Is this a nitrogen or magnesium deficiency?

caca24

caca24

Member
I am wondering that type of deficiency this plant is suffering from.

It's a blueberry auto strain at about 21 days post germination.Growing in potting soil with perlite and compost (20% volume). I haven't given any nutes yet. Growing under a 90W LED and watering every 3-4 days. Current schedule is 24 hours sunlight.

 
Gaz29

Gaz29

Well-Known Member
the leaves look dark green (other than the odd few) is there nutes already in your soil perlite n compost mix.? Could be calcium and/or magnesium def .. Have you over watered.? You say a 90w led then sunlight 24/0 I'm assuming it's under the led 24/0.?! I've seen peeps have mgnsm deficiency using leds, but I think there's enough N already. Good luck happy growing
Gaz
 
caca24

caca24

Member
I believe the lowest leaves are the ones yellowing. It does not appear like it on the picture but that's an optical illusion.
I only water every 3rd or 4th day (very dry and light) and I am using a cloth pot so I don't think overwatering is a problem but I could be wrong.

No nutes in the perlite and compost mix except for what is naturally found in the compost. The LED is always on so 24/0 is accurate.
 
im4satori

im4satori

Well-Known Member
caca24 said:
I believe the lowest leaves are the ones yellowing. It does not appear like it on the picture but that's an optical illusion.
I only water every 3rd or 4th day (very dry and light) and I am using a cloth pot so I don't think overwatering is a problem but I could be wrong.

No nutes in the perlite and compost mix except for what is naturally found in the compost. The LED is always on so 24/0 is accurate.
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then maybe she is N def

the pic doesn't look like lower leaves are yellow but if they are then ya

you might be ready to start adding a balance fertilizer 1x per week or so
or you might prefer to only give it what it asks for it just depends on your style
 
caca24

caca24

Member
How long does it usually take to rectify a nitrogen deficiency?

I gave her some nutes yesterday but I am not seeing any significant change in the color yet.
 
im4satori

im4satori

Well-Known Member
looking at the pic it really doesn't look like N def to me
but its just a pic and only as good what I can see from it

but you should know in a couple more days
 
caca24

caca24

Member
looking at the pic it really doesn't look like N def to me
but its just a pic and only as good what I can see from it

but you should know in a couple more days
Click to expand...
What do you think it is?

Based on pictures of other deficiencies, i'd say that maybe it could be a magnesium deficiency or maybe overwatering, but all the other deficiency look way off from what I see.
 
im4satori

im4satori

Well-Known Member
well

since you've said the pic doesn't show all there is to see maybe another pic would help

but just looking at the pic it looks like at some point it may have gotten too much N or over watered \
(based on the leaves at the top looking like theyre folding down or drooping)

it is possible you over fed it (at some point)and then stopped and maybe those are old signs of over fert. (leaf curl)and the yellowing is new signs of under fert

its hard to be sure

but if your absolutely sure your no and haven't been over watering then I might be incorrect

just looking at that pic alone it doesn't clearly scream N def
 
caca24

caca24

Member
I took some more pictures.

I don't think it looks any better.

I am seeing some purple stems (on the leaves that are yellow) and there is some necrosis of the tip of one lower leaf.

 
im4satori

im4satori

Well-Known Member
id give it some more time

that picture shows yellowing lower down as you stated

is just the other growth is so dark

I would go ahead and add 1/2 tsp Epsom salt also, on your next watering and then 1/4 tsp 1x per week or two there after

your in soil so it wont do any harm and I believe I see sign of magnesium def also

you have some leaf twist and mild cupping which suggests magnesium def
 
caca24

caca24

Member
Ok, I have some new information.

I measured the pH of my tap water with an electronic tester (pen type) and it's around 6.8-6.9. My runoff is at about 6.3-6.4. This means my soil is somewhere around 6.1-6.3. Would that mean that there is a pH lockout that is blocking macros from getting in (most likely Mg)?

Last watering, I added 1 tsp / gallon of Epsom salts.

Latest pics

 
caca24

caca24

Member
1tsp Epsom salt is double what I recommended so don't over do it
Click to expand...
I only watered half of what I usually give on the off chance that overwatering might contribute. Therefore, the total quantity of Mg in the pot should be the same as for a full watering with 0.5 tsp/gallon
 
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