Mullrat ..next week when my ladies dry I'll show dry nug shots....You better have something to match me in a quality
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The myth, of the high P myth?
- Thread starter epicseeds
- Start date
This to me cant even hold a candle stick to what you were talking shit on........just wait ....picture is worth a thousand words right 
Show me some dried nugg shots
Show me some dried nugg shots
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seanseanhen
Member
SS you show off, those are some fine looking ladies.
First person in the game with these Landrace Iranian Genetics... 1000+ seeds...each and everyone different...Having pure genetics that have been growing for thousands of years in 7,000+ feet elevation in one of the lushest parts of the Middle East...
I'd say its history in the making
swizzle
epicseeds
Member
Untrue, visit garden web. They have been discussing this for years. The whole reason I started this thread was largely from readings from garden web. This supposed myth has been known for a long time in the professional rose gardeners.
AN were just the first ones to announce it to us mj growers.
And BTW, Storm Shadow... get over yourself for gods sake. Mullray was offering suggestions on how to compare your current results in the future by trying out with more P. You totally blew a lid. I take it you can't take ANY form of constructive criticism? If so, this thread (let alone forum) isn't for you.
http://pubs.aic.ca/doi/pdf/10.4141/P04-022
Vera, C. L., Malhi, S. S., Raney, J. P. and Wang, Z. H. 2004.
Can. J. Plant Sci. 84: 939–947. Industrial hemp (Cannabis sativa
The effect of N and P fertilization on growth, seed yield
and quality of industrial hemp in the Parkland
region of Saskatchewanand quality of industrial hemp in the Parkland
Vera, C. L., Malhi, S. S., Raney, J. P. and Wang, Z. H. 2004.
The effect of N and P fertilization on growth, seed yield and quality
of industrial hemp in the Parkland region of Saskatchewan. Can. J. Plant Sci. 84: 939–947. Industrial hemp (Cannabis sativa
L.) has sparked renewed interest in western Canada in recent years, and there is very little research information available on its
fertilizer requirements. The objective of this study was to determine the effect of surface-broadcast ammonium nitrate and seedrowplaced monoammonium phosphate fertilizers on the production and seed quality attributes of industrial hemp (cv. Fasamo and
Finola). Field experiments were conducted on a Black Chernozem silty loam soil at Melfort, Saskatchewan, Canada, in 2000, 2001
and 2002. Increasing N rates significantly increased plant height, biomass, seed yield and seed protein content of hemp in all years.
Seed-applied P fertilizer increased plant height in all years, and biomass in 2000, but reduced plant density, biomass and seed yield
in 2001 and 2002. Finola consistently had lower plant height, earlier maturity, heavier seeds, and higher seed yield, seed protein
content and seed oil content than Fasamo. The average amount of nitrate-N in the 0–60 cm soil was 40 kg N ha
and 2002. Increasing N rates significantly increased plant height, biomass, seed yield and seed protein content of hemp in all years.
Seed-applied P fertilizer increased plant height in all years, and biomass in 2000, but reduced plant density, biomass and seed yield
in 2001 and 2002. Finola consistently had lower plant height, earlier maturity, heavier seeds, and higher seed yield, seed protein
content and seed oil content than Fasamo. The average amount of nitrate-N in the 0–60 cm soil was 40 kg N ha
–1. Seed yield kg–1of N was 9.4, 5.9, 4.5 and 3.7 kg ha –1 for Fasamo, and 10.6, 7.7, 6.0 and 4.5 kg ha–1 for Finola, respectively, at 40, 80, 120 and 160 kg ha–1 of soil plus fertilizer N.
https://www.agronomy.org/publications/aj/abstracts/67/4/AJ0670040491
Cannabinoid Profile and Elemental Uptake of Cannabis sativa L. as Influenced by Soil Characteristics
Abstract
The consumption of Cannabis products (marihuana) derived from domestic and foreign sources persists in the United States despite its illegality and health hazards. The objectives of this investigation were: 1) to evaluate relationships between soil and plant elements, cannabinoids, and growth of Cannabis sativa L., and 2) to evaluate the practicality of using chemical analysis of Cannabis products to determine their geographic origin. Knowledge of geographic origin is useful to governmental agencies investigating illicit narcotic traffic.
