PhatNuggz
- 2,121
- 163
You seem to keep dancing around the issue. Let us see where the rubber meets the road. Where is your grow to validate?
Dwc And Rdwc Oxygenation – The Art Of Salesmanship And Making Money
J
J Henry
- 127
- 28
Your getting very demanding asking me dumb little questions like that. Are you in or affiliated in any way with State or Federal law enforcement? I would never validate or publish any image or copy displaying any illegal activity on the internet for you or anyone else. NO
PhatNuggz
- 2,121
- 163
Dumb little questions? Just who the hell do you think you are? Pretty sure you don't want to match intellect with me.
All you would need to do is look at my signature and check out my grows. But NO, no connection to law enforcement, and I haven't asked for anything unreasonable, let alone 'dumb' or that could get you in trouble
Deflection is a known psychological tactic when someone is challenged, and has no truth to support their position. Again you are avoiding the obvious. Keep mind we're talking about pics of ROOTs, not plants
And I would have no problem buying some if I felt they were worth the expense, but I'm not feeling it math wise. If you actually are using OTabs, it's past time to share. Even without pics, you could say 'in my 2 gallon bubbler I use X Otabs which last Y hours...' but you haven't even done that for this dumb questioner
When I grew HPA (high pressure aero) the roots were amazing, as long as the root chamber temp was < 75*s, but that too is hard to do 24/7 without expensive equipment, so I went back to F & D for flowering, and bubbling for veg. Obviously, I want the best/healthiest roots I can get pre flower
If I could see this actually working (and the cost per day was reasonable) I would gladly give it a shot. Where you seem knowledgeable about the process, you're neglecting to support your hypothesis. Not at all scientific, but highly deflective
All you would need to do is look at my signature and check out my grows. But NO, no connection to law enforcement, and I haven't asked for anything unreasonable, let alone 'dumb' or that could get you in trouble
Deflection is a known psychological tactic when someone is challenged, and has no truth to support their position. Again you are avoiding the obvious. Keep mind we're talking about pics of ROOTs, not plants
And I would have no problem buying some if I felt they were worth the expense, but I'm not feeling it math wise. If you actually are using OTabs, it's past time to share. Even without pics, you could say 'in my 2 gallon bubbler I use X Otabs which last Y hours...' but you haven't even done that for this dumb questioner
When I grew HPA (high pressure aero) the roots were amazing, as long as the root chamber temp was < 75*s, but that too is hard to do 24/7 without expensive equipment, so I went back to F & D for flowering, and bubbling for veg. Obviously, I want the best/healthiest roots I can get pre flower
If I could see this actually working (and the cost per day was reasonable) I would gladly give it a shot. Where you seem knowledgeable about the process, you're neglecting to support your hypothesis. Not at all scientific, but highly deflective
Last edited:
J
J Henry
- 127
- 28
OK, chill, roll yourself a big one and don’t get your panties tied up in a knot.
http://pentairaes.com/aeration/oxygen-ozone/show/all
toll free 877-347-4788
Call Pentair, ask for oxygenation tech support, tell the support tech you’re a DWC pot grower and you’re interested in a supplemental oxygen administration system (O2 generator, O2 saturator or O2 diffusers) for your pot operation. Ask the tech to put together equipment cost and yearly operation cost for your operation. Tell the tech that you have looked into using Otabs for oxygenating you pot grow and Otabs cost too much, you can’t afford that. Pentair designs oxygen systems for a living and does not charge for system design work, just for their oxygen equipment.
Ask the tech for operational cost numbers comparing oxygenation to aeration systems.
Ask the tech to explain to you the difference between oxygenation (oxygen) and aeration (air). Tell the tech your goal is continuous 100% DO saturation 24/7 for months to insure the DO never gets below 100% DO Sat. That you are oxygenating 2 symbiotic eco-systems, plants and microbe colonies, like a biological filter. He will understand your oxygenation goal.
Also tell him there are serious issues with fungal disease outbreaks that present when the DO is low for short periods of time and the DO must remain at 100% saturation in order to prevent the fungal outbreaks,
You might get his opinion about thenegative effects of using H2O2 and Clorox on good microbe colonies in your grow.
They have a great tech support team at Pentair. No question is a dumb question when it comes to supplemental oxygenation at Pentair.
The “expense” for real oxygenation and fungal prevention amortizes over months, years for the rest of you DWC pot growing life. If what-ever you are doing is working and you never have root rot outbreaks in your RDWC/DWC, you’re preventing fungal outbreaks. Keep doing what you are doing. If you have root rot disease 1-2 times a year or more, clearly you are failing to prevent low oxygen events and you will fight the raging fungus fire in you grow with all kinds of chemical concoctions.
