cfl veg / hps flower?

Blue light dose–responses of leaf photosynthesis, morphology, and chemical composition of Cucumis sativus grown under different combinations of red and blue light


Abstract

The blue part of the light spectrum has been associated with leaf characteristics which also develop under high irradiances. In this study blue light dose–response curves were made for the photosynthetic properties and related developmental characteristics of cucumber leaves that were grown at an equal irradiance under seven different combinations of red and blue light provided by light-emitting diodes. Only the leaves developed under red light alone (0% blue) displayed dysfunctional photosynthetic operation, characterized by a suboptimal and heterogeneously distributed dark-adapted Fv/Fm, a stomatal conductance unresponsive to irradiance, and a relatively low light-limited quantum yield for CO2 fixation. Only 7% blue light was sufficient to prevent any overt dysfunctional photosynthesis, which can be considered a qualitatively blue light effect. The photosynthetic capacity (Amax) was twice as high for leaves grown at 7% blue compared with 0% blue, and continued to increase with increasing blue percentage during growth measured up to 50% blue. At 100% blue, Amax was lower but photosynthetic functioning was normal. The increase in Amax with blue percentage (0–50%) was associated with an increase in leaf mass per unit leaf area (LMA), nitrogen (N) content per area, chlorophyll (Chl) content per area, and stomatal conductance. Above 15% blue, the parameters Amax, LMA, Chl content, photosynthetic N use efficiency, and the Chl:N ratio had a comparable relationship as reported for leaf responses to irradiance intensity. It is concluded that blue light during growth is qualitatively required for normal photosynthetic functioning and quantitatively mediates leaf responses resembling those to irradiance intensity.




Introduction

Plant development and physiology are strongly influenced by the light spectrum of the growth environment. The underlying mechanisms of the effect of different growth spectra on plant development are not known in detail, although the involvement of photoreceptors has been demonstrated for a wide range of spectrum-dependent plant responses. Cryptochromes and phototropins are specifically blue light sensitive, whereas phytochromes are more sensitive to red than to blue (Whitelam and Halliday, 2007). Blue light is involved in a wide range of plant processes such as phototropism, photomorphogenesis, stomatal opening, and leaf photosynthetic functioning (Whitelam and Halliday, 2007). At the chloroplast level, blue light has been associated with the expression of ‘sun-type’ characteristics such as a high photosynthetic capacity (Lichtenthaler et al., 1980). Most studies assessing blue light effects on the leaf- or whole-plant level have either compared responses to a broad-band light source with responses to blue-deficient light (e.g. Britz and Sager, 1990; Matsuda et al., 2008), or compared plants grown under blue or a combination of red and blue light with plants grown under red light alone (e.g. Brown et al., 1995; Bukhov et al., 1995; Yorio, 2001; Matsuda et al., 2004; Ohashi et al, 2006). Overall there is a trend to higher biomass production and photosynthetic capacity in a blue light-containing irradiance. Before the development of light-emitting diodes (LEDs) that were intense enough to be used for experimental plant cultivation (Tennessen et al., 1994), light sources emitting wavelengths in a broader range than strictly the red (i.e. 600–700 nm) or blue (i.e. 400–500 nm) region were often used (e.g. Voskresenskaya et al., 1977). Other wavelengths can interact with blue light responses. For example, green light has been reported to antagonize some blue light responses, such as stomatal opening and inhibition of hypocotyl elongation in seedlings (Folta and Maruhnich, 2007). The blue light enhancement effect on photosynthetic capacity appears to be greater when using combinations of red and blue light produced by LEDs than when broad-band light is made deficient in blue by a filter (e.g. for spinach compare Matsuda et al., 2007 and 2008). This raises the question of whether plants exposed to red light alone suffer a spectral ‘deficiency’ syndrome, which may be reversed by blue light as well as by longer wavelengths.
Poorter et al. (2010) stress the importance of dose&#8211;response curves for quantitative analysis of the effects of environmental factors on plant phenotypes, allowing a better understanding of plant&#8211;environment interactions than the comparison of two treatments only. It is not clear whether the enhancement effect of blue light on leaf photosynthetic capacity is a qualitative threshold response or a quantitative progressive response, or a combination of both. Only few specific processes in leaves have been identified as quantitative blue light responses, such as chloroplast movement (Jarillo et al., 2001) and stomatal conductance (Sharkey and Raschke, 1981). Matsuda et al. (2007) found a higher photosynthetic capacity for spinach leaves grown under 300&#8201;&#956;mol m&#8722;2 s&#8722;1 mixed red/blue irradiance containing 30&#8201;&#956;mol m&#8722;2 s&#8722;1 blue than for leaves grown under red alone. A higher blue light fraction did not yield a significant further enhancement in light-saturated assimilation (Amax), which may be interpreted as a qualitative blue light effect. However, a quantitative blue light effect at quantum fluxes <30&#8201;&#956;mol m&#8722;2 s&#8722;1 cannot be excluded.
A diverse choice of LEDs powerful enough for use as a growth irradiance source in controlled environments has recently become available (e.g. Massa et al., 2008). These LEDs allow the effect of light quality to be investigated independently of the amount of photosynthetic irradiance. LED illumination has been used here to study the response curves of a range of parameters related to leaf photosynthesis of plants that were grown at an irradiance with a proportion of blue light ranging from 0% to 100%. A range of other leaf characteristics important for the functioning of photosynthesis, such as stomatal development and behaviour, leaf mass per area (LMA), and the content of N, pigments, and carbohydrates, were also determined. The spectra and the extent of variation in the ratio of red and blue irradiance that can be achieved with LED lighting are dissimilar to field conditions. However, the responses of leaves to these unnatural environments provides the possibility to unravel the complex developmental and functional interactions that normally occur in the natural light environment.
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Materials and methods

