Slownickel lounge, pull up a chair. CEC interpretation

[led05]

Those growing inside, in tunnel, GH etc.. good read

Those growing inside, in tunnel, GH etc.. good read

I know some who love Bro Science still don't believe in the significance of this but it's real and I think a huge overlooked factor for many who experience plant issues, it's a piece of the whole, for sure...

https://www.nature.com/articles/srep43461

I know we'll have those chiming in saying I grow in 90F and 35% humidity just fine, maybe outside you do and I'm sure it's fine (definitely could be improved wit higher humidity, guaranteed!) but the %'s for humidity required indoors for optimal, especially at higher temps vs the discrepancies people run at is significant and an area that's especially ripe for improvements !!

in laymen terms, we're talking VPD ;0

this is so critical especially to Ca uptake & B and the way Ca drives everything else, hard, very hard to overlook

 

[slownickel]

I know some who love Bro Science still don't believe in the significance of this but it's real and I think a huge overlooked factor for many who experience plant issues, it's a piece of the whole, for sure...

https://www.nature.com/articles/srep43461

I know we'll have those chiming in saying I grow in 90F and 35% humidity just fine, maybe outside you do and I'm sure it's fine (definitely could be improved wit higher humidity, guaranteed!) but the %'s for humidity required indoors for optimal, especially at higher temps vs the discrepancies people run at is significant and an area that's especially ripe for improvements !!

in laymen terms, we're talking VPD ;0

this is so critical especially to Ca uptake & B and the way Ca drives everything else, hard, very hard to overlook

Been involved in several of these conversations about VPD.

Realize when certain functions in the plant are not working due to nutritional deficiencies or excesses, the result is the stomata shutting down due to what ever stress. We know that this plant doesn't like heat, but everything becomes much more heat tolerant under the same RH, when the plant is grown with nutrient dense high Ca soils.

Dr Albrecht showed the difference in drought resistance from a high Ca vs low Ca field, the results were a decent crop vs no crop.

If you note who the authors are, they are from China and this work was done in China. You don't want to know what yields in China are like, some of the worst in the world which reflects greatly on their mastering of plant nutrition.

I have seen that famous VPD chart flying around on ICMAG and I have my doubts as to the reality of this situation.

I am not denying that there is definitely influence on too much humidity or not enough, the same for too high a temperature, etc.. I just have my doubts if it is really as dramatic as so many might have us think.

 

[led05]

Been involved in several of these conversations about VPD.

Realize when certain functions in the plant are not working due to nutritional deficiencies or excesses, the result is the stomata shutting down due to what ever stress. We know that this plant doesn't like heat, but everything becomes much more heat tolerant under the same RH, when the plant is grown with nutrient dense high Ca soils.

Dr Albrecht showed the difference in drought resistance from a high Ca vs low Ca field, the results were a decent crop vs no crop.

If you note who the authors are, they are from China and this work was done in China. You don't want to know what yields in China are like, some of the worst in the world which reflects greatly on their mastering of plant nutrition.

I have seen that famous VPD chart flying around on ICMAG and I have my doubts as to the reality of this situation.

I am not denying that there is definitely influence on too much humidity or not enough, the same for too high a temperature, etc.. I just have my doubts if it is really as dramatic as so many might have us think.

The chart is way overblown, agreed, but talk to GH growers of tomatoes or peppers and its a critical component... as you know, calcium needs wet/dry cycles, I think too low RH can be especially detrimental when plants are young to this process


Field sounds like outdoors to me too, it seems to me to be much more critical inside a GH, tunnel, building's etc


I hear you on China but this sounds like a good study that regardless showed a significant difference if RH is low vs reasonable to achieve levels

 

[paradoxlost]

I will tell you right now that trying to grow in those fabric pots in vegas is a pain in the ass, but people do outdoor grows in the desert cause they have some of the most fertile soils in the world -- if you add water. Summer is 0% RH all summer essentially

 

[led05]

I will tell you right now that trying to grow in those fabric pots in vegas is a pain in the ass, but people do outdoor grows in the desert cause they have some of the most fertile soils in the world -- if you add water. Summer is 0% RH all summer essentially

I hear that, outdoors is very different though, especially if the plants are in the ground or huge pots....


