References of "Giraud, Frédéric"
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See detailBrown rust disease control in winter wheat: II. Exploring the optimization of fungicide sprays through a decision support system
El Jarroudi, Moussa ULg; kOUADIO, Louis; Giraud, Frédéric et al

in Environmental Science & Pollution Research (2014), 21(4), 4809-4818

A decision support system (DSS) involving an approach for predicting wheat leaf rust (WLR) infection and progress based on night weather variables (i.e., air temperature, relative humidity, and rainfall ... [more ▼]

A decision support system (DSS) involving an approach for predicting wheat leaf rust (WLR) infection and progress based on night weather variables (i.e., air temperature, relative humidity, and rainfall) and a mechanistic model for leaf emergence and development simulation (i.e., PROCULTURE) was tested in order to schedule fungicide time spray for controlling leaf rust progress in wheat fields. Experiments including a single fungicide treatment based upon the DSS along with double and triple treatment were carried out over the 2007–2009 cropping seasons in four representative Luxembourgish wheat field locations. The study showed that the WLR occurrences and severities differed according to the site, cultivar, and year. We also found out that the single fungicide treatment based on the DSS allowed a good protection of the three upper leaves of susceptible cultivars in fields with predominant WLR occurrences. The harvested grain yield was not significantly different from that of the double and triple fungicide-treated plots (P < 0.05). Such results could serve as basis or be coupled to cost-effective and environmentally friendly crop management systems in operational context. [less ▲]

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See detailFactors affecting Tan Spot on winter wheat in the Grand-Duchy of Luxembourg
El Jarroudi, Moussa ULg; Kouadio, Louis; Beyer, Marco et al

in Journal of Plant Pathology [=JPP] (2013), s1

Tan spot caused by Drechslera tritici-repentis was identified for the first time in the Grand-Duchy of Luxembourg (GDL) in 1999 on the basis of morphological characters. In order to optimize disease ... [more ▼]

Tan spot caused by Drechslera tritici-repentis was identified for the first time in the Grand-Duchy of Luxembourg (GDL) in 1999 on the basis of morphological characters. In order to optimize disease control measures in this country, tillage methods, cultivar resistance, and fungicides effects were investigated during 1999-2009 in four sites. Over this period, only three years (i.e. 1999, 2000, and 2009) with epidemic outbreak were recorded. Field experiments showed a significant difference in disease severity between sites (P < 0.001), cultivars (P < 0.0001) and years (P < 0.001). In years with epidemic outbreak, the interaction of cultivars with non-inversion tillage, intensive winter wheat production, and favorable weather conditions caused an early outbreak of the disease and a significant severity at growth stage 83 (early dough). Non-inversion tillage was found to be a major factor increasing the tan spot severity compared to conventional tillage. Furthermore, the analysis revealed that the disease severity was related to the cultivar’s susceptibility. For cultivars with similar phenology, the severity differed between the cultivar with the highest and the one with ne lowest susceptibility by a factor of two to four. The study also showed that no fungicide (mix of triazoles and strobilurins) effect was observed in the epidemic years, except in 2000. [less ▲]

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See detailTypology of the Main Fungal Diseases Affecting Winter Wheat in the Grand Duchy of Luxembourg
El Jarroudi, Moussa ULg; Kouadio, Louis; Delfosse, Philippe et al

in Journal of Agricultural Science and Technology (2012), 2

Over the 2003-2009 period, field campaigns were carried out in order to identify the main fungal diseases of winter wheat (Triticum aestivum) in the Grand-Duchy of Luxembourg. Four fungal diseases ... [more ▼]

Over the 2003-2009 period, field campaigns were carried out in order to identify the main fungal diseases of winter wheat (Triticum aestivum) in the Grand-Duchy of Luxembourg. Four fungal diseases (septoria leaf blotch (SLB), wheat leaf rust (WLR), wheat powdery mildew (WPM) and fusarium head blight (FHB)) were observed and a regional-based typology was established according to their severity and prevalence. In the Gutland (South), SLB severity was strong (about 51% on average) and higher than the severity (about 16%) prevailing in the Oesling (North). Similar typology was observed with the WLR: high severity in the Gutland (66% and 57% for the years 2003 and 2007, respectively) and low severity (< 1%) in the Oesling. The FHB was also present in the Eastern part of the Gutland, with a prevalence and severity significantly higher (P = 0.049 and P = 0.012, respectively, Tukey’s test) compared with their values in the Oesling. On the other hand, the WPM severity was high in the Oesling (15% to 40%) while less than 1% in the Gutland. Such a study is important for the spatial mapping of wheat fungal diseases risk based on agroclimatic parameters and for defining optimal frequencies and dates of chemical treatments. [less ▲]