Cannabis sativa L. was grown on 11 different soils for 45 days in the greenhouse. Soils differed significantly in 15 measured elements and pH. Plants were grown from seed of Afghan origin. The following cannabinoids were extracted and measured from leaf tissue: cannabicyclol (CCC), cannabidiol (CBD), Δ9-Tetrahydrocannabinol (Δ9THC), and cannabinol (CBN). Fifteen elements measured in leaf tissue and correlated with soil and cannabinoid measurements. Soil pH was negatively correlated with leaf concentrations of Mn, Fe, Zn, and S. Extractable soil Mg was negatively correlated with N, Δ9THC and CBD concentrations in leaf tissue (p < 0.05). Plant height was negatively correlated with Δ9THC concentration, suggesting enhancement of the narcotic principle of marihuana when grown under stress. Extractable soil P2O5 was negatively correlated with CBD concentration while extractable soil Zn was positively correlated with CCC concentration. Several correlations between soil and plant characteristics having potential value for determination of geographic origin of marihuana were elucidated. However, environmental, harvesting, and analytical procedures used by different workers which do not conform to one another could result in changes in the soil-plant correlations reported herein. Thus, additional studies are required before determination of the geographic origin of Cannabis products by foliar analysis becomes feasible.
Full Version
http://webcache.googleusercontent.c...d=1&hl=en&ct=clnk&gl=us&source=www.google.com
Cannabinoid Profile and Elemental Uptake of Cannabis sativa L. as Influenced by Soil Characteristics
Abstract
The consumption of Cannabis products (marihuana) derived from domestic and foreign sources persists in the United States despite its illegality and health hazards. The objectives of this investigation were: 1) to evaluate relationships between soil and plant elements, cannabinoids, and growth of Cannabis sativa L., and 2) to evaluate the practicality of using chemical analysis of Cannabis products to determine their geographic origin. Knowledge of geographic origin is useful to governmental agencies investigating illicit narcotic traffic.
Cannabis sativa L. was grown on 11 different soils for 45 days in the greenhouse. Soils differed significantly in 15 measured elements and pH. Plants were grown from seed of Afghan origin. The following cannabinoids were extracted and measured from leaf tissue: cannabicyclol (CCC), cannabidiol (CBD), Δ9-Tetrahydrocannabinol (Δ9THC), and cannabinol (CBN). Fifteen elements measured in leaf tissue and correlated with soil and cannabinoid measurements. Soil pH was negatively correlated with leaf concentrations of Mn, Fe, Zn, and S. Extractable soil Mg was negatively correlated with N, Δ9THC and CBD concentrations in leaf tissue (p < 0.05). Plant height was negatively correlated with Δ9THC concentration, suggesting enhancement of the narcotic principle of marihuana when grown under stress. Extractable soil P2O5 was negatively correlated with CBD concentration while extractable soil Zn was positively correlated with CCC concentration. Several correlations between soil and plant characteristics having potential value for determination of geographic origin of marihuana were elucidated. However, environmental, harvesting, and analytical procedures used by different workers which do not conform to one another could result in changes in the soil-plant correlations reported herein. Thus, additional studies are required before determination of the geographic origin of Cannabis products by foliar analysis becomes feasible.
