Icemud's Far Red LED Journal - Flower Trigger Manipulation - Budmaster LED Lights

[Icemud]

Icemud. That all makes great sense. I'm looking at using it this next round. To cool off a light not to use somewhere lol!

Right! I think its awesome what LED technology allows... I mean with the old HPS and other lights, there was no way to "filter" a light for specific wavelengths, except for using gel filters and optics and such, but now we can have LED panels designed in any color, wavelength, combo or whatever we want I think this is really going to help plant lighting research excel!

 

[Icemud]

Hey, bro. I'm here sitting in the shadows. But I probably won't be commenting much (if at all), because in this particular journal, I know I'll just be a student with nothing to teach, lol.

Hey Tortured! you are always welcome to join in, as with this Far red, we are kind of all learning together the more info and participants juggling ideas and thoughts together, the more we can make sense of how to use this light to our benefit

 

[Icemud]

Here is another intereting study I found with far red to red light ratios

So by this it seems that some red light:far red light can allow flowering with a night interruption (think Gas Lantern Routine) meaning the slight bit of red doesn't influence the night, but the higher the ratio or red to far red the more the night interruption disrupted flowering. Therefor I would suggest based on this and other things I have read that its best to have no red, and only use 730nm (far red) for flower triggering.

A Moderate to High Red to Far-red Light Ratio from Light-emitting Diodes Controls Flowering of Short-day Plants

Daedre S. Craig1 and Erik S. Runkle2

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Author Affiliations

Department of Horticulture, 1066 Bogue Street, Michigan State University, East Lansing, MI 48824


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Abstract

In protected cultivation of short-day (SD) plants, flowering can be inhibited by lighting from incandescent (INC) lamps during the night. INC lamps are being phased out of production and replaced by light-emitting diodes (LEDs), but an effective spectrum to control flowering has not been thoroughly examined. We quantified how the red [R (600 to 700 nm)] to far red [FR (700 to 800 nm)] ratio (R:FR) of photoperiodic lighting from LEDs influenced flowering and extension growth of SD plants. Chrysanthemum (Chrysanthemum ×morifolium), dahlia (Dahlia hortensis), and african marigold (Tagetes erecta) were grown at 20 °C under a 9-hour day with or without a 4-hour night interruption (NI) treatment by INC lamps or LEDs with seven different R:FR ranging from all R to all FR. Flowering in the most sensitive species, chrysanthemum, was not inhibited by an R:FR of 0.28 or lower, whereas an R:FR of 0.66 or above reduced flowering percentage. Flowering in dahlia was incomplete under the FR-only NI and under SDs, but time to flower was similar under the remaining NI treatments. The least sensitive species, african marigold, flowered under all treatments, but flowering was most rapid under the FR-only NI and under SDs. For all species, stem length increased quadratically as the R:FR of the NI increased, reaching a maximum at R:FR of ≈0.66. We conclude that in these SD plants, a moderate to high R:FR (0.66 or greater) is most effective at interrupting the long night, blue light is not needed to interrupt the night, and FR light alone does not regulate flowering.

Many plants exhibit a photoperiodic flowering response, including a broad range of field and ornamental crops (Erwin and Warner, 2002; Mattson and Erwin, 2005; Runkle and Heins, 2003). This photoperiodic response is determined primarily by the duration of the dark period, also known as the critical night length (Thomas and Vince-Prue, 1997). Plants have been classified into photoperiodic response groups depending on how the critical night length influences flowering. Short-day plants (SDPs) flower most rapidly when uninterrupted dark periods are longer than some genotype-specific critical night length (Vince, 1969). Within the SDP response category, plants can be further classified based on whether SDs are required for flowering (a qualitative response) or hasten it (a quantitative response). Photoperiodic (low-intensity) lighting is used by commercial crop producers to alter the natural photoperiod (e.g., to extend the natural daylength or to interrupt the dark period) to manipulate flowering.

The spectral quality of photoperiodic lighting can influence flowering responses. Light quality is perceived by three identified families of plant photoreceptors: cryptochromes, ultraviolet receptors, and phytochromes (Kami et al., 2010). Cryptochromes have been identified in many plant species and mediate a variety of light responses, including playing a role in flowering time regulation in arabidopsis [Arabidopsis thaliana (Cashmore et al., 1999; Mockler et al., 2003)]. The phytochrome photoreceptors mediate extension growth and flowering in photoperiodic plants (Smith, 1994). Five types of phytochrome have been identified in arabidopsis and designated A to E (Kami et al., 2010). Studies with phytochrome mutants of arabidopsis have shown that phyA and phyB play dominant roles mediating flowering and stem extension, respectively, in response to light quality (Franklin and Quail, 2010). Phytochrome exists in a R (600 to 700 nm; peak absorption at 660 nm) and a FR (700 to 800 nm; peak absorption at 730 nm) absorbing form, PR and PFR, respectively (Hayward, 1984; Sager et al., 1988). The R:FR incident on the plant influences the phytochrome photoequilibria (PFR/PR+FR) within the plant. On absorbing R light, PR converts mainly to the PFR form. The PFR form largely converts back to the PR form on absorbing FR light or during a natural, gradual conversion during the dark period (Thomas and Vince-Prue, 1997). Although the total pool of phytochrome in the plant is relatively constant, because natural light environments are ever-changing, the relative amounts of PFR and PR, and thus the overall PFR/PR+FR, also fluctuate throughout the day.

