Field evaluation of weather-based spray programs for the control of downy mildew of lettuce ( <i>Lactuca sativa</i> ), caused by <i>Bremia lactucae</i> , in Quebec and Ontario
Notice bibliographique
Résumé
Each year, downy mildew caused by Bremia lactucae occurs in lettuce-producing regions of Quebec and Ontario. Trials were conducted to determine if the disease could be managed with fewer fungicide applications, using disease forecasting. Disease-forecasting programs designed to time the application of fungicide sprays were evaluated for control of downy mildew of lettuce in 1997 and 1998 at 9 field sites. Disease forecasting was based on lesion development following a recorded sporulation-infection period (SIP), with leaf wetness between 3:00 AM and 10:00 AM and temperature between 5 and 20 °C. Presymptom sprays with the protectant fungicide mancozeb were applied before lesions were expected; they were based on 110 accumulated degree-days following a SIP, but not within 7 days of a previous spray. Post-latent-period sprays with the systemic fungicide metalaxyl-M in combination with mancozeb were applied after forecasted lesion development; they were based on 135 accumulated degree-days, but not within 14 days of a previous spray. The effects of forecasted sprays were compared with those of weekly applications of mancozeb and with those of metalaxyl-M or metalaxyl applied in furrow at the time of seeding or transplanting. Downy mildew developed at 7 of the 9 sites. The number of SIPs recorded at all sites ranged from 7 to 17. In 8 of the 9 sites, there were fewer mancozeb applications with the presymptom program than with the weekly sprays, that is a reduction of one, two, and three sprays at six, one, and one sites, respectively. This resulted in a 16%–60% reduction in applied fungicide. When metalaxyl-M plus mancozeb was applied according to the post-latent-period forecast, one or two sprays were required, that is a reduction of two, three, and four applications at four, three, and two sites, respectively, compared with the weekly application of mancozeb alone. Metalaxyl-M or metalaxyl applied in furrow provided control for 30–40 days after seeding or transplanting. The number of fungicide applications can be reduced with acceptable disease control if a forecasting program is followed.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,002 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».