You’re welcome
PhatNuggz
- 2,121
- 163
Thanks for all that, but as I have said, several times, my bubbler and rez is only ~ 2g each. Otabs would seem a vg way to go, ASSUMING, they saturate the entire water/nutes with O2. You have yet to provide proof of that. Seems I'll have a buy a few
Just watched an interesting YT DIY Chiller ~ $100 using a mini-frig, but they are power hogs
Just watched an interesting YT DIY Chiller ~ $100 using a mini-frig, but they are power hogs
J
J Henry
- 127
- 28
Are you a RDWC/DWC pot grower?
Do you grow pot for your personal recreational use or are you a pot dealer and grow pot commercially and sell it?
Sounds like all is great on your farm, no root rot symptoms or events. If you don't have fungal infestations, I see absolutely no reason for your to waste you money and time with OTabs. There is no reason you need 90% O2 that I see. If you don't have fungal root rot infections, you probably can assume all is well and keep doing what you do best.
But, when your roots and root ball catch the fungal rot disease, then you know for sure that you definitely have a low oxygen problem presenting the ideal opportunity for the fungus to thrive. You have absolutely failed to provide enough oxygen (regardless of how cold the water is or how much air you pumped) to prevent the rot disease. You do not need assume nor do you need to buy a $250 DO meter to see the root rot symptoms. When you see symptoms you know immediately that you have failed to provide enough oxygen and that Eureka realization is immediate, no assumptions and prevention is over and treatment begins. Many RDWC/DWC pot growers experience that horrible Eureka moment every day, that is normal.
You have 2 choices... prevent the rot or cure the rot. It's really simple and easy to understand and you chose.
PhatNuggz
- 2,121
- 163
I bought these today at Bass Outdoor World. 3 cups with 2 tabs per cup $10.50. Said to last up to 9 hours, in 2 gallons- perfect to test
I placed one each under the 2 plants. The seedling has decent root development, whereas the reveg is sorely lacking in new root development, though it keeps growing buds, albeit very slowly
I placed one each under the 2 plants. The seedling has decent root development, whereas the reveg is sorely lacking in new root development, though it keeps growing buds, albeit very slowly
J
J Henry
- 127
- 28
Great. 1st see if 1 tab 90% O2 prevents any fungal symptoms while using the tab . 2nd save some tabs and use them to treat symptoms immediately when you first notice any peculiar root rot symptoms. Re-oxygenating as quickly as possible is important, hours count. Treating early onset of symptoms - use 2 tabs every 9 hours for 24 hours (6 tabs total). See if symptoms begin to resolve.
PhatNuggz
- 2,121
- 163
My plants don't have any symptoms, but the reveg has not made new roots, so dropped one directly under it as a test, and one under the young plant to see how the roots respond
PhatNuggz
- 2,121
- 163
Follow up I don't recommend it for a couple reasons
1. It raised my pH and I couldn't get it down without dumping the nutes,
2. It left a mess. Had to clean the buckets, air stones and tubing
Those issues aside, my ~ 6" tall seedling definitely perked up :)
1. It raised my pH and I couldn't get it down without dumping the nutes,
2. It left a mess. Had to clean the buckets, air stones and tubing
Those issues aside, my ~ 6" tall seedling definitely perked up :)
Last edited:
J
J Henry
- 127
- 28
That's odd - How high was your pH and what did you use to buffer and lower your pH? What was the last pH test result?
10% CO2 would dissolve and combine with water increasing the carbonic acid concentration unless buffered with a basic compound (pH > 7.0) or solution. CO2 + water produces carbonic acid which would lower the pH, not raise the pH. The pH must have been very high, considerably greater than 7.0 before the Tab was activated if the solution remained alkaline even with 10% CO2 gas being dissolved.
Were you bubbling air through these diffusers in your buckets the same time you were using the OTab?
Will you be more specific, please describe this “mess” in your buckets, air stone and tubing please. Residue is dark color, clear, yellow, thick thin, slick sticky and how much of this nasty mess was there, couple cups, ½ gallon, 2 gallons, etc.? Was this mess frothy, foamy and bubbly in your buckets?
Wandering what this mess was, dead Beneficial’s, decayed plant material… how long did it take for this mess to develop, hours, minutes, days?
Are you sure your 6” seedling definitely “perked up” and you saw a positive change within hours after activating the OTab (90% O2 -10% CO2)? Can you/will you describe what “perked-up” means?
Thanks for the feedback, I do appreciate that.