In photoperiodic crops, the PFR/PR+FR, through different types of phytochromes, influences flowering. PFR is the active form of phytochrome, which translocates to the nucleus on receiving light signals and activates downstream pathways (Franklin and Quail, 2010). Under a long, uninterrupted night, the PFR form of phytochrome slowly converts to the PR form, leaving insufficient PFR to inhibit flowering. However, if R light is provided during the long night, PR is converted to PFR (creating a greater PFR/PR+FR), which inhibits flowering in SDPs. The PFR/PR+FR also influences extension growth, especially in shade-avoiding plants.

Incandescent lamps are commonly used as photoperiodic lighting to control development of crops, because they emit an effective spectrum and are inexpensive. However, INC lamps are very energy-inefficient and are being phased out of production in many parts of the world (Waide, 2010). LEDs are an attractive technology for NI lighting of photoperiodic crops. Compared with conventional lamps, LEDs have many desirable characteristics including a very long operating life, narrow bandwidth capability, full instantaneous irradiance when powered, and continually improving electrical efficiencies (Bourget, 2008; Morrow, 2008). Furthermore, LEDs allow researchers to analyze the effects of specific wavebands without extraneous light. Many of the original studies on photoperiodic light quality were limited by the lighting technology of the time. The use of photoselective filters and tinted lamps may have introduced confounding variables into these early experiments such as differences in photon flux between treatments and/or inclusion of potentially confounding, extraneous wavelengths (Borthwick et al., 1952; Cathey and Borthwick, 1957; Downs, 1956).

The objectives of the present study were to use LEDs to quantify the impact of the R:FR of NI lighting on flowering of SD ornamental crops and to compare plant responses with those under traditional INC lamps. To our knowledge, this is the first study that has identified how R:FR ratios control the flowering response of SDPs without the confounding effects of other light wavebands.
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Materials and Methods
Plant material and culture.

On 8 Feb. 2011, 7- to 10-d-old seedlings of african marigold ‘American Antigua Yellow’ grown in 288-cell (6 mL) plug trays and rooted cuttings of chrysanthemum ‘Adiva Purple’ and dahlia ‘Dahlinova Figaro Mix’ grown in 36-cell (32 mL) liner trays were received from a commercial greenhouse (C. Raker & Sons, Litchfield, MI). The young plants were subsequently grown under non-inductive long days [natural daylength extended from 0600 to 2200 hr by high-pressure sodium (HPS) lamps] in a research greenhouse at 20 °C until transfer to the NI treatments.

African marigold and dahlia were transferred to NI treatments on 14 Feb. and chrysanthemum on 25 Feb. On transfer, 10 plants per treatment of each species were transplanted into 10-cm (430 mL) round plastic pots containing a commercial peat–perlite medium (Suremix; Michigan Grower Products, Galesburg, MI). All species were thinned to one plant per pot on the day of transplant. The experiment was repeated in the spring with the same treatments and greenhouse environment as previously described. Dahlia ‘Dahlinova Figaro Mix’ was replaced by dahlia ‘Carolina Burgundy’, which were propagated by stem cuttings harvested from plants received from C. Raker & Sons on 21 Apr. Chrysanthemums from the first replicate of the experiment were grown as stock plants under long days (LDs), and cuttings were subsequently harvested and rooted for the second replicate. Chrysanthemum and dahlia shoot-tip cuttings (two or three nodes) were rooted in 51-cell liner trays filled with 50% Sure-mix and 50% screened coarse perlite (Therm-O-Rock East, New Eagle, PA). Cuttings were rooted under LD in a propagation greenhouse as described by Lopez and Runkle (2008). For the second replicate, african marigold was received and placed in NI treatments on 26 May and chrysanthemum and dahlia were transferred on 7 July.
LED lamps and NI treatments.

Opaque black cloth enclosed all greenhouse benches from 1700 to 0800 hr, creating a 9-h SD. One bench was designated the SD control bench. Above the remaining benches, NI lighting was delivered from 2230 to 0230 hr by either 40-W INC lamps or customized LED fixtures containing three R and/or FR LED diodes per lamp developed by CCS Inc. (Kyoto, Japan). Lamps were paired to produce a total of six diodes and thus, seven R:FR ratios were created (Fig. 1). The R and FR LEDs had peak wavelengths of 660 nm and 735 nm, respectively, which correspond with peaks of phytochrome absorption (Sager et al., 1988). Because the photon flux from the R LEDs was approximately twice that from the FR LEDs, all R diodes were filtered with two layers of aluminum mesh.
Fig. 1.
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Fig. 1.

Light quality emitted from incandescent and light-emitting diodes (LEDs) between 600 and 800 nm. The number of red (R) and far-red (FR) diodes per lamp pair is indicated for each LED treatment. R to far-red FR ratios and estimated phytochrome photoequilibria (PFR/PR+FR) values (Sager et al., 1988) for the night interruption treatments are given in the inset table. R:FRwide equals 600 to 700: 700 to 800 nm; R:FRnarrow equals 655 to 665: 725 to 735 nm.

Light spectra under each treatment were measured by two portable spectroradiometers [LI-1800 (LI-COR, Lincoln, NE) and PS-200 (StellarNet, Tampa, FL)]. Spectral measurements were taken at regular intervals across the bench area of each treatment. Mean photon flux from 600 to 800 nm was 1.3 to 1.6 μmol·m−2·s−1 for all NI treatments, and plants were positioned on benches only where the photon flux was 0.7 μmol·m−2·s−1 or greater. The R:FR was measured and described using 100- or 10-nm-wide wavebands and the phytochrome photoequilibria (PFR/PR + FR) was calculated for each treatment following Sager et al. (1988) (Fig. 1).
Greenhouse environment.