Inside (GH's, Warehouse etc) its' a much larger factor... It becomes every more prevalent with very high light intensity and higher Co2 levels, say > 500 PPM


Slow knows his shit as an Agronomist but I'm pretty sure the overwhelming base of his experience is outdoors in nature, not in controlled environments inside. It also seems his base is much more around Perennials than Annuals, Slow are these assumptions right? I know this is changing, however, as we speak ;0


Do a veg run at 75-80F and say 30-40% humidity then do one at say 60-65% humidity at 75-80F- maintain similar humidity ratios at night and you'll see a WORLD of difference, the stronger the light and if Co2 enriched, you'll see the effects even more....


It has a substantial effect on overall transpiration which of course is directly tied into Nute uptake, Photosynthesis etc....

 

[slownickel]

I hear that, outdoors is very different though, especially if the plants are in the ground or huge pots....


Inside (GH's, Warehouse etc) its' a much larger factor... It becomes every more prevalent with very high light intensity and higher Co2 levels, say > 500 PPM


Slow knows his shit as an Agronomist but I'm pretty sure the overwhelming base of his experience is outdoors in nature, not in controlled environments inside. It also seems his base is much more around Perennials than Annuals, Slow are these assumptions right? I know this is changing, however, as we speak ;0


Do a veg run at 75-80F and say 30-40% humidity then do one at say 60-65% humidity at 75-80F- maintain similar humidity ratios at night and you'll see a WORLD of difference, the stronger the light and if Co2 enriched, you'll see the effects even more....


It has a substantial effect on overall transpiration which of course is directly tied into Nute uptake, Photosynthesis etc....

My experience is mainly outdoors. I worked in roses and gerbera daisies in green house quite a bit, but the issues there were very different.

I did speak to a plant physiologist about VPD and he called it horseshit to quote him directly.

But you are quite correct, I don't have the experience either way to be of much help.

 

[growingcrazy]

As far as cannabis indoors I have found it to be variety dependent. If I have a landrace from Laos, it requires a different VPD than an afghan kush... Each seems to have an ideal zone.

I also don't have low humidity conditions in my area, so I can't do much testing in the vegetable seed house.

 

[slownickel]

There should be some local data where you live on the internet.

Which varieties do you see the most tolerant to heat and low RH?

 

[weedtoker]

As far as cannabis indoors I have found it to be variety dependent. If I have a landrace from Laos, it requires a different VPD than an afghan kush... Each seems to have an ideal zone.

I also don't have low humidity conditions in my area, so I can't do much testing in the vegetable seed house.

I'll have to jump in and second that. Too many variables, but seems the case around here too and it's not linear to WLD-NLD (even more "erratic" if in the hybs). That and at least, watering requirements and nutrition... My bet (and it's a bet based on anecdotal observations, not a study lol) says it has to do with adaptation to their environment, but time will tell that hopefully too.

Example: you bring some heirloom/landrace out of the mountains, generally speaking they eat and drink much less maybe related to field conditions (simple ex: try feeding fast acting N, on cannabis that is used to rocks and almost no organic matter = field time eheh). Fortunately/unfortunately, depending how ya view it, those traits seem inherited in outcrosses, quite easily I would say... The plasticity to withhold extremes (or lack thereof) is thus related, and again, just a personal bet, not a scholar, in part to hybridization without taking into account/not knowing about certain stuff that was going on. People had to survive and dodge bullets during the last decades, so can't censor on my part, but on the other hand we can see clearly more and more what RCC and others have been saying last few years on hybridization and genetic diversity of Cannabis and how it might affect cultivation practices...


Also, to finish bogarting the thread with this semi-off-topic, have a lot to Thanks Mr. Slow, you've gave enough food for my thought while readin' this thread for last few months, knowledge is priceless, and we should never run out of space for it, specially for applying it!

