Leaves curling up on the edge during flowering

[Crescendo]

Hello! My Auto Daiquiri Lime is entering 4th week of flower (sativa dominant). I'm growing it in soil and have been feeding lightly with biocanna fertilizer. The temps is between 25-28 degrees Celsius and RH around 50-55%. The top of the plant is around 20 centimeters from a 1000 spider LED light. The light cycle I'm using is 18/6.

In the past few days I noticed that a number of leaves (not just on the top of the plant but also on lower branches) are showing curled up edges.In addition, the leaves closer to the light are showing a lighter green color. The leaves at the very top look like a light yellow/green colour. I was wondering if this is a typical trait of sativa dominant or a trait of this genetic...

On another note, I haven't noticed any parasite or spot on leaves so I'm excluding deficiencies (albeit one can never know for sure). Given this info and the pics, have you ever experienced something similar and how have you acted to reverse that? Any tips are very welcome!

 

[Merlin1147]

20 cm is pretty close to the plants but sativas usually can take a bit more light. The symptoms are really widespread Down into the canopy for light stress. Def not normal if the color is true to the pics. I have no clue about BIOCANNA and can’t find a label So who knows what’s in it or not in it. Your plant looks micro nutrient deficient. Maybe sulfur, iron. Could be from a fertilizer lack, an imbalance of something else causing lockout or a ph issue. If it were me I would move the light up and check the fertilizer to see what’s in it in terms of macro and micros, and check soil ph.

 

[Crescendo]

20 cm is pretty close to the plants but sativas usually can take a bit more light. The symptoms are really widespread Down into the canopy for light stress. Def not normal if the color is true to the pics. I have no clue about BIOCANNA and can’t find a label So who knows what’s in it or not in it. Your plant looks micro nutrient deficient. Maybe sulfur, iron. Could be from a fertilizer lack, an imbalance of something else causing lockout or a ph issue. If it were me I would move the light up and check the fertilizer to see what’s in it in terms of macro and micros, and check soil ph.

Thanks for that. I'm using the recommended dose of Biocanna Flores together with Biocanna Boost at ph 6.0-6.2. Biocanna Flores is composed by 2.2 Nitrogen, 2 Phosphorous and 5.5. Potassium whilst Biocanna Boost is composed by N 0.02 P 0.12 and K 0.08

You can find out more about these products here but it is true, they do not say exactly the ingredients:

BIOCANNA product overview | CANNA

other.canna.com

What else do you suggest me to add in relation to micronutrients? Could you tell me more about what you can read from the colour of my leaves?

 

[Merlin1147]

Are you in soil or coco? Seeing as your ph ing to 6-6.2 which is a little low for soil I’m going to go with Fe deficiency. Let’s see the other plant. An Iron chelate spray can’t hurt and if it is the issue it will fix it really fast. Botanicare calmag plus has iron in it, if you can get past that they are owned by Monsanto.

 

[Dontjudgeme]

Hello! My Auto Daiquiri Lime is entering 4th week of flower (sativa dominant). I'm growing it in soil and have been feeding lightly with biocanna fertilizer. The temps is between 25-28 degrees Celsius and RH around 50-55%. The top of the plant is around 20 centimeters from a 1000 spider LED light. The light cycle I'm using is 18/6.

In the past few days I noticed that a number of leaves (not just on the top of the plant but also on lower branches) are showing curled up edges.In addition, the leaves closer to the light are showing a lighter green color. The leaves at the very top look like a light yellow/green colour. I was wondering if this is a typical trait of sativa dominant or a trait of this genetic...

On another note, I haven't noticed any parasite or spot on leaves so I'm excluding deficiencies (albeit one can never know for sure). Given this info and the pics, have you ever experienced something similar and how have you acted to reverse that? Any tips are very welcome!

Looks like the good ole taco leaves to me. Heat stress.

 

[Crescendo]

Looks like the good ole taco leaves to me. Heat stress.

I would think the same but there are several leaves that are quite far from the light also curling up along the edges. Temps are never above 28 degrees Celsius so wouldn't think heat is the primary cause.

 

[Crescendo]

Are you in soil or coco? Seeing as your ph ing to 6-6.2 which is a little low for soil I’m going to go with Fe deficiency. Let’s see the other plant. An Iron chelate spray can’t hurt and if it is the issue it will fix it really fast. Botanicare calmag plus has iron in it, if you can get past that they are owned by Monsanto.