The experiment was conducted in a glass-glazed, environmentally controlled greenhouse at a constant temperature set point of 20 °C. In late April, whitewash was applied externally to the greenhouse glazing to reduce light transmission by 30% to 40% and, thus, decrease radiant heating. All treatments received supplemental lighting from 0800 to 1600 hr provided by HPS lamps delivering a photosynthetic photon flux (PPF) of 60 to 90 μmol·m−2·s−1 at plant height. The HPS lamps were operated by an environmental control computer and were switched on when the ambient PPF outside the greenhouse was less than 185 μmol·m−2·s−1, and switched off when ambient PPF was greater than 370 μmol·m−2·s−1. Line quantum sensors (Apogee Instruments, Logan, UT) were positioned at plant height throughout the greenhouse. The sensors measured PPF every 10 s, and hourly averages were recorded by a data logger (CR10; Campbell Scientific, Logan, UT). The mean photosynthetic daily light integrals were 15.2 and 14.5 mol·m−2·d−1 for the first and second experiment replications, respectively.

Air temperature was measured on each greenhouse bench by an aspirated thermocouple [36-gauge (0.127-mm diameter) type E] every 10 s, and hourly averages were recorded by a data logger. The actual mean daily temperature was 19.9 and 21.9 °C for the first and second experiments, respectively. When the nighttime air temperature at bench level was less than 18.9 °C, a 1500-W electric heater, controlled by a data logger, provided supplemental heat during the night. Plants were irrigated as necessary with reverse-osmosis water supplemented with a water-soluble fertilizer providing (milligrams per liter) 125 nitrogen, 12 phosphorus, 100 potassium, 65 calcium, 12 magnesium, 1.0 iron and copper, 0.5 manganese and zinc, 0.3 boron, and 0.1 molybdenum (MSU RO Water Special; GreenCare Fertilizers, Chicago, IL).
Data collection and analysis.

Plant height (from media surface to shoot tip) was measured on the day of transplant, and nodes were counted on each plant. The date of first flowering was recorded; plants were considered flowering when at least 50% of the ray flowers of an inflorescence were reflexed. At flowering, the total number of inflorescences and plant height and number of nodes below the first flower (replicate 2 only) were recorded. Plants that did not have an open flower within 150% of average flowering time were considered non-flowering. Time from transplant to first flower as well as node number increase were calculated for each plant. Data were analyzed with SAS (Version 9.1; SAS Institute, Cary, NC) and data were pooled between replications if statistical interactions between main effects and replication were not significant (P ≥ 0.05). Regression analysis was performed with SAS to relate the data parameters to the estimated PFR/PR+FR of the plants in the NI treatments.
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Results

All chrysanthemum plants flowered under the FR-only NI treatment and under SDs in both replicates (Fig. 2A). Among the other treatments, flowering percentage generally decreased with increasing R:FR. For plants that did flower under an LED NI with a R:FRwide 0.66 or greater (PFR/PR+FR 0.63 or greater), flowering was delayed by 42 d compared with plants under SDs or FR-only NIs (Fig. 2B). Similarly, under the INC NI, flowering was delayed by 30 d compared with under SDs or FR-only NIs. Inflorescence number was greatest (163 or greater) under a moderate R:FRwide and ≈43 under the FR-only NIs or SDs [Fig. 2C (note that inflorescence number was divided by 10 in the figure)]. Extension growth of plants was greater in the second experimental replicate but trends were similar (Fig. 2D; Table 1). Height increased quadratically as the R:FR increased to a maximum at R:FRwide ≈0.66 (PFR/PR+FR 0.63 or greater). Plants grown under the FR-only NIs were 4.3 and 7.8 cm shorter than plants under INC NIs in replicates 1 and 2, respectively. Under SDs, extension growth was 8.2 cm less in replicate 1 and 14.9 cm less in replicate 2 compared with plants under the INC NIs.
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Table 1.

Parameters of regression analysis relating days to flower, inflorescence number, and increase in height to the estimated phytochrome photoequilibrium of plants in the night interruption lighting treatments.
Fig. 2.
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Fig. 2.

(A–L) Influence of the estimated PFR/PR+FR of night interruption lighting on flowering characteristics and extension growth of the short-day (SD) plants chrysanthemum ‘Adiva Purple’, dahlia ‘Figaro Mix’ (solid symbols; replicate 1), dahlia ‘Carolina Burgundy’ (open symbols; replicate 2), and african marigold ‘American Antigua Yellow’. Single open data symbols indicate pooled data. With the exception of flowering percentage, associated correlation coefficients (R2) are presented. Multiple plots indicate replicate 1 data (solid symbols) and replicate 2 data (open symbols) with associated R12 and R22 values, respectively. Dotted circle symbols indicate the incandescent control treatment. Square data symbols indicate the SD control treatment. Data for chrysanthemum inflorescence number has been divided by 10. ns, *, **, *** indicate nonsignificant or significant at P ≤ 0.05, 0.01, and 0.001, respectively. See Table 1 for regression equations. PFR/PR+FR = estimated phytochrome photoequilibria values (Sager et al., 1988).

Flowering of dahlia ‘Figaro Mix’ was incomplete under the FR-only NI and SD treatments (40% and 50%, respectively), which was surprising because dahlia is considered an SD plant (Fig. 2E). However, the ‘Figaro Mix’ plants that flowered under the FR-only NI and SD treatments did so slightly earlier than those under the other LD treatments: flowering was hastened by 11 and 19 d under FR-only NI and SD, respectively, compared with plants in R:FRwide treatments 0.28 or greater (PFR/PR+FR 0.46 or greater) (Fig. 2F). Inflorescence number was variable and statistically similar under all treatments (Fig. 2G). Extension growth exhibited a quadratic trend and was greatest under moderate R:FRwide treatments (Fig. 2H). Height increase of plants grown under FR NIs and SDs was 5.2 and 10.4 cm less, respectively, than that of plants grown under the INC NIs.