Plant material and growth conditions

Cucumber plants (Cucumis sativus cv. Hoffmann's Giganta) were sown in vermiculite and germinated under 100&#8201;&#956;mol m&#8722;2 s&#8722;1 cool white fluorescent lamps (TLD 50&#8201;W 840 HF, Philips, The Netherlands) in a climate chamber. After 1 week, when the cotyledons had just opened, the seedlings were transferred to a hydroponic system (Hoagland's solution, pH=5.9±0.2; EC=1.2&#8201;mScm&#8722;1) in a climate chamber. The day/night temperature was 25&#8201;°C/23&#8201;°C, the relative humidity was 70%, and the CO2 concentration was ambient. All plants were subjected to 100±5&#8201;&#956;mol m&#8722;2 s&#8722;1 irradiance (16&#8201;h/8&#8201;h day/night) provided by a mixture of blue and red LEDs with dominant wavelengths of 450&#8201;nm and 638&#8201;nm, respectively (types Royal Blue and Red Luxeon K2, Lumileds Lighting Company, San Jose, CA, USA). The LEDs were equipped with lenses (6&#8201;º exit angle) and the arrays were suspended &#8764;1&#8201;m above the plants, so irradiance from the two LED types was well mixed. The lenses ensured that small differences in leaf height had only minor effects on the irradiance received. The seven different spectral treatments are expressed as the blue (B) light percentage: 0B, 7B, 15B, 22B, 30B, 50B, and 100B; the remaining percentage was red. Irradiance was measured routinely using a quantum sensor (LI-COR, Lincoln, NE, USA), but was also verified with a spectroradiometer (USB2000 spectrometer, Ocean Optics, Duiven, The Netherlands, calibrated against a standard light source). The difference in irradiance measured with the two devices was <2% for the spectra used.
The plants were allowed to grow until the second leaf was fully mature (17–22&#8201;d after planting the seedlings) when it could be used for photosynthesis measurements. If necessary, the second leaf, which was the leaf used for all measurements, was supported in a horizontal position during growth to ensure that it received the specified irradiance.

Stomata analysis

The stomatal conductance (gsw) was measured on three positions on each leaf surface using a leaf porometer (model SC-1, Decagon Devices, Inc., Pullman, WA, USA) prior to the gas exchange measurements (see below). The ratio of the average gsw of the abaxial and adaxial leaf surface (gsw ratio) was used in the calculations of the gas exchange parameters (n=6). Additionally, silicon rubber impressions were made (see Smith et al., 1989) on both the adaxial and abaxial surface of the leaves grown under 0B, 15B, 30B, and 50B (n &#8805;3). Stomatal density, length, and aperture were determined from images of the impressions using the procedure described in Nejad and van Meeteren (2005).