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See detailMaladies du blé d'hiver au Luxembourg Les interactions entre climat, sol et phytotechnie montrent l'importance primordiale du facteur climat
El Jarroudi, Moussa ULg; Giraud, Frédéric; Delfosse, Philippe et al

in Phytoma : La Défense des Végétaux (2012), 650

Malgré sa petite taille, le GDL est caractérisé par deux régions très contrastées en ce qui concerne les maladies cryptogamiques du blé d’hiver. Une analyse en composante principale a permis d’analyser la ... [more ▼]

Malgré sa petite taille, le GDL est caractérisé par deux régions très contrastées en ce qui concerne les maladies cryptogamiques du blé d’hiver. Une analyse en composante principale a permis d’analyser la distribution des maladies cryptogamiques entre le Gutland et l’Oseling. La distribution des maladies cryptogamiques est significativement différente (P < 0.001) entre le Gutland et l’Oesling. Entre 2003 et 2009, la septoriose et la rouille brune sont des maladies qui caractérisent le Gutland avec respectivement comme pourcentage 51 et 17%. Dans l’Oesling, la sévérité de ces maladies était très faible et n’atteignait même pas 1%. A l’opposé, l’Oesling est caractérisée par l’installation de l’Oïdium surtout en 2003 et 2009 avec respectivement 15 et 40% de sévérité alors cette maladie ne dépassait pas 1% de sévérité en Gutland. Parallèlement à ces maladies, d’autres pathogènes fongiques sont observées uniquement en Gutland et les maladies qu’ils causent sont influencées par la phytotechnie. Il s’agit de l’helminthosporiose et de la rouille jaune avec comme caractéristique le contournement du gène de résistance Yr 17+. La variation dans l’expression des maladies cryptogamiques entre le Gutland et l’Oesling est surtout due aux différences marquées des conditions climatiques entre les deux régions mais aussi aux pratiques agricoles en vigueur (fumure azotée, choix variétal, semis avec labour ou sans labour….). [less ▲]

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See detailImages hémisphériques et leur analyse pour prévoir le rendement du blé d’hiver. Comment la phase de décroissance de la surface verte de la plante nous renseigne-t-elle sur le rendement final ?
Kouadio, Amani Louis ULg; Djaby, Bakary ULg; Giraud, Frédéric et al

in Phytoma : La Défense des Végétaux (2011), 648

The prediction of cereal-crop yield is considered as a priority in most crop research programmes due to the relevance of food grain to feeding the world population. Today, a large number of ... [more ▼]

The prediction of cereal-crop yield is considered as a priority in most crop research programmes due to the relevance of food grain to feeding the world population. Today, a large number of agrometeorological models for crop yield assessment are available with various levels of complexity and empiricism. But, currently the development of wheat yield forecasting models in conventional operational systems do not reflect the loss of active green leaf area and its relation to biotic and abiotic processes implicated in the crop production situation. In 2009 a large field campaign in the Grand-Duchy of Luxembourg was realized to assess the validity of leaf-green-area approach to further improve yield prediction. Hemispherical photography were taken on winter wheat fields during the crop cycle, preferentially from inflorescence emergence to maturity. The variable of interest, the Green Area Index (GAI), was retrieved after image analyses using the CAN-EYE software. The regression-based models calculated with metrics derived from the decreasing curves of GAI showed that final yield could be better estimated with satisfactory precision: range of the coefficient of determination (R²) varies from 0.73 to 0.86 and RMSE (root mean square error) is varying between 0.43 and 0.56 t/ha. The validation of such approach at the scale of an agricultural zone or region is currently under progress, by using green area index temporal profiles and information on the phenology of winter wheat. Such simple models may be considered as a first step towards yield estimation that may be completed by other agrometeorological models in order to provide a better integrated yield assessment. [less ▲]