Flowering of dahlia ‘Carolina Burgundy’ was incomplete under FR-only NI and SD treatments, whereas nearly all plants flowered under the other treatments (Fig. 2E). Time to flower was similar under all NI treatments but 11 d earlier under SDs (Fig. 2F). Node number at flowering was variable and averaged from 13 to 18 in all treatments (data not shown). There was a small, positive correlation between inflorescence number and the R:FRwide of the NI (Fig. 2G). Extension growth of ‘Carolina Burgundy’ exhibited a quadratic trend and was greatest under intermediate LED R:FRwide values (Fig. 2H).

All african marigold plants flowered under all treatments (Fig. 2I), but plants in both replications flowered 10 to 20 d earlier under SDs or the FR-only NI treatment compared with the other treatments (Fig. 2J). Time to flower under the remaining LED treatments (R:FRwide 0.28 or greater) and under INC lamps was similar. However, plants under SDs or the FR-only NI treatment developed five or six nodes from transplant to flowering, whereas those under the other NI treatments developed 11 to 13 nodes (data not shown). There was a small negative correlation between inflorescence number and the R:FRwide of the NI in the second experimental replicate (Fig. 2K). Extension growth of plants grown under the FR-only NI treatment or under SDs was 3.9 to 5.8 cm less than that of plants under the other NI treatments (Fig. 2L).
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Discussion

In several classic photoperiod studies, flowering of cocklebur [Xanthium strumarium (Borthwick et al., 1952; Downs, 1956)], chrysanthemum (Cathey and Borthwick, 1957), and soybean [Glycine max (Downs, 1956)] could be inhibited by an R night break, which promotes formation of PFR and thus increases the PFR/PR+FR. A subsequent FR exposure, however, could reverse the flowering inhibition imposed by R light, showing that the inhibition of flowering in SDPs depends on R light and the resulting formation of the PFR form of phytochrome (Thomas and Vince-Prue, 1997). Although it is well established that R light is most effective at inhibiting flowering in SDPs, some plants are more sensitive than others (Cathey and Borthwick, 1957; Downs, 1956). In addition, these classic R:FR studies used broad-spectrum lamps with or without photoselective filters, which could have introduced confounding wavelengths such as blue light into these experiments.

Like in previous studies (Borthwick et al., 1952; Cathey and Borthwick, 1957; Downs, 1956), R light was as effective as INC for flower inhibition among the SDP species we studied. LED treatments with an R:FRwide of 0.66 or greater and the INC lamps (R:FRwide = 0.59) inhibited flowering the most. Therefore, LEDs with a moderate-to-high R:FR are a viable replacement for INC lamps to inhibit flowering of SDPs. In addition, because the LED treatments did not emit blue light, and flowering was similar to that under INC lamps (which emit a small amount of blue), blue light is apparently not needed to regulate flowering of these SDPs tested. A variety of crop characteristics (e.g., internode length, branching, and bud number) can be influenced using LEDs with different R:FR. However, in terms of flower inhibition and height control, the NI treatments that primarily emitted R light were most effective for the SDP species studied.

Short-day plants differ in their sensitivity to the R:FR and duration of NI lighting. Only 1 min of ≈11 μmol·m−2·s−1 light from an INC lamp during a long night was needed to inhibit flowering of cocklebur and soybean (Downs, 1956), whereas several hours of light at the same irradiance, for multiple cycles, was needed to inhibit flowering of chrysanthemum (Cathey and Borthwick, 1957). Chrysanthemum appears to be particularly sensitive to the light quality of the NI. Flowering can be inhibited by several hours of NI from a fluorescent (FL) or INC lamp or by 1 min of low-intensity FL light (Cathey and Borthwick, 1957). However, 1 min of high-intensity INC light was not sufficient to inhibit flowering. The R:FR of INC light is much lower than that of FL light. Therefore, a brief INC NI converts less phytochrome to the PFR form than would a brief FL NI. Theoretically, R light is most effective at inhibiting flowering of SDPs because the high R:FR of FL light is sufficient to convert enough phytochrome into the PFR form to inhibit flowering, even at low intensity and short duration.

In our study, we also observed variations in sensitivity to the light quality of the NI. In agreement with Cathey and Borthwick (1957), chrysanthemum was highly sensitive to the R:FR of the NI, at least compared with the other species tested. Flowering of chrysanthemum was inhibited more by NI treatments with higher R:FR compared with those with lower R:FR. Because chrysanthemum is an obligate SDP, one might expect a more dramatic response to the R:FR than in dahlia or african marigold (two facultative SDPs). Surprisingly, flowering percentage of chrysanthemum grown under the INC NI treatment was 100 in experimental replicate 1 and 0 in replicate 2. Plants in the first replicate were received from a commercial grower and some may have been exposed to inductive photoperiods before arrival; alternately, we may have had a burned out INC bulb that went unnoticed for a time sufficient to induce them. Within our populations of dahlia plants, sensitivity to NI light quality was variable. Flowering percentage was lowest under the FR-only NI and SD treatments. Among the remaining treatments, the effect on flowering time was similar regardless of the R:FR of the NI. Although these results were unexpected, a variety of photoperiodic responses have been observed in dahlia and our SD conditions may not have been optimal for the cultivars we used. When ‘Royal Dahlietta Yellow’ were grown under photoperiods ranging from 10 to 24 h, the optimal photoperiod for flowering was 12 to 14 h (Brøndum and Heins, 1993). Flowering percentage was reduced and flowers developed abnormally in two cultivars of dahlia grown under 8-h photoperiods compared with plants grown under a 4-h NI or 16-h photoperiod (Durso and De Hertogh, 1977). Some varieties require SD for flower induction but LD for optimal flower bud development (Legnani and Miller, 2001). African marigold exhibited a weakly facultative SD flowering response and was the least photoperiodic species in our study because all plants flowered in all treatments, and flowering was delayed similarly under all NI treatments with an R:FRwide 0.28 or greater.

