References of "El Jarroudi, Moussa"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailSpatial heterogeneity of leaf wetness duration in winter wheat canopy and its influence on plant disease epidemiology
Mahtour, Abdeslam ULg; El Jarroudi, Moussa ULg; Giraud et al

in Phytopathology (2010)

Leaf wetness duration (LWD) is an important factor influencing the occurrence of plant disease epidemiology. Despite considerable efforts to determine LWD, little attention has been given to study its ... [more ▼]

Leaf wetness duration (LWD) is an important factor influencing the occurrence of plant disease epidemiology. Despite considerable efforts to determine LWD, little attention has been given to study its variability within the canopy. The objective of this study was to evaluate its spatiotemporal variability in wheat fields in a heterogeneous landscape. The spatiotemporal variability of LWD was evaluated in a site close to Arlon (Belgium) during the period May to July 2006 and 2007. LWD measurements were made using a set of flat plate sensors deployed at five different distances from a 18 m high hedge (5, 10, 20, 50, 100 m). Each set of two sensors was placed horizontally close the flag leaf. In addition, we collected the amount of dew water that deposited on rigid epoxy plates placed next to each sensors. Experimental results showed that LWD measurements revealed substantial heterogeneity among sensor positions. LWD is longer for sensors closer to the hedge mainly because of its shadowing effect. 3 to 4 hours of difference was observed between sensors located at 5 m and those located at 100 m, and besides, a significant quantitative difference (p < 0.0001) of dew deposit was observed between area beside hedge and those placed at 100 m. In summary, this study provides new information on how wetness is distributed on wheat leaves according to the distance from a hedge. This leads to local microclimate conditions that will contribute to the disease spatial heterogeneity. [less ▲]

Detailed reference viewed: 38 (8 ULg)
Full Text
Peer Reviewed
See detailAssessment Of The Night Weather Parameters And Their Use In Forecasting Model Of Wheat Leaf Rust.
El Jarroudi, Moussa ULg; Giraud, Frédéric; Delfosse, Philippe et al

in Phytopathology (2010), (100), 32

A stochastic model was developed to predict the wheat leaf rust (Puccinia triticina Eriks.) severity (percentage of leaf area with symptoms showing uredinia) in four-replicated field experiments located ... [more ▼]

A stochastic model was developed to predict the wheat leaf rust (Puccinia triticina Eriks.) severity (percentage of leaf area with symptoms showing uredinia) in four-replicated field experiments located in three villages (Diekirch district: Reuler; Grevenmacher district: Burmerange and Christnach), representative of the different agroclimatological zones of Luxembourg. The model was elaborated by the analysis of the night weather and leaf rust incidence. Statistical validation using regression analysis reports a strong correlation between the number of hours with specific meteorological conditions and the percentage leaf area covered by brown rust lesions for the two upper and youngest leaves, which are mostly responsible for photosynthesis activity and assimilates production filling the grains. The development of the brown rust requires a period of at least twelve consecutive hours with temperatures between 8 and 16°C and a relative humidity (RH) greater than 60%, with optimal values lying between 12 and 16°C and RH greater than 80%. <br />During the 2004 to 2009 period, at four sites, the linear regression between simulated and observed values for Puccinia triticina was highly significant (P < 0.01) and R2 (coefficient of determination) explained 80 to 85% of the variability. Efforts are now being developed to better define thresholds for fungicide applications and to spatialize the outputs of the model over the entire Luxembourg territory. [less ▲]

Detailed reference viewed: 253 (7 ULg)
Full Text
Peer Reviewed
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

in Phytopathology (2010), 100

A mechanistic model, PROCULTURE, for assessing in real time the risk of progression of Septoria tritici (teleomorph Mycosphaerella graminicola) on winter wheat (Triticum aestivum L.) was used in Grand ... [more ▼]

