MétaCan
Menu
Back to cohort
Record W2094863758 · doi:10.1614/ws-d-12-00013.1

Early Physiological Mechanisms of Weed Competition

2012· article· en· W2094863758 on OpenAlexafffund
Maha Afifi, Clarence J. Swanton

Bibliographic record

VenueWeed Science · 2012
Typearticle
Languageen
FieldAgricultural and Biological Sciences
TopicWeed Control and Herbicide Applications
Canadian institutionsUniversity of Guelph
FundersNatural Sciences and Engineering Research Council of CanadaOntario Ministry of Agriculture, Food and Rural Affairs
KeywordsPhenylpropanoidWeedCompetition (biology)BiologySeedlingPhytochromePerennial plantAuxinBotanyAgronomyChemistryBiochemistryGeneBiosynthesisEcology

Abstract

fetched live from OpenAlex

Early physiological mechanisms that occur in crop plants in response to neighboring weeds are not well understood. In this experiment, it was hypothesized that, in the absence of direct competition for resources, low red to far red ratio (R:FR) reflected from neighboring weeds will modulate the phenylpropanoid pathway, increase hydrogen peroxide (H2O2), and up-regulate the expression of ethylene biosynthesis and auxin transport genes. Laboratory experiments were conducted under conditions of nonlimiting resources using perennial ryegrass as a model weed species. We discovered that the detection by phytochrome (Phy) of low R:FR signals reflected from both biological and nonbiological sources triggered an up-regulation of ethylene biosynthesis genes and stimulated an auxin transport gene. The low R:FR also modulated the phenylpropanoid pathway resulting in a reduction in anthocyanin content and an enhancement of lignin synthesis. The presence of neighboring weeds also caused an accumulation of H2O2in the first leaf and crown root tissues of the maize seedling. Stomata were observed to be closed as H2O2accumulated in leaf tissue. This is the first study to report the modulation of phenylpropanoid pathway and the accumulation of H2O2attributed to low R:FR. We further suggest that these physiological changes that occur in response to early weed competition result in a physiological cost to the crop plant, which contributes to the rapid loss in yield observed in weed competition studies conducted under field conditions.

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 machine prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.001
Threshold uncertainty score0.005

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0010.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0010.000

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.

Opus teacher head0.025
GPT teacher head0.230
Teacher spread0.206 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designObservational
Domainnot available
GenreEmpirical

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".

Quick stats

Citations64
Published2012
Admission routes2
Has abstractyes

Explore more

Same venueWeed ScienceSame topicWeed Control and Herbicide ApplicationsFrench-language works237,207