Leaf gas exchange and fluorescence measurements

Gas exchange and chlorophyll (Chl) fluorescence were measured using a custom-made leaf chamber within which 4.52&#8201;cm2 of leaf surface was illuminated. A LI-7000 CO2/H2O gas analyser (LI-COR, Lincoln, NE, USA) measured the CO2 and H2O exchange of the leaf and ambient atmospheric pressure. Leaf temperature was monitored by a thermocouple pressed against the abaxial leaf surface. A custom-made measuring-light source comprised of independently controllable red and blue LEDs with attached lenses, emitting a spectrum similar to that of the LEDs used for growth-light, was used to provide the required red/blue combination in the irradiance range 0–1700&#8201;&#956;mol m&#8722;2 s&#8722;1. A polished steel reflector in the form of an inverted truncated cone (i.e. the inlet to the reflector was larger than the outlet) allowed the irradiance to be well mixed and equally distributed over the leaf surface. The gas mix used contained 380&#8201;&#956;mol mol&#8722;1 CO2, 20.8±0.4&#8201;mmol mol&#8722;1 H2O, and either 210&#8201;mmol mol&#8722;1 or 20&#8201;mmol mol&#8722;1 O2 (ambient O2 or low O2), dependent on the type of measurement. A flow rate of 200–700&#8201;ml min&#8722;1 was used, depending on the CO2 depletion which ranged from 18&#8201;&#956;mol mol&#8722;1 to 26&#8201;&#956;mol mol&#8722;1 at saturating irradiance. The equations developed by von Caemmerer and Farquhar (1981) were used to calculate assimilation, gsw, and the CO2 concentration in the substomatal cavity of the leaf relative to that in the leaf chamber air (Ci Ca&#8722;1) from the gas exchange data. The boundary layer resistance of both leaf surfaces in the leaf chamber during gas exchange measurements was estimated using the method of Jarvis (1971). Chl fluorescence was measured using a PAM 101 Chl fluorometer with an emitter detector unit (model 101 ED; Heinz Walz, Effeltrich, Germany). The modulated red measuring-light intensity was <0.5&#8201;&#956;mol m&#8722;2 s&#8722;1. A 250&#8201;W quartz–halogen lamp connected to an additional optical fibre provided a saturating light pulse (7500&#8201;&#956;mol m&#8722;2 s&#8722;1) to allow measurement of the Fm or Fm&#8242; relative fluorescence yield (Baker et al., 2007). The fibres were fixed &#8764;4&#8201;cm above the leaf chamber at such an angle that they did not interfere with the actinic light beam.
Irradiance–response curves were measured on fully expanded second leaves, and each growth-light treatment was performed twice. As there were no significant differences between the two repetitions, the individual plants from the two repetitions were treated as independent repetitions (n=6) in the analysis. An ambient O2 concentration was used for these measurements. After clamping a leaf in the leaf chamber, it was dark adapted for 30&#8201;min, and dark respiration (Rdark) and the dark-adapted Fv/Fm (Baker et al., 2007) were measured. The irradiance–response curve was measured using a spectrum identical to that under which the plants were grown, using 14 intensities in the range 0–1700&#8201;&#956;mol m&#8722;2 s&#8722;1. The leaves were subjected to each irradiance for at least 20&#8201;min, when steady-state assimilation was amply reached. The highest irradiances were omitted if CO2 fixation clearly became light-saturated at lower irradiances. At an irradiance of 100&#8201;&#956;mol m&#8722;2 s&#8722;1, which is equal to the irradiance during growth, the relative quantum yield of photosystem II (PSII) electron transport (&#934;PSII) was measured using the method of Genty et al. (1989). After measuring the irradiance–response curve, the plant was left overnight in the dark in a climate room and the following day samples were taken from the measured leaf in order to measure the light absorptance spectrum, leaf mass per area (LMA), and pigment- and N-content (see below).
In order to assess the possibility that Ci was limiting assimilation at low irradiance, the relationship between assimilation and electron transport rate (ETR) was investigated in more detail. Under photorespiratory conditions a lower assimilation per unit ETR is expected for a leaf with a Ci that is limiting for assimilation than for a leaf with no limiting Ci. Under non-photorespiratory conditions no difference is to be expected (Harbinson et al., 1990). Additional gas exchange and fluorescence measurements were made on leaves grown under 0B and 30B using seven different incident irradiances (0–100&#8201;&#956;mol m&#8722;2 s&#8722;1) and both ambient and low O2 (n=3). Chl fluorescence measurements were made at each irradiance to determine &#934;PSII once CO2 fixation had stabilized, after which the actinic irradiance was switched off to measure Rdark. Gross assimilation (Agross) was calculated as net assimilation (Anet) plus Rdark, which assumes, as is commonly done, that Rdark is a reasonable estimate of respiration in the light. Light absorptance (see below) was measured directly after measuring the photosynthesis irradiance–response. The product of the absorbed actinic irradiance and &#934;PSII serves as an index for ETR (e.g. Kingston-Smith et al., 1997). The distribution of dark-adapted Fv/Fm over these 0B- and 30B-grown leaves was measured by means of Chl fluorescence images. Images of three different leaves from each treatment were made using a PSI Fluorcam 700MF Chl fluorescence imaging system (PSI, Brno, Czech Republic), using the procedure described in Hogewoning and Harbinson (2007).