A mechanistic model, PROCULTURE, for assessing in real time the risk of progression of Septoria tritici (teleomorph Mycosphaerella graminicola) on winter wheat (Triticum aestivum L.) was used in Grand-Duchy of Luxemburg over 2003 to 2009 to simulate disease progression in the canopy at four-replicated field experiments located in three villages (Diekirch district: Reuler; Grevenmacher district: Burmerange and Christnach), representative of the different agroclimatological zones of Luxembourg. This model has been developed in order to guide field observations on the different leaf layers and to find the optimum time of fungicide spray in fields. The model provides information which explains disease progression on the upper leaves. The relationship between disease control by fungicides and yield loss varies from site-to-site and from season-to-season. A weekly PROCULTURE recalibration is routinely done using actual disease levels observed on site. On average, no spray of fungicides or only one application is required to control efficiently the septoria leaf blotch disease. The PROCULTURE forecasts have been validated to be correct in about 85% of all cases. The treatment defined with the simulation model over 2003 to 2009 gave an earning grain yield (80%) more than the other treatments tested and as important as the double treatment for Everlange, Christnach and Burmerange. At Reuler, over 2003 to 2009, treatments based on the Septoria risk simulation model were recommended only in 2007. The climatic conditions of this site tend to favour organic farming in this region where the evolution of the foliar disease is very weak. [less ▲]

Detailed reference viewed: 282 (7 ULg)
Full Text
Peer Reviewed
See detailSpatial Heterogeneity of Leaf Wetness Duration in Winter Wheat Canopy and Its Influence on Plant Disease Epidemiology.
Mahtour, Abdeslam ULg; El Jarroudi, Moussa ULg; Giraud, Frédéric et al

in Phytopathology (2010)

The leaf wetness duration (LWD) is one of the most important factors influencing the occurrence of plant diseases epidemiology. Despite considerable efforts to determine LWD, little attention has been ... [more ▼]

The leaf wetness duration (LWD) is one of the most important factors influencing the occurrence of plant diseases epidemiology. Despite considerable efforts to determine LWD, little attention has been given to studies its variability in the canopy. The objective of this study was to evaluate the spatio-temporal variability in the field sites cultivated in a heterogeneous landscape. The spatial-temporal variability of LWD was evaluated in winter wheat canopy close to the hedge at Arlon (Belgium) during the period May to July 2006 and 2007. LWD measurements were made using flat plate sensors deployed at five different distances from the hedge (5, 10, 20, 50, 100 m). Each set of two sensors was placed horizontally close the flag leaf (L1) facing north. Parallel to these qualitative measures of wetness we made samples of the quantity of dew deposited on rigid epoxy plates (75 x 60 mm) placed next to each set of sensors (two plates per sensor and sampling). Experimental results show that the LWD measurements revealed substantial heterogeneity among sensors positions. LWD is longer for the sensors located at distance proximate the hedge. Three to four hours of difference was observed between sensors located at 5 m and those located at 100 m, and besides, a significant quantitative difference (p<0.0001) of dew deposit was observed between area beside hedge and those placed at 100m. In summary, this study gives a good idea of how wetness appears at the different range of the hedge. So the diversity of situations favor occurrence of very local microclimate conditions that may initiate disease in specific locations of the plot and not in others. [less ▲]

Detailed reference viewed: 234 (3 ULg)
Full Text
Peer Reviewed
See detailFusarium head blight and associated mycotoxin occurrence on winter wheat in Luxembourg in 2007/2008
Giraud, Frédéric; Pasquali, Matias; El Jarroudi, Moussa ULg et al

in Food Additives & Contaminants (2010), 27

Fusarium head blight (FHB) is among the major causes of reduced quality in winter wheat and its products. In addition, the causal fungi produce a variety of toxins. A relatively high FHB infection rate in ... [more ▼]

