An Improved Leaf Disc Bioassay for Detecting <i>Calonectria pseudonaviculata</i> in Soil and Potting Media
Bibliographic record
Abstract
Boxwood blight caused by Calonectria pseudonaviculata results in severe defoliation and dieback to boxwood (Buxus spp.). The pathogen was first described in the United Kingdom and New Zealand in the mid to late 1990s and has since spread throughout Europe and most recently to the United States and Canada. While many Calonectria spp. have an epidemiologically significant soil phase, little is known of the role of the soil phase of C. pseudonaviculata in the epidemiology of boxwood blight. We optimized a leaf disc bioassay for detecting and quantifying this pathogen in soil and compared this bioassay with a standard soil plating assay originally developed for quantifying Calonectria using a Suffolk sandy-loam soil. Additionally, the sensitivity of both assays was compared among three distinct soil types (sand-loam, silt-loam, and sand-peat potting media). The optimal incubation time for baiting C. pseudonaviculata from soil using the leaf disc bioassay was 96 h. The optimal soil moisture for the bioassay was 1,000% of field capacity (flooded with 3 to 5 mm water). The leaf disc bioassay was able to detect C. pseudonaviculata at levels as low as 1 microsclerotium/ g soil while the soil plating bioassay was unable to detect the pathogen below inoculum levels of 10 microsclerotia/g soil in the Suffolk sandy-loam soil. Soil type had a significant impact on the sensitivity of both assays.
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.
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 | 0.000 | 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) | 0.000 | 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".