Petal Blight of Sunflower Caused by <i>Itersonilia perplexans</i>
Bibliographic record
Abstract
In February 1999, a cut-flower grower from Florida reported post-harvest losses of approximately 25% in Helianthus annuus (sunflower) cvs. Sunrich Orange and Sunbright. Symptoms began as small, pinpoint brown lesions on the petals, which enlarged and coalesced, leading to necrosis of the entire blossom. Symptomatic petals were surface disinfested for 30 sec with 0.5% NaOCl and suspended over plates containing acidified 25% potato-dextrose agar. Petals adhered to lids of the petri dishes by the surface tension of the water on the petals. Itersonilia perplexans Derx was consistently isolated. Inoculation of sunflower with I. perplexans was achieved using three detached, mature blossoms of the cv. Sundance Kid with their pedicels placed in sterile water. Each blossom was inoculated with 3.5 ml of a spore suspension (1 × 105 spores/ml) applied as a spray. Three noninoculated control blossoms were sprayed with sterile, distilled water. Blossoms were incubated in a controlled environment chamber at near 100% RH, a constant temperature of 18°C, and a 12-h photoperiod. Three days following inoculation all of the inoculated blossoms were symptomatic, with necrosis ranging from 50 to 100% on individual petals. I. perplexans was recovered from all of the inoculated blossoms. Noninoculated controls remained symptomless, and I. perplexans was not recovered. I. perplexans has been reported to cause lesions on the cotyledons, first true leaves, and the hypocotyl region of sunflower seedlings in Canada and Uruguay (1,2). However, this is the first report of post-harvest petal blight in sunflower caused by I. perplexans and the first report in the United States of infection of sunflower by I. perplexans. References: (1) W. E. Sackston. Can. Phytopath. Soc. 1952:22, 1953. (2) W. E. Sackston. Phytopathology. 48:108, 1958.
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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 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 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".