PhatNuggz
- 2,121
- 163
pH was ~ 5.6-5.8. Afterwards 7.5ish. Used 4Xs as much down as I normally would, but it still wouldn't drop below 6.0
Yes I was bubbling throughout the test
The broken down bits was from the Otabs
The mess was all over the bottom, air tubes, and stones
The leafs on the 6" plant were no longer droopy, though not drooping, and are reaching up towards the light Again, I did not have a rot issue. I was most interested to see what if any affect it would have on the reveg, which was in the same bubbler at that time. However, I had one O tab left which I put in the separate bucket under a separate light
I would say IF someone has a definite root issue to try them, but be prepared to dump your nutes and clean everything aftr 24-48 hours. This is a small price to pay to save your plants
Yes I was bubbling throughout the test
The broken down bits was from the Otabs
The mess was all over the bottom, air tubes, and stones
The leafs on the 6" plant were no longer droopy, though not drooping, and are reaching up towards the light Again, I did not have a rot issue. I was most interested to see what if any affect it would have on the reveg, which was in the same bubbler at that time. However, I had one O tab left which I put in the separate bucket under a separate light
I would say IF someone has a definite root issue to try them, but be prepared to dump your nutes and clean everything aftr 24-48 hours. This is a small price to pay to save your plants
J
J Henry
- 127
- 28
Give Doug a call or email, he's top of the line and loves to teach.
Understanding Effects Of Water With High Alkalinityhttps://www.thcfarmer.com/community/threads/understanding-effects-of-water-with-high-alkalinity.77509/
Prepared by Professor Douglas Cox
Plant and Soil Sciences
University of Massachusetts Amherst
Stockbridge School of Agriculture
208 Bowditch Hall
University of Massachusetts
Amherst, MA 01003
Ph (413) 545-5214
E-mail [email protected]
Contact us or call one of our advisors at 1-413-545-2222.
https://ag.umass.edu/fact-sheets/water-quality-ph-alkalinity
Heres a second link for another look http://www.greenhousegrower.com/pro...ant-nutrition-irrigation-water-alkalinity-ph/
PhatNuggz
- 2,121
- 163
Nice that you provided this. Many will have a need for it.
One of the things following your thread made clear is, leds do not radiate heat like HD does. In my room under LEDs. with room temp of ~ 80*s, a 12 oz frozen water bottle keeps ~ 2 gallons < 75*s for 6-8 hours. Getting my mind around motivated me to start a new thread- so, thanks for that
One of the things following your thread made clear is, leds do not radiate heat like HD does. In my room under LEDs. with room temp of ~ 80*s, a 12 oz frozen water bottle keeps ~ 2 gallons < 75*s for 6-8 hours. Getting my mind around motivated me to start a new thread- so, thanks for that
MGRox
- 597
- 143
100% DO is not in anyway an "answer". What if I'm at 150 degrees, is that enough DO? What if I'm at 40 degrees, is that enough DO? What if I'm 20,000 feet in the air, is that enough DO? What if my roots are in soil vs hydro, what about DO then?
How much to plants use? Easy. A fully matured planted ground can use as much as 17 liters of oxygen per m2 per day. This includes both plant and biological demand and is per square meter!! This works out to be 60% of the Oxygen contained in just 1 cu. ft of air.......for a whole square meter and for a whole 24 hrs. Not that hard to add 17 liters of oxygen with standard Air over 24 hours.
http://link.springer.com/article/10.1007/BF02375564#page-1
As well another study, which noted respiration rates 100 times higher than any other study previously. Here, oxygen consumption was a maximum of 0.288 liters per day per gram of dried root. This works out to be approximately 5% of the oxygen contained in 1 cubic foot of air.
http://link.springer.com/article/10.1007/BF02879221
At what point does low Oxygen cause problems with roots? Well that takes a bit more explanation than I will inclued here. A key note is that when a plant responds to low oxygen, it alters exudates in order to begin breaking down the (now extra) rooting area. This is what becomes a causal factor for pythium related specifically to DO. E.G. Pythium increase is related to the plant response of low DO, not in anyway that actual DO alters pythium occurrence itself.
In the only study conducted relating specifically DO to pythium found that DO levels above 4mg/l "had no beneficial effect on pythium." But that levels below 3mg/l did help. The maximum recommended level to ensure no pythium relating to low DO was 5-7 mg/l. Also, of note was that even at this "high" DO level, pythium was still infected on roots, but that there were no visible syptoms. E.g. DO does NOT remove or prevent pythium nor is it an approved treatment.
http://link.springer.com/article/10.1023/A:1008691226213
Suppose since I'm on the subject let's look at temperatures. The main reason for chillers is related to optimal root temperatures and pythium prevention NOT increasing DO. Sure, mfg's will hop on the ancillary train and add that as a feature; but do not be confused by the sales ploy. There are many types of pythium and they all occur in different circumstances. In hydro, there are types more common in cooler solutions and there are types more common in warmer solutions.