Full Version
http://webcache.googleusercontent.c...d=1&hl=en&ct=clnk&gl=us&source=www.google.com
http://espace.library.uq.edu.au/view/UQ:75819
Assessment of P availability in heavily fertilized soils using the diffusive gradient in thin films (DGT) technique
Phosphorus-availability tests typically provide an indication of quantity of P available (Colwell bicarbonate-extractable P), or of the intensity of supply (0.01 M CaCl2-extractable P). The soil's capacity to buffer P is more difficult to assess, and is generally estimated using a P-adsorption curve. The diffusive gradient in thin films (DGT) approach may provide a simpler means of assessing a soil's ability to maintain soil solution P. Optimal extraction conditions were found to be 24 h exposure of DGT samplers to saturated soil. The DGT approach was evaluated on a range of 24 soils, some of which had high Colwell- (>100 mu g g(-1)) and Bray 1- (>30 mu g g(-1)) extractable P content, but showed a tomato (Lycopersicon esculentum Mill.) yield response to the addition of P fertilizer. The DGT approach provided an excellent separation of soils on which tomato showed a yield response, from those where fertilizer P did not increase dry-matter yield. Phosphorus accumulation was strongly correlated with soil solution P concentration and anion exchange resin-extractable P, but showed poor correlation with Colwell- or Bray 1-extractable P. The DGT P accumulation rate of 3.62 x 10(-7) to 4.79 x 10(-5) mol s(-1) m(-3) for the soils tested was comparable to the uptake rate of roots of tomato plants that were adequately supplied with P (2.25 x 10(-5) mol s(-1) m(-3)).
http://www.springerlink.com/content/v371482106138647/
Assessment of P availability in heavily fertilized soils using the diffusive gradient in thin films (DGT) technique
Phosphorus-availability tests typically provide an indication of quantity of P available (Colwell bicarbonate-extractable P), or of the intensity of supply (0.01 M CaCl2-extractable P). The soil's capacity to buffer P is more difficult to assess, and is generally estimated using a P-adsorption curve. The diffusive gradient in thin films (DGT) approach may provide a simpler means of assessing a soil's ability to maintain soil solution P. Optimal extraction conditions were found to be 24 h exposure of DGT samplers to saturated soil. The DGT approach was evaluated on a range of 24 soils, some of which had high Colwell- (>100 mu g g(-1)) and Bray 1- (>30 mu g g(-1)) extractable P content, but showed a tomato (Lycopersicon esculentum Mill.) yield response to the addition of P fertilizer. The DGT approach provided an excellent separation of soils on which tomato showed a yield response, from those where fertilizer P did not increase dry-matter yield. Phosphorus accumulation was strongly correlated with soil solution P concentration and anion exchange resin-extractable P, but showed poor correlation with Colwell- or Bray 1-extractable P. The DGT P accumulation rate of 3.62 x 10(-7) to 4.79 x 10(-5) mol s(-1) m(-3) for the soils tested was comparable to the uptake rate of roots of tomato plants that were adequately supplied with P (2.25 x 10(-5) mol s(-1) m(-3)).
http://www.springerlink.com/content/v371482106138647/
http://www.fshs.org/Proceedings/Password Protected/1995 Vol. 108/227-232 (SHULER).pdf
FIELD TESTS OF PHOSPHORUS FERTILIZATION OF TOMATO GROWING IN HIGH-P SOILS IN PALM BEACH COUNTY, FLORIDA
FIELD TESTS OF PHOSPHORUS FERTILIZATION OF TOMATO GROWING IN HIGH-P SOILS IN PALM BEACH COUNTY, FLORIDA
Abstract
Tomato (Lycopersicon esculentum) was grown with
Tomato (Lycopersicon esculentum) was grown with
various rates of P application (0,22,44,66, and 88 Ib P/acre) on
a sandy soil in Boynton Beach, FL, during the winter of 1994-
95. The soil used was very high in P and there were negligible
a sandy soil in Boynton Beach, FL, during the winter of 1994-
95. The soil used was very high in P and there were negligible
responses to P fertilization. Yields of medium-size fruit for the
third of four harvests increased in quadratic fashion as P fertil
ization increased but yields of large and extra large fruit were
not affected by P fertilization. Total marketable yield averaged
2400 25-lb cartons per acre and was not influenced by P fertil
2400 25-lb cartons per acre and was not influenced by P fertil
ization. Leaf tissue P concentrations on four sampling dates
were all within sufficiency ranges.
