First Grow, Possible Nute Deficiency, Can someone verify?

[StinkyPete]

Hello,

I've been reading and trying to figure this out on my own, but I really can't tell here.

This is my first time ever growing a cannabis plant. It's been about two months now since seed. I have it indoors mostly under some fluorescent bulbs, and I bring it outside when it's nice and sunny. The seed is some random bagseed; I don't know the strain. It looks 98% healthy except for a few leaves that have this problem you will see in the photo. The one in the photo is probably the largest, and most damaged one. A few other smaller leaves are slowly turning yellow from the tips in, it seems. I also notice a few of the newer, healthy growths at the top have very slight browned tips.

Here are some other angles of the plant for comparison:

I'm confused. From my research, I can't discern whether the plant has nutrient deficiencies, light stress or else.

Some basic info about the grow:

I'm using Roots Organic soil mix. I have not added any additional nutrients other than what the soil contains. I check the runoff pH pretty much after every watering except the last one or two. Last I checked, pH was at around ~6.5. Both plants in the photo have only received carbon-filtered tap water, sunlight, and about 72W of fluorescent light. (I have a little lux meter app on my phone. don't know how accurate it is. seems accurate to me. Reads about 15000 lux on an overcast day. Was about 15,000-50,000 within inches from my bulbs.) Both plants have been under a 24-hour light cycle.

Perhaps, there are a series of deficiencies going on here? I was about to head to the grow shop and pick up some veg grow nutes. But I don't want to waste my time and money (and possibly kill the plant) feeding it nutes if it doesn't need any.

I appreciate any help.


P.S:

I can't tell if what I'm seeing are pre-flowers forming or not. One of those is clearly a stipule. But, the other? Anyone have a guess?

 

[PTSD 4 ME]

kinda the goto on deficiencies

 

[PTSD 4 ME]

phos?

 

[iwltfum]

Not positive, but I believe that is calcium deficiency, which strangely, is not on the chart.

You probably need to up the amount of micro nutrients in your water. Like use well water or add calmag

 

[PTSD 4 ME]

I noticed there is no calcium either..... I wonder why it wouldn't be on the list. who knows.

 

[iwltfum]

I guess calcium deficiency occurs in young growth first as it is stored in high amounts in the mature leaves, so we might be able to cross calcium off the list for now

 

[StinkyPete]

I've looked at those charts to try and troubleshoot this myself. To me it looks like multiple deficiencies at once. Probably calcium, nitrogen and phosphorus at the very least. Because apparently calcium def will appear as little black dots. I'm seeing those dots, but also some rusty red color and a banana-like yellowing.

So, I'm more likely looking at a deficiency than anything else? If so then I need to go out and get some nutes.

 

[iwltfum]

The problem is that it's only happening on one leaf from what I can tell. And that really isn't enough to diagnose a deficiency, esp is it doesn't look like any of them on the list. At this point, I just would remove that leaf and see if it happens to any other ones. even if she is deficient in something, it doesn't look like it's something you need to jump on right away because the rest of the plant looks very healthy. Just keep an eye on it for a week or so.

 

[Stealthboat]

The older plant has a nice green color and you can see the bright green newer growth. It seems to be doing fine atm. That one leaf is probably an older leaf just dying off, doesn't look like a deficiency yet to me. Only thing I see wrong is some slight taco'ing of the leaves. Maybe some additional micronutes/nutes are needed, not quite sure. Whats the temps and humidity like there?

 

[StinkyPete]

The problem is that it's only happening on one leaf from what I can tell. And that really isn't enough to diagnose a deficiency, esp is it doesn't look like any of them on the list. At this point, I just would remove that leaf and see if it happens to any other ones. even if she is deficient in something, it doesn't look like it's something you need to jump on right away because the rest of the plant looks very healthy. Just keep an eye on it for a week or so.

There are approximately 3 leaves with the brown/black/red/yellowing. I removed the one in the photo last night. One of the other two is a smaller, lower leaf. The other is almost as big as the one in the photo.