"When the temperature of the nutrient solution was less than 23c, P. dissorocum was the dominant pathogen; at warmer temperatures, P. aphanidermatum dominated. These observations were confirmed and expanded in laboratory tests. Moreover, if both fungi were present, the optimal temperature of the nutrient solution for lettuce production was 21c (69F)."
http://www.apsnet.org/publications/...cuments/1988Articles/PlantDisease72n02_96.pdf
The above is just one of many papers that all relate to the optimal temperature relative to pythium as being in the 68F-71F range. This is why the "industry standard" for root temps is in this range. There are plants that prefer higher root temperatures (bell pepper), but they have an increased risk to pythium as a result.
On a separate but related note: Looking at raising temperatures solely to increase respiration is of no advantage by itself. While increasing root temperatures will increase CO2 and exudates along with oxygen uptake; it has no bearing or effect on photosynthesis rate, carbon metabolism and thus growth. What it will do is increase the carbon loss out of the roots relative to carbon assimilation in the leaves. This causes an imbalance of carbohydrate to sugars in the root zone. Bad mojo. Link is not needed here as this is pretty basic level plant biology.
@PhatNuggz your pH went up when using those tablets because of the Calcium Hydroxide in that one. Has a pH of 12. I'd prolly stay away from the Hydrogen peroxide generating tablets and instead use tablets designed to produce pure oxygen.
It's better to use Potassium Chlorate and Manganese Dioxide. These are quite a bit cheaper and will probably be more effective without a lot of waste or pH rise.
J
J Henry
- 127
- 28
That is certainly a lot of “what if’s.” What if the crop is potatoes, lettuce, soy beans or cotton, or pot… there are plenty of abiotic and biotic stressors that may negatively affect all cultivates or wild weed plants. One thing for sure, hypoxia (a serious stressor) will kill the whole crop. Chronic sustained oxygen deprivation is (another serious stressor). Both oxygen related stressors alter plant exudate that attract fungi and initiate fungal outbreaks. Dead and decay signals opportunity whether it roots, dogs or a human body, it’s a fungus feast.
"Plant injury and adaptation to oxygen deficiency in the root environment: A review"
Was published in 1983, its 33 years old, please cite more current research within the last 2 years.
Some plant species use more O2 than others, lettuce consumed less oxygen than tomatoes depending on metabolic demands, conditions and other factors. Are cultivated vegetables and weeds the same? This is interesting, but very old and Cannabis is not mentioned in this research.
This potato research "Exploratory study of the rate of oxygen consumption by potato roots"
Was done in 1945-1946 and the paper was published in 1956, 10 years after the initial research… this is 60 years old today.
OK, potatoes require more oxygen than lettuce. Different plant roots have different oxygen requirements. So what is the oxygen requirements for cannabis roots? That is my interest. This WW II era research is old. It’s about oxygen consumption of potatoes roots, not DWC pot roots. Comparing cultivated potatoes in 1945 to cannabis “weeds” in 2016 is a stretch.
**A-ha, now we’re at the meat of the oxygenation matter… “100% DO is not in anyway an "answer".”
“Effect of oxygen concentration on plant growth, lipidperoxidation, and receptivity of tomato roots to Pythium F under hydroponic conditions” Published September 2006. As you said, this is the only study conducted relating to DO and Pythium with cultivated tomato roots, not wild cannabis roots. Considering the effects of oxygenation on plant health which varies between plant species, are cannabis roots more resistant to oxygen deprivation and hypoxic root damage compared to cultivated tomato roots? Weeds are hardy plants, cannabis may be more resistant to cultivated tomatoes (vegetables) when exposed to low oxygen levels.
It’s clear that cannabis cultivation research like most other horticulture research is proportional to commercial crop profitability. It’s not worth the time nor the cost for any research for cannabis cultivation commercially grown in RDWC DWC through March 2016, therefore like you say… there is none.
“Assessment of Plant Diseases in Hydroponic Culture” Published march 1997, this research is 19 years old. Another old study about nutrient solutionoxygenation on the growth of tomato plants and colonization of plant roots by Pythium… tomatoes, not cannabis or lettuce.In these treatments, plants started showing typical symptoms of root decay and infection within 6 days after inoculation with Pythium F, while highly oxygenated plants remained healthy throughout the experiment and showed a significant decrease in root colonization by the pathogen…
*This data suggest that increases in lipoxygenase activity detected in the present study in tomato roots grown under oxygen stress and inoculated with Pythium F may lead to degradation and disorganization of membrane lipids. That disorganization may facilitate root colonization by the pathogen and appearance of decay.
