Phosphorus deficiency treatment

[mingzhu]

Phosphorus-deficient leaf growth is blocked (small) What should I do; ask for help; need to rinse or add extra phosphorus; I use GH3 ensemble + calcium magnesium; the plant has flipped 12/12 after 49 days and has 6 days ! Dutch blueberry seed; from the vegetable 30 days found a hollow stem and this branch seems to grow very strong (I was a hollow stem found in super training) but the current stem of this branch has become wood is not hollow; but the current plant The main stem has purple color and all petioles are purple! And the top leaves are small; (I have planted the same strain, grow well, and the phenotype is completely different! They are densely leafy, and this time the plants seem to have few leaves!) Thank you for reading; very I want to know how to deal with it! Thank you

 

[Iammygod]

Too much calcium, low water/air temperature and pH off are the main reasons of P deficiency in plants.

 

[FlyingDutchPaddy]

hi Mingzhu,

too much P can cause other nutrients to lock-out...
Calcium is best absorbed above pH 6.0
P will be available up to pH 6.2
(pH levels stated are for hydro setups, soil will be slightly higher)

lowering humidity will increase the plant's transpiration rate (water evaporation from the leaves) and thus increase uptake of Calcium and other nutrients.

any measurements on the water pH, relative humidity?

P is actually for the energy of the plant, it doesn't have to be too high.
you may want to have reasonable levels of P, but K (potassium) is more important in bloom.

you could try the following:
- flush with pH'ed water to the medium you use (soil or hydro),
- give a fresh batch of nutrient water for bloom. (not too high N, slightly higher P, and high K)
- after a week or so, same N, lower P but still a high K ratio.

and keep relative humidity low, so the plant can transpire enough water through the leaves so it takes up the calcium and other nutrients.

hope that helps.

 

[mingzhu]

Thank you very much for your reply, detailed and serious! I will take the opinion, thank you again!Can you tell me "there is no too high N suitable P and K" What should their ratio be? I am using a GH3 ensemble.

 

[mingzhu]

Thank you

 

[FlyingDutchPaddy]

hi Mingzhu,

by GH3 ensemble, I'm going to assume its the GH Flora series, Micro+Gro+Bloom.

The ratio question for N-P-K i've been researching as well, and so far I learnt in general:
In vegetative growth, you want K about 1.5 times N,
N -> 1.5 K 1 - X - 1.5
In flowering/bloom, you want 2x K to N.
N -> 2K 1 - X - 2

recently I posted a question about this but got little feedback on it, see this post (there's a few screenshots of a spreadsheet I made):
https://forum.growweedeasy.com/foru...k-ratio-s-what-ratio-s-work-best-for-cannabis

The NPK values we see on the bottles are attributed to the salt concentrations...
N is at 1,
Elemental availability of P (P2O5) is 0.44
Elemental availability of K (K2O) is 0.83

Essentially, if you read a value of 1-2-2 for NPK somewhere, actual availability of elemental NPK is 1 - 0.88 - 1.66

This is a very interesting read on nutrients in hydroponic setups:
https://medteknutrients.com.au/hydroponic-nutrient-fundamentals/