Sulfonylurea herbicide resistance in <i>Sonchus asper</i> biotypes in Alberta, Canada
Bibliographic record
Abstract
Summary Two Sonchus asper (spiny annual sow‐thistle) biotypes, suspected of being resistant to the sulfonylurea herbicide metsulfuron‐methyl, were collected in 1996 from two barley (Hordeum vulgare) fields in central Alberta, Canada. Both fields had received at least six applications of acetolactate synthase (ALS)‐inhibiting herbicide(s). The responses of the two resistant (R) biotypes and two susceptible (S) biotypes to several sulfonylurea herbicides, and to herbicides and herbicide mixtures with other mechanisms of action, were compared. Both R biotypes were highly resistant to all sulfonylurea herbicides, but their control with other herbicides and mixtures was effective and comparable to that of the S biotypes. ALS extracted from an R biotype was about 440 times more resistant to metsulfuron‐methyl than that of an S biotype, indicating that resistance was conferred by an ALS enzyme that was less sensitive to inhibition by the herbicide. Competitiveness and seed production of S. asper varied among biotypes, but the differences were probably the result of ecotype differences rather than resistance or susceptibility to sulfonylurea herbicides. This is the first reported occurrence of target site‐based S. asper resistance to ALS‐inhibiting herbicides.
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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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| 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".