Interestingly, flowering percentage and time to flower for each species were similar under SDs and the FR NI, indicating that the FR-only NI was largely ineffective and perceived as an SD. Because R light is most effective at inhibiting flowering of SDPs, we postulated that as the proportion of R light relative to FR light increased (as the R:FR increased), inhibition of flowering in SDPs would progressively increase. Indeed, the higher R:FR NI treatments were more effective and those without R light were relatively ineffective. Therefore, it appears that some threshold amount of R light (or some threshold R:FR value) is required for SDPs to perceive an NI. The threshold R:FRwide for delaying flowering was 0.66 or greater (PFR/PR+FR 0.63 or greater) for chrysanthemum and african marigold, but one was not identified for dahlia.

Regardless of photoperiodic classification, most plants exhibit some degree of shade-avoidance response. Natural daylight has an R:FR of ≈1.15, and when plants detect a reduced R:FR (resulting from mutual shading, canopy cover, photoselective filters, etc.), extension growth increases in an effort to better harvest photosynthetic light (Smith, 1982). Alternatively, stem extension can be inhibited by growing plants under an increased R:FR, especially in shade-avoiding plants. For example, chrysanthemum grown under an FR-absorbing photoselective filter (R:FR = 2.2) were 20% shorter than plants grown under a neutral filter (Li et al., 2000). Yamada et al. (2008) used FR FL lamps (R:FR = 0.01), INC lamps (R:FR = 0.65), and FL lamps (R:FR = 5.00) as NI treatments on lisianthus (Eustoma grandiflorum) ‘Niel Peach Neo’, an LD plant. Lamps with an R:FR of 0.01 and 0.65 increased internode length by 26% and 23%, respectively, compared with plants grown without an NI. In contrast, plants grown with FL NI had 14% shorter internodes than plants grown without an NI. Internode length of the LDPs petunia (Petunia ×hybrida) ‘Wave Purple Classic’ and black-eyed susan (Rudbeckia hirta) ‘Becky Cinnamon Bicolor’ was significantly shorter when a 4-h NI was provided by compact FL lamps (R:FR = 8.5) than by INC lamps (R:FR = 0.6) (Runkle et al., 2012).

In our study, plant height of chrysanthemum and dahlia ‘Figaro’ under an NI with a high proportion of R light (R:FRwide 2.38 or greater) was shorter than when grown under a moderate R:FRwide (0.66 and 1.07). Surprisingly, plants grown under the FR-only NI were generally shorter than plants in the other NI treatments. We anticipated that plants grown under the FR-only NI (R:FRwide = 0.05) would exhibit a shade-avoidance response and thus have greater stem elongation. However, because plants did not perceive an FR NI as an LD, flowering occurred earlier in development, so there was less time for stems to elongate before flowering. For example, marigold grown under an FR NI flowered with six fewer nodes than plants in the other NI treatments, so their overall height at first flowering was actually less.

Commercial growers have traditionally used INC lamps to provide photoperiod lighting because they are effective and inexpensive to install. However, INC lamps convert less than 10% of the energy consumed into visible light (Thimijan and Heins, 1983; Waide, 2010). With the phaseout of INC lamps, greenhouse growers will need other sources of light to control flowering of photoperiodic crops. As we have shown, LED technology provides an alternative to INC lamps for photoperiodic lighting. In addition to the improvements in lamp lifespan and energy efficiency, the narrow waveband nature of LEDs can be used to create lamps that are tailored to ornamental crop production needs. In SDPs, LEDs with a moderate to high R:FR are effective at preventing premature flowering and, thus, are a viable replacement for INC lamps.
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Notes

 

[Gazoo]

Thanks for posting that Article, Yes the last line sentence is a little disappointing but as you mentioned it may have
to do with the ratio's and finding the correct Ratio could be the Key.

Also thanks for explaining the emerson effect I Was not well informed on that so it much appreciated.

I have been told it takes a few hours for plants to wake up so it could be interesting to start with more Blue in the morning
to see it that helps increase yield.

 

[Icemud]

Actually, lol...

I can imagine a scenario in which, for whatever reason, the "darkness" of the dark period is sub-optimum. Say... more light getting in to the grow than the average illumination provided by the sunlight reflecting off the moon at night. Maybe enough to interfere somewhat with flowering. Is there any way that these kinds of wavelengths could offset this?

I don't mean a short period of (relatively) bright light - I mean dim (but still significant) light during the entire lights-off period. So it would not be a case of quickly firing up the "far red LED panel" for a short period of time and then hoping that the remainder of the "night" would then be sufficient. But maybe, IDK, leave such a product on all "night" long? Or does it not work like that.

I'm feeling dumber by the minute!

