Dictionnaire en plus de cent langues et plus d’un milliard d’exemples de traductions

Langues sources	Langues cibles

Keybot 197 Résultats www5.agr.gc.ca Page 4

Projets de mise en oeuv...

Montrer texte Montrer source en cache Montrer URL avec texte source	Détermination des doses minimales biologiquement efficaces d'herbicides pour le désherbage dans la rotation maïs-soya
Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire	Determining the minimum biologically effective dose of herbicides for weed control in corn-soybean rotations

Toxicity of spinosad an...

Montrer texte Montrer source en cache Montrer URL avec texte source

Le principal objectif de cette étude était d’évaluer la sensibilité du vers-gris noir (Agrotis ipsilon) au biopesticide spinosad et à une préparation commerciale (souche GHA) du champignon entomopathogène Beauveria bassiana. Nous avons également quantifié les effets de doses sublétales de spinosad sur certains paramètres de valeur adaptative chez l’A.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

The main objective of this study was to assess the susceptibility of the black cutworm (Agrotis ipsilon) to the biopesticide spinosad and to a commercial formulation (GHA strain) of the entomopathogenic fungus, Beauveria bassiana. Secondly, we quantified the effects of sublethal doses of spinosad on a number of A. ipsilon fitness parameters, and interactions resulting from simultaneous applications of sub-lethal doses of spinosad and B. bassiana. Under laboratory conditions, A. ipsilon third instar larvae were highly susceptible to spinosad, with an estimated LC50 of 50 ppm. The entomopathogenic fungus, B. bassiana had a lower efficacy with an estimated LC50 of 7 107 spores mL-1. Topical applications of 5, 7.5 and 10 ppm of spinosad on third instar larvae reduced larval size and increased time to pupation and to emergence. However, pupal and adult weights were not significantly different between treated and control individuals. Additivity was observed from most spinosad-B. bassiana combinations tested, thus indicating compatibility between products. We concluded that spinosad is a promising tool for controlling black cutworm larvae alone or in combination with other products.

Toxicity of spinosad an...

Montrer texte Montrer source en cache Montrer URL avec texte source

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Categorization and nume...

Montrer texte Montrer source en cache Montrer URL avec texte source

Nous analysons l’effet de l’insecticide pyréthroïde bifenthrine incorporé au sol à raison de 100, 200 et 300 g m.a./ha sur les larves du dernier stade du taupin obscur (Agriotes obscurus) (Coleoptera: Elateridae), et nous présentons une méthode permettant d’évaluer l’état de santé et la mobilité des larves en fonction du temps. Les larves de taupin sont devenues moribondes dans l’heure qui a suivi leur transfert dans du sol amendé avec de la bifenthrine à l’une ou l’autre des trois doses susmentionnées.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

We discuss the effect of the pyrethroid insecticide bifenthrin incorporated into soil at 100, 200, and 300 g AI/ha on late-instar larvae of the dusky wireworm, Agriotes obscurus (Coleoptera: Elateridae), and present a method of assessing wireworm health and mobility over time. Wireworms became moribund within 1 h of placement in soil amended with bifenthrin at all rates. After 2 weeks of morbidity in amended soils, wireworms recovered within 7 days of being placed in clean soil. A considerable proportion (0.13–0.93) of wireworms placed in amended soil moved to the soil surface and remained there for 2 weeks or more in a moribund state; wireworms transferred to clean soil no longer moved to the soil surface. Eight distinct mobility categories were observed and are described, and a new method for assessing wireworm health and mobility over time is discussed.

Évaluation de l'efficac...

Montrer texte Montrer source en cache Montrer URL avec texte source

Le Diméthenamide-P, fut efficace contre plusieurs mauvaises herbes à feuilles larges. Cet herbicide, appliqué à des doses de 0,5X, 1X ou 2X n'a causé aucun dommage aux cultures et n'a causé aucune réduction importante de rendement des racines la saison suivante.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Only one of the seven reduced-risk herbicides tested did not cause serious injury to the ginseng plants, namely Outlook (dimethenamid-P). Dimethenamid-P was effective against several broadleaf weeds. This herbicide, applied at rates of 0.5X, 1X or 2X, caused no crop injury and did not result in any major reduction in root yield the following season. Outlook must be applied prior to weed emergence, directly in the weed germination zone.

Essai de contrôle des h...

Montrer texte Montrer source en cache Montrer URL avec texte source

Le plan expérimental utilisé fut un bloc aléatoire complet, comportant 4 répétitions et utilisant des parcelles de 2.25m × 8m. Les sept herbicides évalués ont été utilisés à 3 doses différentes, soient 0.5×, 1× et 2×.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Field trials were conducted in 2007 at the Simcoe Research Station of the University of Guelph, in Ontario. The experimental design was a randomized complete block design with four replications. Plots were 2.25 m by 8 m. The seven herbicides evaluated were applied at three rates: 0.5×, 1× and 2×. The herbicide treatments were either pre-emergence or post-emergence to the weeds. Data were collected on injury to peas and efficacy in controlling broadleaf weeds.

Mise au point et impact...

Montrer texte Montrer source en cache Montrer URL avec texte source	Les études de terrain ont été menées de 2004 à 2007 sur deux champs en rotation maïs-soja à Beaumont et à St-Jean-sur-Richelieu au Québec. Des sections de champs ont été traitées en post-levée soit avec des doses d'herbicide variables, soit avec une pleine dose constante.
Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire	Field studies were conducted from 2004 to 2007 on two corn and soybean crop rotations in Beaumont and St-Jean-sur-Richelieu, Quebec. Sections of fields were treated with varying in-crop herbicides, with a full constant dose. Variable doses (no herbicide, half or full doses) were based on the calculated RC value.

Mise au point et impact...

Montrer texte Montrer source en cache Montrer URL avec texte source	Les études de terrain ont été menées de 2004 à 2007 sur deux champs en rotation maïs-soja à Beaumont et à St-Jean-sur-Richelieu au Québec. Des sections de champs ont été traitées en post-levée soit avec des doses d'herbicide variables, soit avec une pleine dose constante.
Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire	Field studies were conducted from 2004 to 2007 on two corn and soybean crop rotations in Beaumont and St-Jean-sur-Richelieu, Quebec. Sections of fields were treated with varying in-crop herbicides, with a full constant dose. Variable doses (no herbicide, half or full doses) were based on the calculated RC value.

Nurse, Robert E., Ph.D....

Montrer texte Montrer source en cache Montrer URL avec texte source	Soltani, N., Nurse, R.E., Van Eerd, L.L., Vyn, R.J., Shropshire, C., et Sikkema, P.H. (2010). « Weed control, environmental impact and profitability with trifluralin plus reduced doses of imazethapyr in dry bean. », Crop Protection, 29(4), p.
Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire	Soltani, N., Nurse, R.E., Van Eerd, L.L., Vyn, R.J., Shropshire, C., and Sikkema, P.H. (2010). "Weed control, environmental impact and profitability with trifluralin plus reduced doses of imazethapyr in dry bean.", Crop Protection, 29(4), pp. 364-368. doi : 10.1016/j.cropro.2009.07.011

Weed control, environme...

Montrer texte Montrer source en cache Montrer URL avec texte source	Soltani, N., Nurse, R.E., Van Eerd, L.L., Vyn, R.J., Shropshire, C., et Sikkema, P.H. (2010). « Weed control, environmental impact and profitability with trifluralin plus reduced doses of imazethapyr in dry bean. », Crop Protection, 29(4), p.
Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire	Soltani, N., Nurse, R.E., Van Eerd, L.L., Vyn, R.J., Shropshire, C., and Sikkema, P.H. (2010). "Weed control, environmental impact and profitability with trifluralin plus reduced doses of imazethapyr in dry bean.", Crop Protection, 29(4), pp. 364-368. doi : 10.1016/j.cropro.2009.07.011 Access to full text

Évaluation de l'efficac...

Montrer texte Montrer source en cache Montrer URL avec texte source	Les sept herbicides évalués ont été utilisés à 3 doses différentes, soient 0.5X, 1X et 2X. L'efficacité des herbicides fut évaluée en recueillant des données sur les dommages causés aux plants de ginseng (été 2006) et sur le rendement de leurs racines (au printemps 2007).
Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire	The seven herbicides evaluated were applied at three rates: 0.5X, 1X and 2X. Herbicide efficacy was evaluated by collecting data on injury caused to the ginseng plants (summer 2006) and on root yield (spring of 2007).

Bélair, Guy, M.Sc. - Ag...

Montrer texte Montrer source en cache Montrer URL avec texte source	, Bélair, G., Simard, L., et Brodeur, J. (2009). « Toxicity of spinosad and Beauveria bassiana to the black cutworm, and the additivity of subletal doses. », Biocontrol Science and Technology, 19(2), p.
Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire	Gosselin, M.-E., Bélair, G., Simard, L., and Brodeur, J. (2009). "Toxicity of spinosad and Beauveria bassiana to the black cutworm, and the additivity of subletal doses.", Biocontrol Science and Technology, 19(2), pp. 201-217. doi : 10.1080/09583150802663285

Mise au point et impact...

Montrer texte Montrer source en cache Montrer URL avec texte source	Effectuer une analyse spatiale des mauvaises herbes présentes dans les champs de maïs et des champs de soja traités avec différents herbicides et diverses doses; valider les stratégies de gestion des mauvaises herbes au moyen de traitements herbicides localisés et de doses réduite
Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire	To conduct a spatial analysis of weed coverage in corn and soybean fields treated with various herbicides and rates and validate weed management strategies using localized and reduced rate herbicide applications

Mise au point et impact...

Montrer texte Montrer source en cache Montrer URL avec texte source	Effectuer une analyse spatiale des mauvaises herbes présentes dans les champs de maïs et des champs de soja traités avec différents herbicides et diverses doses; valider les stratégies de gestion des mauvaises herbes au moyen de traitements herbicides localisés et de doses réduite
Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire	To conduct a spatial analysis of weed coverage in corn and soybean fields treated with various herbicides and rates and validate weed management strategies using localized and reduced rate herbicide applications

Toxicity of spinosad an...

Montrer texte Montrer source en cache Montrer URL avec texte source	, Bélair, G., Simard, L., et Brodeur, J. (2009). « Toxicity of spinosad and Beauveria bassiana to the black cutworm, and the additivity of subletal doses. », Biocontrol Science and Technology, 19(2), p.
Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire	Gosselin, M.-E., Bélair, G., Simard, L., and Brodeur, J. (2009). "Toxicity of spinosad and Beauveria bassiana to the black cutworm, and the additivity of subletal doses.", Biocontrol Science and Technology, 19(2), pp. 201-217. doi : 10.1080/09583150802663285 Access to full text

Benchaar, Chaouki, Ph.D...

Montrer texte Montrer source en cache Montrer URL avec texte source	Ingestion, fermentation ruminale, résultats de croissance et caractéristiques de carcasse des agneaux recevant différentes doses de cinnamaldéhyde
Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire	Intake, ruminal fermentation, growth performance, and carcass characteristics in lambs fed different doses of cinnamaldehyde

The effect of MSW compo...