Again tomato plants that are under O2 stress encourage opportunist fungi to colonize and raise a large family so to speak in the roots and root zone. Could this also be projected onto cannabis grown hydroponically? There appears to be no scientific research like this with hydroponically grown cannabis so who knows. Oxygen stressed plants set a fine table dead and decaying tissue for the fungal feast.
I can't read the product label. Can this stuff be purchased with a label written in English? Asian writing is difficult to decipher by the average Billy Bob pot grower and me. Are you really sure what this stuff is in this bag sold on who knows from somewhere on eBay with an Asian label?
MGRox
- 597
- 143
Does this mean that A. Plants have evolved to be different in 33 years or B. That people were incompetent to measure or understand oxygen usage 33 years ago or C. is it just the only point you could think of to poop on?
Yes lettuce can tolerate lower oxygen than some other plants. Plants that can develop aerenchyma or readily can develop adventitious roots also can tolerate lower oxygen levels than plants which cannot. Specifically I did not link lettuce as it does tolerate down to the "defined hypoxia point" without issue (which is impressive for 75F), whereas the tomatoes linked require fully double this point (4mg/l with respect to pythium though). Of note with the link quote below is that there was NO growth improvements up to 200% DO.
"There was no significant difference in fresh weight, shoot and root dry weights among the DO concentrations: 2.1 (25% of saturated at 24 degrees C), 4.2 (50%), 8.4 (saturated), and 16.8 (200%) mg/L. The critical DO concentration for vigorous lettuce growth was considered to be lower than 2.1 mg/L."
http://www.ncbi.nlm.nih.gov/pubmed/11541573
Yet again I ask: are you insinuating incompetence, an evolutionary change in 60 years or just something to poop on?
The most widely used hydroponic nutrient solution in research is the Hoagland solution. It was developed in 1938 and still is the most common and unchanged today. Yes, I definitely Balk at questioning research with a few years on it. Whenever cannabis becomes legal to research, guess what nutrient solution it will be given? Guess too, this solution was developed around tomatoes. Interestingly as well, if you compare typical NPK profiles used in the Cannabis hobby to research with various plants, you will find the closest NPK to what we use is with Tomatoes.
The potato was linked and referenced (separately from average ground Oxygen consumption per m2) as potato, being a tuber, requires MORE oxygen than most all plants with just roots. So, that is a link to show the maximum possible oxygen demand of pretty much any plant. Also again, it was noted as being 100 times higher than other plant recordings.
"Potato plants are more sensitive to soil oxygen stress than many other common crops. Some recent literature suggests this may be due to a relatively high oxygen requirement for tuber growth, rather than a greater requirement for the roots per se."
.......
"The oxygen relations of potato tubers may be quite different than those of the roots. The tubers create a relatively large oxygen sink. Moreover, their surfaces are not uniformly permeable to oxygen for most of it must enter through the lenticels."
--Even with a higher O2 usage with the potato, the minimum level of hypoxia is still similar to other plants @ 4% minimum (just under 2mg/l).
"Therefore, the minimum diffusion coefficient should be at least 2.7 to hold the oxygen above 2% if one wishes to avoid ethylene production around the tuber in this particular soil. However, due to periderm permeability, one needs at least a 4% oxygen atmosphere surrounding the tuber."
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.502.6874&rep=rep1&type=pdf
Again the intention is to show the maximum theoretical oxygen consumption with a plant that undoubtedly will utilize more oxygen than cannabis. Not at all making a connection other than this, no stretching needed.
No no. This is the ONLY study on ANY plant, specifically with respect to dissolved oxygen and pytium period.
Again excluding specialized root alterations mentioned above, most plants will be "similar" in oxygen requirements under similar conditions (hypoxia point). The main aspect to relate here for analogy would be comparative annual rainfall or naturalized growth regions.
"Southeastern Kansas, with an annual rainfall of 40 inches. has a better possibilitv of growing tomatoes than western Kansas with an annual rainfall of 18 inches. Tomatoes of the market garden varieties can be grown with fairly good success in eastern Kansas where the annual rainfall is 30 inches (76cm) or more."
....
"Tomatoes do best at monthly mean temperatures of 70 to 75° F. while a mean temperature of 80° F."
.......
"The essential requirements of a soil are that it be well drained and yet capable of retaining moisture, making sandy and clay soils least desirable"
....
"A soil well supplied with humus, having a fairly open structure, moderately rich in nutrients, well drained, which warms readily and yet retains sufficient water to insure against severe injury during drought, would seem ideal for the best root development."
https://www.ksre.k-state.edu/historicpublications/pubs/SB313.PDF
"Searches for tolerance to waterlogged or saturated soil conditions in tomato have been less well adressed, with only very little tolerance being found in tomato germplasm. ............" This level of tolerance was shown to be relatively weak compared to tolerance by other species such as chinese cabbage, sweet potatoe and mungbean."