http://cat.inist.fr/?aModele=afficheN&cpsidt=1299858
Experiments were conducted to evaluate the yield response of tomato (Lycopersicon esculentum Mill.) to P, either preplant-incorporated or injected through the drip irrigation system, on soils with low, high, or very high soil P content. Fertilization through the drip irrigation system (fertigation) was more efficient than preplant incorporation of P for soil that tested low in P (9 mg.kg-1 Mehlich-1 P). On soil testing low in P, marketable yield response to preplant soil P application rates (0 to 100 kg.ha-1) was maximum at 61 kg.ha-1 P according to the linear-plateau model, but 37 kg.ha-1 P according to the quadratic-plateau model. The lower value is about one-half the P recommended by Univ. of Florida for low-P soils. On soil testing high in P (48 mg.kg-1 Mehlich-1 P) the linear-plateau model predicted a maximum yield of 72.8 t-ha-1 with 25 kg-ha-' P. The Univ. of Florida recommended no P for that soil. On soil testing very high in P (85 mg.kg-1 Mehlich-1 P), there was no yield improvement with P fertilization
Experiments were conducted to evaluate the yield response of tomato (Lycopersicon esculentum Mill.) to P, either preplant-incorporated or injected through the drip irrigation system, on soils with low, high, or very high soil P content. Fertilization through the drip irrigation system (fertigation) was more efficient than preplant incorporation of P for soil that tested low in P (9 mg.kg-1 Mehlich-1 P). On soil testing low in P, marketable yield response to preplant soil P application rates (0 to 100 kg.ha-1) was maximum at 61 kg.ha-1 P according to the linear-plateau model, but 37 kg.ha-1 P according to the quadratic-plateau model. The lower value is about one-half the P recommended by Univ. of Florida for low-P soils. On soil testing high in P (48 mg.kg-1 Mehlich-1 P) the linear-plateau model predicted a maximum yield of 72.8 t-ha-1 with 25 kg-ha-' P. The Univ. of Florida recommended no P for that soil. On soil testing very high in P (85 mg.kg-1 Mehlich-1 P), there was no yield improvement with P fertilization
Y
YosemiteSam
I will say this for SS. If you have ever grown Larry OG x anything you will know those are excellent looking buds. That stuff just flat does not grow what anyone would call trophy colas. So I am giving you a big ol well done SS. There is no question that Spurr formula is a good one...the only question is if it is the best one or not.
What I found...I think...is that P just flat does not influence yield much at all. My plan is to stick to 40 ppm through stretch. But here is where I disagree SS. I think bumping it after stretch, at least for a couple of weeks, increased trichome production quite a bit.
That is based on actually trying it, not on a study.
I also found that while a K:Ca:Mg ratio of 4:2:1 works pretty damn good it does end up showing some Ca and/or Mg deficiencies late in the cycle. This time around I am going to hold most other things equal but go to a 3:2:1 ratio for those things. We will see what we see.
The plant I have been posting, the ISS, is harvested. It is not dry yet but it is gonna be somewhere between 2 and 3 pounds. It is a 15 light, 15 plant setup...so should be at least 1 gram per watt or more.
But...it is an ISS, not an OG...so comparison really don't mean shit.
Anyways...next go around my peak will be...125-90-250-166-83-98...N-P-K-Ca-Mg-SiO2.
My thinking is that the healthier you keep the plant all of the way to the end the more you let it express its genetic potential. I failed that this time with the Ca/Mg problem. Live and learn.
What I found...I think...is that P just flat does not influence yield much at all. My plan is to stick to 40 ppm through stretch. But here is where I disagree SS. I think bumping it after stretch, at least for a couple of weeks, increased trichome production quite a bit.
That is based on actually trying it, not on a study.
I also found that while a K:Ca:Mg ratio of 4:2:1 works pretty damn good it does end up showing some Ca and/or Mg deficiencies late in the cycle. This time around I am going to hold most other things equal but go to a 3:2:1 ratio for those things. We will see what we see.
The plant I have been posting, the ISS, is harvested. It is not dry yet but it is gonna be somewhere between 2 and 3 pounds. It is a 15 light, 15 plant setup...so should be at least 1 gram per watt or more.
But...it is an ISS, not an OG...so comparison really don't mean shit.