Fusarium head blight (FHB) is among the major causes of reduced quality in winter wheat and its products. In addition, the causal fungi produce a variety of toxins. A relatively high FHB infection rate in winter wheat was observed in 2007 and 2008 in Luxembourg. A fusariotoxin survey was carried out in 17 different geographical locations. Three groups of Fusarium mycotoxins (trichothecenes A and B and zearalenone) were analysed by a multi-detection HPLC–MS/MS method. Fusarium strains were also investigated by morphological and molecular methods. In addition, questionnaires relating to cultural practices were sent to the farmers managing the 17 fields investigated. FHB prevalence ranged from 0.3 to 65.8% (mean: 8.5%) in 2007 and from 0 to 24.5% (mean: 8.3%) in 2008. Results of morphological and molecular identification showed that the most common species isolated from diseased wheat spikes was F. graminearum (33.1%), followed by F. avenaceum (20.3%) and F. poae (17.8%). The chemical analysis revealed that 75% of the investigated fields were contaminated by deoxynivalenol (DON, range 0–8111 mg/kg). The preceding crop was highly and significantly correlated to the number of grains infected and had a significant impact on disease prevalence ( p¼0.025 and 0.017, respectively, Fisher’s F-test). A trend was found for maize as the preceding crop ( p¼0.084, Tukey’s test) to predict the amount of DON in the fields. This is the first report on the occurrence of DON and ZON in naturally infected wheat grains sampled from Luxembourg. [less ▲]

Detailed reference viewed: 38 (5 ULg)
Peer Reviewed
See detailForecasting epidemic outbreaks ofwheat leaf blotch based on meteorological parameters
Junk, Jürgen; El Jarroudi, Moussa ULg; Pogoda, Frederik et al

Poster (2010, April 12)

Detailed reference viewed: 10 (0 ULg)
Full Text
Peer Reviewed
See detailAssessing the Accuracy of Simulation Model for Septoria Leaf Blotch Disease Progress on Winter Wheat.
El Jarroudi, Moussa ULg; Delfosse, Philippe; Maraite, Henri et al

in Plant Disease (2009), 93

A mechanistic model, PROCULTURE, for assessing the development of each of the last five leaf layers and the progress of Septoria leaf blotch, caused by Septoria tritici (teleomorph Mycosphaerella ... [more ▼]

A mechanistic model, PROCULTURE, for assessing the development of each of the last five leaf layers and the progress of Septoria leaf blotch, caused by Septoria tritici (teleomorph Mycosphaerella graminicola), has been applied on susceptible and weakly susceptible winter wheat (Triticum aestivum) cultivars in two locations (Everlange and Reuland) in Luxembourg over a 3-year period (2000 to 2002). A double performance assessment of PROCULTURE was conducted in this study. First, the capability of PROCULTURE to correctly simulate S. tritici incidence was checked. Second, the model's ability to accurately estimate disease severity was assessed on the basis of the difference between simulated and observed levels of disease development at each leaf layer. The model accurately predicted disease occurrence in the 2000 and 2002 seasons, on susceptible and semi-susceptible cultivars, with a probability of detection (POD) exceeding 0.90. However, in 2001, even though the POD never fell below 0.90, the false alarm ratio (FAR) was too high to consider the simulations satisfactory. Concerning the evaluation of disease severity modeling, statistical tests revealed accurate simulations performed by PROCULTURE for susceptible cultivars in 2000 and 2002. By contrast, for weakly susceptible cultivars, the model overestimated disease severity, especially for the upper leaves, for the same period. [less ▲]

Detailed reference viewed: 60 (8 ULg)
Full Text
Peer Reviewed
See detailFirst Report of Wheat Leaf Rust in the Grand Duchy of Luxembourg and the Progress of its Appearance over the 2003–2008 Period
El Jarroudi, Moussa ULg; Giraud, Frédéric; Vrancken, Carine et al

in Plant Disease (2009), 93

Wheat leaf rust caused by Puccinia triticina Eriks. was identified for the first time in 2000 in the Grand Duchy of Luxembourg on the basis of orange-to-brown, round-to-ovoid, erumpent uredinia (1 to 1.5 ... [more ▼]