Montrer texte Montrer source en cache Montrer URL avec texte source

Trois doses de compost (DMS1, DMS2 et DMS3), une d’engrais chimique (NPK) et un mélange de deux parts égales de DMS1 et d’engrais NPK (MÉLANGE) ont été appliqués chaque année aux parcelles d’un système de rotation de trois cultures.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Municipal solid waste (MSW) compost is an ‘organic’ amendment and can influence nutrient mineralization and subsequent plant growth. A three-year field experiment evaluated the effects of MSW compost and fertilizer on soil fertility and elemental analysis of squash (Cucurbita maxima cv. Buttercup) grown in a Pugwash sandy loam soil in Nova Scotia, Canada. Three rates of compost (MSW1, MSW2, and MSW3), one rate of chemical fertilizer (NPK), and one mixture of 1/2 MSW1 compost and 1/2 NPK fertilizer (MIXTURE) were applied each year to plots in a three crop rotation. The experimental design was a randomized complete block (RCB) design with four replications. The NPK treatment produced the highest yields in 1996 and numerically the highest yields in 1997 and 1998. In the last year of the study, significant differences were found between soil fertility treatments for K, S, Cu, Zn, B, and Na in Mehlich 3 extracts at the 0-15 cm soil depth; however, only leaf Mn, Cd, and Cr were found to be influenced by the treatments. In two of the three years, the highest rates of MSW compost produced the highest levels of leaf S, Cu, and Zn. The study found that MSW compost was a good source of nutrients, however, the relatively low availability of mineralizable nutrients means that high rates of compost and/or supplementary N-P-K in the form of inorganic fertilizer may have to be added in order to enhance nutrient availability to winter squash.

Identification of diffe...

Montrer texte Montrer source en cache Montrer URL avec texte source

Bien qu’ils fournissent des données précieuses, les modèles in vitro du développement des adipocytes nécessitent souvent l’emploi de fortes doses d’hormones et de facteurs de croissance, ce qui peut influer sur l’expression des gènes et le processus de différenciation adipocytaire.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Although they provide valuable information, in vitro models of adipocyte development often require high doses of hormones and growth factors, which may influence gene expression and adipocyte differentiation patterns. To overcome these problems, a novel in vivo model of adipose tissue development was used to characterize genes involved in adipogenesis. The suppression subtractive hybridization technique was used to identify genes showing differential expression between the adipose tissue of a day 90 gestating sow, which is enriched in adipocytes, and day 90 fetal adipose tissue, which is enriched in preadipocytes. A total of 149 expressed sequence tags corresponding to identified genes and tentative consensus sequences emerged. Thirty-seven clones matched expressed sequence tags or genomic DNA sequences and six novel sequences were also identified. Adipogenesis-related genes were identified, many of which have never been reported to be expressed in mammalian adipose tissue, and may play a role in regulation of adipose tissue differentiation. Validation of differentially expressed genes was confirmed for perilipin, monocyte to macrophage differentiation-associated, myocilin, paraoxonase 3, stearoyl-CoA desaturase, angiotensinogen and adiponectin genes using real-time RT-PCR.

Oat β-glucan supplement...

Montrer texte Montrer source en cache Montrer URL avec texte source

Les β-glucanes d’avoine, des fibres solubles, ont un effet sur les hormones régulant l’appétit et la satiété subjective dans des études examinant les effets d’un régime à court terme, mais ces effets n’ont pas été démontrés à long terme. La présente étude vise à évaluer les effets de deux doses différentes de β-glucanes d’avoine sur la perte de poids et les hormones associées avec la régulation de l’appétit chez la femme.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Epidemiological evidence shows an inverse relationship between dietary fibre intake and body weight gain. Oat β-glucan, a soluble fibre alters appetite hormones and subjective satiety in acute meal test studies, but its effects have not been demonstrated with chronic consumption. The present study aimed to test the effects in women of two different doses of oat β-glucan on weight loss and hormones associated with appetite regulation. In a 3-month parallel trial, sixty-six overweight females were randomised into one of three 2 MJ energy-deficit diets: a control and two interventions including 5-6 g or 8-9 g β-glucan. Anthropometric and metabolic variables (blood glucose level, insulin, total cholesterol (TC), LDL, HDL, TAG and leptin), together with markers of appetite regulation (cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1), ghrelin, peptide YY (PYY) and PYY3-36) were measured at baseline and at 3 months. After 3 months, all groups lost weight (P < 0·001) and showed a reduced waist circumference (P < 0·001). The study sample also showed reductions in TC, LDL, HDL, leptin, PYY, GLP-1 values (all P < 0·001) and an increase in CCK levels (P < 0·001). No significant differences were noted between the groups for all outcome values except PYY levels (P = 0·018). In broad terms, the addition of oat β-glucan did not enhance the effect of energy restriction on weight loss in mildly overweight women, although wide variations in observed results suggests that individual responsiveness may be an issue.

Weed control, environme...

Montrer texte Montrer source en cache Montrer URL avec texte source

Nous avons réalisé des expériences au champ en 2003, 2006 et 2007, en Ontario, afin de déterminer si l’utilisation de doses réduites d’imazéthapyr avec la trifluraline en traitement de présemis avec incorporation (PPI) pouvait constituer une option rentable et écologiquement acceptable pour la suppression des mauvaises herbes dans les cultures de haricot blanc et de haricot rouge.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Field experiments were conducted in 2003, 2006, and 2007 in Ontario to determine if reduced doses of imazethapyr combined with trifluralin applied pre-plant incorporated (PPI) can be used as an economically and environmentally feasible weed management strategy for broad spectrum weed control in white and kidney bean. There was minimal injury (<5%) in white or kidney bean from imazethapyr applied alone or in combination with trifluralin, regardless of dose. The dose of imazethapyr required for 80 and 95% control of Setaria viridis (L.) Beauv. (green foxtail), Chenopodium album L. (common lambsquarters) and Ambrosia artemisiifolia L. (common ragweed) was reduced when combined with trifluralin (600 g ai ha-1). There was a trend for increased yield of white and kidney bean with increasing doses of imazethapyr applied alone and in combination with trifluralin. Combining trifluralin with imazethapyr increased the environmental impact (EI) by more than ten-fold compared to imazethapyr alone. The lowest dose of imazethapyr used in this study resulted in the lowest environmental risk. The doses of imazethapyr that maximized profit were 38 g ai ha-1 for white bean and 47 g ai ha-1 for kidney bean. Combining imazethapyr with trifluralin will provide growers with a weed management strategy that provides acceptable weed control, with only a small increase in environmental impact, and has the potential to increase yields and net returns.

Fertilizer Source Influ...

Montrer texte Montrer source en cache Montrer URL avec texte source

On a procédé à une expérience sur le terrain au cours de trois saisons de croissance (de 2004 à 2006) sur un sol argileux (fin, mélangé, à régime de température frigide, Humaquept typique) sur du maïs (Zea mays L.) afin d’évaluer l’impact des sources et des doses d’application d’engrais azoté sur les émissions de N2O.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Synthetic N fertilizers are a major source of emissions from soil. A field experiment was conducted during three growing seasons (2004–2006) on a clay soil (fine, mixed, frigid Typic Humaquept) under corn (Zea mays L.) to evaluate the impact of N fertilizer source and application rate on N2O emissions. Treatments consisted of three sources of N fertilizer (urea–NH4NO3 32% [UAN], Ca–NH4NO3 [CAN], and aqua NH3 [AA]) at four different rates (0, 100, 150, and 200 kg N ha-1). Fertilizers were banded 5 cm below the soil surface between corn rows at the six-leaf stage and N2O emissions were measured weekly. For all 3 yr of this study, cumulative N2O emission decreased in the order UAN ≥ CAN ≥ AA. Averaged across years, fertilizer-induced post-sidedress emissions were greater than the Intergovernmental Panel on Climate Change default factor (0.01 kg N2O -N kg-1 N), with values of 0.038, 0.033, and 0.027 kg N2O -N kg-1 N for UAN, CAN, and AA, respectively. The N2O emissions increased linearly with N rate, even at rates exceeding the optimum level for grain yield. Peaks of N2O flux occurred on the days following fertilizer application and in early fall when the soil was re-wetted. Emissions of N2O were higher at water-filled pore space >0.57 m3 m-3 and were also related to soil inorganic N and water-extractable organic C contents. Our results confirm that N fertilizer source and application rate can impact N2O emissions but these effects are modulated by soil environmental conditions.

Development and validat...

Montrer texte Montrer source en cache Montrer URL avec texte source

Nous avons déterminé les principales propriétés du sol et des plantes à partir d’expériences dans lesquelles nous avons utilisé des doses comprises entre 0 et 250 kg N ha-1 appliquées au cours de trois saisons (2005, 2006 et 2007) sur des champs présentant différentes valeurs de conductivité électrique apparente (CEa), d’élévation (ELE) et de pente (PTE).

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

A fuzzy inference system (FIS) was developed to generate recommendations for spatially variable applications of N fertilizer. Key soil and plant properties were identified based on experiments with rates ranging from 0 to 250 kg N ha-1 conducted over three seasons (2005, 2006 and 2007) on fields with contrasting apparent soil electrical conductivity (ECa), elevation (ELE) and slope (SLP) features. Mid-season growth was assessed from remotely sensed imagery at 1-m2 resolution. Optimization of N rate by the FIS was defined against maximum corn growth in the weeks following in-season N application. The best mid-season growth was in areas of low ECa, high ELE and low SLP. Under favourable soil conditions, maximum mid-season growth was obtained with low in-season N. Responses to N fertilizer application were better where soil conditions were naturally unfavourable to growth. The N sufficiency index (NSI) was used to judge plant N status just prior to in-season N application. Expert knowledge was formalized as a set of rules involving ECa, ELE, SLP and NSI levels to deliver economically optimal N rates (EONRs). The resulting FIS was tested on an independent set of data (2008). A simulation revealed that using the FIS would have led to an average N saving of 41 kg N ha-1 compared to the recommended uniform rate of 170 kg N ha-1, without a loss of yield. The FIS therefore appears to be useful for incorporating expert knowledge into spatially variable N recommendations.

Tolerance of adzuki bea...

Montrer texte Montrer source en cache Montrer URL avec texte source

En 2007 et en 2008, nous avons mené quatre essais au champ dans trois emplacements du sud-ouest de l’Ontario afin de déterminer la tolérance des haricots adzuki à plusieurs herbicides appliqués en présemis avec incorporation (PSI), en prélevée (PRE) et en postlevée (POST). Tous les herbicides ont été appliqués aux doses homologuées pour leur utilisation sur des cultures de soja.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Weed management options for adzuki-bean growers in Ontario, Canada are limited due to few herbicide registrations. Four field trials were conducted at three locations in south-western Ontario in 2007 and 2008 to determine the tolerance of adzuki bean to several preplant-incorporated (PPI), pre-emergence (PRE), and post-emergence (POST) herbicides. All the herbicides were applied at the doses registered for use in soybean. The application of pendimethalin, cloransulam-methyl, and halosulfuron-methyl (PPI), flumetsulam, cloransulam-methyl, and halosulfuron-methyl (PRE), and acifluorfen and fomesafen (POST) caused ≤15% crop injury; however, the injury was transient and did not reduce the adzuki bean yield. The POST application of cloransulam-methyl and imazethapyr caused ≤23% crop injury and reduced the biomass by ≤50%, but did not reduce the plant height or crop yield. Metribuzin, flumetsulam, atrazine, and pyroxasulfone (PPI), metribuzin, linuron, pyroxasulfone, and atrazine (PRE), and bentazon, imazethapyr plus bentazon, halosulfuron-methyl, and thifensulfuron-methyl (POST) caused ≤61% crop injury. These treatments reduced the biomass, plant height, and crop yield. Based on these results, pendimethalin, cloransulam-methyl, and halosulfuron-methyl applied PPI, flumetsulam, cloransulam-methyl, and halosulfuron-methyl applied PRE, and acifluorfen and fomesafen applied POST might be potential weed management options for weed management in adzuki bean. Cloransulam-methyl and imazethapyr applied POST will need further evaluation due to phytotoxicity concerns. Metribuzin, flumetsulam, atrazine, and pyroxasulfone applied PPI, metribuzin, linuron, atrazine, and pyroxasulfone applied PRE, and bentazon, imazethapyr plus bentazon, halosulfuron-methyl, and thifensulfuron-methyl applied POST did not have an adequate margin of safety.

