Phénomène de résistance : des rouages encore méconnus

Dpmt SPEPôle GEAPSI; absent

Membres du comité d’organisation scientifique et logistique

National audience

Désherbage : changement climatique, quel avenir pour les mauvaises herbes ?

National audience; Le réchauffement climatique a un certain nombre d’effets sur le fonctionnement de l’agriculture. En matière de désherbage, des travaux sont en cours pour évaluer les risques d’évolution des espèces adventices. Les caractéristiques biologiques de certaines espèces les prédisposent à devenir des problèmes majeurs.

Le désherbage d’automne contre l’ergot du seigle les traitements herbicides d’automne, un levier chimique efficace de lutte contre l’ergot du seigle

Context and study: Trials in field allowed to show a link between a good grass weeding (blackgrass and rye grass) and extent of ergot contaminations. Makhteshim Agan France and Arvalis tested on 15 trials in 2011-2012, 2 ureas, as isoproturon against blackgrass, alone or in pro-gram with a sulfonylurea, to evaluate their indirect effect against ergot. Field trials were set up on sensitive crops to ergot (rye, wheat and triticale) infested with artificial ergot contaminations and weed seeds sensible to ALS. Contaminations were evaluated first in field on weeds and on crop, and then on harvest, by assessing sclerotia and alkaloids content in harvested samples. results: For all evaluation mean…

Membres du comité d’organisation scientifique et logistique

SPEEAGESTADAGROSUP; Membres du comité d’organisation scientifique et logistique. 23. Conférence du COLUMA - Journées Internationales sur la Lutte contre les Mauvaises Herbes

AFPP - 22nd COLUMA Conference - International Meeting on Weed Control

Characterisation of rye-grass (Lolium sp.) transcriptome-wide response to ALS-inhibiting herbicides

International audience; Non-target-site-resistance (NTSR) to herbicides is a major cause for failure in the chemical control of a number of weeds, and is especially widespread and important in grass weeds. Although several gene families have been shown to be involved in NTSR (cytochromes p450, glutathione-S-transferases, glycosyl-transferases, ABC transporters, esterases…), the genetic determinants of NTSR are still poorly known to date. NTSR is part of the response of weeds to herbicides. To unravel NTSR, it is thus of interest to firstly characterise the processes involved in herbicide stress response in grasses. For this purpose, we implemented a comparative whole-transcriptome sequencin…

Identification de gènes liés à la résistance aux herbicides non liée à la cible chez les Ivraies : vers des tests « moléculaires » de diagnostic

Identification of genes linked to non-target-site resistance to herbicides in ryegrass : towards "molecular" diagnosis assays. Setting up molecular diagnosis tools would greatly foster preventing and managing non-target-sitebased resistance to herbicides (NTSR). This is currently hampered by the complexity of NTSR genetic determinism, which is largely based upon differences in the expression of an unknown number of genes between resistant and sensitive plants. Identifying NTSR genes is thus a challenging task. Herein, we report the identification of 19 genes which expression patterns are correlated to NTSR to ALS-inhibiting herbicides in rye-grasses (Lolium sp.). We demonstrate the potentia…

La nuisibilité directe des adventices en grandes cultures : quelles réponses nous apportent les essais désherbages ?

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…