Optimising inoculum yield and shelf life of <i>Plectosphaerella cucumerina</i> , a potential bioherbicide for <i>Cirsium arvense</i>
Bibliographic record
Abstract
Plectosphaerella cucumerina was identified as a potential bioherbicide for controlling Cirsium arvense in Canada and New Zealand. The current study evaluated production conditions using two isolates (one from each country) to determine whether the yield and shelf life of inoculum are suitable for mass production. Mycelial growth and sporulation in culture both increased from 15°C to 25°C and declined at higher temperatures with no mycelial growth at 37°C. The Canadian isolate produced fewer conidia than a New Zealand isolate. Potato dextrose-based liquid media with moderate to high concentrations of carbohydrates (25%, 50%, and 100%) maximised conidia production and these base media produced conidia with the highest germination rate (>80%) both at harvest and after 4 weeks stored at 4°C in 2.5% glycerol, 40% milk glycerol or after air drying. However, after 10-week storage, the conidia failed to germinate. Sporulation occurred during growth on all solid substrates tested (rice, rolled barley, and triticale), but conidial germination was highest on rice and barley, both before and after air drying. By contrast to conidia, 90% of mycelia-infested barley grains were viable after 3 years of storage at room temperature, although viability was lost by this time on the other substrates. This study has shown that the nutritional base is an important determinant of sporulation and shelf life for P. cucumerina. Although the yield of conidia in liquid medium was adequate to justify further development of P. cucumerina as a bioherbicide, improvement in its shelf life, or alternate formulation types that extend the shelf life, must be made for commercial efficiency.
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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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 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".