First Report of Powdery Mildew of Greenhouse Pepper Caused by <i>Leveillula taurica</i> in British Columbia, Canada
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
In 2003, powdery mildew of greenhouse pepper (Capsicum annuum L.) was reported simultaneously in two commercial greenhouses at two separate locations near Langley in southern British Columbia. Trace amounts of mildew on the foliage of cv. Zamboni in one operation, and 10 to 80% of the foliage of cv. Triple Four was affected in an organic operation, with losses in fruit yield of 2 to 4 kg/m 2 , were noted. The greenhouse pepper industry in British Columbia in 2001 comprised 76 ha with sales of $41.3 million (Canadian). Affected areas appeared as a white, powdery coating on the abaxial leaf surface of older foliage while diffuse chlorotic spots were present at corresponding locations on the adaxial surface. In some cases, pale yellow spots appeared on the adaxial portion of the affected foliage during later stages of disease development (2). Hyaline, single-celled pyriform and cylindrical conidia were present in 40:60 proportion, respectively. Both conidia had a network of crests and granules sometimes with tiny thorn-like projections on the surface. These projections were evident also on the lower half of conidiophores. Pyriform conidia ranged in length from 53.8 to 79.5 μm (mean = 68.0, SE = 0.8), and in width from 12.9 to 28.0 μm (mean = 20.1, SE = 0.6, n = 50) with a mean length to width ratio of 3.5. Cylindrical conidia had a length from 48.2 to 84.0 μm (mean = 66.0, SE = 0.9), and in width from 13.4 to 25.2 μm (mean = 18.6, SE = 0.4, n = 50) with a mean length to width ratio of 3.6. Short conidial chains borne on conidiophores consisted of a basal pyriform conidium followed by cylindrical conidium. No cleistothecia were observed. Stomatal penetration and extensive endophytic mycelial growth in the mesophyll layer were evident in foliar tissue cleared with glacial acetic acid/EtOH (1:2) and stained with lactophenol cotton blue. To confirm pathogenicity, a suspension of 2 × 10 4 conidia/ml from infected pepper leaves was applied onto the abaxial and adaxial leaf surfaces of 60-, 42-, and 28-day-old greenhouse pepper cv. Cubico, tomato cv. Trust, and cucumber cv. Corona, respectively. Plants were maintained in a growth chamber at 25/21°C day/night temperature and 80% relative humidity. Control plants in the same chamber were treated identically but not inoculated. After 21 days, inoculated pepper plants developed foliar powdery mildew symptoms on the abaxial surface, including sporulation similar to that of naturally infected plants. Occurrence of the fungus on the abaxial surface of pepper foliage, presence of endophytic mycelium, and the morphological characteristics of the imperfect state confirm the identity of the fungus (2). To our knowledge, this is the first report of Leveillula taurica (Lév.) G. Arnaud on pepper in British Columbia. The disease was first reported in Ontario, Canada in 1999 (1). References: (1) R. Cerkauskas et al. Plant Dis. 83:781,1999. (2) J. Palti. Bot. Rev. 54:423, 1988.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.000 | 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 it