(pg 190) https://books.google.com/books?id=c...f+Tropical+Horticulture&source=gbs_navlinks_s
"Recommended target nutrient rates are currently 200-150-225 lb/acre N, P2O5, K2O"
http://edis.ifas.ufl.edu/cv236
....
"Tomatoes do best at monthly mean temperatures of 70 to 75° F. while a mean temperature of 80° F."
.......
"The essential requirements of a soil are that it be well drained and yet capable of retaining moisture, making sandy and clay soils least desirable"
....
"A soil well supplied with humus, having a fairly open structure, moderately rich in nutrients, well drained, which warms readily and yet retains sufficient water to insure against severe injury during drought, would seem ideal for the best root development."
https://www.ksre.k-state.edu/historicpublications/pubs/SB313.PDF
"Searches for tolerance to waterlogged or saturated soil conditions in tomato have been less well adressed, with only very little tolerance being found in tomato germplasm. ............" This level of tolerance was shown to be relatively weak compared to tolerance by other species such as chinese cabbage, sweet potatoe and mungbean."
(pg 190) https://books.google.com/books?id=c...f+Tropical+Horticulture&source=gbs_navlinks_s
"Recommended target nutrient rates are currently 200-150-225 lb/acre N, P2O5, K2O"
http://edis.ifas.ufl.edu/cv236
"The preference is full sun, moist conditions, and a fertile loamy soil. Mesic conditions and other kinds of soil are also tolerated, but the size of plants will be smaller. Hemp is little bothered by pests and disease. It tolerates occasional flooding."
.......
"Habitats include borders of floodplain woodlands, borders of low-lying fields, weedy meadows along rivers, fence rows, and roadside ditches."
http://www.illinoiswildflowers.info/weeds/plants/hemp.htm
"Cannabis is very adaptable to soil and climatic conditions[269]. It prefers a rich loamy soil with plenty of humus[171] but it succeeds in ordinary garden soil[1] and also in calcareous soils[171]. When grown for fibre, it requires a mild temperate climate with at least 67cm (26in) annual rainfall. ..............."Cannabis is reported to tolerate an annual precipitation range of 30 to 400cm, an average annual temperature range of 6 to 27°C and a pH in the range of 4.5 to 8.2[269]"
http://www.pfaf.org/user/plant.aspx?LatinName=Cannabis+sativa
"Following the LGM, in the present of cool temperate latitudes of Japan, large areas of grassland or forest-steppe developed in combination with open cool temperate and deciduous woodland cover. This vegetation response graded northward into open woodland on Hokkaido, presenting widely favorable habitat for the expansion of cannabis"
......
"Tropical regions are not where cannabis flourishes today, and feral populations are absent. Although Cannabis could have survived the LGM in a cryptic temperate microclimate within the tropical zone, there is no paleoecological evidence to support this scenario."
(pg. 337) https://books.google.com/books?id=poenY6QMq8UC&source=gbs_navlinks_s
"Cannabis naturally colonizes open streamside habitats with ample sunlight, water, nutrients, and air movement. The plants shown here are Cannabis spontaneously along a watercourse (A) in the northeastern State of Megalaya in India. Feral Cannabis is highly adaptable and can grow and reproduce in a wide variety of temperate habitats, even under extreme conditions such as in a concrete culvert (B) along a highway in rural southwestern China. Cannabis is opportunistic and thrives in nutrient-rich waste heaps resulting from human activities (C) as illustrated by this population in Arunachal Pradesh, India. Cannabis is also a formidable weed in field crops as seedlings (D) grow rapidly in competition for sunlight.
http://content.ucpress.edu/chapters/11892.ch01.pdf
"The hemp plant is known for its ability to grow in varied climates, however, it thrives in temperate ones."
......
"there are many claims made that hem is drought tolerant. In fact, hemp is intolerant of drought and while it may continue to grow under such conditions, the yields will be severely depressed."
........
"frequent rains are beneficial as hemp grows best when well supplied with moisture througout its' growing season and especcially in the early stages of growth. However, flooding and excessively saturated soils can affect the uniform growth of the crop"
"Fifty years ago farmers were advised that only land in a very productive condition, capable of yielding a minimum of 50 bushels of corn to the acre, should be chosen for growing hemp seed. Furthermore, soil capable of growing 74-80 bushels of hybrid corn under favourable growing conditions could reportedly produce profitable hemp crops of 2.6-3.4 tons of fiber per hectare."
.........
