Comparison of light emitting diode and high pressure sodium light for hydroponics growth of Boston lettuce
Bibliographic record
Abstract
Sustained developments in light emitting diode (LED) technology have brought their irradiance to a suitable level for being considered as a replacement to traditional high pressure sodium (HPS) lamps in hydroponics growth environments. LED lamps are anticipated to replace HPS lamps in most applications due to their reduced electricity consumption, improved quality of light and the possibility for customization of the light spectrum for increased yields. While equipment costs are still high, as is the case with most new technologies, greenhouse growers across the world stand to substantially decrease their energy use which directly translates into reduced costs and reduced carbon emissions from the energy stand point. We have compared the effects of LED lamps (LED Innovation Design, TI-SL600) made by LED Innovation Design (Terrebonne, Quebec) against HPS lamps (ballast: Philips Advance Model 71A85F5; Bulb: General electric, model LU600X0PSLT40) used at HydroSerre Mirabel (Mirabel, Quebec) for the growth of Boston lettuce (Lactuca sativa var. capitata) for both biomass yields and nutrient content. The light treatments were applied for eight hours after sunset to extend the photoperiod to sixteen hours. Wet and dry masses of plants and roots were weighed on a weekly basis during the course of the experiment. On average, optimum HPS light treatment produced statistically similar masses compared to optimum LED light treatment even though the LED lamps provided roughly half the amount of moles of light per meter2 compared to the HPS lamps at final harvest time (71.3moles/m2 for HPS and 35.8moles/m2 for LED over four weeks).There was no statistical difference between the samples taken from LED and HPS optimum light treatments, regular HPS greenhouse levels and control (no supplemental light) treatment for both wet and dry masses. However, LED light treatments showed improved homogeneity of plant mass across the entire area while HPS light treatment showed potential for elevated production in limited areas. Dry ratios of plant mass (in grams) by artificial irradiation (in moles per plant) normalized by the percentage of supplemental light versus total light were of 0.54 g/mol/plant and 0.35 g/mol/plant for both HPS experimental replications and of 0.59 g/mol/plant and 0.26 g/mol/plant for both LED experimental replications. This indicates that while there is an intensity difference between both light treatments, plant mass production remained similar. Health benefits are linked with increased consumption of β-carotene and other phytochemicals present in vegetables, such as lettuce. Photomorphogenesis may enable increased concentrations of those healthy compounds at little cost to the growers. However, contrary to expected results, chemical analysis of LED-treated samples showed the smallest concentrations of β-carotene, chlorophyll a and b, neoxanthin, lutein, antheraxanthin and violaxanthin. Both control replications are significantly more concentrated in xanthophylls and chlorophylls than the samples taken from the HPS plots, which were also more concentrated than the samples harvested from LED plots. Additional research needs to be performed to optimize the LED-based photomorphogenesis process.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".