Please help

[BobTheGrower]

Hi,

My top leaves like on this one on photo. Plant is 15 day in flowering state. PH medium 6.0. temp 24.. all is ok.. what happen??

 

[ShiggityFlip]

It would be great to see the whole plant. Early guess is that you are having a phosphorus deficiency but more info will help. Try to include all the info you can. Grow medium,type of nutes, watering methods, amount of light and type, location on plant, pics of plant,etc.

 

[Papageno]

I like to test myself when pics are included.

I just went straight to the pics and was going to say heat damage. Then I read the post and you said top leaves...so I am going to say heat damage.

Please try to adjust the lighting because that can cause a hermaphrodite in bloom.

 

[Cultivator]

looks more like heat damage to me. how close is top of plants to light?

 

[ShiggityFlip]

Didn't read the top leaves part. I am with village and cult now on this one but would love more pics pls!

 

[BobTheGrower]

led panel 80w (box is 60x60cm)
panel is 30cm above plants
im used only watter in last wattering becouse i thinked its from too much manure? (i used canna terra)

 

[ShiggityFlip]

Guys it seems a lot of the damage is on lower leaves and a lot of the top leaves are not very affected. The damage is also not all in the direction of the light. A few questions Bob.

1 are all the plants turned regularly? Was all the damage facing the center at one point?
2. Did you have a fan off or other issue? Was there a heat wave?
3. What is your nute solution NPK and pH?

The reason I ask is because the damage seems to be some top but not all and appears middle on some plants and not in direction of light.
Potassium deficiency can sometimes be mistaken for nute burn and light burn.

 

[BobTheGrower]

yesterday there was a two cfl bulbs 25w hanging in the middle of the box (below the top of plants). i removed them yesterday.

right plant was turned first (i have fans of the left side). first damage got the top leaves (the biggest ones).
my fans are from pc - they not work strong (12v fans are pluged into 6v) 1x120mm and two very little. i just order a big fan
water's ph is 6.0 (i buying mineral watter in shop)

 

[ShiggityFlip]

So when the damage happened first was it all facing the center?

 

[BobTheGrower]

huh i dont remember. sorry

 

[BobTheGrower]

ermm.. i think i just solved the problem but i need to know 1 thing

if the led panel was too low (though the heat from panel is low (it is warm but not hot)) then too much light (only light) can make that?

if yes then im f.. retard becouse i was always thinkin that 'never too much light'

led panel was 18cm (7 inch) above plant

 

[ShiggityFlip]

That's totally fine Bob. So here's my advice. Monitor the heat in the grow room. If the heat is not an issue pay attention to the leaves and what they do. Hopefully since you are watching the heat the problem will not go anywhere. The big fan you ordered should be a great help.
If things continue to get worse even with the fan then it may be a deficiency issue. Keep us posted so we can keep helping you to succeed. We all want you to have big crystally buds!

 

[Papageno]

I think shig is correct but that could also be Potassium Deficiency.

And since you are in bloom that could be a real thing.


Quote:

"With a marijuana potassium deficiency, you'll generally see symptoms on older leaves, but not always. Sometimes you'll see the symptoms at the top of the plant. Leaves with a potassium deficiency get yellow, brown, or burnt tips around the edges and tips. The burnt edges may look a little like nutrient burn, except the affected leaves also start turning yellow in the margins.

Yellow leaves with brown edges and tips are the signs of a weed potassium deficiency

You may see the brown burnt edges first, or you may see the yellowing first. When the leaf symptoms are both present, it's a good sign you have a potassium deficiency in your leaves.

Plants may stretch and stems may become weak, but leaf symptoms are more noticeable. The leaf symptoms appear somewhat similar to an iron deficiency in that they can turn bright yellow, but the tips of the leaves curl as the edges turn brown, burn and die."


"Sometimes the first symptoms of a cannabis potassium deficiency look a lot like nutrient burn. One difference is the edges of the leaves will also start turning brown, where nutrient burn usually only affects the tips. And unlike with nutrient burn the leaves of a potassium deficiency turn yellow in the margins, especially near the burn edges."



But this is commonly confused with light burn. The 2 are often misdiagnosed for the other.

Just wanted you to think about this if it doesn't go away.

 

[ShiggityFlip]

I think shig is correct but that could also be Potassium Deficiency.

And since you are in bloom that could be a real thing.


Quote:

"With a marijuana potassium deficiency, you'll generally see symptoms on older leaves, but not always. Sometimes you'll see the symptoms at the top of the plant. Leaves with a potassium deficiency get yellow, brown, or burnt tips around the edges and tips. The burnt edges may look a little like nutrient burn, except the affected leaves also start turning yellow in the margins.

Yellow leaves with brown edges and tips are the signs of a weed potassium deficiency

You may see the brown burnt edges first, or you may see the yellowing first. When the leaf symptoms are both present, it's a good sign you have a potassium deficiency in your leaves.

Plants may stretch and stems may become weak, but leaf symptoms are more noticeable. The leaf symptoms appear somewhat similar to an iron deficiency in that they can turn bright yellow, but the tips of the leaves curl as the edges turn brown, burn and die."


"Sometimes the first symptoms of a cannabis potassium deficiency look a lot like nutrient burn. One difference is the edges of the leaves will also start turning brown, where nutrient burn usually only affects the tips. And unlike with nutrient burn the leaves of a potassium deficiency turn yellow in the margins, especially near the burn edges."



But this is commonly confused with light burn. The 2 are often misdiagnosed for the other.

Just wanted you to think about this if it doesn't go away.

Nice to see we are both thinking it could be potassium def. Something definitely to look at. I see you are watering at 6.0 pH. If your pH is dropping for some reason in the soil it could make potassium unavailable. What is the exact makeup of your soil so we can determine the pH effect?

To answer your light question, If there was not much heat at the light just too much light you would probably see bleaching of your top bud.

 

[BobTheGrower]

huh.. damage progress has been stopped. they probaly were overwattered.

why? ok sooo the hole at the bottom of the pot was plugged. the pots was very.. veeeeeery heavy. when i unpluged the hole leaked a lot of water

btw. potassium effect could be probaly right. why? ph of the watter was 5.8 i used ph+ to rise it to 6.2

this two sisters are my first plants. i hope that i can bring them to the harvest...and i dont fail whole 'after-harvest' process

 

[ShiggityFlip]

Only water when plant pots become light. I always lift the pot a little to see how heavy it is. A pot should be almost dry again before watering.

 

[BobTheGrower]

yup.. from now i will

 

[Tead]

Not really much help.... but it's not heat damage. Heat damage causes the leaf margins to curl up long before it causes the issue you're seeing.
I'd bet your swamped soil was the cause of your issues... perhaps all the water was sitting too long and the ph was drifting during it's long rest in your pots.

 

[Papageno]

Stagnate water can cause the pH shift that create all kinds of problems including the one we were talking about. In fact the primary reason for the problem we were leaning towards is pH being off and stagnant water will do just that fast.

Glad to see it is back under control.


I would seriously consider getting some enzymes in there at this point.

 

[Papageno]

And I would add that the preferred pots for Cannabis are fabric pots which prevent this from really being an issue. You might want to try them on your next grow.