Is this a sulfuric deficiency..?

[JAYAR]

Morning everyone I have a problem with my critical+, I have posted on the live help thread a couple days ago but I think I was mis-diagnosed. After a little research and checking on JM's self-diagnose thread and the classic drawings chart of deficiencies, I'm 99% sure it's related to sulfur.

I'm growing in coco
ph 5.8
ec 1
canna a and b, little bit of pk

The yellowing is all near the top and affecting the main cola and some fan leaves that are facing the light, at first I thought my LED was too close since then I've raised it but the yellowing continues. Also tried adding extra Nitrogen and I think that helped a little.

I found this link http://www.soil.ncsu.edu/publications/Soilfacts/AG-439-15_Archived/AG-439-15.pdf and it talks about how a sulfur deficiency looks just like a nitrogen deficiency and it's commonly missed.

The only product I have with any type of sulfur is pk13/14 which has potassium sulfate, one of the weaker sulfates according to the link. What worries me is causing nute burn which almost always happens when I use a lot of pk.

What do y'all think?? My last grow a TD got the same thing, I did not attempt to fix it because it happened late in flower, but look how bad it turned. Also, it started with the side facing the light then spread just like it's starting to on the critical+..

Please help me turn my to If there's a way to get it directly to the affected spots without burning them or if I need to feed it a certain way, any advice is greatly appreciated.

 

[JAYAR]

Here's the chart for reference, notice how sulfur looks very similar to N deficiency.

 

[namvet25]

Sulfur def is rather rare so i'm not sure that is your problem.It still might be low on nitrogen and also could be low on magnesium.Are you using cal/mag?

 

[Muddy]

I agree with Nammy, sulfur deficiencies are very rare. In fact, I've never seen one on an auto. If it were sulfur I would expect the veins to also be yellow. Same with bleaching. The whole leaf, including he veins will be yellow/white. Both start from the center of the leaf and work outwards toward the tip and edges. I tend to think they are underfed. An EC of 1 is low for a plant that size in full bloom. Usually by that point in the grow I'm feeding in the 1.7 - 1.8 range.

 

[JAYAR]

Sulfur def is rather rare so i'm not sure that is your problem.It still might be low on nitrogen and also could be low on magnesium.Are you using cal/mag?

Nam I don't think it's cal mag because the canna coco A has 4.5% calcium and the B has 1.1% magnesium... I feed that every day too. Plus the coco itself is charged with extra calmag too.

Yeah I was told it might be low on N but after upping the dosage considerably, nothing changed and the yellowing is spreading down the plant. Thank you for the response!!

I agree with Nammy, sulfur deficiencies are very rare. In fact, I've never seen one on an auto. If it were sulfur I would expect the veins to also be yellow. Same with bleaching. The whole leaf, including he veins will be yellow/white. Both start from the center of the leaf and work outwards toward the tip and edges. I tend to think they are underfed. An EC of 1 is low for a plant that size in full bloom. Usually by that point in the grow I'm feeding in the 1.7 - 1.8 range.

Muddy nice to meet you, 2 weeks ago ago I upped the EC to 1.1 and burned the tips a little, but I probably should raise it now. Also I water and feed every day so I try to feed a more conservative amount. I want to be on the safe side here, the critical+ is a treasure to me since I stunted the other 2 plants I have going.

I want to do a foliar feed with pk13/14 and see if I have the first sulfur deficiency known for an autoflower.. any advice on doing that?

Edit: Now that I look at it, it kind of looks like a magnesium deficiency. I will up my EC to 1.2 with A&B and see if the added mag will help it before attempting a foliar feed of pk13/14.

 

[namvet25]

You could also do a good flush with plain ph water to get rid of salt build up.Then up the cal/mag dose feed her a lighyt dose of veg nutes along with reg dose of flower nutes.You may also consider skipping feeding every other water and see if this helps.

 

[JAYAR]

Thank you vet, unfortunately I cant feed pure ph'd water because it ruins the coco, I always need to have it at least .8 EC.. what I'm going to do today is up her feed of magnesium and overall ec to see if I am underfeeding. If it doesn't work I'll report back here.

 

[Muddy]

I normally wouldn't expect to see a mag deficiency show on the top leaves like that. If you feel that strongly that it is a mag issue, I'd be more inclined to do a foliar with some epsom salts over the PK13/14. I teaspoon per gallon of pHed water.

 

[JAYAR]

I normally wouldn't expect to see a mag deficiency show on the top leaves like that. If you feel that strongly that it is a mag issue, I'd be more inclined to do a foliar with some epsom salts over the PK13/14. I teaspoon per gallon of pHed water.

Sorry let me clarify, I thought it was a sulfuric deficiency, which is why I was going to overload on the pk.. but nam chimed in on the possible mag deficiency and Cannas B solution contains extra mag.

So it's been a couple of days and the problem was in fact underfeeding lol I have upped the EC from 1 to 1.4 now and she has gotten most of her green back!!

So thanks to you, both namvet and muddy!!! I really appreciate it, this is my second grow running coco with canna nutes and yall have helped me inch closer to dialing in my setup!!!

Feel free to stop by my thread anytime.

"AFN smoke out"

 

[Dr Fluff]

Dinafem say Critical+ Auto is a 60 - 70 day flower, whereas Critical+ 2.0 is a 80 day flower.

Checking on Seedfinder.EU in the user generated Strain profile flowering time is between 45 & 55 with the mean being 50 days.

I have notice looking at seed seller websites that flowering time is given as X number of days yet doesn't state veg time. some seed companies state time from seed to weed.

It seem to me sometimes when see companies state flowering time they actually mean entire grow to finish time.

Critical+ auto is mostly Indica looking at the stats on Seedfinder.Eu and so shouldn't have a massively long flowering period.

From looking at your journal your plant is 68 days from seed , so would seem that maybe it is just coming the the end of its life and showing def because it is in it's last throws.

I could be wrong , but could this be a possibility?

Btw lovely looking buds, looks like they might be ready to come down.