Validation of a Managem...

Montrer texte Montrer source en cache Montrer URL avec texte source

Des herbicides ont été appliqués en postlevée sur chacune de ces sections selon des doses variables, établies en fonction de valeurs seuils de mauvaises herbes, ou selon des doses constantes complètes.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Weed management decisions based on weed threshold models offer the opportunity to reduce herbicide use by allowing the possibility of forgoing treatment or lowering rates. Weed thresholds based on a relative leaf-cover model were tested during a 4-yr period at two locations. Two 1.62-ha fields, planted to conventional and glyphosate-resistant corn (2004, 2005, 2007) or soybean (2006), were divided in 900 m2 sections. Herbicides were applied postemergence to each of these sections with either variable rates based on weed thresholds, or constant full rates. Variable herbicide rates included: no application, half rate, or full rate. Relative weed cover values of 0.2 and 0.4 (corn) or 0.1 and 0.3 (soybean) served as thresholds for incremental rates. Digital images were used to evaluate the relative weed cover. Weed density was assessed before and after herbicide application. Weed seed production was estimated for two species in 2004 and 2005. No difference in crop yield, relative weed cover, weed density, or weed seed production was observed between conventional and glyphosate-resistant cropping systems. During the first year, herbicide use reduction was obtained (-85.4%) with marginal crop yield loss (5 to 15%). In the subsequent 3 yr, preherbicide weed densities increased and concomitant increases in relative weed cover values did not allow more than a 10% overall reduction in herbicide use. This threshold model designed to maintain crop yields within a given year did not allow significant reduction in herbicide use during the following 3 yr. Residual weed populations most likely replenished the seed bank to levels that allowed weed densities to increase afterward. Increased weed density over time in plots treated with full rates of herbicide every year also indicated that a single postemergence herbicide treatment was not sufficient to contain weed populations at low levels every year in this corn-soybean rotation.

Fractionnement de la fe...

Montrer texte Montrer source en cache Montrer URL avec texte source

Les objectifs du projet ont été de déterminer l’effet du fractionnement de l’azote (N) sur la productivité du bleuet nain sauvage et sur le N minéral du sol dans six bleuetières situées au Saguenay-Lac-Saint-Jean (Québec, Canada). Des doses de 0, 30, 60 et 90 kg ha-1 de sulfate d’ammonium ont été appliquées au printemps de l’année de végétation.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

In wild lowbush blueberry production, fertilizers are applied in the spring of the vegetative year. To increase fertilizers efficiency and to reduce environmental losses, fertilizer split applications between vegetative and production year have been proposed. The objectives of this project were to determine the effect of split application of the nitrogen (N) in the vegetative and production year on the wild blueberry production and on soil mineral N in six blueberry fields located in Saguenay-Lac-Saint Jean (Québec, Canada). Four rates of ammonium sulfate were applied in the spring of the vegetative year (0, 30, 60 and 90 kg ha-1). These same rates were applied in the spring of the vegetative (50%) and production (50%) years. The 30 kg N ha-1 rate was also applied only in the production year. For all sites, maximum fruit yields (3800 kg ha-1) were obtained with 62 kg N ha-1. However, the maximum rate ranged from 25 to 90 kg N ha-1 according to the sites. Applying N in the vegetative and production years had comparable fruits yields to those obtained with the fertilizer applied only in the vegetative year. One month after N application, the amount of N-NH4 in the soil profile increased by 4 to 38 kg ha-1 compared with the control. Split N application reduced by 55 to 76% the amount of NH4-N in soil layers only in the vegetative year. Soil nitrate increased with N rates at the end of the growing season, indicating that a part of NH4-N was nitrified and can be potentially leached the under root zone. According to the various maximum N rates obtained and N fertilizer impacts on soil N mineral, there would be no agronomic or environmental benefit to splitting low rates (<30 kg ha-1). However, with higher rates, splitting N between vegetation and production years would maximize fruit yields and reduce environmental risk.

Réduction de la dépenda...

Montrer texte Montrer source en cache Montrer URL avec texte source

Aux doses testées, l'énantiomère + de l'acide grandisoïque n'a pas modifié le comportement des mâles et des femelles du charançon de la prune et aucune préférence n'a été décelée lorsque les adultes étaient mis en présence de mélanges de phéromone contenant différentes proportions d'énantiomère bioactif.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

The attractive properties of grandisoic acid, the main component of the plum curculio, have been tested in laboratories with an olfactometer. The grandisoic acid was obtained through chemical synthesis and divided into its two components (enantiomer + and enantiomer -). Tests were conducted to determine the optimal attraction concentration of enantiomer + (the pheromone's bioactive component). At the doses tested, grandisoic acid enantiomer + did not change the behaviour of the male and female plum curculio, and no preference was noted when the adults were exposed to the pheromone blending different proportions of the bioactive enantiomer.

Crop protection and mor...

Montrer texte Montrer source en cache Montrer URL avec texte source

Utilisé individuellement à des doses variant entre 5 et 50 g m.a./100 kg de semence de blé, le fipronil a permis de bien protéger les cultures et les rendements et a induit une forte mortalité parmi les effectifs larvaires résidents et néonates.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

In Canada, as in much of the northern hemisphere, insecticidal seed treatments for cereals that both protect crops from damage by wireworms (Coleoptera: Elateridae) and actually reduce wireworm populations to sub-economic levels are lacking. Thiamethoxam and fipronil applied alone or in combination as wheat seed treatments were evaluated in field studies between 2006 and 2008 in protecting wheat from damage and reducing populations of resident and neonate wireworms. Thiamethoxam alone applied at 5 or 10 g a.i./100 kg seed provided adequate wheat stand and yield protection, but did not significantly reduce Agriotes obscurus wireworm populations. Fipronil alone at 5–50 g a.i./100 kg seed provided adequate wheat stand and yield protection, and also killed significant numbers of both resident and neonate wireworms. Thiamethoxam (10 g a.i.) was initially combined with fipronil at 50, 5, 0.5, 0.05, and 0.005 g a.i./100 kg seed, and subsequently with a delimiting range of fipronil at 50, 5, 1, 0.5, and 0.1 g a.i. Blends of thiamethoxam (10 g a.i.) + fipronil at rates of 50, 5, or 1 g a.i. provided stand and yield as good or better than the former industry standard Vitavax Dual (containing lindane). Combinations of thiamethoxam (10 g a.i.) + fipronil at rates of 50, 5, 1, and 0.5 g a.i. had very low numbers of resident or neonate wireworms relative to the untreated check and were comparable to the Vitavax Dual standard. The benefit of combined thiamethoxam + fipronil seed treatments at these rates, is that crop stand and yield are improved over the individual chemicals applied alone, and resident and neonate wireworm mortality is high. The large reductions in resident and neonate wireworms observed with these combined seed treatments would remove the economic threat of wireworms in fields for 3+ years with rates of insecticides much lower than the formerly used Vitavax Dual.

Hydraulic Properties of...

Montrer texte Montrer source en cache Montrer URL avec texte source

Les boues à base d’eau (BBE) sont utilisées dans le secteur pétrolier pour le forage de puits de pétrole et de gaz naturel. Dans l’ouest du Canada, la réglementation provinciale autorise l’épandage des BBE usées sur les terres arables et parfois sur la prairie indigène en faibles doses.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Water-based drilling mud (WBM) systems are used by the petroleum industry during drilling of oil and natural gas wells. Provincial regulations in western Canada allow disposal of spent WBM on cropland and sometimes native prairie at low rates. There is concern, however, that application of drilling waste on native prairie in semiarid climates may alter soil properties, which may adversely affect soil biophysical processes and overall ecosystem productivity. This study was initiated to examine the effects of single and multiple applications of differential rates (0, 40, and 80 m3 ha-1) of summer-applied WBM on hydraulic conductivity (K ѱ) and macropore indices. Results from unconfined, steady-state infiltration measurements taken at -0.03 - and - 0.01-m supply pressure potentials (Ѱ) at the soil surface provide evidence of a significant alteration of these hydraulic parameters with excessive (80 m3 ha-1) drilling mud application. Across the Ѱ range investigated, K ѱ measured 5 to 7 wk after a single mud application and the effective water-transmission macroporosity (θΔѱ) calculated using the K ѱ decreased by 54 and 61%, respectively, at 80 m3 ha-1 compared with the control (0) and 40 m3 ha-1 rates. Corresponding decreases 5 to 8 wk after a third annual mud application were 62 and 72%. While the rate effect had disappeared 1 yr after the single application, the effect of three annual applications persisted into the following summer. By modifying soil hydrophysical properties, excessive drilling mud applications may adversely affect the soil water balance and alter the plant community structure in this sensitive ecosystem, with important implications on overall biological productivity.

Induction of viable but...

Montrer texte Montrer source en cache Montrer URL avec texte source

Dans les expériences utilisant différentes doses d’inoculum (109 et 106 bactéries E. coli O157:H7 par gramme de feuille), la réaction de non‑cultivabilité liée à la souche était plus évidente lorsque la souche BRMSID 188 a perdu sa cultivabilité après 15 jours et que la souche ATCC 43895 l’a perdue en 7 jours, indépendamment de la dose de l’inoculum.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Escherichia coli O157:H7 continues to be an important human pathogen and has been increasingly linked to food-borne illness associated with fresh produce, particularly leafy greens. The aim of this work was to investigate the fate of E. coli O157:H7 on the phyllosphere of lettuce under low temperature and to evaluate the potential hazard of viable but nonculturable (VBNC) cells induced under such stressful conditions. First, we studied the survival of six bacterial strains following prolonged storage in water at low temperature (4°C) and selected two strains with different nonculturable responses for the construction of E. coli O157:H7 Tn7gfp transformants in order to quantitatively assess the occurrence of human pathogens on the plant surface. Under a suboptimal growth temperature (16°C), both E. coli O157:H7 strains maintained culturability on lettuce leaves, but under more stressful conditions (8°C), the bacterial populations evolved toward the VBNC state. The strain-dependent nonculturable response was more evident in the experiments with different inoculum doses (109 and 106 E. coli O157:H7 bacteria per g of leaf) when strain BRMSID 188 lost culturability after 15 days and strain ATCC 43895 lost culturability within 7 days, regardless of the inoculum dose. However, the number of cells entering the VBNC state in high-cell-density inoculum (approximately 55%) was lower than in low-cell-density inoculum (approximately 70%). We recorded the presence of verotoxin for 3 days in samples that contained a VBNC population of 4 to 5 log10 cells but did not detect culturable cells. These findings indicate that E. coli O157:H7 VBNC cells are induced on lettuce plants, and this may have implications regarding food safety.

Crop protection and mor...

Montrer texte Montrer source en cache Montrer URL avec texte source

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Contrasting soil microb...

Montrer texte Montrer source en cache Montrer URL avec texte source

Dans un essai au champ avec des cultures de canola (Brassica napus L.) et d’orge (Hordeum vulgare L.), nous avons étudié les effets sur les propriétés microbiologiques du sol d’une réduction des apports d’engrais ou d’herbicide par rapport aux doses recommandées.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

The combination of high input costs and low commodity prices is forcing some farmers to consider reducing crop inputs like seed, fertilizer and herbicides. In a field trial in which different canola (Brassica napus L.) and barley (Hordeum vulgare L.) inputs were subtracted from a full package, or added to an empty package, we studied the effects of full or reduced fertilizer and herbicide inputs on soil microbiological characteristics at two sites from 2005 to 2008. The full package consisted of a high-yielding crop variety seeded at an optimum rate, with fertilizers and herbicides applied at recommended rates. The empty package consisted of a less expensive, low-yielding crop variety seeded at a low rate, with no fertilizer or herbicide applied. Between these two extremes were treatments in which fertilizers or herbicides were applied at 50% of recommended rates or not at all. Each treatment was repeated year after year in the same plot, i.e., treatment effects were cumulative. Fertilizer effects on soil microbial biomass C (MBC), β-glucosidase enzyme activity and bacterial functional diversity (based on community-level physiological profiles) were usually positive. Reduced fertilizer application rates reduced the beneficial fertilizer effects. Significant herbicide effects on soil microbiological properties occurred less often, were smaller in magnitude than fertilizer effects, and were mostly negative. Reduced herbicide rates reduced the deleterious herbicide effects. These significant fertilizer and herbicide effects were observed in canola more than barley, and mostly in the final year of the study, indicating the cumulative nature of treatment effects over time. Therefore, repeated applications of agricultural inputs like fertilizers and herbicides can have more significant effects on soil biology and biological processes than single applications indicate.