Great question and I don't actually know. I will have to look more into moonlight effects on plants. Im sure that somehow the moonlight may play a factor, but there also is a thing called the "light compensation point" and this is the amount of PPFD or photons that will start photosynthesis processes in a plant. Some plants that are "low light plants" like some mosses and forest floor plants have very very low light compensation points as they naturally developed to grow in shaded areas, where as plants like tomatoes, and cannabis have much higher light compensation points. I don't know exactly what PPFD that cannabis would start photosynthesis, but for the moonlight to influence it, it would have to meet or exceed that required PPFD. Now thinking about plant photomorphogeneis, light growth effects, this may be where the moonlight may play a role as these processes can be influence by very very little amounts of light. A lot is still unknown

 

[Icemud]

I am so happy right now! All my hard work at my job is paying off, and we are working to change california law. Our bill goes before the senate hearing tomorrow!!!!

In California, the use of any chemicals to extract cannabinoids is illegal, and hosts the same penalties as running a meth lab. This has lead to many residential explosions, burn victims and deaths due to an influx of black market butane extraction and open blasting. The current laws in California would not change the legality of extractions until 2018, so as a direct result of my research, my company, our lobbyists and partners, we have actively changed the content of legislation going to the senate committee tomorrow to allow for immediate licensing of regulated and approved extraction facilities. I couldn't be prouder of myself, my team/company (not mine but you know what I mean) and our partners and lobbyists!

I swear, I am smiling ear to ear right now, reading the bill text which is almost copied exactly from the research I did, and the narratives, summaries and outlines with facts I provided to our lobbyist team I'm changing the laws for millions of patients to have better meds, and for the producers of extracts to be able to emerge from the shadows and legally do what they love, in support of the community! I'm so proud!


(I reduced the content of the original post as I thought about it and I'm not sure how much information i can actually share about my companies involvement with this just yet... ) under a NDA

 

[Billyjack]

Outstanding Man, Well done!

 

[Icemud]

Outstanding Man, Well done!

Thank you!!! I feel proud It still has to pass, but with the overwhelming support and no opposition, plus some powerhouse organizations supporting it, we feel very confident California will vote in favor of legal and regulated extraction

 

[Icemud]

Hey Everyone!!!

Quick update time!!1

Well I am on cloud 9 today, with the announcement of our bill going to the senate committee for approval, that I helped right, and coming home from work with some new cannabis products to sample... Feeling great and oh yea, my seeds are drying too haha

Anyhow, we are still in veg with the current Emerson Far red grow, and as soon as my clones/cuttings root, then I will be flipping to flowering. I like to make sure they all have root incase I have to take more cuttings, I would rather take them from a veg state plant than one that is already transitioning to flowering so I don't mind waiting.

I noticed that over the last couple weeks, the plants started showing a MG deficiency along with what looks like a slight cal/mag deficiency so I got a nice soil/compost tea going with some added cal mag and epsom salts, bubbled it for 2 days, checked the ph and it was a solid 6.5ph, and fed the girls tonight, giving a good drench to help flush the soil with tea and good old bennies I do want to make sure the issue is corrected before I flip to flowering which I imagine it will be by the time my clones root, all they need is a little love

I'm really excited to get to testing the Far Red panel from Budmaster sorry that it took so long to respond to some of your questions regarding the use of far red, but last night i researched until my eyes were burning to gather some more info for all of us on this topic. There is still a lot to explore, and learn, but hopefully with this grow I can prove that either 14/10 with far red light will flower plants, or it wont... other than that, if it does work, i want to know if the extra 2 hours of light will really make a big difference on yield, trichome formation or any other traits. From the research I gathered, it looks like the use of Far Red light at night does increase internode length, so I am expecting quite a stretch as soon as I flip the lights, so I will have to do it soon or the plants will definitely get too tall, which I don't want

Other than that, not much else to report on today, but stay tuned as I will be testing out another Budmaster Product soon, which I will reveal as soon as they arrive

Here are today's photos

 

[Icemud]

I also just thought about it, and wanted to post... Since I plan on running a 14/10 schedule for flowering, this means with the extra 2 hours of daylight, the PPFD or PAR needs of the plant will actually be reduced as the DLI for cannabis is at optimal top range 65 mol/day. This means that for optimal lighting at peak PPFD:

24/0 schedule should have a PPFD of at most: 752 umol/m2/s-1
18/6 schedule should have a PPFD of at most: 1128.47 umol/m2/s-1
14/10 schedule should have a PPFD of at most: 1316.47 umol/m2/s-1
12/12 Schedule should have a PPFD of at most: 1504.62 umol/m2/s-1

and at minimum should have a DLI of around 30 or: (for optimal lighting)

24/0 schedule should have a PPFD of at minimum: 347 umol/m2/s-1
18/6 schedule should have a PPFD of at minimum: 520.83 umol/m2/s-1
14/10 schedule should have a PPFD of at minimum: 608 umol/m2/s-1
12/12 Schedule should have a PPFD of at minimum: 694 umol/m2/s-1


So my target PPFD will be between 608 and 1316 micromoles of photons/second.

 

[Kalimaki420]

great info and good job on that extraction

I see a lot of different options with far red.

Some say you should keep 12/12 the first 2 weeks and from 15min to 2hr after light out.

Hope you can clear up some of that in action.

 

[TorturedSoul]

Hey, I just remembered that some strains will flower under 13/11 or even (to an extent, a few strains) 14/10. Are you running a test group in which you use a 14/10 light/dark schedule but without the supplemental far red? I do not recall which strains (or more properly, which landrace strains and the "mixes" that have those genetics) they were - the old brain cells have flowed like waters through a broken dam .

