Effects of phosphorus on cannabis

[Yamumzbum]

This is a gooqqd read..
or if your a lazy fucker like me you can listen to Patrick Veazie talk to Tad Hussey on his cannabis science and cultivation podcast

 

[RiverRat]

‎Cannabis Cultivation and Science Podcast: Episode 103: Phosphorus Research in Cannabis with Paul Cockson and Patrick Veazie on Apple Podcasts

‎Show Cannabis Cultivation and Science Podcast, Ep Episode 103: Phosphorus Research in Cannabis with Paul Cockson and Patrick Veazie - 28 Oct 2022

podcasts.apple.com

 

[frankreynolds]

Studies like that are good, but also not so enlightening due to the fact they only change one variable.

"Fertilization treatments began the day of transplant. Four fertility concentrations of 15, 60, 120, and 180 mg·L–1"

It's often hard to guage what's happening when only making slight changes to one element due to the synergism/antagonism between minerals in the rootzone.

For example the negative effects of increased P could be because it is starting to lock out calcium within the rootzone and without a subsequent increase in calcium your gonna have issues.

Regardless I have dropped P and Mg levels in my most recent salt mix and it seems to be working well. Down to running P at around 60ppm in solution

 

[Old fox]

Studies like that are good, but also not so enlightening due to the fact they only change one variable.

"Fertilization treatments began the day of transplant. Four fertility concentrations of 15, 60, 120, and 180 mg·L–1"

It's often hard to guage what's happening when only making slight changes to one element due to the synergism/antagonism between minerals in the rootzone.

For example the negative effects of increased P could be because it is starting to lock out calcium within the rootzone and without a subsequent increase in calcium your gonna have issues.

Regardless I have dropped P and Mg levels in my most recent salt mix and it seems to be working well. Down to running P at around 60ppm in solution

Welcome back Frank. What salts are you using to allow you to change the ratios? Would be useful for dealing in during transition from veg to flower nutes. Any discernible differences to plant health/growth?

 

[frankreynolds]

Hey mate, I've been using Calcium Nitrate, Mono potassium Phosphate, Potassium Sulfate, Magnesium sulfate and a micronutrient mix, i am using hydrobuddy to formulate and just mixing salts per 100l res at the moment until I find a general recipe that works the best in my enviorment for multiple strains then I will make a concentrated stock solution of it for future use.

Last run I was running very high P and MG in my mix, with large drybacks at 3.0 ec I was finding I was having calcium issues not due to lack of calcium. I assumed it as the extra P and MG abuilding up in the media and locking out Calcium. No issues since dropping P down a bit I also have gone back to 2.4ec inputs and aiming to build up EC in medium with drybacks rather than smashing the plants at 3.0ec seems to work better and I get less wastage.

 

[Old fox]

Hey mate, I've been using Calcium Nitrate, Mono potassium Phosphate, Potassium Sulfate, Magnesium sulfate and a micronutrient mix, i am using hydrobuddy to formulate and just mixing salts per 100l res at the moment until I find a general recipe that works the best in my enviorment for multiple strains then I will make a concentrated stock solution of it for future use.

Last run I was running very high P and MG in my mix, with large drybacks at 3.0 ec I was finding I was having calcium issues not due to lack of calcium. I assumed it as the extra P and MG abuilding up in the media and locking out Calcium. No issues since dropping P down a bit I also have gone back to 2.4ec inputs and aiming to build up EC in medium with drybacks rather than smashing the plants at 3.0ec seems to work better and I get less wastage.

3.0 ec is impressive across multiple strains. Are you able to run those levels because your nutrient ratios, relative to each other, are dialled in ? There's an off the shelf line from "Athena" that few growers seem to be regularly running around 3.0ec levels.

 

[frankreynolds]

Yeh, that old chestnut of Athena hehe. I've heard decent things about em, I hate the hype marketing they do. I am generally following there Hign K to N ratio though. I'm at about 1 N : 2.5 K.

I feel the aim in the end is to get the pwEC(pore water EC) within the media to spike and trigger the plant to flower quicker/better (generative crop steering) whether you achieve that through 3.0ec shots or 2.4ec shots it doesnt really matter the aim is getting medium ec up and you can just change frequency of irrigations to match the input EC your putting in.

Having said that I don't have the electronic equiptment to monitor pwEC and I also run multiple strains or phenos usually that need different watering schedules so its all a bit of a crapshoot for me in that regard. I just try to get the plants looking healthy and happy for now.

Pushing the EC isn't an issue if your giving plant enough light and c02. It's the ratio of elemnts in the feeds that are most important, with a high N flowering nute i dont think your gonna have a good time pushing ec with that much nitrogen.

 

[RiverRat]

The other interesting this about this study was the poor job in growing / quality of the plants in the first place along with the limited root space.

It's a good topic but because of the above the experiment was almost null and void to me.

 

[Donothing-garden]

This is a gooqqd read..
or if your a lazy fucker like me you can listen to Patrick Veazie talk to Tad Hussey on his cannabis science and cultivation podcast

This was a really interesting podcast! So many variables though... Like what targets are required in relation to calcium, potassium and magnesium saturation? I have a feeling that higher P levels become much more important in higher CEC soils with high saturation of other cations, especially potassium.

 

[Donothing-garden]

Studies like that are good, but also not so enlightening due to the fact they only change one variable.

"Fertilization treatments began the day of transplant. Four fertility concentrations of 15, 60, 120, and 180 mg·L–1"

It's often hard to guage what's happening when only making slight changes to one element due to the synergism/antagonism between minerals in the rootzone.

For example the negative effects of increased P could be because it is starting to lock out calcium within the rootzone and without a subsequent increase in calcium your gonna have issues.

Regardless I have dropped P and Mg levels in my most recent salt mix and it seems to be working well. Down to running P at around 60ppm in solution

Yeah my thoughts too, I agree.

This was a really interesting podcast! So many variables though... Like what targets are required in relation to calcium, potassium and magnesium saturation? I have a feeling that higher P levels become much more important in higher CEC soils with high saturation of other cations, especially potassium.

Apparently P binds with aluminium and iron to create a cation, pushing out Ca, Mg, K etc... So lower numbers of iron and aluminium would definitely help. So many variables