing of higher-pH (~8.0) seemed to take care of that -- by day 3 (last night), I couldn't even find the two prominent branches, so they must have gone back to normal.

I think you're right about 'confusing signs' -- I've seen some weird stuff in the weeks after serious pH adjustment, even on this grow. But everything had been going great for well about a month, and they had been getting water only for a few weeks.

I would have leaned toward high pH myself, except I've seen how these plants react to high pH and this wasn't anything like that. I'm not saying that it's not high pH, just that this doesn't look anything like the episode I had over a month ago, which was definitely caused by high pH and fixed by a very low pH solution.

There's no chance of it being overwatering. I had only watered them very lightly after the flush. Once I installed the blumats things dried out even more. This issue corresponds perfectly to the pots drying out. The pots that were drier show the symptoms worse consistently throughout the room. I had one blumat runaway when I first installed them, so all the water that ran out flowed to the 'low' side of the room. The three plants on that side (one of which was the runaway) got soaked that day. They are the ones that are not pictured here, because they are not showing signs of def. But I guarantee if I let them dry out right now they'll show these same signs.
 
W

whythefnot

Member
I guess I should also mention that I did a light neem spray on day 2 with lights on. I've never had an issue spraying with lights on, and my lights go off in the middle of my sleep cycle, so I usually ignore that rule of thumb. It was the only time I've sprayed them with anything. Could that have caused the spotting in particular? Problem is, I saw similar spotting before spraying neem...
 
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