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Manganese tolerant weed sucks!

First off, where does the Manganese go? Into the bud? Manganese-sensitive bud tries to keep it in the root and leaf, away from reproductive organs. What makes Mn tolerant varieties different? This is obviously an important question. Do you test your bud for heavy metals? Manganese specifically?

If manganese tolerant Cannabis is allowing the heavy metal to build up in the bud, that would explain the Indica smoking pothead stereotype, as seen here:


A youtube guru grower inflicted with manganism, pondering his heavy metal toxicity as a plant deficiency


Just kidding. That dude is fucked up from huffing glues, spray paints and sharpie markers. (That's a subject for another day.)

In reality, manganese tolerant strains are tolerant to Mn simply because they excel at uptaking Calcium, Iron, and Magnesium, which in combination is effective at restricting excess manganese from accumulating in Cannabis.


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Calima, the Mn tolerant green bean variety


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Cannabis-specific fertilizer additives


Cannabis is said to be a heavy feeder by many farmers, and "finicky" to many more. This is only true on farms with high levels of Manganese, such as those who have been sold rock dusts from Mn-mining regions, or who use unfiltered fertigation with high levels of Mn.

I see tons of leafless plants being harvested and no one seems to think it's odd these days. The die down vs the dry down debate. Sugar leaves giving harvesters more paper cuts than charas. Any time a grower asks about his damaged leaves he is told "nute burn" or pH imbalance, or some environmental factor that ultimately is affecting or has a root cause in nutrient ratios. Which nute is at play then, in any scenario?


Let's investgate.


Although immobile in the plant Calcium deficiency (c) and Iron deficiency (d) are known to pot growers by the "burn" on older, mature fan leaves. Why?
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Zn deficiency (c) Mg deficiency (middle) and B deficiency (lower) all induce the same light sensitivity issues as Mn toxicity.
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Potassium is yet another "deficiency" that causes Mn-induced light sensitivity in light loving crops.
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Manganese deficiency trial preformed on Cannabis shows zero Mn deficiency symptoms. In fact the control is suffering from more leave burn than the deficiency.


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Flawed Cannabis deficiency study. Mn was kept at toxic levels throughout. No information is derived except that Cannabis hyper accumulates Mn when levels of most other nutrients drop to average.




2nd...

Monoterpenes suck! High Mn:Mg ratios put your plant's genetic flaws in the spotlight. If you hate fake vape pen terps, and think terp-perfumed Integra boost packs are a total joke (,and everyone does whether they admit it or not,) then you hate monoterps. They are Cannabis breeding flaws, not Cannabis flavors or entourage metabolites. No one in their right mind would ever want their bud to taste like terpinolene yet people constantly talk about it? And constantly run premix nutrients that cause quality/shelf life issues?

And which hemiterp is worth it's weight in rec sales or medicinal value? Prenol. BUT.. Do we need MEP for 3-methyl-2-buten-1-ol? I don't think so..


Every other worthwhile hemiterp is from branch chain aminos (3 methyl butanoic from leucine for example). A manganese toxic plant will be depleting its resources to wrangle its manganese-induced oxidation, not creating flavor compounds. The only other interesting product of MEP is GPP/FPP. But, we have the assymetric pathway in Cannabis thanks to mutated small side-chain aminos like alanine and lysine (with a C15 group and a C5 (hemi) group!)

Breeding for 0.73ppm Mn fertigation is more senseless than doing Calcium deficiency trials with 0.73ppm Mn. Every good plant gets culled. Every useless Mn tolerant strain is labeled a keeper. Where did pot growers get the idea that Cannabis needed toxic levels of heavy metals burning up their leaves and shutting down the MVA pathway responsible for the medicinal compounds in the plant?



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The only thing Bruce has ever been right about is that low Ph is synonymous with manganese toxicity. How about.. ...stop using so much Manganese, and let the pH ride low?? Is that the sole reason growers worry about pH? They are concerned with blocking excess Manganese?
 

blaze02

Member
You mentioned 0.75ppm is potentially problematic..what kind of ratio to Mg ( or other nutrients) is ideal?

My current veg level is at:
0.8 ppm Mn : 65ppm Mg : 180 ppm Ca : ~180 N.

Starting week 3 flower I keep Mn the same (as well as other micros)and drop N to 120, and Ca to ~150 —keeping same ratio to Mg.

How low should you drop Mn? And does its level need to change if you have a very high water use efficiency (leds and co2)?
 
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