I also - very, very vaguely - remember reading a decades-old study where it was determined that the cannabinoid content was higher with more uninterrupted light hours. <SCRATCHES HEAD> I don't remember whether or not they experimented with more than 13/11, though. But I am wondering if you are likely to harvest some extra-potent/useful cannabis this time, lol?

Before I took my "little" self-imposed vacation from the forum, there was a member who was attempting to experiment with longer light periods - but with regular dark periods. Seems like there might have been some difficulty with timer selection and setup, since most of them are based on a 24-hour day. I do not remember if his "day" was 28 hours, 32 hours, or what. And I don't know if he ever managed to complete the experiment.

Back when I didn't know any better, I thought I was supposed to gradually reduce the light hours... and I had several initiate flowering before I had gotten to 12/12. <SHRUGS> I have no idea whether they would have completed flowering had I held the schedule to what it was at that point (and do not, at this time, remember specifically what the schedule would have been at that point), but... a control group seems like a very good idea. EDIT: Not just to gauge the flowering behavior overall, but also to gauge the stretch during the first 40% of it - and it just occurred to me to wonder if those lights will change the length (err... in terms of time) of the stretch period... which would mess up my ratios for calculating harvest dates ahead of time .

 

[Graytail]

Heheh, Icemud ... have you ever wondered who actually writes legislation?

Sometimes legislators do, but usually it's a lobbyist organization who brings them prewritten language, which they then insert into a bill. Exactly like you just did.

Yer a special interest lobbyist now!



And @TS ... I learned last year about the trouble you have if you put out a flowering plant before the summer solstice. The plant also responds according to whether days are getting longer or shorter. At some point of daylight hours, simply getting shorter is enough to start bloom. And if they're blooming, longer days will make them stall, even if it's still 11/13.

 

[Icemud]

great info and good job on that extraction

I see a lot of different options with far red.

Some say you should keep 12/12 the first 2 weeks and from 15min to 2hr after light out.

Hope you can clear up some of that in action.

Thank you, it means a lot.

I never was an extraction guy, for the exact reasons mentioned about the dirty product and all, I never trusted it, and the people I knew doing it I know didn't have the right equipment to distill the butane first, remove contaminants and the mystery oil, and then purge it right to remove residuals. For me Dabs always were painful and not enjoyable as I didn't like the feeling like my lungs were going to explode in a ball of fire... lol, plus the lack of flavor turned me off. So the research on extraction I went deep on, because I wanted to know all I could to help better the community, the products and also to help my company too lol

So jumping into the research on this was very eye opening for me, and I learned a ton, and I never even knew about cuticle wax and winterization and the harm that cuticle wax can do to the lungs...if not removed. I never knew that even most people that say they use pharmaceutical grade or medical grade butane which isn't really a such a thing, dont know that even when it says 99.995% pure, there still is unknown oils and reside in the gas, and many times they are mixed with Iso-butane or propane, and even sometimes containing odor agents which in low concentration are not good. Then to see the amount of explosions, injuries, death and property damage happening, even in san diego area a hotel room near seaworld blew up because of open blasting so I really found a lot of stats that showed that backyard open blasting and bad practice is really becoming a rising statistic and the only way to stop this is to allow legal extraction professionals to do their thing and mass produce at the highest quality, reducing demand, price, cleaning up the product, and making less of a market for backyard blasters.

So not only am I helping to make for a better industry for us all, but also learned a ton about liquefied gas extraction too



With the Far red, there really isn't much knowledge of this at all, as its only been a few years really since Far Red LED's came onto the market which is allowing for tests and research to be done. And the issue is that most of the research is done on other plants than cannabis, so finding good reputable sources of information on this is hard, actually most lighting topics or research on cannabis is hard to find, but it is starting to become more available as laws lesson their grips, and LED tech emerges allowing for wavelength specific testing to take place. I just hope with this grow to determine if 14/10 with far red works, and if it does, does it really increase my yield for using 2 extra hours of light each day. In studies of other plants, the use of far red light did in fact create more flowers but I haven't found much mention of yields or much at all on far red and cannabis. I hope we all can learn, and those here at 420 magazine can all collectively dial this in

 

[Icemud]

Hey, I just remembered that some strains will flower under 13/11 or even (to an extent, a few strains) 14/10. Are you running a test group in which you use a 14/10 light/dark schedule but without the supplemental far red? I do not recall which strains (or more properly, which landrace strains and the "mixes" that have those genetics) they were - the old brain cells have flowed like waters through a broken dam .

I also - very, very vaguely - remember reading a decades-old study where it was determined that the cannabinoid content was higher with more uninterrupted light hours. <SCRATCHES HEAD> I don't remember whether or not they experimented with more than 13/11, though. But I am wondering if you are likely to harvest some extra-potent/useful cannabis this time, lol?

Before I took my "little" self-imposed vacation from the forum, there was a member who was attempting to experiment with longer light periods - but with regular dark periods. Seems like there might have been some difficulty with timer selection and setup, since most of them are based on a 24-hour day. I do not remember if his "day" was 28 hours, 32 hours, or what. And I don't know if he ever managed to complete the experiment.

Back when I didn't know any better, I thought I was supposed to gradually reduce the light hours... and I had several initiate flowering before I had gotten to 12/12. <SHRUGS> I have no idea whether they would have completed flowering had I held the schedule to what it was at that point (and do not, at this time, remember specifically what the schedule would have been at that point), but... a control group seems like a very good idea. EDIT: Not just to gauge the flowering behavior overall, but also to gauge the stretch during the first 40% of it - and it just occurred to me to wonder if those lights will change the length (err... in terms of time) of the stretch period... which would mess up my ratios for calculating harvest dates ahead of time .