Thanks for that! I'm using soil. I'll increase my pH and foliar feed it with some iron (a local brand instead). That should address the colour issue, what about the curling edges? Would you think is related to iron or some other factor/nutrient deficiency?

 

[Merlin1147]

Thanks for that! I'm using soil. I'll increase my pH and foliar feed it with some iron (a local brand instead). That should address the colour issue, what about the curling edges? Would you think is related to iron or some other factor/nutrient deficiency?

Yes could be all related

 

[Crescendo]

Yes could be all related

Which other factor or nutrient deficiency should I look into regarding curling around the edges?

 

[Merlin1147]

Normally that canoeing is heat or light stress. Are you monitoring temperature and Rh continually like with a SensorPush wireless data recorder? Are you sure there are no prolonged spikes when you aren’t around?

 

[Crescendo]

Normally that canoeing is heat or light stress. Are you monitoring temperature and Rh continually like with a SensorPush wireless data recorder? Are you sure there are no prolonged spikes when you aren’t around?

I check everyday the max and min values for temp and RH and it all fluctuates between 25-28 celsius and RH 45-55%...

 

[My Name is Mike]

I check everyday the max and min values for temp and RH and it all fluctuates between 25-28 celsius and RH 45-55%...

Light stress isn't in the form of temperature, it's the intensity of the light which can stress the top plant if too close and cause canoing. Making sure that's not confused with heat stress, their different.

I think your issue is PH and light stress. Nutes, less is better. I wouldn't be seeking what more to add, find the source of your issue first. PH closer to 6.5 PRIOR to watering. I would test the runoff PH as well at your next opportunity.

 

[Crescendo]

Light stress isn't in the form of temperature, it's the intensity of the light which can stress the top plant if too close and cause canoing. Making sure that's not confused with heat stress, their different.

I think your issue is PH and light stress. Nutes, less is better. I wouldn't be seeking what more to add, find the source of your issue first. PH closer to 6.5 PRIOR to watering. I would test the runoff PH as well at your next opportunity.

That's useful. I'll double check my pH to make sure it's closer to 6.5 instead of 6.2 in future watering. For the light stress, I appreciate it looks like it but even leaves that are way down the canopy are curling up and the other plant next to it is not showing any sign of light stress that's why I was wondering. Would you also make the connection of leaves curling along the edges far from the light to be a reaction from low Ph?

 

[My Name is Mike]

That's useful. I'll double check my pH to make sure it's closer to 6.5 instead of 6.2 in future watering. For the light stress, I appreciate it looks like it but even leaves that are way down the canopy are curling up and the other plant next to it is not showing any sign of light stress that's why I was wondering. Would you also make the connection of leaves curling along the edges far from the light to be a reaction from low Ph?

Absolutely. PH can fuck a lot up and give signs of deficiencies or burns because it could be causing nute lock out. Since you are on a consistent nute regime, that's what tells me your not burning or deficient based on feed. I would lean on certain micros and macros are being locked out which is a PH issue IMO.

Light stress even if we're wrong, easy fix. You raised the light, done.

Addressing the lower leaves since that wouldn't be light stress is next. This fix also doesn't cost more money, just some data, trial and error.

I would do a clean flush and allow plants to bounce back for few days. Dial in PH, maybe do a smidge less nute mix and go for it. Make sure your nute is mixed in proper order to. PH the mix last after all is mixed.

 

[cowboylogic]

The leaves are pretty light green. Its possible they are praying for magnesium. A foliar spray using a mix of 2 tablespoons of epsoms salt per gallon of water may help and wouldnt hurt at all.

 

[Crescendo]

Absolutely. PH can fuck a lot up and give signs of deficiencies or burns because it could be causing nute lock out. Since you are on a consistent nute regime, that's what tells me your not burning or deficient based on feed. I would lean on certain micros and macros are being locked out which is a PH issue IMO.

Light stress even if we're wrong, easy fix. You raised the light, done.

Addressing the lower leaves since that wouldn't be light stress is next. This fix also doesn't cost more money, just some data, trial and error.

I would do a clean flush and allow plants to bounce back for few days. Dial in PH, maybe do a smidge less nute mix and go for it. Make sure your nute is mixed in proper order to. PH the mix last after all is mixed.

I totally get it, I am just surprised that such a slight differential in Ph (I check every time before I water and it is always within 6.0-6.2) can have such an effect but I am quite new to this so it is totally possible and learning along the way. I will follow your tip, thanks!