In-feed administered su...

Montrer texte Montrer source en cache Montrer URL avec texte source

Nous avons étudié les effets de l’administration continue de doses subthérapeutiques de chlortétracycline sur la structure et la composition de la communauté bactérienne des excréments du rat ainsi que sur l’abondance des gènes de résistance aux tétracyclines dans cette communauté.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

The impact of continuous sub-therapeutic chlortetracycline on community structure, composition and abundance of tetracycline resistance genes in the rat fecal community was investigated. Rats were fed a standard diet containing chlortetracycline at 15 mg g-1 diet for 28 days, followed by 30 mg g-1 diet to completion of the study on day-56. These levels are similar to those administered to swine during the grow-out phase. Sub-therapeutic chlortetracycline affected the fecal community as determined through change in the cultivable anaerobic community and through molecular-based analyses including denaturing gradient gel electrophoresis profiles of the variable 2-3 region community 16S rRNA genes over time and through comparative sequence analysis of 16S rRNA gene community libraries. Significant decreases in fecal phylotype diversity occurred in response to sub-therapeutic chlortetracycline, although total bacterial output remained constant over the entire feeding trial. Chlortetracycline at 15 mg g-1 diet resulted in significant change in community composition, but only modest change to the fecal community structure in terms of the distribution of individual phylotypes among the major fecal lineages. Chlortetracycline at 30 mg g-1 diet significantly altered the distribution of phylotypes among the major fecal lineages shifting the overall community such that Gram-negative phylotypes aligning within the phylum Bacteroidetes became the dominant lineage (>60% of total community). While chlortetracycline impacted both fecal community structure and composition, there was no significant effect on the abundance of community tetracycline resistance genes [tet(Q), tet(W), tet(O)] or on the emergence of a new putative tetracycline resistance gene identified within the fecal community. While sub-therapeutic chlortetracycline provides sufficient selective pressure to significantly alter the fecal community, the primary outcome appears to be the development of a community which may have a higher inherent tolerance to sub-therapeutic levels of chlortetracycline rather than an overgrowth of the tetracycline resistant bacteria already present within the community.

Fertilisation phosphaté...

Montrer texte Montrer source en cache Montrer URL avec texte source

L’objectif de ce projet a donc été de réévaluer les besoins en P et en K de la culture du pois sec sous les conditions climatiques du Saguenay-Lac-Saint-Jean (Québec, Canada) pour des sols de différentes richesses en P et en K. Les traitements ont consisté en quatre doses de P (0, 20, 40, 80 et 160 kg P2O5 ha-1) et trois doses de K (0, 50 et 150 kg K2O ha-1).

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

In Québec, the P recommendations for dry peas (Pisum sativum L.) are nearly three times higher than those in western Canada, while recommendations for K are at least 20% lower. The objective of this project was to re-evaluate the P and K needs of dry peas under the climatic conditions of the Saguenay-Lac-Saint-Jean region (Québec, Canada) in soils with a range of soil P and K availabilities. The treatments consisted of four P rates (0, 20, 40, 80 and 160 kg P2O5 ha-1) and three K rates (0, 50 and 150 kg K2O ha-1). The trials were conducted at two sites over 3 yr. Site 1 was classified as low in P availability and site 2 as medium according to the soil analysis. Both sites had a medium level of soil K availability. Grain yields increased significantly, by 6%, with increasing fertilizer P (3246 to 3437 kg ha-1). Potassium fertilization had no significant effect on grain yields. Grain yields were also 37% higher in the highest soil P site. This low response of the crop to mineral fertilizers was attributed to the significant soil contribution to crop P and K needs. Soil tests have also indicated an enrichment of P and K with large inputs of mineral fertilizers. Thus, a rate of 30-35 kg P2O5 ha-1 for P poor soils would be sufficient to meet the crop needs. For soils with moderate levels of K (201-400 kg K2O ha-1), a rate of 50 kg K2O ha-1 would be sufficient to meet the crop needs and to maintain the soil fertility.

Fertilisation phosphaté...

Montrer texte Montrer source en cache Montrer URL avec texte source

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Fertilisation azotée et...

Montrer texte Montrer source en cache Montrer URL avec texte source

Ainsi, l’objectif de cette étude a été de déterminer la réponse du bleuet à la fertilisation en N et en P sous les conditions climatiques et édaphiques du Saguenay-Lac-Saint-Jean, Québec, Canada. Les traitements ont consisté en quatre doses de N (0, 30, 60 et 90 kg N ha-1) et quatre doses de P (0, 30, 60 et 90 kg R = ha-1).

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Few studies have evaluated the interactions between nitrogen (N) and phosphorus (P) in wild lowbush blueberry (Vaccinium angustifoliumAit.) production. The objective of this study was to determine the response of blueberry to N and P fertilization under the climatic and edaphic conditions of the Saguenay–Lac-Saint-Jean (Québec, Canada). The treatments consisted of four N rates (0, 30, 60 and 90 kg ha-1) and four P rates (0, 30, 60 and 90 kg P2O5 ha-1). The optimum fruit yields (5361 kg ha-1) were determined by solving the first derivative of the regression equation and were obtained with a rate of 64 kg N ha-1 while P fertilization had no significant effect on yields in this experiment. The density of stem, the number of flower buds and the height of the plants have only increased with N fertilization. In the sprout year, leaf N, P and potassium (K) concentrations increased with N and P. Phosphorus fertilizer only increased leaf P concentration. However, a high rate of N decreased leaf calcium and magnesium concentrations. Fruit yields were significantly correlated with plant height (r =0.75), number of flower buds (r =0.82), stem density (r =0.52), and leaf N, P and K concentrations (r =0.58, 0.57 and 0.72, respectively). The productivity of wild blueberry was strongly influenced by N fertilization and the interactions with P have been limited. This lack of response to P fertilization confirmed that the crop P requirements were limited and can be met by soil P.

Weed control, environme...

Montrer texte Montrer source en cache Montrer URL avec texte source

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Fertilisation azotée et...

Montrer texte Montrer source en cache Montrer URL avec texte source

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Plant and soil response...

Montrer texte Montrer source en cache Montrer URL avec texte source

Les traitements ont été réalisés à des doses de 56, 112 et 224 kg N ha-1, avec ajout de P à un taux de 28 kg de P2O5 ha-1 et sans ajout de P. Les trois sites étaient de peuplements de 7 à 8 ans, non fertilisés, de prairies de fauche principalement dominées par le brome des prés (Bromus riparius).

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Field experiments were conducted at three different sites in Saskatchewan, Canada (Colonsay, Vanscoy and Rosthern) over two years (2005 and 2006) to determine the effects of dribble-banded and coulter-injected liquid fertilizer applied in the spring of 2005 at 56, 112 and 224kg Nha-1 with and without P at 28kg P2O5ha-1. The three sites were unfertilized, 7- to 8-year old stands of mainly meadow bromegrass (Bromus riparius)-dominated haylands. All fertilization treatments produced significantly (P≤0.05) higher dry matter yield than the control in the year of application at the three Saskatchewan sites. There was no significant difference between the two application methods (surface dribble band vs. coulter injected) for any fertilizer treatments. The addition of 28kg P2O5ha-1 P fertilizer along with the N fertilizer did not have a significant effect on yield in most cases. In the year of application, increasing N rates above 56kg Nha-1 did not significantly increase yield over the 56kg Nha-1 rate in most cases, but did increase N concentration, N uptake and protein concentration. A significant residual effect was found in the high N-rate treatments in 2006, with significantly higher yield and N uptake. In 2005, the forage N and P uptake in the fertilized treatments were significantly higher than the control in all cases. The N uptake at the three Saskatchewan sites increased with increasing N rate up to the high rate of 224kg Nha-1, although the percent recovery of applied N decreased with increasing rate. The P fertilization with 28kg P2O5ha-1 also increased P uptake. Overall, rates of fertilizer of approximately 56kg Nha-1 appear to be sufficient to produce nearly maximum forage yield and protein concentration of the grass in the year of application.

How long can a herbicid...

Montrer texte Montrer source en cache Montrer URL avec texte source

Cinq essais au champ ont été réalisés sur une période de trois ans (2006-2008) à deux endroits différents dans le sud-ouest de l’Ontario afin de déterminer la période durant laquelle on peut laisser des herbicides dans un réservoir de pulvérisation avant de les appliquer au champ sans que leur efficacité soit diminuée. On a procédé au mélange de quatre herbicides de prélevée et de cinq herbicides de postlevée selon les doses prescrites sur les étiquettes.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Five field trials were conducted over a three-year period (2006-2008) at two locations in southwestern Ontario to determine the length of time herbicides can remain in the spray tank prior to application in the field without impacting efficacy. Four pre-emergence and five post-emergence herbicides were mixed at their labelled rates and then applied in maize. Herbicides were either applied immediately after mixing in water, or after being held in solution for 1, 3 or 7 days. The most common weed species in the trials were Abutilon theophrasti, Amaranthus retroflexus, Ambrosia artemisiifolia, and Chenopodium album. Holding the herbicides in spray solution for up to 7 days did not affect the efficacy of the post-emergence herbicides in this study. Similarly, control of A. retroflexus and C. album with the pre-emergence herbicides was not affected holding the herbicides in spray solution for up to 7 days. However, control of A. theophrasti was decreased when isoxaflutole plus atrazine, dimethenamid plus dicamba/atrazine, or rimsulfuron plus S-metolachlor plus dicamba was in spray solution for more than 1 day. Nonetheless, there were no decreases in yield for any of the treatments evaluated. These data provide valuable information which growers can use to make informed decisions on whether to apply herbicides in non-ideal weather or to postpone application. The results of this study suggest that for the herbicides and weed species tested it is better to postpone application rather than make applications under non-ideal conditions.

Seed yield and yield co...

Montrer texte Montrer source en cache Montrer URL avec texte source

Les essais, réalisés en blocs complets randomisés, comportaient vingt traitements portant sur deux génotypes oléagineux de colza (B. napus de type canola) et de moutarde (B. juncea de type canola), trois doses d’application d’engrais soufré (15, 30 et 45 kg S ha-1) et potassique (30, 60 et 90 kg K ha-1) étant prévues pour chacun.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Improper sulfur (S) and potassium (K) fertilizer management, particularly with continued soil nutrient mining, is one of the major factors contributing to low seed yield of canola in northwestern Pakistan. A field experiment was conducted in 2007-2008 on a S and K deficient clay loam soil at the Research Farm of NWFP (Northwest Frontier Province) Agricultural University, Peshawar, Pakistan, with an objective to determine seed yield and yield components response of Brassica oilseed rape versus mustard to S and K application. Twenty treatments in a randomized complete block design were consisted of two oilseed rape (B. napus canola) and mustard (B. juncea canola) genotypes at three rates each of S (15, 30, and 45 kg S ha-1) and K (30, 60, and 90 kg K ha-1) fertilizers plus one control (no S and K applied). Seed yield and yield components increased significantly with K and S fertilization as compared to the zero-S/zero-K control. Both genotypes responded positively for seed yield and yield components to K and S fertilization, but the magnitude of response varied with levels of S and K, as well as combined K + S applications. It is concluded that a combination of 60 kg K + 30 kg S ha-1 would improve seed yield and yield components of rape and mustard in the study area and contribute significantly to increased production. Growing B. napus was better than B. juncea in the study area, because B. napus produced significantly higher seed yield and yield components than B. juncea, indicating that yield components are the most important criteria for selection of Brassica genotypes for higher seed yield.