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See detailRegional-based typology of the main fungal diseases affecting winter wheat.
El Jarroudi, Moussa ULg; Giraud, Frédéric; Delfosse, Philippe et al

Poster (2011, August 06)

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See detailNew method for establishing a network of operational warning of Septoria leaf blotch disease in winter wheat
El Jarroudi, Moussa ULg; Giraud, Frédéric; Defosse, Philippe et al

Poster (2011, August 06)

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See detailNew method for establishing a network of operational warning of Septoria leaf blotch disease in winter wheat
El Jarroudi, Moussa ULg; Giraud, Frédéric; Delfosse, Philippe et al

in Phytopathology (2011), 101

A mechanistic model, PROCULTURE, based on commonly available meteorological data and assessing in real time the risk of progression of septoria leaf blotch disease on winter wheat has been developed in ... [more ▼]

A mechanistic model, PROCULTURE, based on commonly available meteorological data and assessing in real time the risk of progression of septoria leaf blotch disease on winter wheat has been developed in Belgium and the Grand-Duchy of Luxemburg (GDL) to limit fungicide use. However, the reliability of meteorological stations used for the warning system varies according to the distance to the fields. A weather analysis based on the Fourier transform highlighted a great difference in the intraday variation between two sites in the GDL (Everlange and Reuland). The correlation between these two sites is very high for the hourly temperature (R = 0.96), and for the hourly relative humidity (RH) (R = 0.86), (P < 0.05). However, the intraday variation (<11 hours) highlights contrasts for a given meteorological parameter. Hence, the correlation between temperature or RH decreased respectively from 0.96 to 0.43 and from 0.86 to 0.30. The comparison between infection conditions given by PROCULTURE using the Fourier transform, shows: (i) a positive but weak correlation between temperature at Reuland and Everlange (R = 0.64), (ii) a good correlation between RH for these two sites (R = 0.86), and (iii) a contrasted difference for rain (R = 0.27), (P < 0.05). This Fourier transform based method enables to take into account the RH and temperature variation related to topography levels in the warning system and to understand and explain the variation in disease expression between a plateau and a valley bottom or between North and South slopes. [less ▲]

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See detailPrévoir la septoriose : un modèle belge au Luxembourg
El Jarroudi, Moussa ULg; Giraud, Frédéric; Tychon, Bernard ULg et al

in Phytoma : La Défense des Végétaux (2011), 642

Septoria leaf blight caused by Septoria tritici Roberge ex Desmaz. (anamorph of Mycosphaerella graminicola) is one of the most serious foliar diseases on winter wheat which farmers in Luxembourg. It need ... [more ▼]

Septoria leaf blight caused by Septoria tritici Roberge ex Desmaz. (anamorph of Mycosphaerella graminicola) is one of the most serious foliar diseases on winter wheat which farmers in Luxembourg. It need to take into account when deciding upon fungicide application during stem elongation. Management of S. tritici aims at keeping the top two leaf layers free from infection, as these leaves contribute most to grain yield. The model PROCULTURE has been developed to simulate the progress of the Septoria leaf blotch disease on winter wheat during the cropping season. The model has been validated in Luxembourg for 3-years (2000 to 2002) at distinct representative sites. Proculture forecasts have been shown to be correct in about 85% of all cases. This model has since 2004 been used in the Grand-Duchy of Luxemburg in order to find the optimum time of fungicide spray in fields. On average, no spray of fungicides or only one application is required to efficiently control Septoria leaf blotch. In the Oesling (north of G-D of Luxembourg), treatments based on the Septoria risk simulation model were recommended only once, in 2007. The climatic conditions of the Oesling tend to favour organic farming in a region where foliar disease pressure is very weak. [less ▲]

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See detailTIMELY FUNGICIDE APPLICATION: A STRATEGY TO MINIMIZE FUSARIUM HEAD BLIGHT AND ASSOCIATED MYCOTOXIN PRODUCTION IN WINTER WHEAT
Giraud, Frédéric; Pasquali, Mattias; El Jarroudi, Moussa ULg et al

in Journal of Plant Pathology [=JPP] (2011), 93(1, supplement), 115-118

Re-emergence of Fusarium head blight (FHB) on wheat should be taken into account in the global management of cropped fields, especially with respect to fungicide application schemes, due to harmful toxin ... [more ▼]