Cheers

 

[led05]

As far as cannabis indoors I have found it to be variety dependent. If I have a landrace from Laos, it requires a different VPD than an afghan kush... Each seems to have an ideal zone.

I also don't have low humidity conditions in my area, so I can't do much testing in the vegetable seed house.

very true in regards to Varieties, I lean heavily toward NLD and if the humidity is too low they tell you it very clearly, WLD native in the dry mountains would prefer & tolerate otherwise.

When plants are young the room creates much less humidity on its' own and it seems younger plants are more effected by lack of humidity in the room, especially the closer you are to seedling stage, IMHE

 

[redlaser]

I hear that, outdoors is very different though, especially if the plants are in the ground or huge pots....


Inside (GH's, Warehouse etc) its' a much larger factor... It becomes every more prevalent with very high light intensity and higher Co2 levels, say > 500 PPM


Slow knows his shit as an Agronomist but I'm pretty sure the overwhelming base of his experience is outdoors in nature, not in controlled environments inside. It also seems his base is much more around Perennials than Annuals, Slow are these assumptions right? I know this is changing, however, as we speak ;0



Do a veg run at 75-80F and say 30-40% humidity then do one at say 60-65% humidity at 75-80F- maintain similar humidity ratios at night and you'll see a WORLD of difference, the stronger the light and if Co2 enriched, you'll see the effects even more....



It has a substantial effect on overall transpiration which of course is directly tied into Nute uptake, Photosynthesis etc....

The vpd charts I've looked at generally show an even higher humidity to temp ratio, generally speaking the difference is 6-8. Like 70% humidity and 76 degrees for example as ideal.

75% humidity for 79-84 degrees is a recommendation , and at that humidity offsetting dew points when lights go out is challenging.

Probably veering off topic unless you consider nutrient uptake related to vpd.
I'd like to hear how people are managing or avoiding reaching dew points at nighttime . I'm simply running exhaust for an hour before and after sunset. You lose the vpd for that time, but if you are starting to see botrytis, it's really not an option not to ventilate to avoid reaching dew point on the pistils and petioles

^ That last paragraph is also a good summation of the difficulty of maintaining vpd 24/7 indoors.
Life of the farmer I suppose, if it was easy everyone would be doing it.

 

[slownickel]

Red,

I think VPD is much more of an issue when the plant is poorly fed.

Everyone that has tried (and I mean everyone) to use Ca, P and micros correctly has seen a different result than they have ever seen before.

So we must assume that those that come up with some of these things are farming just as bad if not worse than most.

The poorer the root system, the more the plant will be affected by VPD.

I would also argue that if you got your metals into a good range, your botrytis events would be minimized greatly.

 

[plantingplants]

7-10 Day old seedling after emergence, this is root hairs with proper nutrition out the gates, a leg up, if you start bad you chase for the entire grow.... the hard truth we've all learned

[URL=https://www.icmag.com/ic/picture.php?albumid=75390&pictureid=1806285&thumb=1]View Image[/URL]

Led do you have an analysis for that soil? What does metals in balance look like to you?

 

[growingcrazy]

Led do you have an analysis for that soil? What does metals in balance look like to you?

I second that... I wasn't going to ask what is in His hand, but since You did...

I wouldn't mind seeing an analysis of what Slow considers to be His best balancing job yet...

 

[led05]

Led do you have an analysis for that soil? What does metals in balance look like to you?

I don’t sorry... but I can tell when the roots are ok, good or great around this stage, these for me are near ideal...

The soil is lower CEC but very heavy in Ca, the tree pots and how I use them also forces root development as soon as tap root hits bottom and explosion of lateral growth happens you can watch as it hits edge... the microbial life is decent too, the fine root hairs supports this.

I still disagree with the VPD thing though and since I see it directly related to nutrition and uptake it’s relevant in here to me and hopefully others.

