Stem Smut (<i>Ustilago hypodytes</i>) on Intermediate Wheatgrass in Canada
Bibliographic record
Abstract
Intermediate wheatgrass (Thinopyrum intermedium [Host] Barkworth & D.R. Dewey) (syn. Agropyron intermedium [Host] Beauv.) is becoming an important forage grass species in Alberta, Canada. Severe losses in seed yield due to stem smut (Ustilago hypodytes [Schlecht.] Fr.) were noted in a 70-acre field near Warner, AB, in 1999. The crop had been established in 1993 and harvested for seed each year. Smut symptoms (5% incidence) were noted initially in 1997. Incidence, determined by counting the number of symptomatic stems, increased to 10% in 1998 and 50% in 1999. The symptoms usually appeared in the first week of June. Brown sori developed on infected stems, especially between the uppermost node and the leaf below the flag leaf, and gradually became black during the period of seed filling, which is characteristic of stem smut (1). Teliospores were smooth, spherical to oval, light to dark brown, and 4.5 to 5.0 × 5.0 to 6.8 μm in dimension, which is also consistent with previous descriptions of U. hypodytes. Infected stems occasionally flowered, but did not set seed, so seed yield losses were proportional to disease incidence. Plants infected with stem smut were often stunted. Tissues in the smutty stem often became sunken and stems became twisted and thinner than normal due to the propagation of sori in the stem over time. Stem smut has been reported on crested wheatgrass and slender wheatgrass in other parts of Canada (2) and on T. intermedium in the United States (3). This is the first report of stem smut affecting commercial grass seed production in Alberta, Canada. This disease could also have a significant impact on the seed production of intermediate wheatgrass elsewhere. References: (1) G. W. Fischer. 1953. Manual of the North American Smut Fungi. Ronald Press, New York. (2) B. D. Gossen and D. Regnier. Can. Plant Dis. Surv. 71:88-89, 1991. (3) J. F. Karn and J. M. Krupinsky. Phytopathology 73:1152-1155, 1983.
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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 | 0.000 | 0.001 |
| Science and technology studies | 0.002 | 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) | 0.002 | 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".