Vesicular-arbuscular mycorrhizae and apples (Malus domestica Borkh.) in the nursery and in apple replant desease
Bibliographic record
Abstract
The purpose of this study was to determine if different clonal rootstock from apple (Malus domestica Borkh.) formed different vesicular arbuscular mycorrhizal (VAM) associations. Different fertilizers and VAM fungi were tested to determine their effects on apple seedling growth in apple replant diseased (ARD) soils. VAM associations in apple stoolbed nursery were low. Over 80% of all samples had less than 10% mycorrhizal colonization. This reduction in VAM colonization amongst various rootstock clones is a result of detrimental management practices in the stoolbed nursery. Apples grown in a budded nursery had high mycorrhizal colonization, the lowest colonization rate was 30%. Different rootstocks from the budded nursery do not show any significant differences in VAM colonization, whereas clonal rootstocks from the stoolbed nursery do. From the stoolbed nursery, Mailing (M) 2 consistantly showed higher VAM colonization rates, compared to M 4, M7, M9, M 26, Mailing Merton (MM) 106, MM 111, Alnarp 2 and Ottawa 3. Apple replant disease (ARD) is identified as the reason for poor growth of apple seddlings in 5 soils from the Okanagan Valley of British Columbia. Sterilization by autoclaving, pasteurization and formalin increased test seedling height. Air-drying test soil does not affect ARD pot bioassays. However, air-drying the soil and pasteurizing or adding formalin increased plant height significantly more than these treatments in nonair-dried soils. The fertilizer monoammonium phosphate (11-55-0) increased plant height more than ammonium nitrate (34-0-0) while triple superphosphate (0-45-0) did not increase plant height. Root growth was increased by 0-45-0 only. VAM fungi were drastically reduced or eliminated by sterilization and 11-55-0, but not by the other fertilizers. VAM fungi in 2 ARD soils do not overcome ARD. Test seedlings grown in sterilized ARD soils inoculated with 4 species of VAM fungi do not show as great an increase in shoot height compared to the addition of 11-55-0 fertilizer. Root growth shows the inverse response. Glomus intraradices Schenck and Smith, was the best colonizer but inoculation with G. versiforme (Karsten) Berch resulted in the greatest shoot and root growth. Glomus clarum Nicholson and Schenck, and G. monosporum Gerdemann and Trappe, did not result in increases in plant growth in ARD soils. In sterilized ARD soils, VAM fungi do not increase shoot growth as expected, but do increase root growth, suggesting the initial growth of inoculated apple seedlings is root mass. Seedlings given 11-55-0 fertilizers show the reverse pattern of growth. In nonsterilized ARD soils, the growth of seedlings appears to be inversely proportional to VAM colonization.
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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) | 0.000 | 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 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".