Wheat leaf rust caused by Puccinia triticina Eriks. was identified for the first time in 2000 in the Grand Duchy of Luxembourg on the basis of orange-to-brown, round-to-ovoid, erumpent uredinia (1 to 1.5 mm in diameter) scattered on the upper and lower leaf surfaces and producing orange-brown urediniospores that are subgloboid, approximately 20 μm in diameter, and with up to eight germ pore scattered in thick, echinulate walls. In a second phase, wheat was monitored weekly (starting from Zadoks growth stage 30, pseudo stem erection) during the 2003–2008 cropping seasons for wheat leaf rust. Disease severity (percentage of leaf area with symptoms) was recorded in four, replicated field experiments located in three villages (Diekirch District: Reuler; and Grevenmacher District: Burmerange and Christnach), which are representative of the different agroclimatological zones of Luxembourg. A significant difference in severity was observed between the sites (P < 0.01) and the years (P < 0.05). Over the 6-year period, Burmerange and Reuler consistently showed the highest and lowest disease severity, respectively. In 2003 and 2007, Burmerange (a southern site with the highest average spring temperatures of 13.6 and 14.0°C, respectively) showed the highest disease severity with 66 and 57%, respectively, whereas the lowest severity (<1% for both years) was observed in the north at Reuler (site with the lowest average spring temperatures of 12.0 and 12.4°C, respectively). Christnach, located midway between Reuler and Burmerange, showed an intermediate disease severity with 7% (2003) and 22% (2007). The disease appeared at growth stages 77 (late milk) and 87 (hard dough) in the period 2003–2005, but at an earlier stage (45, boots swollen) for 2006–2008 (P < 0.001). In 2005, low severity was recorded due to a severe drought during May, June, and July. A reason for this earlier appearance of leaf rust occurrences in the two districts may be related to an increase in the average spring temperature (average March to May temperature for Luxembourg was 8.3°C for the 1971–2000 period, 9.5°C for the 2003–2005 period, 9.9°C for the 2006–2008 period, 2007 was exceptional with 11.9°C, P < 0.01). In the past, cereal disease management strategies were oriented toward the control of predominant and yield-reducing diseases such as that caused by Septoria tritici Desm. Because the succession of mild winters and warm springs during the last 5 years allowed the early occurrence and the fast development of wheat leaf rust in the Grand Duchy of Luxembourg, it is advisable to take this disease into account in fungicide application schemes. [less ▲]

Detailed reference viewed: 41 (2 ULg)
Full Text
Peer Reviewed
See detailFusarioses sur blé d'hiver au Grand-Duché de Luxembourg
Giraud, Frédéric; Pasquali, Matias; Vrancken, Carine et al

in Phytoma - la Défense des Végétaux (2009), 622-623

Au Grand-Duché de Luxembourg, la campagne 2006-2007 a été caractérisée par un hiver relativement doux et un printemps pluvieux. Ces conditions météorologiques ont permis le développement de nombreuses ... [more ▼]

Au Grand-Duché de Luxembourg, la campagne 2006-2007 a été caractérisée par un hiver relativement doux et un printemps pluvieux. Ces conditions météorologiques ont permis le développement de nombreuses maladies cryptogamiques sur le blé d’hiver, dont la fusariose. Cette maladie a été suivie sur 17 sites couvrant le G-D de Luxembourg par des mesures de prévalence (pourcentage moyen d’épis visuellement infectés) et de sévérité (pourcentage moyen d’épillets atteints par épi). Des valeurs moyennes de 8,9± +/- 15,5 % pour la prévalence et de 21,0± +/- 17,8 % pour la sévérité ont été enregistrées avec des différences significatives entre les cantons nord et sud pour la sévérité. Plus de 600 souches isolées des 17 sites ont été identifiées suivant des critères morphologiques et l’emploi d’outils moléculaires. 5 espèces semblent associées à la fusariose : Fusarium graminearum (23,5 %), F. culmorum (12,8 %), F. poae (19,4 %) (3 espèces potentiellement productrices de mycotoxines), F. avenaceum (20 %) et Microdochium nivale (18,7 %). Cette étude est la première du genre à avoir été faite au Grand-Duché de Luxembourg. [less ▲]