Phosphorus fertilizer e...

Montrer texte Montrer source en cache Montrer URL avec texte source

Au moyen d’une expérience en conditions contrôlées, nous avons étudié l’effet de trois doses de P sur la capacité de compétition de quatre espèces de mauvaises herbes, que nous avons cultivées avec du blé.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Information on phosphorus (P) fertilizer affecting crop-weed competitive interactions might aid in developing improved weed management systems. A controlled environment study was conducted to examine the effect of three P doses on the competitive ability of four weed species that were grown with wheat. Two grass and two broad-leaved weed species were chosen to represent the species that varied in their growth responsiveness to P: wild oat (medium), Persian darnel (low), round-leaved mallow (high), and kochia (low). Wheat and each weed species were grown in a replacement series design at P doses of 5, 15, and 45 mg P kg-1 soil. The competitive ability of the low P-responsive species, Persian darnel and kochia, decreased as the P dose increased, supporting our hypothesis that the competitiveness of species responding minimally to P would remain unchanged or decrease at higher P levels. As expected, the competitiveness of the high P-responsive species, round-leaved mallow, progressively improved as the P dose increased. However, wild oat's competitive ability with wheat was not affected by the P fertilizer. The results suggest that fertilizer management strategies that favor crops over weeds might deserve greater attention when weed infestations consist of species known to be highly responsive to higher soil P levels. The information gained in this study could be used to advise farmers of the importance of strategic fertilizer management in terms of both weed management and crop yield.

Dietary Oat β-Glucan Re...

Montrer texte Montrer source en cache Montrer URL avec texte source

Le flux net de glucose et d’acides gras à chaîne courte (AGCC) ainsi que la sécrétion d’insuline dans la veine porte pourraient être associés à deux incrétines, le GIP (polypeptide insulinotrope glucose-dépendant) et le GLP 1 (glucagon like peptide-1). Nos objectifs étaient de comprendre cette association et d’étudier l’effet de deux doses de β glucane d’avoine alimentaire sur les variables en jeu.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Net glucose and SCFA flux and insulin secretion into the portal vein might be associated with the incretins glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1). Our objectives were to clarify this association and study the impact of 2 doses of dietary oat β-glucan on the variables. Three 35-kg portal vein-catheterized pigs were fed 3 diets containing 0, 3, or 6% oat β-glucan concentrate (BG0, BG3, and BG6) for 7 d in a repeated 3 x 3 Latin square. On d 7, blood was sampled for 12 h postprandially. Net glucose flux and apparent hormone production were calculated from plasma portal-arterial differences x flow. Postprandially, pigs fed BG6 had lower (P < 0.05) portal glucose at 15, 30, and 45 min and a lower (P < 0.05) net glucose flux during the first hour. Pigs fed BG6 tended to have lower (P < 0.10) portal C-peptide without lowering insulin, indicating that pigs fed BG6 had lower actual insulin release combined with a higher prehepatic retention of insulin. Pigs fed BG6 had lower (P < 0.05) portal GIP and GLP-1, which in turn were correlated (R2 = 0.81 and 0.88, respectively; P < 0.01) with portal glucose. Pigs fed BG3 and BG6 had a higher (P < 0.05) net SCFA flux than pigs fed BG0, indicating increased fermentation. In conclusion, dietary supplementation of 6% oat β-glucan concentrate decreased net glucose flux, increased net SCFA flux, and decreased peak apparent insulin production, changes that were associated with GIP and GLP-1 mediation.

Response of the dusky w...

Montrer texte Montrer source en cache Montrer URL avec texte source

En 2010, des larves de taupin placées dans du sol provenant d’un champ traité à la bifenthrine 343 jours plus tôt à raison de 100, 200 et 300 g m.a./ha ont réagi comme les larves exposées en 2009, leur degré de morbidité augmentant en fonction de la dose d’insecticide utilisée et, pour chacune des doses utilisées, les larves ayant atteint un stade ne se nourrissant pas étant plus gravement touchées que celles se nourrissant activement.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

To determine if bifenthrin residues elicit morbidity and surfacing behavior in wireworms, larvae of the dusky wireworm, Agriotes obscurus (Coleoptera: Elateridae) were placed in field soil treated with the pyrethroid insecticide bifenthrin ~1 year previous. Morbidity was immediate and lasted as long as wireworms remained in the soil, disappearing quickly after transfer to clean soil. In 2009, field soil treated 336 days previous with bifenthrin at 340 g AI/ha elicited morbidity symptoms similar to that elicited by soil freshly amended with bifenthrin at 100 g AI, and analysis of the field soil confirmed residual levels of bifenthrin exceeding 100 g AI/ha. In 2010, wireworms placed in field soil treated 343 days previous with bifenthrin at 100, 200, and 300 g AI/ha responded as in 2009, with the degree of morbidity increasing with the rate of insecticide, and with wireworms in a non-feeding state more affected than those in a feeding state at each rate. In both 2009 and 2010, moribund wireworms moved to the soil surface within 1 day of placement in the soil containing residual bifenthrin and remained there until reburied, after which they often resurfaced. To confirm that the bifenthrin residues elicited repellency, wireworms were placed in soil window bioassays containing field soil with residual bifenthrin. Wireworms behaved markedly different upon contacting soil containing the residues than when exposed to untreated soil, both in the presence and absence of an attractant, but were less likely to avoid soil containing residual bifenthrin when attracted by wheat seedlings placed inside it.

Fractionnement de la fe...

Montrer texte Montrer source en cache Montrer URL avec texte source

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Crop protection and mor...

Montrer texte Montrer source en cache Montrer URL avec texte source

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

The Effect of MSW Compo...

Montrer texte Montrer source en cache Montrer URL avec texte source

Nous avons appliqué chaque année à des parcelles, dans le cadre d’une rotation de trois cultures, trois doses de compost (DUS1, DUS2 et DUS3), une dose d’engrais (NPK) et un mélange de 1/2 compost de DUS1 et 1/2 engrais NPK; chaque année, nous avons tenté d’apparier la dose de DUS1 à la dose de P appliquée dans le traitement à l’engrais NPK.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Municipal solid waste (MSW) compost is readily available in eastern Canada and may be a good source of fertility. A 3-year experiment evaluated the effects of MSW compost and fertilizer on soil fertility, elemental composition and yield of potato (Solanum tuberosum L.) grown in a sandy loam soil. Three rates of compost (MSW1, MSW2, and MSW3), one rate of fertilizer (NPK), and one mixture of 1/2 MSW1 compost and 1/2 NPK fertilizer were applied annually to plots in a three-crop rotation; each year the MSW1 rate attempted to match the rate of P applied in the NPK treatment. Mehlich-3 extracts were evaluated for 11 elements at two soil depths (0-15 and 15-30 cm). Potato shoots and roots or whole plants were assessed for 16 elements. Treatments had no consistent significant influence on marketable tuber yields although the NPK treatment produced mathematically the highest yields. After 3 years, treatments had influenced soil concentrations of K, Ca, S, Cu, Zn, and Na in Mehlich-3 extracts at the 0-15 cm depth, but only the concentration of Na at the 15-30 cm depth. The concentration of Mg in the plant tissue was consistently highest in plants fertilized with NPK; this treatment also produced higher Mn concentrations in the last 2 years. Shoot Cu concentrations were highest in the MSW3 plots. The compost did not increase heavy metal concentrations in shoot, root or whole-plant tissue and would be safe to use at agronomic rates of application.

Effects of Polymer Char...

Montrer texte Montrer source en cache Montrer URL avec texte source

Avec les polymères de masse moléculaire élevée, il fallait des doses moindres, et l’élimination des matières en suspension et du phosphore était plus efficace qu’avec les polymères de masse moléculaire moyenne; des résultats comparables ont été obtenus avec les polymères de masse moléculaire élevée et très élevée.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

This study investigated the effects of polymer charge density (CD) and molecular weight (MW) on the efficiency of solid‐liquid separation of swine manure at various dry matter (DM) contents. Flocculated manures were filtered through 1 mm screens. The dose of high MW polymers required for optimum suspended solids (SS) removal increased with increasing CD. At manure DM content ranging from 29 to 90 g L-1, optimum dose averaged 22, 29, 63, and 85 mg L-1 with the 2%, 10%, 35%, and 55% CD polymers, respectively. Chemical cost (in U.S. dollars) was estimated at $0.12, $0.18, $0.47, and 0.69 per m3 of manure for the four polymers, respectively. However, maximum SS and P reductions tended to increase with increasing CD and averaged 84%, 89%, 94%, and 95% for SS and 62%, 67%, 70%, and 71% for P with the 2%, 10%, 35%, and 55% CD polymers, respectively. High MW polymers required lower doses and were more efficient in terms of SS and P removals than medium MW polymers, while similar results were obtained with high and very high MW polymers. Results suggested that bridging was the main mechanism involved in manure flocculation, but high SS removal required the bridging as well as the charge neutralization effect of high CD polymers. There was no consistent correlation between optimum dose and manure DM content between 29 and 106 g L-1 for the 10% and 35% CD, high MW polymers. Manure dilution at the farm would thus increase cost because of higher polymer requirements and the need for equipments able to handle larger volumes.

Nitrogen, phosphorus, a...

Montrer texte Montrer source en cache Montrer URL avec texte source

Cependant, lorsque nous avons doublé les doses, qui étaient initialement de 180 kg N ha-1, 40 kg P ha-1 et 75 kg K ha-1, nous n’avons observé qu’une faible augmentation du taux de remplissage (0,8 %), de la durée du stade de remplissage (1,6 %), du volume du grain (1,3 %) et du rendement grainier (0,4 %).

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

A three-site-year field experiment was conducted to determine nitrogen (N), phosphorus (P), and potassium (K) fertilizer effects on grain filling dynamics and yield formation of high-yielding summer corn (Zea mays L.) in a wheat (Triticum aestivum L.)-corn double crop cropping system. Application of combined NPK fertilizers resulted in the greatest grain yield, largest grain number and grain weight when compared with the treatments receiving N, NP, or NK. Grain filling rate and duration, grain volume, and grain yield increased with NPK rates; however, doubling the rate of 180 kg N ha-1, 40 kg P ha-1, and 75 kg K ha-1 fertilizer only led to minimal increases in grain filling rate (0.8%), grain filling duration (1.6%), grain volume (1.3%) and grain yield (0.4%). Our results suggested that for the high-yielding summer corn, a combined NPK fertilization is required to enhance grain filling and yield, and that under well-fertilized circumstances, limited increases in both grain filling and sink capacity might be the main factor restricting further yield improvement.

Effects of glucose, pro...

Montrer texte Montrer source en cache Montrer URL avec texte source

En supplément à la ration témoin (Ctl), nous avons perfusé des doses isoénergétiques (5,15 Mcal/j d’énergie digestible) de Glc dans le duodénum (7,7 mol/j), de C3 dans le rumen (14,1 mol/j) et de NEAAm dans le duodénum (en mol/j; Ala : 1,60; Asp : 0,60; Glu : 5,94; Gly : 1,22; Ser : 2,45).