"A rich, moist soil, with good drainage is ideal. ..................... Hemp is partucularly adapted to heavy clays and loams rich in organic matter provided the organic matter is reasonably well decomposed. Hemp should not be grown in light soils, especially sandy soils nor acidic soils."
"commonly cited amounts for fertilizer are 80-120N, 80-120P2O5, and 160-200 K2O kg/ha"
http://www.collectionscanada.gc.ca/obj/s4/f2/dsk3/ftp04/mq24965.pdf
.......
"Habitats include borders of floodplain woodlands, borders of low-lying fields, weedy meadows along rivers, fence rows, and roadside ditches."
http://www.illinoiswildflowers.info/weeds/plants/hemp.htm
"Cannabis is very adaptable to soil and climatic conditions[269]. It prefers a rich loamy soil with plenty of humus[171] but it succeeds in ordinary garden soil[1] and also in calcareous soils[171]. When grown for fibre, it requires a mild temperate climate with at least 67cm (26in) annual rainfall. ..............."Cannabis is reported to tolerate an annual precipitation range of 30 to 400cm, an average annual temperature range of 6 to 27°C and a pH in the range of 4.5 to 8.2[269]"
http://www.pfaf.org/user/plant.aspx?LatinName=Cannabis+sativa
"Following the LGM, in the present of cool temperate latitudes of Japan, large areas of grassland or forest-steppe developed in combination with open cool temperate and deciduous woodland cover. This vegetation response graded northward into open woodland on Hokkaido, presenting widely favorable habitat for the expansion of cannabis"
......
"Tropical regions are not where cannabis flourishes today, and feral populations are absent. Although Cannabis could have survived the LGM in a cryptic temperate microclimate within the tropical zone, there is no paleoecological evidence to support this scenario."
(pg. 337) https://books.google.com/books?id=poenY6QMq8UC&source=gbs_navlinks_s
"Cannabis naturally colonizes open streamside habitats with ample sunlight, water, nutrients, and air movement. The plants shown here are Cannabis spontaneously along a watercourse (A) in the northeastern State of Megalaya in India. Feral Cannabis is highly adaptable and can grow and reproduce in a wide variety of temperate habitats, even under extreme conditions such as in a concrete culvert (B) along a highway in rural southwestern China. Cannabis is opportunistic and thrives in nutrient-rich waste heaps resulting from human activities (C) as illustrated by this population in Arunachal Pradesh, India. Cannabis is also a formidable weed in field crops as seedlings (D) grow rapidly in competition for sunlight.
http://content.ucpress.edu/chapters/11892.ch01.pdf
"The hemp plant is known for its ability to grow in varied climates, however, it thrives in temperate ones."
......
"there are many claims made that hem is drought tolerant. In fact, hemp is intolerant of drought and while it may continue to grow under such conditions, the yields will be severely depressed."
........
"frequent rains are beneficial as hemp grows best when well supplied with moisture througout its' growing season and especcially in the early stages of growth. However, flooding and excessively saturated soils can affect the uniform growth of the crop"
"Fifty years ago farmers were advised that only land in a very productive condition, capable of yielding a minimum of 50 bushels of corn to the acre, should be chosen for growing hemp seed. Furthermore, soil capable of growing 74-80 bushels of hybrid corn under favourable growing conditions could reportedly produce profitable hemp crops of 2.6-3.4 tons of fiber per hectare."
.........
"A rich, moist soil, with good drainage is ideal. ..................... Hemp is partucularly adapted to heavy clays and loams rich in organic matter provided the organic matter is reasonably well decomposed. Hemp should not be grown in light soils, especially sandy soils nor acidic soils."
"commonly cited amounts for fertilizer are 80-120N, 80-120P2O5, and 160-200 K2O kg/ha"
http://www.collectionscanada.gc.ca/obj/s4/f2/dsk3/ftp04/mq24965.pdf
IMHO, this would preclude cannabis to possibly tolerating the same if not slightly less DO than tomato (higher rainfall and flood tolerance); But that Cannabis probably has a slightly lower resistance to root pathogens as noted by the requirement of higher organics (as organics suppress pathogens https://execdeanagriculture.rutgers.edu/pdfs/goodman-086.pdf ).
You did not include the largest factor. Legality. There is virtually no place in the world which can legally conduct research at the scientific level with Cannabis. Well, at least for the prior 60-70 years. I suppose when / if it gets de-scehduled federally; then we may begin to see the start of real research related to cannabis (not hobby level).
You should really read the whole paper linked and see that colonization was still apparent regardless of oxygen level. E.g. Oxygen will not under any circumstance "prevent" pythium.