Detailed reference viewed: 19 (1 ULg)
Full Text
Peer Reviewed
See detailFirst report of wheat powdery mildew and its severity in the Grand-Duchy of Luxembourg over the 2003-2009 period
El Jarroudi, Moussa ULg; Giraud, Frédéric; Tychon, Bernard ULg et al

in Journal of Plant Pathology [=JPP] (2009), 91(S4), 109

Detailed reference viewed: 46 (11 ULg)
Full Text
Peer Reviewed
See detailFirst Report of Fusarium Head Blight (FHB) on Winter Wheat in the Grand Duchy of Luxembourg
Giraud, Frédéric; Vrancken, Carine; Delfosse, Philippe et al

in Plant Disease (2008), 92

Detailed reference viewed: 8 (2 ULg)
Full Text
Peer Reviewed
See detailStatistical Analysis of the night weather conditions favouring the epidemic of the brown rust in the Grand-Duchy of Luxemburg.
El Jarroudi, Moussa ULg; Tychon, Bernard ULg; Maraite, Henri et al

in Italian Journal of Agronomy/ Rivista di Agronomia (2008), 3

Detailed reference viewed: 34 (4 ULg)
Full Text
Peer Reviewed
See detailStatistical Analysis of the night weather conditions favouring the epidemic of the brown rust in the Grand-Duchy of Luxemburg.
El Jarroudi, Moussa ULg; Tychon, Bernard ULg; Maraite, H. et al

in Italian Journal of Agronomy [=IJA] = Rivista di Agronomia (2008), 3(3), 611-612

Detailed reference viewed: 17 (4 ULg)
Full Text
Peer Reviewed
See detailA special year for Fusarium Head Blight and associated mycotoxins in Luxembourg
Giraud, Frédéric; Vrancken, Carine; El Jarroudi, Moussa ULg et al

in Toxicology Letters (2008), 180

Detailed reference viewed: 9 (1 ULg)
Peer Reviewed
See detailAssessing the impact of fungal diseases management on crops and environment. Using dynamic models in the case of foliar diseases in wheat
Bancal, Marie-Odile; Roche, Romain; Gabrielle, Benoit et al

Conference (2007, November 13)

Detailed reference viewed: 14 (0 ULg)
Full Text
Peer Reviewed
See detailGreen leaf area decline of wheat top three leaves in Belgium and G-D of Luxembourg from 2003 to 2006 : the relationships with grain yield.
Martin, B.; Tychon, Bernard ULg; El Jarroudi, Moussa ULg et al

Conference (2006, October)

The modified Gompertz model developed by Gooding et al. (2000) was used to describe the decline in green area of wheat top three leaves in field experiments where green leaf area at time t = 100*exp[-exp ... [more ▼]

The modified Gompertz model developed by Gooding et al. (2000) was used to describe the decline in green area of wheat top three leaves in field experiments where green leaf area at time t = 100*exp[-exp(-k*(t-m))]. In the absence of fungicide, green leaf area decline was associated with drought or infection with a number of foliar pathogens including Septoria tritici (sexual stage Mycospherella graminicola) and Puccinia recondita f.sp. tritici and Erysiphe graminis. On the whole experiments and cultivars there was no effect of fungicide on k but it was highly significant on m (P<0.001). When main effects are considered, fungicide delayed green leaf area decline rather than reduced its rate of progress once started. Fungicide had variable effects on grain yield, largely reflecting variation in disease infection pressures in the different years and susceptibility of the different cultivars. If no correlation was observed between k values and grain yields, m was at the contrary very closely associated with grain yields. This study supports the view of Gooding (2000) and Gaunt (1995) that, for many diseases, effects on green area duration give an adequate estimate of host yield reduction. Therefore we have use the close relationship between the parameter m of the Gompertz model and grain yield to improve the Belgium-Crop Growth Monitoring System (B-CGMS) by recalibrating LAI evolution simulated by B-CGMS according to the evolution of LAI derived from the Gompertz model. The system includes indeed a component allowing taking into account senescence in the evolution of LAI during the growing season. Recalibration has been realized through the modification of one of the parameters influencing the leaf senescence, the SPAN parameter. Modifying the SPAN parameter comes down to modify the lifespan of leaves. Considering that parasitic pressure reduces leaves lifespan and therefore the photosynthetic capacity, this approach makes it possible to take into account the influence of this pressure on yield predictions in the Belgian Crop Growth Monitoring System. [less ▲]

Detailed reference viewed: 21 (5 ULg)