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Whole-body glucose rate of appearance (Ra) responses and milk lactose secretion were compared in dairy cows receiving duodenal infusions of glucose (Glc), a mixture of 5 nonessential amino acids (NEAAm), or ruminal infusions of propionic acid (C3). Four mid-lactation Holstein cows, fitted with both duodenum and rumen cannulas, were used in a 4 x 4 Latin square design with 14-d periods. Cows were fed a grass silage-based diet (Ctrl) that provided 88% of net energy of lactation and 122% of protein requirements. Concentrate was formulated with wheat (21.5%) and barley (20%) containing some starch. Isoenergetic infusions (5.15 Mcal/d of digestible energy) of Glc into the duodenum (7.7 mol/d), C3 into the rumen (14.1 mol/d), or NEAAm into the duodenum (in mol/d; Ala: 1.60; Asp: 0.60; Glu: 5.94; Gly: 1.22; Ser: 2.45) were given as a supplement to the Ctrl diet. During each period on d 13, [6,6-2H2]glucose was infused into one jugular vein and blood samples were taken from the other jugular vein to measure glucose enrichment and determine Ra. Dry matter intake decreased slightly with the infusions (6%), but did not differ among them. Whole body glucose Ra averaged 502, 745, 600, and 576 mmol/h for Ctrl, Glc, C3, and NEAAm, respectively. It increased with the increase in energy supply (Ctrl vs. infusions) and differed according to the nutrients infused. The Ra response was higher with Glc and C3 than with NEAAm and higher with Glc than with C3. Plasma concentrations of insulin were not affected, but insulin-like growth factor 1 increased with infusions. Plasma glucagon increased with NEAAm, which could favor the increased Ra. Overall, milk lactose yield (137, 141, 142, and 130 mmol/h for Ctrl, Glc, C3, and NEAAm, respectively) was not modified by the infusions, but was lower with NEAAm compared with Glc and C3. Changes in lactose yield did not parallel the increase in Ra, and therefore the ratio of lactose yield to Ra decreased with the infusions and was lower in Glc compared with C3, suggesting a shift of glucose utilization away from lactose synthesis toward other pathways, including mammary metabolism. Intestinal Glc was the most efficient nutrient in terms of increasing glucose Ra; however, there was no direct link between the increases in whole body glucose Ra observed with the 3 types of nutrients and milk lactose yield.

Nitrogen and phosphorus...

Montrer texte Montrer source en cache Montrer URL avec texte source

La fertilisation en N a eu une incidence significative sur les rendements totaux en fruits, lesquels n’ont toutefois pas été modifiés par la fertilisation en P. Les doses de N requises pour obtenir les rendements maximaux ont été estimées à 254, 302 et 322 kg/ha respectivement pour les années 2003, 2004 et 2005.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Sufficient nutrient and water supplies are vital for processing tomato production. Excessive N and P supplies, however, can reduce farmers' profitability and cause adverse impacts on environmental quality. A 3-year study was conducted to evaluate agronomic and environmental consequences of applied fertilizer N and P to processing tomato (Lycopersicon esculentum Mill.) under drip fertigation in southwestern Ontario, Canada. Nitrogen application significantly affected total fruit yields, which, however, were not affected by addition of fertilizer P. Fertilizer N rates required for the production of maximum yield were estimated at 254, 302, and 322 kg N ha-1, for 2003, 2004, and 2005, respectively. Addition of fertilizer N above the rates required for the maximum yield production caused significant increases of post-harvest soil residual NO3-N, which may increase leaching losses during the non- growing season. Total N uptake was averaged at 265 kg N ha-1 and total P uptake averaged 44 kg P ha-1. The results demonstrate that with the improved production of fruit yield under fertigation N application rate needs to be increased to satisfy the optimum growth under prevailing conditions.

Validation of a Managem...

Montrer texte Montrer source en cache Montrer URL avec texte source

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Validation of a Managem...

Montrer texte Montrer source en cache Montrer URL avec texte source

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Thirty-seven years of s...

Montrer texte Montrer source en cache Montrer URL avec texte source

Nous avons déterminé le carbone organique, le N et le P dissous dans le sol, de même que la structure (profil des acides gras des phospholipides) et la fonction (activités enzymatiques) des communautés microbiennes durant les phases de jachère et de premier ensemencement en blé (Triticum aestivum L. cv. AC Eatonia) de rotations jachère blé blé, dans lesquelles la culture de blé a reçu les doses d’engrais de N et de P minéraux (+N+P) recommandées selon l’analyse du sol, ou dans lesquelles l’utilisation d’engrais de N ( N+P) ou de P (+N P) a été interrompue pendant 37 ans.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

We tested whether levels of soil available nitrogen (N) and phosphorus (P) control the composition and function of the soil microbial community in a Brown Chernozemic soil on the Canadian Prairie. Soil dissolved organic carbon, N and P, and microbial communities structure (phospholipid fatty acid profile) and function (enzyme activity) were evaluated in the fallow and first wheat (Triticum aestivum L. cv. AC Eatonia) phases of fallow-wheat-wheat rotations where the wheat received soil test recommended rates of mineral N and P fertilizers (+N+P), or where N (-N+P) or P (+N-P) fertilizer use was withheld for 37 years. Differential fertilization modified soil N and P availability, and microbial community structure. Low N level was a major constraint when a rapidly growing wheat crop (heading stage) was drawing on the resource, reducing both plant N uptake and soil microbial biomass-C in -N+P soils. Available P level in +N-P soils was about half that measured in P-fertilized soils, but P did not limit plant productivity or microbial development at that time. Changes in the microbial community structure seemingly buffered the impact of lower P availability in +N-P soils. Phosphatase activity was not involved, but increased abundance of arbuscular mycorrhizal fungi might be associated with this effect. Low soil N availability explained lower specific denitrification and higher specific nitrogenase activities in -N+P soil growing wheat. Higher denitrification activity in +N+P soil could be attributed to higher soil C level and fertilization-induced shifts observed in the structure of the soil microbial community. Irrespective of the fertility level of the soil, all microbial communities grew at the relative growth rate of 17% day-1 in a nutrient limitation assay that revealed no C, N or P limitation in these communities. We conclude that mineral fertilization, which modifies soil available N and P fertility, can be a selective force causing structural and functional shifts in the soil microbial community with a resulting impact on soil quality and nutrient fluxes.

Lincomycin and spectino...

Montrer texte Montrer source en cache Montrer URL avec texte source

Une analyse d’extraits de fumier par CPL-SM/SM a montré que les concentrations de lincomycine et de spectinomycine dans le fumier liquide accumulé à la fin de l’étude représentaient respectivement 32 et 3 % des doses administrées à la ration des porcelets sevrés.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Antimicrobials administered to livestock can be excreted up to 75% in the feces and urine. Liquid swine manure from confined animal feeding operations is generally retained in lagoon storage until it is applied as a nutrient source to crop and pasture land. Thus, the applied manure becomes a possible source of antimicrobials to aquatic ecosystems. In the prairie region of Canada, lincomycin and spectinomycin are two antimicrobials that are frequently administered to pigs for prevention of post-weaning diarrhea. In order to assess the potential for contamination of prairie wetlands, concentrations of both antimicrobials were monitored in liquid manure from a commercial-scale barn during a 5-week study, and their persistence during simulated manure storage was investigated. LC-MS/MS analysis of manure extracts showed that concentrations of lincomycin and spectinomycin in the accumulating liquid manure at the end of the study were equivalent to 32 and 3%, respectively, of the doses administered to weanling pigs in their feed. In a laboratory study in which lagoon storage was simulated at room temperature using fortified liquid manure, concentrations of both antimicrobials showed a rapid initial decrease during the first 6 days, followed by a much slower dissipation, over a period of 5 months. Such persistence indicates that lincomycin and spectinomycin may be present in lagoon manure when applied as an amendment to agricultural land since many lagoons are emptied every 6 months (early spring and late fall).

Canola response to ESN ...

Montrer texte Montrer source en cache Montrer URL avec texte source

Nous avons employé comme traitements deux cultivars de canola (un hybride et un PL), deux types d’urée (UEP et urée ordinaire), deux taux de fertilisation azotée (100 % et 150 % du taux recommandé en fonction de l’analyse du sol) et deux doses d’herbicide appliqué en cours de culture (50 % et 100 % de la dose homologuée).

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Nitrogen fertilizer is a major input cost in canola (Brassica napus L.) production and farmers are interested in improving N use efficiencies. A multi-site study in western Canada was conducted to determine the merits of polymer-coated urea (Environmentally Smart Nitrogen, ESN) compared with urea on weed management and yield of hybrid and open-pollinated (OP) canola. Treatments included a hybrid and OP canola cultivar, ESN and urea, 100 and 150% of soil test N fertilizer rates, and 50 and 100% of registered in-crop herbicide rates. Canola was grown in rotation with barley (Hordeum vulgare L.) in a no-till system and both crops of the rotation were present each year. Fertilizer and herbicide rate treatments were applied to the same plots in four consecutive years to determine annual and cumulative effects. Hybrid compared with OP canola reduced weed tissue N concentration in 40% of the cases and reduced weed biomass in 80% of the cases. Additionally, weed tissue N concentration was lower with ESN than with urea in 70% of the cases, indicating that crop–weed competition for soil N might be reduced if ESN were used. Canola yield was greater for the hybrid cultivar in 15 of 20 site-years. Both cultivars expressed a positive yield response to the 150% N fertilizer rate in 10 of 20 site-years. This yield response occurred in three additional site-years with hybrid canola, indicating that hybrid cultivars have a higher N demand under favorable growing conditions. Canola yield was similar with ESN and urea in 14 of 20 site-years. The ESN compared with urea increased canola yield in 4 site-years and in one additional site-year for hybrid canola, indicating that ESN may be advantageous in some situations. Canola seed oil concentration was similar with ESN and urea in 19 of 20 site-years. Information gained in this study will be used to develop improved fertilization strategies for canola production on the semiarid Canadian prairies.

Contrasting soil microb...

Montrer texte Montrer source en cache Montrer URL avec texte source

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

In-feed administered su...

Montrer texte Montrer source en cache Montrer URL avec texte source

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Effect of polymer-coate...

Montrer texte Montrer source en cache Montrer URL avec texte source

Les traitements comprenaient des combinaisons des éléments suivants : deux régimes de travail du sol (travail classique du sol et régime sans travail du sol), deux formes d’urée (appliquées selon les doses commerciales, soit 50-60 kg N ha-1), et calendrier d’application (épandage en bandes au printemps ou à l’automne).

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Two field experiments were conducted to assess the effectiveness of polymer-coated urea (PCU) vs. conventional urea (urea) in minimizing nitrate accumulation in soil and nitrous oxide (N2O) emission while optimizing available N supply. The trials were located on Dark Gray Luvisols (Typic Cryoboralf) near Beaverlodge, Alberta (2004-2007) and Star City, Saskatchewan (2004-2006), in the north western Canadian Prairies. The treatments comprised of combinations of two tillage systems (conventional and no tillage), the two forms of urea (applied at commercial rates, 50-60 kg N ha-1), and time of application (side-banded in spring or fall). Tillage had little effect on the measured soil variables. Available N at the anthesis growth stage was higher with spring- than fall-banded N in three of four site-years, and with PCU than urea in two site-years. At seeding, nitrate in the soil layers to 60-cm depth, especially the top 15 cm, was mostly higher for fall- than spring-banded treatments but differed less between the forms of urea. Fall application, therefore, has greater potential for gaseous N and leaching losses early in the growing season when crops have low N requirements, and hence is not advisable. Nitrous oxide emission from spring to fall was higher with the fertilized treatments in three of five site-years and not different between fertilized and unfertilized treatments in the other site-years. At Beaverlodge, N2O loss was low in 2 years and showed few significant treatment effects. At Star City, N2O loss was 1.5- to 1.7-fold higher from urea than PCU treatments, and up to 1.5-fold lower from spring than fall application. It is concluded that although PCU can increase available N during the growth period and reduce N2O loss in some years compared with urea, the time of N application had a consistently greater effect than the type of urea in enhancing crop N recovery and reducing N loss to the environment.