Aside from that, there seems to be a general yellowing among the very bottom small leaves. And a few random smooth brown burn-like marks on some of the middle leaves.

I went and got some Roots Organic Uprising Foundation dry fertilizer today and watered with 1/2 tsp. Will wait for any type of results.

 

[iwltfum]

There are approximately 3 leaves with the brown/black/red/yellowing. I removed the one in the photo last night. One of the other two is a smaller, lower leaf. The other is almost as big as the one in the photo.

Aside from that, there seems to be a general yellowing among the very bottom small leaves. And a few random smooth brown burn-like marks on some of the middle leaves.

I went and got some Roots Organic Uprising Foundation dry fertilizer today and watered with 1/2 tsp. Will wait for any type of results.

Good on ya mate. Be easy with the ferts as you still probably have some in your soil mix

 

[StinkyPete]

The older plant has a nice green color and you can see the bright green newer growth. It seems to be doing fine atm. That one leaf is probably an older leaf just dying off, doesn't look like a deficiency yet to me. Only thing I see wrong is some slight taco'ing of the leaves. Maybe some additional micronutes/nutes are needed, not quite sure. Whats the temps and humidity like there?

My average temps are around 85-86F with a small fan running, when the plants are indoors. When they are in the sun, my temperature gun picks up anywhere from 90-120F on ground level. I haven't checked the humidity with a device yet. To me, it generally feels like the humidity is ideal. Except some days when it's like 90% and about to rain. I don't know what to do about the tacoing. No matter what the temperature is, it seems like some of the leaves are always a little taco'd. Unfortunately, I can't really change the indoor temps for now. 85 is about as good as I can do. And the sun gives amazing light, but also seems like it would be too hot for the plants.

 

[StinkyPete]

Here's an update from today. I removed some of the afflicted leaves last night. This is what it currently looks like after applying some dry fertilizer and a bit of water.

Is this normal looking?

P.S. Temps outside were rather mild today. Between 65-75 and mostly overcast. Still don't understand why the leaves are cupping.

 

[Cruizer]

I'm thinking it could be the start of a root bound problem.

 

[StinkyPete]

I'm thinking it could be the start of a root bound problem.

After a bit of reading, I think you may be right.

Since this is my first grow, and I got the plant from a friend who started it off, not everything is ideal. I have a feeling that I've been generally re-potting too early. But I would re-pot whenever I noticed signs of slowed growth. Growth would then continue, so I think I'm doing something right. My big plant is currently in a 1-2 gallon pot. When I transferred it to this pot, I noticed there weren't a mass of roots. It was definitely not root bound like in photos I've seen. The roots had reached the bottom, but didn't really take up the whole mass. So, right now I'm thinking there's no way it could be root bound in it's current pot. There's no way the roots have already taken up the whole mass of soil.

I just checked the plant about 20 minutes ago and noticed it had started drooping overnight. Stems felt weak and bending over. I fed it some water and tested the runoff pH at about 6.5-7.

If this is a root related problem, I'm not sure what to do. I'm assuming to just re-pot it in the same pot and try to clean up the root area a bit.

Side note: My smaller plant seems to grow with intense force. Not long after the taproot sprung from the surface, the main root had already reached the bottom drainage hole! Another root even popped up out of the surface! I had thought surely this plant was root bound and it was time for a transplant. Wrong! I took the seedling out of the soil and noticed there were barely any roots at all. Strange. Well, regardless, the smaller plant is gigantic. Half the size of the older plant already. Stem is already thicker and bigger too. Bigger leaves.

 

[Cruizer]

Can you get her out of the pot and check the roots? Is the soil still wet or drying slow? I have a plant in one of those plastic pots and she didn't like it until I cut some vertical slits around the perimeter of the pot to let in fresh air. If you want to re-pot in the same pot you can do a root prune and cut off 1/3 of the roots, make up some fresh soil, and replant. Down time is about a week.

Edit: I think the other leaf got burned by the light.