Re-emergence of Fusarium head blight (FHB) on wheat should be taken into account in the global management of cropped fields, especially with respect to fungicide application schemes, due to harmful toxin production. The aim of this study was to assess, in three experimental fields representative of the various topoclimatological zones of Luxembourg, the impact of timing of fungicide spray application on the prevalence and severity of FHB, the concentration of mycotoxins, and Fusarium strain pattern in winter wheat. It was found that fungicide treatments and the time of application had a significant impact on the amount of deoxynivalenol (DON) detected (P=0.027, ANOVA). In our experimental design, the application of fungicides at 3 different times increased the amount of DON in winter wheat compared to two and single applications. The importance of the timing of fungicide application is discussed in relation to limiting toxin contamination in the field. [less ▲]

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See detailRegional-based typology of the main fungal diseases affecting winter wheat in the Grand-Duchy of Luxembourg
El Jarroudi, Moussa ULg; Giraud, Frédéric; Delfosse, Philippe et al

in Phytopathology (2011), 101

Despite its small territory size, the Grand-Duchy of Luxembourg (GDL) has several microclimates that result in a variability of disease severity between the South (Gutland) and the North (Oesling ... [more ▼]

Despite its small territory size, the Grand-Duchy of Luxembourg (GDL) has several microclimates that result in a variability of disease severity between the South (Gutland) and the North (Oesling). Septoria leaf blotch disease of wheat is an important disease in the GDL. Over 2003–2009, the severity was strong in Gutland (51% on average over the last two upper leaves at the late milk growth stage) and low in the Oesling (16% for the same leaves). For the years 2006, 2008 and 2009, the disease severity was less than 6% in the Oesling while it exceeded 40% in the Gutland. The second fungal disease that has become economically important is the wheat leaf rust. Over the same period, the Gutland and the Oesling showed consistently the highest and lowest disease severity respectively. In 2003 and 2007, the Gutland showed the highest disease severity with 66% and 57% respectively, whereas the lowest severity (<1%) was observed in the Oesling. Another important disease is wheat powdery mildew. The 2003 and 2009 cropping seasons showed the highest disease severity with 15% and 40%, respectively, in the Oesling whereas less than 1% severity was registered in the Gutland. Fusarium head blight was also present in the eastern part of the Gutland showing the highest prevalence and severity in 2007 and 2008 (8.5% and 8.3% respectively). These prevalence and severity percentages were significantly higher compared to the Oesling (% prevalence % severity, p = 0.049 and p = 0.012, respectively, Tukey’s test). [less ▲]

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See detailSITE – SPECIFIC MONITORING FOR DISEASE FORECASTING IN WINTER WHEAT.
El Jarroudi, Moussa ULg; Giraud, Frédéric; Delfosse, Philippe et al

in Journal of Plant Pathology [=JPP] (2011), 93(Supplement 1), 19-20

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See detailFirst report of the breakdown of the YR17 resistance gene to wheat stripe rust in the Grand Duchy of Luxembourg
El Jarroudi, Moussa ULg; Giraud, Frédéric; Tychon, Bernard ULg et al

in Journal of Plant Pathology [=JPP] (2011), 93(1), 243

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See detailAzoxystrobin and epoximazole sensitivity profiles of Mycosphaerella graminicola populations from the Grand-Duchy of Luxemburg in 2007 and 2008
Vrancken, Carine; Dubos, Tiphaine; El Jarroudi, Moussa ULg et al

Poster (2010, December 07)

Mycosphaerella graminicola strains were isolated from symptomatic winter wheat (Triticum aestivum) and spelt (Triticum spelta) leaves sampled across the Grand-Duchy of Luxembourg. In total, 484 strains ... [more ▼]

