Possible phosphorus deficiency? Pls help diagnosing!

shrine420 said:

Okay thanks for the advice. What do you reckon constitutes a little bit? I have A very fine powdered (micronised) dolomite. Plant pot is 50L. I was thinking perhaps 100ml?

Click to expand...

General applications are 1tbsp/trade gallon.
A trade gallon is about 1/3 smaller than a standard gallon. 1tbsp is equal to 15ml

myke said:

Leave your ph sample for 24-48 hrs,re test again see if any difference.

Click to expand...

Okay, thanks.

shrine420 said:

Thanks for your reply jimihendrix1!

I looked into Leaf Septoria and it seems that in general that condition appears a bit more spotty with more circular spots. It also seems to be usually a result of high moisture/humidity.

The conditions here are very dry and often windy.

Most of the examples on my plant look like it affects the tips first and then sometimes emerges as a gradual patch in on other parts of the leaf.

View attachment 5090688View attachment 5090689View attachment 5090690

Click to expand...

Thats P def all day long. Easy to diagnose IMO. Blotchy grey brown patch’s abs yellowing on OLDER leaves!

Look familiar? Up the P

McShnutz said:

General applications are 1tbsp/trade gallon.
A trade gallon is about 1/3 smaller than a standard gallon. 1tbsp is equal to 15ml

Click to expand...

Thank you for this.
Okay so 50L is perhaps 13 trade gallons give or take. So that would amount to 13 table spoons or 195ml of Dolomite Lime.
It seems a bit much some how. I think I will start with a bit less as the acidity might just be concentrated at the top layer because of the bat guano.

shrine420 said:

Thank you for this.
Okay so 50L is perhaps 13 trade gallons give or take. So that would amount to 13 table spoons or 195ml of Dolomite Lime.
It seems a bit much some how. I think I will start with a bit less as the acidity might just be concentrated at the top layer because of the bat guano.

Click to expand...

Right, that's the standard amount to add to soil when you make it. You'd be safe with a 1/4 cup (4 tblsp)

If you can brew some AACT to water in the lime that would help the plant some. But your goingbto need a faster acting source of P. I'd suggest mono potassium phosphate.

McShnutz said:

Right, that's the standard amount to add to soil when you make it. You'd be safe with a 1/4 cup (4 tblsp)

If you can brew some AACT to water in the lime that would help the plant some. But your goingbto need a faster acting source of P. I'd suggest mono potassium phosphate.

Click to expand...

Thanks! I was thinking somewhere in the region of a 1/4 cup as well.

AACT is a bit of a push as I don't have a bubbler currently but I have microbes and other fermented extracts I could add. Thanks for the suggestion.

How would Biobloom be as my fast acting source of phosphorous given that I start supplying it at the recommended dosage?
I've been cautiously under doing it a bit since I added the bat guano.

I really appreciate your time helping me with this McShnutz!