Essential oils and oppo...

Montrer texte Montrer source en cache Montrer URL avec texte source

Toutefois, l’inhibition de la production de CH4 n’a été obtenue qu’à fortes doses (> 300 mg/L de liquide de culture) et, dans bien des cas, elle était associée à une diminution de la concentration totale d’acides gras volatiles et de la digestion des aliments.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

The well documented antimicrobial activity of essential oils has prompted interest in whether these bioactive compounds can be used to selectively inhibit rumen methanogenesis. A number of studies have recently evaluated the ability of essential oils to reduce enteric CH4 production. Most studies conducted have been in vitro and short term. Essential oils derived from thyme, oregano, cinnamon, garlic, horse radish, rhubarb and frangula have decreased CH4 production in vitro in a dose dependent manner. However, inhibition of CH4 production occurred at high doses (i.e., >300 mg/L of culture fluid) and was, in many cases, associated with a decrease in total volatile fatty acid concentrations and feed digestion. Some essential oils, such as garlic, cinnamon, rhubarb and frangula, may exert a direct effect on methanogens. Evidence for in vivo antimicrobial activity of essential oils has been equivocal to date, probably because of the capacity of rumen microbes to adapt and degrade these secondary metabolites. Further, many of the concentrations of essential oils that have favourably affected rumen fermentation in vitro are too high for in vivo use as they would likely have deleterious effects on efficiency of rumen fermentation, palatability and possibly cause toxicity. Based on available results, it appears that some essential oils (e.g., garlic and its derivatives and cinnamon) reduce CH4 production in vitro. However, there is a need for in vivo investigation to determine whether these compounds can be used successfully to inhibit rumen methanogenesis. The challenge remains to identify essential oils that selectively inhibit rumen methanogenesis at practical feeding rates, with lasting effects and without depressing feed digestion and animal productivity.

Barley yield and nutrie...

Montrer texte Montrer source en cache Montrer URL avec texte source

Les différents traitements étaient les suivants : trois différentes doses (13, 39 ou 77 Mg ha-1 poids sec) de fumier frais ou composté renfermant de la litière de paille ou de copeaux de bois; engrais inorganique; aucun apport (traitement témoin).

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Limited research exists on the long-term effect of fresh (FM) versus composted manure (CM) from beef cattle on barley (Hordeum vulgare L.) yield and nutrient uptake. Barley was grown (1999-2007) as silage on an irrigated clay loam soil in southern Alberta where organic amendments and fertilizer were annually applied for 9 yr in the fall of 1998 to 2006. The treatments were three rates (13, 39, 77 Mg ha-1 dry wt.) of FM or CM containing either straw or wood-chip bedding, one inorganic fertilizer treatment, and a nonfertilized control. Nine years of annual application of FM and CM resulted in similar aboveground dry matter yield, and total N and total P uptake compared with inorganic fertilizer. However, apparent nitrogen recovery (ANR) and phosphorus recovery (APR) were significantly lower for FM and CM (5-9%) than inorganic (22-47%). Barley dry matter yield, ANR, and APR were similar for FM and CM. Manure type influenced N and P uptake, but the effects varied with bedding type and year. The N and P uptake were greater for CM with straw than the other three treatments except FM with straw. The DM yield was similar for straw and wood bedding, but ANR was greater for straw (10%) than wood (7%). Bedding influenced N uptake, P uptake, and APR, but the effects varied with manure type, rate, and year. Based on the results of this study, producers converting from FM to CM, or from straw to wood-chip bedding, should suffer no loss in barley silage production.

Development and validat...

Montrer texte Montrer source en cache Montrer URL avec texte source

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Using Ethylene Gas and ...

Montrer texte Montrer source en cache Montrer URL avec texte source

Dans le cadre de l’étude, d’une durée de 3 ans, nous avons utilisé des pommes de terre Shepody (frites) et NorValley (croustilles), en vue de déterminer si la combinaison de doses réduites de chlorprophame et d’éthylène gazeux permet d’empêcher la germination tout en obtenant des produits transformés de bonne couleur.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Marketplace preference for lower pesticide residues in foods has led to research to reduce the residue of chlorpropham (isopropyl N-3-chlorophenyl carbamate; CIPC), a postharvest-applied sprout inhibitor which is widely used around the globe to prevent sprouting of stored potatoes (Solanum tuberosum L.). Ethylene gas, an effective, safe and non-toxic sprout inhibitor used in several countries, sometimes has negative effects on the colour of processed potato products when used alone. Trials were conducted over 3 years using cv. Shepody (French fry) and cv. NorValley (potato chips/crisps) to determine whether a combination of these two sprout inhibitors, at reduced dosages, could inhibit sprouting while maintaining good processing colour. CIPC applied at 0, 0.1, 0.25 and 1.0 times the recommended dosage was combined with 4 μl-1 of ethylene gas applied or no ethylene at all (0 ethylene), for 1 day in 4 days, for 1 day in 2 days or continuously, in a factorial design. Sprout inhibition in both cultivars was excellent at all levels of CIPC application except the 0 rate. In both cultivars, sprouting was inhibited by the continuous ethylene treatment. However, all levels of ethylene exposure except the 0 rate negatively affected processing colour in both cultivars. The darkening was dose dependent, whereby the colour was darkest in continuous ethylene and was less affected by the intermittent exposures. In continuous ethylene, the colour was progressively lighter during storage after initial darkening. Shepody tubers appeared to be more sensitive to ethylene than the NorValley tubers. In Shepody only, colour in the ethylene of 1 day in 4 days treatments was progressively darker with increasing time in storage.

Knowledge and practices...

Montrer texte Montrer source en cache Montrer URL avec texte source

Les gardiens de bétail ne savaient ni lire ni écrire en anglais et ne possédaient aucune formation précise sur l’utilisation des parasiticides. Les répondants utilisaient les deux parasiticides selon des doses inférieures aux doses recommandées.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

A survey was conducted to assess the label information of acaricides and gastrointestinal anthelminthes used by farmers (n = 70) and herdsmen (n = 30) and their knowledge and practices in the administration of these parasiticides in the Sissila East district of the Upper West region of Ghana. Respondents were interviewed with semi-structured questionnaires and data analyzed using Statistical Package for Social Sciences (SPSS 11). Examination of the labels on the packages showed that a significant number of acaricides (14%; n = 45) and anthelminthes (30%; n = 102) were not certified by the Food and Drugs Board of Ghana as required by law (P<0.05). Administration of both parasiticides was done by veterinary personnel (9%), community-based livestock health workers (11%), livestock farmers (30%) or herdsmen (50%; P<0.05). The herdsmen were neither literate in the English language nor had any formal training in the use of agro-parasiticides. Both parasiticides were used by majority of respondents at levels below the recommended rate. There was also widespread cross-application of crop-designated pesticides and petroleum products in the control of ticks. Animals that did not respond to treatment were slaughtered and consumed in the household (65%; P<0.05). In addition, a significant number of farmers (35%; P<0.05) did not practice parasiticide withdrawal prior to slaughter or sale of livestock. Our results indicate that inappropriate handling and use of livestock parasiticides were prevalent and raised serious public health and food safety concerns in the Sissila East district of the Upper West region of Ghana.

Intracellular Expressio...

Montrer texte Montrer source en cache Montrer URL avec texte source

Nous avons déterminé la cytotoxicité et l’immunomodulation du VHH en mesurant continuellement la croissance cellulaire. À des doses équivalentes, le 15 AcDON était beaucoup plus toxique que le DON pour la souche sauvage de P. pastoris.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

15-Acetyldeoxynivalenol (15-AcDON) is a low molecular weight sesquiterpenoid trichothecene mycotoxin associated with Fusarium ear rot of maize and Fusarium head blight of small grain cereals. The accumulation of mycotoxins such as deoxynivalenol (DON) and 15-AcDON within harvested grain is subject to stringent regulation as both toxins pose dietary health risks to humans and animals. These toxins inhibit peptidyltransferase activity, which in turn limits eukaryotic protein synthesis. To assess the ability of intracellular antibodies (intrabodies) to modulate mycotoxin-specific cytotoxocity, a gene encoding a camelid single domain antibody fragment (VHH) with specificity and affinity for 15-AcDON was expressed in the methylotropic yeast Pichia pastoris. Cytotoxicity and VHH immunomodulation were assessed by continuous measurement of cellular growth. At equivalent doses, 15-AcDON was significantly more toxic to wild-type P. pastoris than was DON. In turn, DON was orders of magnitude more toxic than 3-acetyldeoxynivalenol. Intracellular expression of a mycotoxin-specific VHH within P. pastoris conveyed significant (p = 0.01) resistance to 15-AcDON cytotoxicity at doses ranging from 20 to 100 μg·ml-1. We also documented a biochemical transformation of DON to 15-AcDON to account for the attenuation of DON cytotoxicity at 100 and 200 μg·ml-1. The proof of concept established within this eukaryotic system suggests that in planta VHH expression may lead to enhanced tolerance to mycotoxins and thereby limit Fusarium infection of commercial agricultural crops.

Epidermal Growth Factor...

Montrer texte Montrer source en cache Montrer URL avec texte source

Dans les travaux présentés ici, nous avons constitué 4 groupes de 8 porcs chacun et nous leur avons donné la bactérie L. lactis exprimant le facteur EGF (LL EGF), la bactérie L. lactis exprimant le vecteur vide (LL VV), du facteur EGF humain recombinant ou du milieu bactérien sans supplément; dans tous les cas, les porcs recevaient chaque jour deux doses de 50 mL par voie intragastrique.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Stress and incomplete gastrointestinal development in early-weaned piglets represent significant challenges in commercial swine farming. Orally ingested recombinant epidermal growth factor (EGF) has been shown to remain biologically active in the gastrointestinal tract as well as stimulate intestinal development, reducing the incidence of pathogen infection and diarrhea. We have previously shown that the food-grade bacterium Lactococcus lactis can be genetically altered to express biologically active EGF when fed to early-weaned mice. In this study, we assigned 8 pigs to each of 4 groups that were given EGF-expressing L. lactis (EGF-LL), empty vector-expressing L. lactis (EV-LL), recombinant human EGF, or unsupplemented bacterial media, all of which were delivered as 50-mL i.g. doses twice per day. All pigs were killed after 14 d to examine intestinal morphology. Pigs in the EGF-LL group had greater jejunal and duodenal villus heights (P < 0.0001) and intestinal length (P = 0.049) than pigs in the control group. Immunohistochemistry with antibodies against proliferating cell nuclear antigen (PCNA) revealed that the proliferation of intestinal cells was significantly greater in the EGF-LL group than in the control group. PCNA expression and intestinal length also were greater in the EV-LL group, which received L. lactis that did not express EGF, than in the control group (P = 0.049), further supporting the use of naturally occurring intestinal microbes as desirable vectors for recombinant protein delivery. Our data demonstrates the feasibility of delivering a growth factor using common probiotic bacteria to farm animals for commercial practice.

Improving organic C and...

