Cannabis Nutrient Deficiency Research Paper

[BongFu]

Probably 20 years behind others on most things - e.g. cannabis growers etc have long understood the deficiency symptoms associated to the various nutrients but some interesting findings never the less re point at which a deficiency becomes apparent and other.



https://www.mdpi.com/2076-3417/9/20/4432/htm

 

[CannaRed]

Thanks for the link.

Interested to hear what everyone thinks.

 

[CannaRed]

So this was just veg?

 

[Douwe Egbert]

So this was just veg?

Cheers - That's really useful, comprehensive information. It's great to have good pics of the progression of deficiencies alongside a credible empirical analysis.

If only "sorrows came not as single spies, but in battalions" e.g. when you get antagonistic interaction of deficiencies / excesses of other nutes - just to complicate things But still great info.

 

[pongster]

So this was just veg?

In addition, measurements of dry weights of floral parts at harvest and concentrations of cannabinoids from those floral could offer insight into the effects of these essential nutrients on plant growth and yield parameters other than vegetative biomass

yes, it's only veg.
useful pictures, reassuring conclussions,
thank you for sharing

 

[CannaRed]

Thanks pong, I looked all over, but didn't see that part!

Douwe, welcome to icmag!



Yes, these pics are cool! And this is only beginning!!

More and more, studies and papers are going to released, as more states legalize.
With all the bullshit that may come with federal legalization, and Big AG stepping in, that's when the science will happen.

 

[bsgospel]

If only "sorrows came not as single spies, but in battalions" e.g. when you get antagonistic interaction of deficiencies / excesses of other nutes - just to complicate things But still great info.

This. This paper needed to show the other nutrient values were kept in check while limiting the nutrient in question. Also the re-use of the solution that was changed weekly- an analysis should have been included to tell that no other effects were occurring/other minimums being affected.

As far as I can tell, the only person growing in the Millersville #2 silica sand is this Whipker guy. He's got a dozen papers (as a directing Professor, aided by undergrads) from North Carolina State University dating back to at least 2008 that all look exactly like this one. Why the Millersville #2 w/ Dolomite? Not ripping, just curious.

 

[zif]

They probably use sand because it’s (relatively) inert and very inexpensive. Both good qualities for a research program!

 

[f-e]

Good link. For me, it's very useful for outdoor growing, where things such as K deficiency look to express themselves quite differently. With a total lack of the burnt tips and margins seen under HID's in hot conditions.

No one paper can ever tell us everything, but this one has a place on my favourites list. As another marker along the way to a better all round understanding.

Sand? yeah.. I know? But then if an extract is all you want, and space is abundant, a rough and ready, cheap and reusable substrate is a good thing. People were selling us silica based mediums in a more granular form for flood drain not ling ago. I didn't get involved, but gains were claimed from this not exactly inert medium

 

[pongster]

This. This paper needed to show the other nutrient values were kept in check while limiting the nutrient in question.

To establish nutrient concentrations when deficiency or toxicity symptoms are expressed, Cannabis sativa ‘T1’ plants were grown in silica sand culture, and control plants received a complete modified Hoagland’s all-nitrate solution, whereas nutrient-deficient treatments were induced with a complete nutrient formula withholding a single nutrient.

it's right there...
in the abstract...

still you can't show just a single symptom, since they are all chained together;
they can only use a solution lacking a certain element, and see what happens.
cheers

 

[bsgospel]

They probably use sand because it’s (relatively) inert and very inexpensive. Both good qualities for a research program!

it's right there...
in the abstract...

still you can't show just a single symptom, since they are all chained together;
they can only use a solution lacking a certain element, and see what happens.
cheers

I hear ya but that's not really what I was asking. I'm (1) just questioning why that medium is the most practical. In practice, none of us will be using that medium. Zif's explanation is good enough for me. And then (2) because one nutrient is withheld, I would like to see what happened to the tissue numbers of the other elements. It's not enough to say Ca was reduced when we withheld Ca and here's a picture. There's more to be gleaned like you said because there is a chain- and I just want to see the other numbers. When they withheld the Ca, what happened to K, Mg, P etc. And they have them. Clearly they do. And they should have included water analysis on the run off before switching it out each week.

Seems like a lot but not really. It's a fairly thorough paper but it missed a huge opportunity to show what was happening elsewhere in the tissue numbers. Which again, they have them.

 

[pongster]

I hear ya but that's not really what I was asking. I'm (1) just questioning why that medium is the most practical. In practice, none of us will be using that medium. Zif's explanation is good enough for me. And then (2) because one nutrient is withheld, I would like to see what happened to the tissue numbers of the other elements. It's not enough to say Ca was reduced when we withheld Ca and here's a picture. There's more to be gleaned like you said because there is a chain- and I just want to see the other numbers. When they withheld the Ca, what happened to K, Mg, P etc. And they have them. Clearly they do. And they should have included water analysis on the run off before switching it out each week.

Seems like a lot but not really. It's a fairly thorough paper but it missed a huge opportunity to show what was happening elsewhere in the tissue numbers. Which again, they have them.

you are correct, sorry for my misunderstanding;
indeed, it is data that they might have, perhaps research money ran out?
cheers brother, thanks for the input

 

[f-e]

Nothing caused 'spotting' Even advanced calcium problems. No spots of necrosis at all, regardless of what they did. We have seen it enough times to know it happens though.

I'm content to see not everything caused stripes though. There is a common set of drawing go around where everything seems to cause the same stripy symptom.

Most of image collections I have seen are barely related. Making the average picture they all give, a somewhat unlikely truth itself.

 

[slownickel]

Actually there is useful information there, just have to sift it. Lots of conclusions which are wrong to say the least! But if you look at their data are look at it correctly, lots of great info there!

 

[Douglas.Curtis]

Sand? yeah.. I know? But then if an extract is all you want, and space is abundant,

It's lab work, so space usually is not abundant. The silica is a known media. It can be batch tested for consistency, it's well known how it reacts chemically, it drains well, cannabis grows in it quite well, and it's readily inexpensive and available.

When doing scientific research, your goal is to eliminate as many variables as possible. Silica sand, in this situation, does this admirably.

 

[f-e]

At the end of each description, they give the reduction in bio mass seen from that particular deficiency. Often stating the result is from when the signs first showed, rather than an advanced case. In the case of N they don't say when the weigh-in occurred but... 50% reduction in bio mass. Or, half the weight. From an N problem. Perhaps when it was first seen. N deficiency is so common going into flower that I have at times thought it inevitable. Constant leaf drop at the bottoms through flower has barely been a concern.

Copper, 45%
K, 27%


50%!!!! I have never used so many exclaimation marks

 

[f-e]

I'm loosing sleep. I can't believe nobody has replied

K & N effect the uptake of each other. Too much of one makes the other less available.

I do delay my PK boost till week 6 of 8. It does seem to do something then, but at week 5 I'm just doing it because the bottle says. I don't see results that way. I can't be doing it any good by getting it in early, if the result is mild N signs.

 

[Douglas.Curtis]

In the case of N they don't say when the weigh-in occurred but... 50% reduction in bio mass.


50%!!!! I have never used so many exclaimation marks

This is exactly why I grow low N cannabis. That 50% biomass is mostly plant. I grow to produce maximum trichomes/terpenes/cannabinoids instead of plant matter.

High N makes for such leaaaafy cannabis. heh

 

[f-e]

Can we grow trichomes/terpenes/cannabinoids without a plant though.

I have lost your diary, but I was watching

 

[ReikoX]

Thanks for sharing the paper, I found it interesting. This is a good start, but it has a small population size (N=4) and a single cultivar. There is a lot more work to be done in this field.