Potted Gerbera Production in a Subirrigation System Using Low-concentration Nutrient Solutions
Bibliographic record
Abstract
To determine whether currently used commercial nutrient solution concentrations can be reduced during the final stage (last 4 to 5 weeks) of production of potted gerbera ( Gerbera jamesonii `Shogun') under recirculating subirrigation conditions, plants were grown under one of four nutrient levels (10%, 25%, 50%, and 100% of full strength). Nutrient concentration levels did not affect leaf area, flower number and appearance, and plant total dry weight. There were no significant differences in the greenness (as measured by SPAD meter) of leaves from plants that received the 50% and 100% strength nutrient solutions. However, leaves from plants that received the 10% and 25% strength solution showed significantly less greenness than that of the plants that received 50% and 100% strength nutrient solutions. There were interveinal chlorosis symptoms on the younger leaves of some plants in the 10% and 25% strength nutrient treatments. It is suspected that this interveinal chlorosis was due to iron (Fe) deficiency caused by the increased substrate pH. It is concluded that the nutrient solution concentrations typically used for potted gerbera production in commercial greenhouses at the final stage (4 to 5 weeks) under recirculating subirrigation conditions, can be safely reduced by at least 50% without adversely affecting crop production. Nutrient salts accumulated in the top section of the growth substrate under all treatments levels; however, no phytotoxic effects were observed. No differences in water use (141 mL per plant per day) were observed amid the various nutrient levels. Fertilizer inputs were reduced in the 50%, 25%, and 10% treatments by 54%, 75%, and 90% respectively, relative to the 100% treatment. After 4 weeks under recirculating conditions, the qualities of the nutrient solutions were still within acceptable limits.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".