Seeding rate, fertilizer level and disease management effects on hybrid versus open pollinated canola (<i>Brassica napus</i> L.)
Bibliographic record
Abstract
New canola cultivars have much higher yield potential than conventional canola cultivars and changes in production practices may be needed to achieve optimum yield from these cultivars. Studies were conducted to investigate the influence of seeding rates (2.8, 5.6 and 8.4 kg ha -1 ), fertilizer level (67% – low, 100% – medium, 133% – high of the commercial recommendation) and fungicide application on growth, dry matter accumulation, seed yield and seed quality using two high-yielding canola cultivars [cv. Quantum, open pollinated (OP), and cv. Invigor™, hybrid (HYB)]. The studies were conducted from 1999 to 2001 at three sites in the Parkland region of the Canadian prairies. The two cultivars did not differ in their responses to seeding and fertilizer rates, or fungicide application. Plant density was lower for the HYB than the OP because the HYB had larger seeds, with fewer seeds per kilogram. Emergence declined slightly at high fertilizer levels in some site-years due to fertilizer induced seedling damage, but increased with seeding rate. Time to onset of flowering and maturity showed no consistent influence of cultivar, and tended to be somewhat prolonged with an increase in fertilizer levels, but reduced by an increase in seeding rate. On average, the HYB produced 822 kg ha -1 more biomass and 200 kg ha -1 more seed yield than the OP. Sclerotinia stem rot incidence was very low, except at Melfort in 2000, and fungicide application generally failed to benefit the crop. Seed yield was generally increased when seeding rate was increased, with the largest increase occurring from 2.8 to 5.8 kg ha -1 . Seed yield responses to the high rates of seeding or fertilizer only occurred where both inputs were at the highest level, indicating that the optimum level of one was dependent upon the level of the other input. Oil and protein concentration in the seed was higher for the HYB than the OP. High fertilizer levels generally increased the total yield of biomass and seed, and protein concentration in the seed, but usually reduced oil concentration in the seed. Increased seeding rate resulted in a small increase in oil concentration and a small reduction in protein concentration in the seed. Net returns were greatest and least variable for the HYB cultivar. Overall, the HYB performed better than the OP, and the full economic value of high-yielding canola cultivars was only realized when fertilizer and seeding rates were at or above the current recommended rates. Key words: Canola (Brassica napus L.), fertilizer rate, fungicide, hybrid canola, oil content, open pollinated canola, protein content, seeding rate, seed quality, yield
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 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 | 0.000 | 0.000 |
| 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".