Measurement of leaf light absorptance

Leaf light absorptance was calculated in 1&#8201;nm steps in the range 400–800&#8201;nm from measurements of leaf reflectance and transmittance made on 12 leaf discs per leaf. Details of the procedure and measurement system, which consisted of two integrating spheres, each connected to a spectrometer and a custom-made light source, are described in Hogewoning et al. (2010) and Zheng et al. (2010). The integrated absorptance of the actinic measuring irradiance used during gas exchange measurements was subsequently calculated by multiplying the relative leaf absorptance spectrum by the spectrum of the measuring-light.

LMA, nitrogen, pigment, and carbohydrate analysis

From each leaf, 10 leaf discs (1.28&#8201;cm2) were cut randomly over the leaf area, avoiding the leaf margins and main veins. The discs were stored at –22&#8201;°C, freeze dried, and weighed, and LMA was calculated. After weighing, the C and N contents were determined for all treatments by a C/N analyser (n=5) and the nitrate content was determined for the treatments 0B and 30B (n=4) according to Trouwborst et al. (2010).
An additional eight leaf discs (0.65&#8201;cm2) were cut from the same leaf and stored in 10&#8201;ml of dimethylformamide (DMF) in the dark at –22&#8201;°C. The absorbance of the extract was measured in the range 400–750&#8201;nm using a Cary 4000 spectrophotometer (Varian Instruments, Walnut Creek, CA, USA), and the Chl and carotenoid concentrations were calculated using the equations of Wellburn (1994).
The carbohydrate content of leaves grown under 0B, 30B, and 100B was measured by cutting 10–15 discs (1.28&#8201;cm2) from one side of the main vein at the end of the photoperiod and 10–15 discs from the other side of the main vein just before the start of the photoperiod (n=4). Soluble carbohydrate and starch concentrations were analysed as described in Hogewoning and Harbinson (2007).

Curve fitting and statistics

The photosynthesis data measured to obtain light–response curves of the leaves grown under different blue/red combinations were fitted with a non-rectangular hyperbola (Thornley, 1976) using the non-linear fitting procedure NLIN in SAS (SAS Institute Inc. 9.1, Cary, NC, USA) in order to determine the light-limited quantum yield for CO2 fixation (&#945.
Tukey's HSD was used to make post-hoc multiple comparisons among spectral treatment means from significant one-way analysis of variance (ANOVA) tests (P <0.05), and regression analysis was used to test for significant differences (P <0.05) between the slope of the Agross– &#934;PSII×absorbed measuring-light relationship using Genstat (release 9.2, Rothamsted Experimental Station, Harpenden, UK).

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Results

Leaf photosynthesis

The Amax differed significantly for the leaves grown under different blue (B) light percentages (Fig. 1). Increasing the blue light fraction from 0% to 50% resulted in an increasing Amax, with the greatest increase occurring at the increase from 0% to 7% blue. The 100B-grown leaves had an Amax that was lower than that of the 50B leaves. The light-limited quantum yield for CO2 fixation (&#945 was lowest for 0B and 100B leaves and highest for the 7B–30B leaves (within this range there was no significant difference in &#945;; Table 1). Dark respiration was lowest for 0B leaves and tended to increase with blue light percentage, except for 100B (Table 1), similar to the pattern found for Amax. The dark-adapted Fv/Fm was typical for an unstressed leaf (i.e. &#8805;0. in all treatments, except 0B, where it was significantly reduced (Table 1). The &#934;PSII measured at growth-light intensity (i.e. 100&#8201;&#956;mol m&#8722;2 s &#8722;1) and spectrum was similar for the 15B–100B leaves, but was markedly lower for 0B leaves and slightly, but significantly, lower for 7B leaves.

