Search results for "tournesol"
showing 6 items of 6 documents
Les paradoxes du glufosinate et glyphosate. Comportement dans l'ambroisie à feuilles d'armoise
2006
BEHAVIOUR OF GLUFOSINATE ANDGLYPHOSATE IN COMMONRAGWEED:APPARENT PARADOXAND SURPRISES We examined the foliar epidermis of commonragweed (Ambrosia artemisiifolia L.) plants and studied the behaviour of the herbicides glufosinate and glyphosate in this species. Both leaf surfaces exhibited 3 types of trichomes, according to their size and shape. Epicuticular waxes appeared amorphous, which may explain high levels of spray retention. Glufosinate and glyphosate were rapidly and almost completely taken up by common ragweed leaves; half maximum uptake was nearly reached after 5 and 3 h, respectively. The longest trichomes were stained with AgN03, indicating the presence of hydrophilic domains, wh…
Adventices du tournesol : la nuisibilité n'est pas linéaire
2018
Prod 2018-41 EA GESTAD INRA; Une étude a analysé la relation entre le rendement du tournesol et la densité d’adventices présentes sur des parcelles n’ayant subi aucun désherbage. La nuisibilité des adventices croît avec la densité des adventices, mais pas de façon proportionnelle. En particulier, la nuisibilité directe ne s’exprime pas à faible densité d’adventice.
La stérilité male cytoplasmique du tournesol (Helianthus annuus L.) : caractérisation des ADN chloroplastiques
1984
Notice présente dans BelInra (https://belinra.inra.fr/gestion/catalog.php?categ=isbd&id=83503); il s'agit d'un type de produit dont les métadonnées ne correspondent pas aux métadonnées attendues dans les autres types de produit : DISSERTATION; La stérilité male cytoplasmique du tournesol (Helianthus annuus L.) : caractérisation des ADN chloroplastiques
La nuisibilité directe des adventices en grandes cultures : quelles réponses nous apportent les essais désherbages ?
2016
The direct harmful effect of weeds in field crops : what do herbicide trials tell us ? Weeds are plants whose undesirable qualities (“harmfulness") outweigh their desirable qualities (trophic resources). Few studies conclude that weeds do not affect crop yield. However, it is difficult to generalize since weeds compete with crops for resources and these resources are spatially and temporally variable. This study analyzed 110 herbicide trials (untreated vs. treated plots) performed in France from 1993 to 2015 on three major grain crops: winter wheat, winter oilseed rape and sunflower. Significant yield losses were found in 92% of wheat trials (average over all trials: -2.6 t/ha), 51% of wint…
Analyse de risque phytosanitaire [i]Plasmopara halstedii[/i] agent responsable de la maladie du mildiou du tournesol
2014
Contribution des pollinisateurs dans la production de colza et de tournesol en zone atelier « Plaine et Val de Sèvre »
2018
Insect pollination is essential for over 70% of crops around the world. However, the contribution of pollinators to crop production and the insects involved in crop pollination have rarely been studied. Moreover, assessments of pollinator contributions have mostly been conducted on a small scale or under simplified conditions, which do not represent the real contributions at the field scale and do not take into account possible interactions between pollinators and farming practices. The aim of this study is to quantify directly under field conditions, the contribution of pollinators in two crops frequently cultivated in Europe: oilseed rape and sunflower. Estimations are realized both at th…