Auto in bloom showing spots on upper leaves?

[Budclarkson]

Auto is 7weeks about 3 wks in bloom. RH was 65%. Just lowere to 58%. Temp is 74F.

Just noticed these spots on some top leaves. Not sure why or what.

 

[Budclarkson]

Here is a pic from a week ago - it’s the bug one with the bent LST branches.

I fed it General Hydoponics Micro and Bloom about half dose last week. CalMag every other watering. I did see one bottom leaf with some yellowing after the feed.

 

[SnoopingAsUsualI]

Phosphorous deficiency as far as I can tell

 

[Budclarkson]

I have been perusing “brown spot” threads and light stress and Mag deficiency seem to be a common theme. @GNick55

Some good commentary by Member @Bdubs here:
https://www.thcfarmer.com/threads/p...s-on-leaves.154379/?post=3024530#post-3024530

The idea of magnesium is that it is a core building block for photosynthesis and absorption of light. When a deficiency of magnesium shows up, it can be in the form of light burn and browning. The plant can’t take more light from a deficiency of Mag and therefore burns the leaf. With a magnesium deficiency also follows a lesser ability to process phosphorus and enzyme creation is hindered. Which can show up as other deficiencies basically pointing back to magnesium. I think this is why so many people with a deficiency showing up, people always recommend magnesium, but can be difficult to indenting if not spotted earlier. It may be misconstrued as to needing other nutrients and leads to toxicity of the other nutrients because it just can’t perform the correct reactions with the low magnesium availability.

That CalMag is going to kick up this girls production and reward you for reaching out! Add the calmag and make no adjustments to your feed schedule/mix. If you want another critical nutrient that can help dramatically, along with the calmag, is Floralicious by gh. You’ll use 1-2ml/gallon of it all grow and taper off last couple weeks, same as the calmag.

 

[Budclarkson]

So maybe raise or lower the light intensity. Wait for the plant to dry out and hit it with Calmag - what concentration? Also does cal mag alter PH of your water - have not been checking it.

Should I get this GH Floralicious? Non-plus version if I can find it?

 

[GNick55]

So maybe raise or lower the light intensity. Wait for the plant to dry out and hit it with Calmag - what concentration? Also does cal mag alter PH of your water - have not been checking it.

Should I get this GH Floralicious? Non-plus version if I can find it?

there’s probably a bit of calmag in your nutrients already so you won’t need much 2-3 ml per gallon,. some calmag has nitrogen in it which i wouldn’t want.
i’m curious about why soo many 3-4 bladed leaves?

 

[RGWD0202]

Gnick per usual is correct.. top of plant issues typically light stress or a micro nutrient deficiency such as magnesium. magnesium and phosphorus usually go deficient together, typically caused by too low of a Ph. I see you are using general hydroponics, it’s what I use as well and it drops your Ph way down. It says not to ph but make sure you do. If you aren’t checking ph both magnesium and phosphorus uptake better in the 6.5-6.8 ph range. I’d start with checking your ph make sure it’s in range, (soil 6.2-6.8) (coco I believe is 5.8-6.2…) if it’s the ph very easy fix and should return back to healthy once corrected. If not ph go on to adding nutrients such as calmag. After mixing your general hydro nutes let it sit for 30-40 minutes, this allows the buffers in the solution time to work and should bring the ph back up before applying to the plants. Check the ph again and see if it’s gone back up.

 

[LoveGrowingIt]

I have been perusing “brown spot” threads and light stress and Mag deficiency seem to be a common theme.

Plants often need more Mg when grown under LED lights. I've been trying to learn why that occurs. According to one theory, it may be due to an incomplete light spectrum.

 

[Bdubs]

I always associate 3 leaf finger growth with major root stress. Root bound, root strangling, root decay and rot, over saturated soil (suffocation), fungus gnat maggots eating roots. Some of the things. But it is going to have to do with the root health on the 3 finger leaf growth. Major stress signal.

 

[Bdubs]

I always associate 3 leaf finger growth with major root stress. Root bound, root strangling, root decay and rot, over saturated soil (suffocation), fungus gnat maggots eating roots. Some of the things. But it is going to have to do with the root health on the 3 finger leaf growth. Major stress signal.

Light is a big one for 3 fingers, like revenging. Also, medium/soil temperature.

 

[climbit]

Plants often need more Mg when grown under LED lights. I've been trying to learn why that occurs. According to one theory, it may be due to an incomplete light spectrum.

I’m thinking it’s cause it’s concentrated light. It peaks at blue and red, everything in between is overlooked by most.

 

[Budclarkson]

Brown spots look worse today. Dropped light intensity from 60 to 50% and raised the light higher.

This leaf is in the middle.

 

[Budclarkson]

Pushed the plant to the side of the tent so it’s not in direct light. Tied back the branch with the affected leaves just behind the fan. I bent this branch down (LST attempt) to open up the center of the plant and it was in the center of the lamp previously.

 

[Budclarkson]

Light is a big one for 3 fingers, like revenging. Also, medium/soil temperature.

I dunno why the 3 fingers. If you look close on a lot of leaves it’s 3 big ones with one small
4th dwarf one on the end.

I meant to mention that. I believe there is another plant like that, different strain.

 

[Budclarkson]

Spotted 3 Finger plant is a Blueberry strain. Older leaves are 5 finger but the new growth is 3. The only other stress I can think of is when the power went out the temp dropped to 60F RH to 40ish and the lights off for most of a day.

The other 3 finger is a Bubble gum kush but all leaves are 3 finger. Smallest plant, I think this is the one that had trouble shedding the seed shell and I had to remove it with tools. Otherwise Maybe genetics?

 

[Budclarkson]

Light is a big one for 3 fingers, like revenging. Also, medium/soil temperature.

What soil temp is problematic?
Used the strips tor sanity check PH since the pen is whacked (needs a recal I think). Strips are reading between 6 and 7. Tap abs cal mag mix are the same.

 

[Bdubs]

Over 75 degrees and below 65 is detrimental. How far out from those numbers either enzyme activity is too great or too slow.

The soil temps should not exceed outside room temps for optimal.

 

[Bdubs]

Single leaf growth is progressive prolonged root stress and is the ultimate stress signal, beyond the 3 leaf. If it isn’t a sugar leaf with a single leaf, it is def. a big stress. Leafs are an indicator of root health. Therefore all 3 leaf and single leaf count, above/after a 5 leaf count growth is major root stress.

I would guess and say that your roots are balled up and strangling each other. Because you have growth it’s just weird. If it were rot she would be showing more problems. I am almost certain you are experiencing root strangling.

As the root ball was already formed, either at a transfer or just the way the roots were growing caused them to strangle as the roots grew outward (typically happens if you didn’t transfer at the right time and let it go too long. Root pruning is the key for the mistake of not transferring at the right time and allowing a root ball to form before transplanting to a bigger pot. This is most likely the exact thing happening in the pot.

 

[Bdubs]

what do you think OP?

 

[cannafarmer420]

Plants often need more Mg when grown under LED lights. I've been trying to learn why that occurs. According to one theory, it may be due to an incomplete light spectrum.

I just think LEDs push them harder and it makes them eat more