Bright Yellowing?! Ahh

[akreso]

Can anyone help me diagnose this?

I have a grow thread started in Mephisto area, but thought I would throw this here too. I have four plants going. All things are consistent, the other plants are looking pretty great. . . but this one plant Sour Orange Diesel Kush is looking a bit off, to say the least.

My gut was two things - Cal Mag def and Nitrogen. I have upped both for the plants but not sure I am seeing any positive response yet over the last week.

Thanks in advance!!

 

[Joe383]

I am not for sure what is wrong but it is not cal/mag or nitrogen.

 

[akreso]

well @Joe383 i am not sure whether to be relieved or even more scared at that news

 

[Joe383]

Don't take my word for any thing but an opinion but I think you have an iron deficiency. Look up the symptoms your self and see what you think because I could be wrong.

 

[Waira]

ak'-- when it's the new growth going chlorotic especially the very newest leaves, it's very likely one of the immobile micronutrient metals,... Yours looks mostly like Fe defc., but it's not following the typical pattern yellowing from the "palms" out toward the tips, -->

.... still, it's the best fit, given the totally bleached newest leaves,... Zn defc. can do some odd patterns too,... in any case, you need a micronutrient supplement, which should contain Fe, Zn, Cu, Mn, B, Mo, etc,.... and also, we need to find out why, meaning lack of defc. or pH lockout type defc.,... Fe locks out fast around 7.0+ pH...can you get me a reading? If you do run-off testing, follow this guide and calculation- https://www.autoflower.org/threads/...-testing-and-ph-estimation.41733/#post-928975
...this will help confirm the diagnosis,...

 

[akreso]

Thanks Waira. I'll get a pH reading here in a bit. Stand by

 

[akreso]

A small update. After some back and forth conversation with @Waira. We came to the conclusion there is indeed a strong possibility of some iron deficiency. I attempted a pH reading,. . . but botched the process (I wasn't even baked!). I think my digital meter needs calibrating. . . I have ordered an Accurate 8 pH meter for soil readings and that should help things out.

That said, though, he recommended a foliar spray. So I headed to one of our local hydroponics stores. Goodness it is great to live in a legal state, where i can talk opening about this stuff with the folks at the store. One staff member thought I had a microbial issue, but after a long chat with his boss and looking at pictures, he came to the same conclusion that this was likely a deficiency and it was presenting in a way that confirmed what Waira has suspected all along - iron. Not that I doubted Waira, but it's nice to see the detailed conversation come back around to the same conclusion.

Or. . . the local store owner also thought that if the foliar spray didn't fix things in 48 hours or so, then I was perhaps looking at something systemic and I should just cull the two plants that have the yellowing. Given that 2 of the 4 plants look healthy and given that my previous grows have gone smoothly and all things remain constant on the grows, he didn't want to rule out something systemic or viral. . .

So, foliar spray was applied last night. . we'll see what happens and report back in 36 hours.

 

[Waira]

good to hear mate! I'm glad the other folks concluded similarly,... it'll take a few days for results to start showing,... these symptoms are not viral in any case, thank the green gods! ...If they fail to improve significantly in a week or so, yank'm.... :smoking:

 

[akreso]

Well an update for you folks. At Waira's suggestion, I purchased some foliar spray. Sadly that did not help the situation. After more than a week after the spray, it didn't seem to improve at all.

So, I culled two plants. One plant - the SODK x Alien was the worst. The second plant Deep Blue C, was also pretty bad. Both are now in my compost.

The other two plants, however, are actually looking pretty good. They are filling out and showing some good development. I am going to keep them going.

Here's a quick look, I'll post a more thorough update on the grow journal.

The second plant has a few issues, perhaps early nute burn on 2 or 3 lower fan leaves, but everything else on the plant is looking health and strong, particulalry as it continues to grow.