Different parameters measured or calculated on leaves grown under different light qualities (the proportion of total PAR that is from the blue rather than from the red part of the spectrum).
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Fig. 1. The effect of light quality (the proportion of total PAR that is from the blue rather than from the red part of the spectrum) during growth on the photosynthetic capacity (Amax) of cucumber leaves. Error bars indicate the SEM (n=6).


Concerning the more detailed measurements of the photosynthesis irradiance–response between 0&#8201;&#956;mol m&#8722;2 s &#8722;1 and 100&#8201;&#956;mol m&#8722;2 s &#8722;1 incident irradiance on 0B- and 30B-grown leaves, Agross was markedly higher for the low O2 measurements than it was for the ambient O2 measurements (Fig. 2). At all light intensities, &#934;PSII was consistently lower for the 0B leaves than it was for the 30B leaves. In both treatments the O2 concentration did not affect &#934;PSII (not shown). The absorptance in the green region of the spectrum was 5–10% lower for the 0B- and 100B-grown leaves than for the other treatments, whereas differences in absorptance between the growth-light treatments were negligible for the blue and red region (not shown). Only the red and blue wavelength regions are relevant for integrated absorbed irradiance in this experiment. The integrated absorptance of the growth and measuring-light increased with the percentage of blue light (Table 1), as the blue light was better absorbed than the red light. At both low and ambient O2 concentration there were no significant differences between 0B and 30B for the linear regression between Agross and the product of &#934;PSII and the absorbed actinic irradiance (Fig. 2).
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Fig. 2. Relationship between gross CO2 assimilation (Agross) and the product of &#934;PSII and the actinic measuring-light absorbed by the leaves, which serves as an index of electron transport (e.g. Kingston-Smith et al., 1997), at an incident irradiance &#8804;100 &#956;mol m&#8722;2 s&#8722;1. The cucumber leaves were grown under and also measured with 0B (=100% red; circles) and 30B (squares) irradiance, and gas exchange was measured under low (open symbols) and ambient O2 (filled symbols). Gross assimilation was calculated as dark respiration plus net assimilation. The slopes of the regression lines are significantly different for the two O2 levels (P <0.001), but not for the spectral treatments (P &#8805;0.23).


The images of dark-adapted Fv/Fm obtained via Chl fluorescence imaging showed conspicuous differences between the 0B and 30B leaves. Whereas the images from 30B-grown leaves were perfectly homogeneous with an Fv/Fm >0.8, the images of the 0B-grown leaves showed a heterogeneous distribution with dark-adapted Fv/Fm values of &#8764;0.8 adjacent to the veins and with zones of lower Fv/Fm (typically 0.55–0.70) between the veins (Fig. 3). The 0B leaves also occasionally appeared slightly chlorotic between the veins.
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Fig. 3. Image of the dark-adapted Fv/Fm distribution over an 0B (=100% red; A) and 30B (B) irradiance-grown cucumber leaf. The mixed blue–red-grown leaf (B) has a homogeneous Fv/Fm distribution centred around an Fv/Fm of 0.82, whereas the 0B-grown leaf (A) has a heterogeneous distribution with a high Fv/Fm around the veins and lower values between the veins.

http://jxb.oxfordjournals.org/content/61/11/3107.full

see the difference

Perhaps but what about combined lighting? Like CFL's,Metal halide,and High pressure Sodium? I have all 3 so wouldn't it be best then according to what's been presented to use all 3 for a full light spectrum and greater penetration?

Hey guys. Wow that was a lot of info. I am growing my first grow and I germinated bunch of seeds my buddy gave me. I have them under a 400mh covered with a dome. its about 2 feet from the light. I am using a enclosed reflector. The grow box average temp for the first 18 hours was about 80F. Will I be ok with this light for seedlings. I don't really want to go out and spend more money on cfls or t5.

Planc, that ligting seems great. Some are blessed to have a 400. I highly suggest you get an hps bulb for flowering later. You can find a cheap one on eBay for 10 bucks including shipping. Also, I highly suggest you get a 130cfh fan, or a small inline fan for your bulb, with ducting. That way, use the air from inside the box, flow it through the bulb and out the grow box. Your temps would be drastically lower, and the fan itself is 30-50 bucks. These 2 cheap items would help be the best money you spend.