Good points, but unfortunately I don't have a "control" group without Far red to see if they also flower in 14/10. Maybe I can start the plants at 14/10, let them run for 3 weeks and see what happens. Usually at that time they have a good flower set growing, so if I see the flowers set, then I know they flower at 14/10 without Far red. If none of them show any flowers after 3 weeks of 14/10, or very weak flowering I can then use the Far red with the 14/10 schedule to then see if they go full flowering or stay in a state of confusion? ??

I know that I have used 13/11 before for flowering, but then I found a study that was done of 13, 12 and 11 hour flowering daylengths, and it was determined that the 13 hour daylength did not provide enough extra yeild over 12 to to make sense economically for the extra hour of light used per day. The also determined that 11/13 also was not worth saving the extra hour of light, as the yield with 11/13 was dramatically reduced.

The same study also took note of the cannabinoids, and found that with a 13/11 schedule, there was a higher content of CBG-V, where as the 11/13 schedule had a higher level of THC-V. So the light length definitely played a role on the precursors of THC and other cannabinoids but I don't believe they tested total THC content either. I will try to dig it up.


I've seen a lot of "out of the box" light schedules and manipulation claims, but most of them don't have a conclusion, or the grow stops, or the user disappears so I don't really know if they work. Most of these light manipulation claims though are only on forums related to cannabis and I haven't ever found any support in the research community supporting the same claims so its hard to say... Who knows, they may be right... I mean we reprove things with time, I mean just a few years ago nobody thought plants really used green light and now its becomming generally accepted with science that they do.. so who knows.. there is much more to nature than I think the human brain can even conceive at this point in time


I'm not sure now that you mentioned about some strains flowering with longer daylight, as I have read that somewhere too. I'm not sure how I can conduct this trial to see if it works... should I run a 14/10 for a couple weeks and see, or just use the far red with a 14/10 to see if it works, and then go from there? hmmmm

 

[Icemud]

Heheh, Icemud ... have you ever wondered who actually writes legislation?

Sometimes legislators do, but usually it's a lobbyist organization who brings them prewritten language, which they then insert into a bill. Exactly like you just did.

Yer a special interest lobbyist now!



And @TS ... I learned last year about the trouble you have if you put out a flowering plant before the summer solstice. The plant also responds according to whether days are getting longer or shorter. At some point of daylight hours, simply getting shorter is enough to start bloom. And if they're blooming, longer days will make them stall, even if it's still 11/13.

LOL! that's funny as I never really even thought about it until you said that... and yea...your right... I'm a special interest lobbyist now...LMAO... geeze.. kill my buzz why dont you!! LOL honestly I'm so proud that I helped to put this into play, and really think that this may allow our industry to grow in a positive way Feels good to know little me can actually make a big difference, kind of inspiring

 

[Graytail]

LOL! that's funny as I never really even thought about it until you said that... and yea...your right... I'm a special interest lobbyist now...LMAO... geeze.. kill my buzz why dont you!! LOL honestly I'm so proud that I helped to put this into play, and really think that this may allow our industry to grow in a positive way Feels good to know little me can actually make a big difference, kind of inspiring

I think it's pretty cool, too!

I was a debater in high school and college, and we had to pore through a lot of this stuff sometimes - all the language and clauses and contradictions and exceptions ...

If it makes it through committee you can point to those words in State law and feel pretty fuggin smug about it, I'd say.

 

[Icemud]

I think it's pretty cool, too!

I was a debater in high school and college, and we had to pore through a lot of this stuff sometimes - all the language and clauses and contradictions and exceptions ...

If it makes it through committee you can point to those words in State law and feel pretty fuggin smug about it, I'd say.

Thats funny, I was a debater too, actually my personality type is ENTP which is "The debater" lol I was on a debate team in middle school and did fairly well, as well as had to do some debates in college. I love that kind of thing, taking an issue, researching it in and out and proving a point... as you may have noticed over my past journals lol


I definitely already feel the excitement and that warm feeling just seeing my research in the bill draft now, and if it passes to law... wow. that will feel so cool!

 

[CronicHempHog]

I never was a debater per say but
anyone who doesn't like being wrong always has to say something
especially if you know your right

 

[Mr. Krip]

I am so happy right now! All my hard work at my job is paying off, and we are working to change california law. Our bill goes before the senate hearing tomorrow!!!!

In California, the use of any chemicals to extract cannabinoids is illegal, and hosts the same penalties as running a meth lab. This has lead to many residential explosions, burn victims and deaths due to an influx of black market butane extraction and open blasting. The current laws in California would not change the legality of extractions until 2018, so as a direct result of my research, my company, our lobbyists and partners, we have actively changed the content of legislation going to the senate committee tomorrow to allow for immediate licensing of regulated and approved extraction facilities. I couldn't be prouder of myself, my team/company (not mine but you know what I mean) and our partners and lobbyists!

I swear, I am smiling ear to ear right now, reading the bill text which is almost copied exactly from the research I did, and the narratives, summaries and outlines with facts I provided to our lobbyist team I'm changing the laws for millions of patients to have better meds, and for the producers of extracts to be able to emerge from the shadows and legally do what they love, in support of the community! I'm so proud!


(I reduced the content of the original post as I thought about it and I'm not sure how much information i can actually share about my companies involvement with this just yet... ) under a NDA

Thank you!!! I feel proud It still has to pass, but with the overwhelming support and no opposition, plus some powerhouse organizations supporting it, we feel very confident California will vote in favor of legal and regulated extraction

That's awesome, Brother!