Anyways...next go around my peak will be...125-90-250-166-83-98...N-P-K-Ca-Mg-SiO2.
My thinking is that the healthier you keep the plant all of the way to the end the more you let it express its genetic potential. I failed that this time with the Ca/Mg problem. Live and learn.
BasementBreeder
Member
I feel that varying the ppm of P(as well as the ratios between all of the nutes) over the course of the grow is the best solution. I'd start low(40ish) and increase after stretch; similar to YS. Most of the reading I've done seems to recommend low P, however I've come across at least 1 study(possible more. can't remember) that linked P to increasing THC content. This excellent post by tester shows the increasing percentage of P as flowering progresses; this would support the idea of increasing P.
This is just nitpicking, but I personally don't consider 80ppm of P as "high". It's medium. To me, high levels would put it around 120. I mean, even at 80, it's still less that N, K, and Ca should be, so I feel the "high phosphorous myth" is still true.
Fwiw, my latest batch(staggered over the course of 6 weeks or so) is beginning to finish. I used a modified steiner solution at 40-50ppm of P the entire grow. I feel the buds filled out quite nicely(and very resinous too) but would up the amount after stretch if I could do it over again as I think I saw a little P def starting around week 4(of 7-8). I'll see if I can't post a crappy picture or two of some finished ladies...
SS, you're coming off as an ass in this. Chill out and smoke some of those dank looking nugs you have.
This is just nitpicking, but I personally don't consider 80ppm of P as "high". It's medium. To me, high levels would put it around 120. I mean, even at 80, it's still less that N, K, and Ca should be, so I feel the "high phosphorous myth" is still true.
Fwiw, my latest batch(staggered over the course of 6 weeks or so) is beginning to finish. I used a modified steiner solution at 40-50ppm of P the entire grow. I feel the buds filled out quite nicely(and very resinous too) but would up the amount after stretch if I could do it over again as I think I saw a little P def starting around week 4(of 7-8). I'll see if I can't post a crappy picture or two of some finished ladies...
SS, you're coming off as an ass in this. Chill out and smoke some of those dank looking nugs you have.
Come towards the light Pet...individual salts forces one to develop a deeper understanding of how the puzzle pieces fit together. You start to understand that ratios of elements are what matters...not simply adding this additive or that additive and hoping for the best...cause some stoner on IC told you it is bomb
Kidding a little bit. If I were going to use bottled nutes I would put them into one of the online calculators so I would know ppms so I could make informed decisions on how much and what to add.
Pardon The Interruption. I do not intend to hi-jack this thread, but do want to respond to YS:
I totally agree, but DM is not some IC stoner lol, and basically, the same salts are used in both grow and flower, it's primarily the ratios of P & K that change.
I grow 2-5 plants at a time, just depends on how many females. The upfront expense of buying even one pound each of the necessary dry nutes is costly (if you could get such small quantities) , and would last me several life times due to my grow technique being HPA.
In my 30G HPA pod, I D2W, and still only use ~ 5 g of nutes per week. PPMs ramp up to < 650ppm during late grow and to < 850ppm during late flower.
Being pragmatic, and now knowing our beloved mj grows quite well with the full line of DM Gold nutrients (DM nutes are formulated for mj), I decided to simplify my life and save money, switching to DM ONE: 5 L was < $50 and 1 Liter of Potash+ < $20, plus shipping. I'm good for many years to come.
After finishing off Gold Grow A/B, I will use ONE Grow throughout but add varying amounts of Potash+ during flower. FYI, I also use DM Zone and Silica, plus I foliar feed with DM LL/S.
Oh, I came across a company in Europe that sells small quantities of premixed dry nutes. http://www.formulaflora.com/home.php
Let's return to the thread subject.
hth
BasementBreeder
Member
Y
YosemiteSam
That seems low in Ca for Jack's/CaNO3. Are you using it at their suggested ratios?
If those are the numbers I would be afraid of a Ca deficiency showing up pretty quick.
Everything else looks good though.
Y
YosemiteSam
I did not mean to disrespect you. If it came off that way I apologize.
You make valid points. Best of luck with the DM