CFL , Tube Florescent lights work but depending where you live like I found out that you can buy MH and HPS lights as low as 35w. They aren't made to cover a big area light the higher wattage bulbs buy it gives you the chance to do a mix of 1 or 2 35w MH lights and 1 or 2 35w HPS lights. Don't forget you might have to buy a ballast for them if they aren't self ballast.

PlanC said:

Hey guys. Wow that was a lot of info. I am growing my first grow and I germinated bunch of seeds my buddy gave me. I have them under a 400mh covered with a dome. its about 2 feet from the light. I am using a enclosed reflector. The grow box average temp for the first 18 hours was about 80F. Will I be ok with this light for seedlings. I don't really want to go out and spend more money on cfls or t5.

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For seedlings a 400 mh is to strong it might kill them. The 400 is to intense and will burn unless you keep it 4 feet away at least. then they will stretch like a mutha .you just might have to go with a single strip t5 or a few cfls. Around 30 dol for either.Once they got strong root foundation and a few sets of leaves you can put em back under the 400. DO NOT KEEP SEEDS UNDER A DOME. THEY WILL ROT FROM TOO MUCH HUMIDITY. Only clones need to be under a dome


Its a very expensive hobby

You can keep the 400mh light on them as long as there is plenty of room in-between, like 3 feet. Once they stretch, put soil over the stem up until a point where in doesn't look much stretched, this gives them an awesome structure. Don't need to buy t5 or Flores, you're good. Hyroot just has his head up his arse, if you haven't already noticed.

Tebin said:

Perhaps but what about combined lighting? Like CFL's,Metal halide,and High pressure Sodium? I have all 3 so wouldn't it be best then according to what's been presented to use all 3 for a full light spectrum and greater penetration?

Click to expand...

No. Yo will have a fuller spectrum ...... But hid's depending on bulb have 5% to 10% PAR (Photosynthetically available radiation (PAR) is defined as the amount of radiant energy available within the approximate spectral range of 350 to 750 nm) So all together you still won't have much PAR. Most of the light that comes from hid's is visible light or lumens and not infrared light which is what plants mostly absorb

My T5 set up is around 90% PAR. At the beginning of the the thread I listed the bulbs I use and spectrum graphs and links to where to buy them

The sun is 100% PAR

Thanks guys, I remember someone telling me to keep a dome on when starting seeds. I will take it off. I have an inline fan venting the box. I am using Solar Palau mix flow fan. I have the td125. On low speed it pulls about 100cfm or so. They are awesome, really quiet, energy efficient and can handle static. Right now I have it running 24h but I would like to put it on the light circuit or temperature and install a smaller fan that would run 24h to supply fresch air. Any thoughts?

http://www.solerpalaucanada.com/td_mixvent.html

Out of all the seeds that I have germinated and grown have never been in a humidity dome. If you want you could put the fan on a digital timer and set it so that its on a cretin time and turns off at a cretin time. The one that I bight you can do up to I think 20 or 24 on/off times. Having the fan on a temperature activation thing would be good if you can set it to come on once it hits a cretin temp.

hyroot, how about you post some pics of your plants at 3 weeks old..

how about t5 for the first part of veg then switch to mh for the last 2 weeks?
or t5's plus one 600 on a mover
opinions?

Hyroot, you talk about ignorant people with closed minds; well, by reading this thread, anyone can see that YOU are the most closed minded person in this entire thread. You post all these charts etc, from who knows where, but don't post ANY pictures of an actual grow - the only pics you refer to you say are your "friend's." The louder you yell (by posting several pages of someone elses work - people with self interests?) doesn't mean it makes you more right, it just makes you look stupid (aka ignorant). Everyone knows that something on paper isn't always the same as reality. MANY growers have posted here. ALL have good grows with their methods, but NONE act like an arrogant a-hole - other than one - YOU... You can take your inferior t5's and shove them where the sun DON'T shine.

Spelljunkie said:

Hyroot, you talk about ignorant people with closed minds; well, by reading this thread, anyone can see that YOU are the most closed minded person in this entire thread. You post all these charts etc, from who knows where, but don't post ANY pictures of an actual grow - the only pics you refer to you say are your "friend's." The louder you yell (by posting several pages of someone elses work - people with self interests?) doesn't mean it makes you more right, it just makes you look stupid (aka ignorant). Everyone knows that something on paper isn't always the same as reality. MANY growers have posted here. ALL have good grows with their methods, but NONE act like an arrogant a-hole - other than one - YOU... You can take your inferior t5's and shove them where the sun DON'T shine.