We can even look at an extreme case of oxidation in relation to pythium to prove that there is no reality in which Oxygen will prevent pythium.
"Even at 12,500ppm in the present study, hydrogen peroxide provided only moderate suppression of Pythium and had no significant effect on Fusarium, despite having sporicidal activity and not readily being inactivated by organic matter."
http://repository.up.ac.za/bitstream/handle/2263/25940/Complete.pdf?sequence=8
Right. This includes both beneficial and pathogenic microbes. In the absence of sufficient quantities of beneficial microbes, then yes pathogenic microbes can dominate (if they exist the system) as is specifically seen much more commonly in hydro vs soil.
Racist much?
If your concerned about its' origin or language you can buy the same product at a more retail level. It's in english and even lists the ingredients. Just is a more expensive avenue, though still cheaper than O-tabs for bait.
http://www.ebay.com/itm/50-Supa-Oxy...021853?hash=item2357cebc9d:g:-QMAAOSw0JpV4sqW
**I just have one question then for you. Could you ake a look at this paper (2014) on soilless culture and tell me which method your "RDWC or DWC" fit into, or would be classified as? Since RDWC is a "hobby term" it may be helpful for you to know what method you are using.
http://ijagcs.com/wp-content/uploads/2014/08/833-842.pdf
J
J Henry
- 127
- 28
Again, I really do appreciate your time and the research you have provided relating to this oxygenation matter. I found the research you provided informative along with many other papers cited in the bibliography. The research you kindly provided opened doors to numerous other papers which lead to more questions and answers. I have many hours of reading left.
Someday, maybe research will be published specifically related to cannabis cultivation, for now tomato research and NPK profiles correlate best. Your point regarding cannabis research legality and Federal drug rescheduling may take more time, so for now hobby growers experiment and I won’t get my hopes up that cannabis research and publication is in the immediate future for now.
Basically anoxia and severe hypoxia are a cause plant and microbial stress. Whereas low oxygen, normoxic, high oxygen with mechanical aeration with air has no detrimental effect inhibiting Pythium outbreaks and some other root zone diseases. And all the hub-bub about “low oxygen” causing Pythium and other fungal outbreaks and “high oxygen” preventing Pythium outbreaks is no more than an idea dreamed up as a kicker by maybe the water chiller manufacturers and seriously promoted by salesmen and on line hobbyist grower’s on forums. I chuckle now when I see so many hobbyist whining and treating fungal infections with H2O2 and Clorox with fungal infections blamed on “low oxygen in the root zone” and nutrient water. That is quiet the story and many people write it and many believe it, but very few forum hobbyist know what a DO Meter, what it is used for. Maybe their DO is OK, maybe not, healthy microbes do poorly in low O2 environments… are they really that important anyway? I think microbial health is vitally important to the symbiotic relationship as veggie research suggest.
So clearly the opportunity for fungal and other disease outbreaks is initiated by the release of plant stress chemical, many hobbyist are not aware of nor recognize that many plant stressors initiate fungal outbreaks. That under continuing stress conditions, the roots will emit ethylene, a stress hormone that accumulates in the roots and participates to the slow degradation of the root system. Furthermore, ethylene is recognized by some pathogens as the sign for a weak individual, and a motivation to attack. If Cannabis does have slightly lower resistance to root pathogens as noted by the requirement of higher organics (as organics suppress pathogens) that may be problematic for hobbyist. The stress process is very systematic and also predictable. If stress is predictable, prevention is an option.
Poor growing practices, poor water quality, failure to maintain healthy plants and microbial colonies sets-up ideal conditions for fungal outbreaks. Healthy growing environments and health microbial colonies are necessary to be successful. But if you can’t do this… you will be treating diseases or replanting. That’s as simple as it gets without all the hype and sales gimmicks.
I appreciate A Review On The Science Of Growing Crops Without Soil (Soilless Culture) – A Novel Alternative For Growing Crops.
For commercial soilless farming, I lean toward N.F.T. (Nutrient Film Technique) and Deep flow technique (DFT)/ pipe system. Of course back up electrical power would be essential in case of electrical outages and “clean protocol.”
Racist Much? That's an odd question, what does "Racist" mean to you? Thanks for the chemical with a label written in English.
Again, thank you so much for all your time and direction.
Latest posts
-
Long time grower - Back at it - Interesting Genetics.- Thatoneguyyouknow_ posted
-
What kind of problem does this plant have? magensium or calcium?- wolfszeit posted
-
SGG#4 strain we’ve had bout a decade
- Saintpaulshit posted
-
KWhat the hell do i do next!!! Im so new at this….
- Krystinmadviv3164 posted
-
🔥 Fire from the Shire 🔥 Come on in ✌️- Stokes posted