That young plant with identical soil at same temps with 40 humidity vs 60% show significant difference both above and below the surface and I’d argue it’s well balanced nutrient wise ...

Ca ( & others) is huge and slow correctly has show the light as to the easiest and arguably most critical hanging fruit there is but there’s other low hanging fruit and bumping up humidity some during lights on to me is well worth it...

Living in a desert w little rain and proving to the world you can in fact grow great fruit there could create a slight bias, no offense

 

[plantingplants]

You put the tree pot inside another pot right? The humid air coaxes the roots out. Not to say you don't have great root development.

Anyway, in what form do you add metals to your soil and how do you determine how much to add?

 

[led05]

You put the tree pot inside another pot right? The humid air coaxes the roots out. Not to say you don't have great root development.

Anyway, in what form do you add metals to your soil and how do you determine how much to add?

correct...The tree pots sit very tightly inside another cavity (in my case a tray the pots I use fit inside, I have also used other pots as well, lots of trial and error to find best) which creates almost an aeroponic effect for the roots (it's not aeroponics at all, the roots just look this way but it's a very humid cavity / area that creates fine root hairs extremely well with proper soil)...

as for soil.. I have a number of large beds here I've been building for years and I take some from that (my micros), use some Pro-Mix (just regular old clean pro-mix bales from AG suppliers, not the BS hydro stores try and sell all juiced up and overpriced). I amend to this, I have posted base ratios I target as well as one of many soil recipes I use somewhere in this thread before, the base ratios at least a couple of times.

I have tested my soils here locally (via Cornell, not sure who they use or if in house) enough times I don't that often anymore as I know fairly well what I'm working with, sorry if that makes others cringe.

I fully agree with most needing more Ca, P, B, Mn, Cu, Zn & Si and less Fe, Mg and especially K - when I add K during grow it's almost always or only Potassium Silicate fwiw. I use a lot of Baicor products, sometimes Amazon carries what I need and they mess up pricing, have gotten a few Gallons of Chelates there recently for under $30 delivered, their selection is limited though.

I foliar feed until I can't anymore and by then I hope I've built the soil enough to get me through till end, if not I use liquid fertilizer and drench, I also use a lot of Ca heavy slurries whether it be Gypsum based or Cal Carb etc

for those on the East Coast, this place is great and they don't FK you on shipping, pretty much charge you exactly what it costs. I have no affiliation but they carry a lot of what any organic farmers use and send out fast and fair pricing.

http://www.7springsfarm.com/

 

[growingcrazy]

This makes 5-6 CF - it works great for starts/seeds, some would think burn when looking at it but it doesn't if you mix it well, Kushlan makes a nice cement mixer (6 CF model) that works to mix small amounts up better than anything else I've ever tried

PEAT MOSS 2 CF Local POT MIX 1 CF PERLITE 5 G VERMICULITE 2 G SAND 1 G DE (Silica) 4-5 C EWC 4-5 C CRAB SHELL 4-5 C THORVIN KELP 4-5 C GYPSUM 4-5 C CALPHOS 2-3 C Supplimate 2 C GUANO 1 C LIME 1.5-2 C SULFATE OF POTASH 1/2 C MYKOS 2 Oz BORON 2 TBS MANGANESE 4TBS

If you on east coast 7springs farms is a good place to buy small and large amounts of minerals etc, I have no affiliation, ship quick, package well, ship as cheap as possible and good people to work with....

Here is the mix, still looking for other micro #s.

 

[led05]

Here is the mix, still looking for other micro #s.

That is a HOT one , you could half or even quarter all the amendments and be good... after that mix is used there’s a ton left in the soil which will be recycled into one of the beds outside... most of my outdoor beds don’t need any more additives when dumping this “used” mix, pretty close to just going full mix from one of the older beds here, no amendments and just mix in peat or pro mix

I’m lucky to live where there’s tons of worms naturally in all my beds etc, I add food, plant & lawn scraps to them also and the worms love to gather there

 

[plantingplants]

Whoops thought you meant micros when you said metals. Thanks for your response though.