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Thats so laughable

you obviously didn't read the thread. you just glanced at a few charts maybe. I proved it with plenty of references

thats the pot calling the kettle black. you talk shit and yet don't offer any insight or scientific method to back up anything. i don't need to pics to prove anything. mine friends pics already proved that enough aside from the scientific fact and charts. Not one single person on this thread has combated with any scientific proof. i got those charts from the manufacturer of each bulb.

Have you ever tried to grow with a t5 or even the bulbs i suggested. Im sure you haven't so you have no room to say anything.

I'll believe a scientist over some stoner any day.

your hid's are over priced and inferior my friend. there are several people who agree with me and use the same lighting on this forum.

posting pics is very stupid. it incriminates you. i tried deleting all mine . theres a few it wouldn't let me delete.

all this has already been proven by scientist and botanists at oxford university , university of maryland and mississippi university and nasa.

so once again another idiot goes off on shit he knows nothing about.


You should watch what you say in public. People will laugh at you. Your post is definitely ignorant. Again you talk shit and don't back it up and obviously don't understand the subject matter

I have scientific proof buddy...

3 weeks


Do that with your t5's, good luck... catch me if you can.

hyroot said:

Thats so laughable

you obviously didn't read the thread. you just glanced at a few charts maybe. I proved it with plenty of references

thats the pot calling the kettle black. you talk shit and yet don't offer any insight or scientific method to back up anything. i don't need to pics to prove anything. mine friends pics already proved that enough aside from the scientific fact and charts. Not one single person on this thread has combated with any scientific proof. i got those charts from the manufacturer of each bulb.

Have you ever tried to grow with a t5 or even the bulbs i suggested. Im sure you haven't so you have no room to say anything.

I'll believe a scientist over some stoner any day.

your hid's are over priced and inferior my friend. there are several people who agree with me and use the same lighting on this forum.

posting pics is very stupid. it incriminates you. i tried deleting all mine . theres a few it wouldn't let me delete.

all this has already been proven by scientist and botanists at oxford university , university of maryland and mississippi university and nasa.

so once again another idiot goes off on shit he knows nothing about.


You should watch what you say in public. People will laugh at you. Your post is definitely ignorant. Again you talk shit and don't back it up and obviously don't understand the subject matter

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You should give the guy who's thread you hijacked all your pretty charts, graphs, and pictures from some of the credit for being brilliant as well, or don't you think the professor deserves credit for originally posting the information you claim to have painstakingly gathered from various bulb manufacturers, ivy league universities and scientists?

By the way, the guy whos post hyroot cut and pasted all this stuff from got popped by the cops, and had his crop destroyed by mites.
So take his growing info for what it's worth.

el ohhh el !!!

probo24 said:

You should give the guy who's thread you hijacked all your pretty charts, graphs, and pictures from some of the credit for being brilliant as well, or don't you think the professor deserves credit for originally posting the information you claim to have painstakingly gathered from various bulb manufacturers, ivy league universities and scientists?

By the way, the guy whos post hyroot cut and pasted all this stuff from got popped by the cops, and had his crop destroyed by mites.
So take his growing info for what it's worth.

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read every post i did. I did give credit where credit was due.look at the end. i did get charts from a manufacturer. i even said in earlier post my friend came up with the idea. i also said i spent months researching it on my own before i tried it to see if there was any validity to the goings on.

once again another person talking shit who didn't read anything . that was his first crop that the cops took he since had more crops. i only cut and pasted one 2 of his. and i reworded it myself and i gave him credit at the end if you actually read any of it. you are just another person talking shit. you obviously didn't read all his stuff either.

people are so funny

the references i gave from online library and oxford and so on did not come from him at all,. he never posted any links

when you read a book or go to school for a degree you are learning off some one elses work. so did anyone on here write any of the horticulture books at universities? did anyone write those microbiology books? no they did not so that is learning off some one elses work. when you post a link to a university backing up the validity of what you are saying. did you writ write that paper. everything prof has quoted from scientist, he did not write those papers either. so that can be considered plagiarism. knowledge is knowledge no matter where you get it just as long as it's valid