Mycosphaerella graminicola strains were isolated from symptomatic winter wheat (Triticum aestivum) and spelt (Triticum spelta) leaves sampled across the Grand-Duchy of Luxembourg. In total, 484 strains were isolated from winter wheat, and 31 from spelt leaves. The sensitivity profiles of these strains towards azoxystrobin (Amistar®, Syngenta Agro GmbH, Germany) and against epoxiconazole (Opus®, BASF Belgium NV/S A, Brussels, Belgium) were assessed in microplates, allowing to test 10 different concentrations for each active substance (0, 0.00316, 0.01, 0.0316, 0.1, 0.316, 1, 3.16, 10 and 31.6μg/mL). 100μ g/mL of salicylhydroxamic acid (SHAM) was also added to the medium, in order to prevent the strains from using alternative respiration. Results of the sensitivity tests for azoxystrobin showed a dose-dependent decrease of in vitro growth for all the strains. During both years, strains could be divided into two distinct sub-populations in relation to their azoxystrobin sensitivity, thus forming a bimodal distribution commonly reported to be associated with a single gene-mediated resistance. For wheat, the dominant sub-population was the one showing full resistance to azoxystrobin. The results of the sensitivity tests to epoxiconazole in liquid media showed a dose-dependent decrease of fungal growth for all the strains tested. The EC50 values followed an unimodal distribution. When the sensitivity distribution of the strains collected in 2008 (n=379) was compared to that observed in 2007, although the populations have remained unimodal, a minor shift towards less sensitive populations was observed. Compared to strains originating from wheat, the spelt strains were more sensitive towards both fungicides (p ≤ 0.001). [less ▲]

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See detailSite–specific monitoring for disease forecasting in winter wheat.
El Jarroudi, Moussa ULg; Giraud, Frédéric; Delfosse, Philippe et al

Conference (2010, November 22)

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See detailRouille brune du blé, un modèle pour évaluer les risques
El Jarroudi, Moussa ULg; Giraud, Frédéric; Tychon, Bernard ULg et al

in Phytoma-la défense des végétaux (2010), 637

L’article présente un outil de prévision de la rouille brune au G.-D. de Luxembourg. De 2000 à 2003, cette maladie apparaissait à la fin de l’épiaison, mais depuis 2003, elle apparaît de plus en plus tôt ... [more ▼]

L’article présente un outil de prévision de la rouille brune au G.-D. de Luxembourg. De 2000 à 2003, cette maladie apparaissait à la fin de l’épiaison, mais depuis 2003, elle apparaît de plus en plus tôt (GS45 stade gonflement). Cette apparition précoce est probablement liée à des températures printanières supérieures par rapport à la normale 1971-2000. Une analyse des données météorologiques nocturnes et des données d’observation de la maladie sur quatre sites expérimentaux (Everlange, Christnach, Burmerange et Reuler) entre 2000 et 2003 a révélé une forte corrélation positive entre la prédiction de la maladie basée sur le critère d’au moins 12 heures consécutives avec une température comprise entre 8 et 16°C et une humidité supérieure à 60% et la maladie observée sur la F1 (R = 0.93 ; P < 0.05) et sur la F2 (R = 0.87 ; P < 0.05). Les sorties de ce modèle qui a été développé sur base d’une approche stochastique ont été utilisées dans les bulletins d’avertissements diffusés conjointement par le Centre de Recherche Public – Gabriel Lippmann et l’Université de Liège-Campus d’Arlon à partir de 2004. La mise en application de ce modèle a montré un taux de réussite oscillant entre 80 et 85% pour la simulation de la rouille brune au G.-D. de Luxembourg. L’effort se poursuit pour spatialiser les sorties du modèle sur tout le territoire luxembourgeois et faciliter son utilisation par tous les vulgarisateurs agricoles. [less ▲]

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See detailModelling plant diseases impact with the Belgium Crop Growth Monitoring System.
El Jarroudi, Moussa ULg; Kouadio, Amani Louis ULg; Martin, Bertrand ULg et al

in Wery, Jacque; Shili-Touzi, I.; Perrin, A. (Eds.) PROCEEDING OF AGRO2010 the XIth ESA Congress (2010, September)

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See detailTime spray strategies for Septoria Leaf Blotch disease progress on winter wheat: the use of forecasting model
El Jarroudi, Moussa ULg; Giraud, Frédéric; Delfosse, Philippe et al

Conference (2010, August 07)

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See detailAssessment of the night weather parameters and their use in forecasting model of leaf rust.
El Jarroudi, Moussa ULg; Giraud, Frédéric; Delfosse, Philippe et al

Conference (2010, August 07)

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