Help diagnose deficiency (N?) or too much light?

[zipperdoyle]

Hello all! I have three cloned plants in 2x4, the sick middle one and the one on the right come from the same mother. They are in the second week of flower and lights were changed to 12 hours.

Background info:
- 3 clones, 2 from same mother (photo-period).
- On 12 hours of lights right now (2 weeks in).
- Autotpots with 100% coco.
- Keep the reservoir PH around 5.6-5.8
- CalMag + Canna A & B + Canna Boost being used now ~ 1.6 EC
- DLI for 12 hours is now at around 32 for center plant a little lower for the others. I lowered it a little a few days ago, I think it was in 36ish range.
- Middle plant is showing lime greenish, yellowing from top down. Bottom half of middle plant has normal color.
- I keep the VPD around 1-1.2. Temps are about 75-78F and RH is around low to below 60%.

Trying to figure out if the middle one is having a deficiency problem or maybe a too powerful lighting issue (gets the strongest rays). How would you go about troubleshooting this? Thanks again for your help!

 

[Glomus]

Definitely a deficiency of some kind. Either a micro like iorn zinc or magnesium. Doesn’t look like a N deficiency.

 

[empty]

Hello all! I have three cloned plants in 2x4, the sick middle one and the one on the right come from the same mother. They are in the second week of flower and lights were changed to 12 hours.

Background info:
- 3 clones, 2 from same mother (photo-period).
- On 12 hours of lights right now (2 weeks in).
- Autotpots with 100% coco.
- Keep the reservoir PH around 5.6-5.8
- CalMag + Canna A & B + Canna Boost being used now ~ 1.6 EC
- DLI for 12 hours is now at around 32 for center plant a little lower for the others. I lowered it a little a few days ago, I think it was in 36ish range.
- Middle plant is showing lime greenish, yellowing from top down. Bottom half of middle plant has normal color.
- I keep the VPD around 1-1.2. Temps are about 75-78F and RH is around low to below 60%.

Trying to figure out if the middle one is having a deficiency problem or maybe a too powerful lighting issue (gets the strongest rays). How would you go about troubleshooting this? Thanks again for your help!

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This is tricky, nitrogen deficiency and magnesium deficiency can look similar since they both cause yellowing. It looks like it might be an N deficiency, but usually starts on the bottom leaves of the plant. But it also looks a bit like a Mg deficiency, which typically starts with yellowing between the veins and then spreads to the whole leaf. As an organic grower, I usually add worm castings or blood meal to fix it. Maybe others pro grower can help to diagnose it.​

 

[zipperdoyle]

Thanks for the feedback. Just trying to figure out where to go from here and try to help the girl in the middle.

 

[OldSalty]

Have you checked the runoff ec? I have had runaway ec levels in a single plant even though all plants were treated the same. I have no idea why. It looked similar to yours. Just a thought.

 

[zipperdoyle]

Have you checked the runoff ec? I have had runaway ec levels in a single plant even though all plants were treated the same. I have no idea why. It looked similar to yours. Just a thought.

Hey thanks for the feedback. I'm actually using autopots which feed from the bottom up directly from the attached shared reservoir. I'm assuming I need to feed this middle one differently I'm just a little lost on how to troubleshoot it. The reservoir ph is around 5.6 and 1.6 EC in the reservoir.

 

[OldSalty]

Hey thanks for the feedback. I'm actually using autopots which feed from the bottom up directly from the attached shared reservoir. I'm assuming I need to feed this middle one differently I'm just a little lost on how to troubleshoot it. The reservoir ph is around 5.6 and 1.6 EC in the reservoir.

Gotcha. I haven’t ran autopots but they’re on my list.

 

[homiefromtheshowme]

Looks like iron deficiency. Check the sticky for the charts on cannabis infirmary.