Plant sap testing

[Humphry Davy]

Was looking to buy a hydraulic plant press, but considered using a masticating juicer that removes all the pulp, yay or nay?

Also I recall seeing a guide from I believe AEA about what guidelines to follow regarding plant sap testing w pH, K, Ca, and N meters....anyone have those guides accessible? Can't seem to find them online....or any literature on the subject would be appreciated.

 

[GHGrower]

Why not just use a garlic press with a piece of muslin cloth in the bottom? All you need are a few drops for a refractometer.

 

[Humphry Davy]

I've tried a few different garlic presses and dislike how difficult it is to get anything, plus w the multitude of samples Ill be processing Id like somethig a little easier

 

[GHGrower]

Some other options also include purchasing an actual sap extractor from Australia (Think they're about $140 USD online last I looked). Those might be your best bet. https://www.planthealthsolutions.com.au seem to have a range of things that may be able to help.

 

[leadsled]

Pike has a manual for there tissue testing kits. That the one you are looking for?
http://www.pikeagri.com/images/PDFs/plant-tissue-test-kit-instructions.pdf

Having good luck with the Pike vice grips for getting sap.

 

[wodi]

Nutri tech solutions stock a press for plant sap extraction. Good quality heavy duty.

 

[Humphry Davy]

Yeah that press is most likely what I'm going to get, my buddy offered the juicer, thought it might not be a bad idea.

Thanks for that link! That's what I was after

 

[green path]

yes I use the pike ag vice grips... works very well


gp

 

[FatherEarth]

what are the desired PPM ranges of plant sap for K and Ca?

 

[odkin]

Whoa- plant sap analysis and testing for brix are two entirely differing things. A simple set of vice grips or a garlic press are good for brix testing, but plant sap analysis requires something completely different, no?

 

[milkyjoe]

Horiba meters use sap just like refractometers.

If you measure K on old and new leaves you will quickly find out what K should be just like Nova Crop Control. Then, in general, Ca = K is what you want.

pH should be 6.4 or a hair higher...it means you have enough base cations in the plant. I like this number better than brix.

edit...the nitrate meter may measure anions beside NO3...put some Epsom salt in soln in it and see if it does not read.

 

[FatherEarth]

I only have the Ca ion meter and the PH from Horiba.. So now what? Lol

 

[Jellyfish]

Check out the Gallagher Corporation, they have a product call the sledge-o-magic.

 

[FatherEarth]

Im going to get the k meter though since it seems to be a regular problem in our soils being too high in it. I just sent off a new soil blend for testing hoping it comes back spot on....ill post up once its in. Thanks

 

[milkyjoe]

So technically when you do this type of work you start by plotting a run chart. When you get enough data you use fancy statistics to calculate std deviation. Std d gives you how big of sample size you need for various confidence levels 95% is the standard used in 6 sigma work. Then you use design of expsriment.

I am at the graphing run chart data. It is a most excellent way to look really fucking stupid to give advise at this point.

Havind said that if you want a wild ass guess somewhere around 4000 ppm Ca. If your pH drops below 6.4 you lack base cations. If you do not see burnt edges on old leaves it is not K. If Ca below maybe 3k probably that...4 or above look to Mg

But I cannot say that with confidence yet...so proceed at your own risk

I have another theory if you wanna confirm some numers...I will pm you in a day or two

 

[FatherEarth]

~

~

Thanks MJ.
Thats what I needed to know. If you need any help collecting data, please dont hesitate to ask. Ill contribute what ever I can to help get a protocol established and get some solid numbers. My first Ca test I did at a friends house on new growth shoots... Tested at 30ppm. So I assume 4000ppm is super high for new shoots since that is where Ca def will show first .. should new leaves be that high 3-4000ppm?

For the record: Personally when I ask a question online, and anyone answers. If I chose to use that info in my garden, I dont hold anyone responsible for what happens in my garden except me. If I was too lazy to double check to confirm if your answer was right and then something goes awry, thats what I deserve. Being unable is one thing. Being lazy and expecting to use another growers research and hard work to get instant results is deserving of failure. Thanks for the disclaimer though. Ive been searching for the answers and havent found anything definitive not even loosely. That helps me get at least a ballpark est..

I guess once your soil hits Albrecht numbers then you test sap levels that should be the baseline. Your thoughts on that?

 

[milkyjoe]

What was your sap pH.

 

[milkyjoe]

Right now my indoor plants are at 83% Ca and 1.7% K. No sign of K def and Ca/Mg uptake is not hindered. I don't know how it will end but the plants look good now. Albion K on hand for foliar if I see any sign of K def...24% K vs 7 for phtk

 

[MountZionCollec]

Awsome thread, question was brought up a couple times in aea thread thx for posting your results!

 

[milkyjoe]

It is a constant debate my different brain compartments have with each other.

You spend a yr working on something. You are no where near a conclusion. Do you share?

If you do find an answer...do you share or enjoy an advantage?

I believe life is 100% random events...so the karma argument is meaningless to me. On the other hand people return things and group knowledge builds on itself. What to do?