Montrer texte Montrer source en cache Montrer URL avec texte source

Les résultats mettent en évidence l’importance de l’application de doses équilibrées/combinées d’engrais azoté et soufré aux cultures pour le stockage de plus grandes quantités de C et de N organiques dans les sols carencés en S.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

A field experiment was conducted over 9 years (1999 to 2007 growing seasons) in northeastern Saskatchewan on a S-deficient Gray Luvisol (Typic Haplocryalf) soil. The objective was to determine the relative effectiveness of N alone versus combined annual application of N (120 kg N ha-1) and S (15 kg S ha-1) fertilizers to a wheat-canola rotation on storage of total organic C (TOC) and N (TON) and on the light fraction organic C (LFOC) and N (LFON) in soil. Compared to N alone, annual applications of S fertilizer in spring in a combination with N resulted in an increase in soil of TOC (by 2.18 Mg C ha-1), TON (by 0.138 Mg N ha-1), LFOC (by 1,018 kg C ha-1), and LFON (by 42 kg N ha-1). The relative increases in organic C or N due to S fertilizer application were much higher for the light organic fractions (36.9% for LFOC and 27.5% for LFON) than for the total organic fractions (9.2% for TOC and 7.3% for TON). The findings demonstrate the importance of a balanced/combined application of N and S fertilizers to crops in storing more organic C and N in this S-deficient soil.

Efficacy of

Montrer texte Montrer source en cache Montrer URL avec texte source

La présente étude vise à évaluer l’efficacité du bioherbicide P. macrostoma en conditions simulées de pluie pour déterminer si la bioactivité est retenue dans le sol et si les métabolites du bioherbicide sont solubles dans l’eau, ce qui pourrait poser un risque pour des hôtes à l’extérieur du site ciblé. Diverses doses d’application du bioherbicide ont été lessivées dans une quantité d’eau équivalant à des précipitations de 25 à 250 mm.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

This study evaluated the efficacy of the bioherbicide P. macrostoma under simulated rainfall conditions to determine whether bioactivity was retained in the soil and whether bioherbicidal metabolites would be soluble in water possibly posing a risk to off-site hosts. Various application rates of the bioherbicide were leached with water equivalent to 25-250 mm of precipitation and tested for efficacy before and after leaching using a dandelion bioassay. The percolated water was collected in six fractions (F1-F6) and similarly tested for bioactivity using a dandelion bioassay. Relative concentrations of macrocidin A, the main bioherbicidal metabolite, were estimated by HPLC. DNA-specific primers were used to detect the presence of the fungus in soil. Of three soil types treated with the bioherbicide, all lost the ability to control dandelion after being leached. Clay, as compared to sandy loam and greenhouse soil mix, retained the most bioherbicidal activity. The bioherbicidal metabolite was soluble in water with up to 80% macrocidin A being released in 75 mm of water and bioactivity occurring in fractions F1-F3, with much less or no activity in fractions F4-F6. The impact of water on the distribution of the living component of the bioherbicide was not clearly determined. The study shows that water releases macrocidins from the bioherbicide allowing the compound to be taken up by the roots of the plant, subsequently resulting in plant death. When soils are at field capacity or drier, this amount of rainfall is of little concern as the bioactivity is localized. However under saturated soils, macrocidins may be released in the soil water and if not taken up by the plants, run-off water may pose a risk to off-site hosts. Factors that mitigate the risks associated with off-site movement are discussed.

Managing crop losses fr...

Montrer texte Montrer source en cache Montrer URL avec texte source

Nous avons appliqué les fongicides requis contre les maladies associées à chaque plante cultivée, au cours du stade de développement recommandé et selon les doses recommandées, puis nous avons évalué leur effet sur la gravité des maladies.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

The impact of tillage system, rotation sequence and foliar fungicides on diseases and seed yield and quality of wheat, barley, pea, canola and flax was determined in the second cycle of three, 4-year rotations from 1998 to 2001 on a Black Chernozem (Udic Boroll) at Melfort, Saskatchewan, Canada. The objective of the study was to evaluate the impact of reduced-tillage production systems, broadleaf cropping intensity and fungicide use on cereal, oilseed and pulse crops in northeastern Saskatchewan, a sub-humid region of the northern Great Plains. A split-split plot design was used with three tillage systems (conventional, minimum and no-till) as main plots, three rotations of increasing broadleaf crop intensity (1. canola-wheat-barley-barley; 2. canola-barley-pea-wheat; and 3. canola-pea-flax-barley) as sub-plots, and fungicide treatments (treated or untreated) as sub-sub-plots. Fungicides appropriate for the diseases of concern were applied at recommended crop development stages and application rates, followed by assessment of diseases. Tillage system had little impact on diseases of any crop, although seed yield was usually greater under no-till for most crops under dry conditions. Rotation was not a major factor in disease severity of most of the crops, except barley in the rotation where it was grown for two consecutive years. Under dry conditions, barley yield was reduced when it followed flax compared with other crops, most likely due to less available soil moisture after flax. Fungicide application had the greatest impact on disease control and seed yield increase, although results varied among crops and years. In conclusion, the findings indicate that tillage system had little effect on disease severity, rotation contributed to greater disease severity only when a crop was grown intensively, such as on its own stubble, and fungicide application had variable effects on both disease control and seed yield.

The effect of MSW compo...

Montrer texte Montrer source en cache Montrer URL avec texte source

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Guidelines for in-seaso...

Montrer texte Montrer source en cache Montrer URL avec texte source

On applique souvent au maïs (Zea mays L.) des engrais azotés à des doses supérieures à la dose économiquement optimale en raison de l’incertitude liée à la variabilité saisonnière et spatiale. Une meilleure compréhension des relations qui lient le terrain, la conductivité électrique apparente (CEa) du sol, l’altitude, la pente et les caractéristiques saisonnières est donc essentielle pour une application différentielle d’engrais azoté qui soit optimale.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Nitrogen (N) fertilizers are often applied to maize (Zea mays L.) in excess of economically optimal rates because of the uncertainty of dealing with seasonal and spatial variability. A better understanding of the relationships among field, apparent soil electrical conductivity (ECa), elevation, slope and seasonal characteristics is therefore essential for performing optimal variable-rate N applications. This study focused on responses during the exponential growth phase, when it is critical that N supply be not limited. Measurements at high spatial resolution allowed to understand the effects of the relationships among N, ECa, elevation, slope and season on future yield formation. The study was conducted over three years (2005-2007). Mid-season growth responses to applied N were greatest where ECa levels were high and elevation was low in 2005 and 2007, but not in 2006. Areas with slope ≥1 degree were also more responsive to N rates. Overall best mid-season growth was found in areas of low ECa, high Elevation and low Slope. However, the best responses to in-season N fertilization were found in areas with opposite properties (high ECa, low Elevation and high Slope). Indeed, relatively high rates of in-season N were needed to enhance crop growth in areas of high ECa, low Elevation and high Slope, which are characteristic of unfavourable growth conditions. In counterpart, lower N rates were sufficient for optimal growth in soils at low ECa high Elevation and low Slope. Also, despite the fact that conditions of high soil variability were specifically selected for the study, the effects and interactions reported for soil NO3-N content were small. The interaction of ECa with early seasonal precipitation is likely a key relationship to consider in variable-rate N application: low-lying areas with fine soil texture showed the greatest dependence on weather for optimal N rates. Indeed, the relationships among factors influencing the response to in-season N fertilization were stronger when seasonal conditions were particularly favourable to maize growth. These results are fundamental to the establishment of in-season application rules for spatially variable N algorithms.

Phosphorus fertilizer e...

Montrer texte Montrer source en cache Montrer URL avec texte source

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Intracellular Expressio...

Montrer texte Montrer source en cache Montrer URL avec texte source

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Using Ethylene Gas and ...

Montrer texte Montrer source en cache Montrer URL avec texte source

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Lutte contre les mauvai...

Montrer texte Montrer source en cache Montrer URL avec texte source

L’application séquentielle des deux traitements, à diverses doses, détruit 100% du chénopode blanc, 100 % de l’amarante ré fléchie, 100 % de la moutarde sauvage, de 96 à 100 % de la petite herbe à poux et de 97 à 100 % de la sétaire verte.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Field studies were conducted at the Huron Research Station near Exeter, Ontario, in 2006 to 2009 to determine if the sequential application of trifluralin plus imazethapyr applied preplant incorporated (PPI) followed by linuron applied pre-emergence (PRE) at various doses can be used as an effective weed management strategy in cranberry bean production. There was minimal crop injury (6% or less) with various herbicides evaluated at 1 and 4 wk after emergence (WAE). Trifluralin plus imazethapyr applied PPI provided 97 to 100% control of common lambsquarters, 100% control of redroot pigweed, 99 to 100% control of wild mustard, 93 to 100% control of common ragweed, and 97 to 100% control of green foxtail. Linuron applied PRE provided 11 to 100% control of common lambsquarters, 90 to 100% control of redroot pigweed, 78 to 100% control of wild mustard, 71 to 100% control of common ragweed, and 20 to 100% control of green foxtail. The sequential application of trifluralin plus imazethapyr applied PPI followed by linuron applied PRE at various doses provided 100% control of common lambsquarters, 100% control of redroot pigweed, 100% control of wild mustard, 96 to 100% control of common ragweed, and 97 to 100% control of green foxtail. Weed density and shoot dry weight correlated well with the level of weed control. All of the herbicide treatments evaluated increased cranberry bean yield compared with the weedy control. Based on these results the sequential application of imazethapyr plus trifluralin applied PPI followed by linuron applied PRE at 1000 and 2500 g a.i. ha-1 provides a safe and efficacious weed management strategy in cranberry bean production.

Effect of halosulfuron ...

Montrer texte Montrer source en cache Montrer URL avec texte source

L’halosulfuron appliqué en PPI, en PRE ou en POST à raison de 35 ou 70 g/ha n’a causé aucune diminution de la hauteur de la plante, sauf dans le cas du haricot rognon, dont la hauteur a été réduite de 6 % par la dose de 70 g/ha, et du haricot blanc, dont la hauteur a été réduite de 3 % par les deux doses.

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

Five field trials were conducted over a 2-yr period (2007, 2008) at various locations in Ontario to evaluate the tolerance of black, cranberry, kidney, otebo, pink, pinto, small red Mexican (SRM), and white bean to halosulfuron applied PPI, PRE, and POST at 35 and 70 g ai/ha. There was minimal injury (3% or less) with halosulfuron applied PPI or PRE in dry bean. At Exeter and Ridgetown, halosulfuron applied POST at 35 and 70 g/ha caused 3 to 5% and 4 to 8% injury in dry bean, respectively at 1 wk after herbicide application (WAA). The injury was transient with no significant injury at 2 and 4 WAA. At Harrow, halosulfuron POST at 35 and 70 g/ha caused as much as 4% injury at 35 g/ha and 14% injury at 70 g/ ha in dry bean. Halosulfuron applied PPI, PRE, and POST at 35 and 70 g/ha caused no decrease in plant height of dry bean except for kidney bean, which was reduced 6% at 70 g/ha, and white bean, which was reduced 3% at both 35 and 70 g/ha. Halosulfuron applied PPI, PRE, and POST at 35 and 70 g/ha caused no decrease in dry bean yield except for kidney bean, which was reduced 9% at 35 g/ha and 10% at 70 g/ha; otebo bean, which was reduced 3% at 70 g/ha; and white bean, which was reduced 7% at both 35 and 70 g/ha. On the basis of these results, there is an adequate margin of crop safety in dry bean to halosulfuron applied PPI or PRE at 35 and 70 g/ha. In addition, there is an adequate margin of crop safety in black, cranberry, pink, pinto, and SRM bean to halosulfuron applied POST at 35 and 70 g/ha. However, further research is required to ascertain the tolerance of kidney, otebo, and white bean to halosulfuron applied POST.

Validation of a Managem...

Montrer texte Montrer source en cache Montrer URL avec texte source

Comparer pages textes Comparer pages HTM Montrer URL avec texte source Montrer URL avec langue cible Définir www5.agr.gc.ca comme domaine prioritaire

1 2 3 4 5 6 7 8 9 10

capta – Traduction – Dictionnaire Keybot