Manganese [Mn] deficiency? Looking for verification.

Silversun

Silversun

Active Member
I have a purple kush clone I picked up on the 5th of July from my local collective. She vegged for over 2 months while I trained her into a scrog screen. I started 12/12 on Aug 27th. I am using a 3 gallon black and white poly grow bag with FFOF soil, after the soils nutes where depleted I started feeding with Tiger bloom (yes even in veg, the plant did great).

I've read the sticky in this section of the forum and believe that it is Mn def. I'm just looking for some verification from someone knowledgeable in MN def, or if this isn't from lack of Mn what my other possibilities maybe. There is a bit more info and pictures of this grow in the link in my sig. My current grow starts mid second page. Thanks in advance.

IMAG0409.jpgIMAG0410.jpgIMAG0411.jpgIMAG0412.jpg

The brown spots are what make me think it is most likely Mn def.
 
cannabineer

cannabineer

Ursus marijanus
I have not seen one confirmed case of Mn deficiency on this site. The pics are suggestive of lockout, perhaps due to low pH. FF soils are based on sphagnum, which has a tendency to go sour, and not enough lime in the mix to keep that controlled. I would check, in order:
soil pH
administering Cal-mag
"lesser stressors" like heat, light, humidity
before reaching for an exotic explanation. Jmo. cn
 
Silversun

Silversun

Active Member
Sorry should have mentioned that my soil has plenty of dolomite lime in it because I have experienced FFOF soil going "sour" before. Over all I liked the soil so I suck with it and added the lime, that doesn't mean I'm dismissing pH issues. Thanks for the check list, my pH(per a two prong soil tester) is about 6.0 or so. I'll test runoff on my next watering.
 
cannabineer

cannabineer

Ursus marijanus
Silversun said:
Sorry should have mentioned that my soil has plenty of dolomite lime in it because I have experienced FFOF soil going "sour" before. Over all I liked the soil so I suck with it and added the lime, that doesn't mean I'm dismissing PH issues.
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Well you blew my leading hypotheses out of the water! (Good!) I have one left however, now that I know it is probably not divalent ion lockout: potassium. K def can provide the symptoms your plants show, and if you're using the "soil" Tiger Bloom (2-8-4) some K supplementation may be just the ticket. I'd find a feed with low-low-high numbers (or a straight K salt like potassium sulfate, if you can find it) and give that a go. cn
 
Silversun

Silversun

Active Member
Awesome CN, now thats the kind of info I was looking for. Thanks for all your help, I'll update this thread with what I find out.
 
Silversun

Silversun

Active Member
So as per cannabinner's suggestion I picked up some all K nute. I got natures nectar potassium (0-0-5) the recommended feeding is 3ml to a liter, I used 15ml in a gallon, a little over the recommended but I wanted to overcompensate a bit. This was done last night and today I see more progression of whatever this is, how soon should I see changes if this is the issue?

View attachment 2338454View attachment 2338455

It may not look like its getting worse but I trim of bad leaves off so I can track the newly decaying spots.
 
cannabineer

cannabineer

Ursus marijanus
Silversun said:
So as per cannabinner's suggestion I picked up some all K nute. I got natures nectar potassium (0-0-5) the recommended feeding is 3ml to a liter, I used 15ml in a gallon, a little over the recommended but I wanted to overcompensate a bit. This was done last night and today I see more progression of whatever this is, how soon should I see changes if this is the issue?

View attachment 2338454View attachment 2338455

It may not look like its getting worse but I trim of bad leaves off so I can track the newly decaying spots.
Click to expand...
It'll take a few days. The injured leaves probably won't recover. But if the part-injured leaves stay green in the green parts, that's "hypothesis confirmed". If they don't, it might not have been the answer. cn
 
king.kush420

king.kush420

Member
as i'm sure you have learned already, but ya. I just had the same problem. it was right about in the same stage of progression that you are in. check your pH make sure it's not to low. that was my problem. but didn't fix the problem in time and lost the plant. too bad too, would have had some glorious tops on it. good luck bro.
 
Silversun

Silversun

Active Member
Well if it if manganese, how do I correct it? some say Epsom salt but are they confusing this with magnesium?
 
Silversun

Silversun

Active Member
I just gave her another feeding with the Potash water mix. I'll monitor it over the next few days and see how things go. If things don't look better after that I'm going to do a few waterings of 8.0 ph to see if rising the ph helps. Thanks everyone for all your help. +Rep to all.
 
Jman305

Jman305

Active Member
cannabineer said:
Well you blew my leading hypotheses out of the water! (Good!) I have one left however, now that I know it is probably not divalent ion lockout: potassium. K def can provide the symptoms your plants show, and if you're using the "soil" Tiger Bloom (2-8-4) some K supplementation may be just the ticket. I'd find a feed with low-low-high numbers (or a straight K salt like potassium sulfate, if you can find it) and give that a go. cn
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I use kelp meal from burpee as a foliar spray, I don't know the number of K it has in it, but it has been shown to reduce stress from drought, and improve yield and overall plant health. It's super cheap, too. $14 got me enough concentrate to do 60 gallons of it. That's with shipping. Glad you guys pointed out the pH issue with FFOF. I haven't heard that one, only that I needed to add perlite. I did but not enough and I learned it the hard way this year.
 
Silversun

Silversun

Active Member
tusseltussel said:
do we all know the diffrance tween magnesium and manganese??????
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I have read up on some of the differences, but don't know much about manganese. Do you have any info to share?

Problem is still persisting through, upping pH, boosting K, and flushing.
 
tusseltussel

tusseltussel

Well-Known Member
Silversun said:
I have read up on some of the differences, but don't know much about manganese. Do you have any info to share?

Problem is still persisting through, upping pH, boosting K, and flushing.
Click to expand...
Actually I read an article about it a few days ago I will try to find it when I get home.
 
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