References of "Delfosse, Philippe"
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See detailComparison of Indicators to Evaluate the Resilience of Lab Scale Continuously Stirred Anaerobic Reactors Submitted to Biological Dysfunctions
Lemaigre, Sébastien; Adam, Gilles ULg; Goux, Xavier et al

Poster (2014, June 02)

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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 detailProfitability of using warning system for foliar disease of wheat in the Grand-Duchy of Luxembourg.
El Jarroudi, Moussa ULg; Kouadio, Louis; Beyer, Marco et al

Poster (2013, August 10)

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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 detailProfitability of using warning system for foliar disease of wheat in the Grand-Duchy of Luxembourg
El Jarroudi, Moussa ULg; Kouadio, Louis; Beyer, Marco et al

in Phytopathology (2013), 103

Although small grain cereals (i.e. winter wheat) are routinely protected with two or three foliar treatments in the Grand-Duchy of Luxembourg (GDL), environmental concerns and changes in the cost-benefit ... [more ▼]

Although small grain cereals (i.e. winter wheat) are routinely protected with two or three foliar treatments in the Grand-Duchy of Luxembourg (GDL), environmental concerns and changes in the cost-benefit ratio are likely to increase the demand for more accurate identification of spraying needs. A Vol. 103 (Supplement 2), No. 6, 2013 S2.39 warning system assessing in real time the risk of progression of fungal diseases on winter wheat (Triticum aestivum L.) was tested in the GDL over the 2009-2012 period in four-replicated field experiments located in three representative villages of the different agro-climatological zones. The fungicide treatments recommended by the warning system during this period have ensured economic profitability equivalent to or even better than double and triple treatments. In 2010 and 2011, weather conditions impeded fungal infections of wheat and no warning was issued, reducing fungicide use. The study also highlighted that multiple fungicide applications were not better than a single application. In 2009 and 2012, although the weather conditions were very favourable for fungal wheat diseases, the single recommended fungicide application resulted in an additional yield of 30% compared to untreated plots. This study shows the importance of the positioning of fungicide treatment in such a warning system and in strategies aiming at reducing the spread fungicide molecules in the environment. [less ▲]

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See detailOperational warning for Septoria leaf blotch and leaf rust in winter wheat: Importance of fungicide dosage, formulation, and spray time
El Jarroudi, Moussa ULg; Kouadio, Louis; Beyer, Marco et al

in Phytopathology (2013), 103

Field experiments were conducted in 2010 to investigate the effect of fungicide commercial formulation, timing and dosages on the severity of these two diseases in winter wheat in Luxembourg. Different ... [more ▼]

Field experiments were conducted in 2010 to investigate the effect of fungicide commercial formulation, timing and dosages on the severity of these two diseases in winter wheat in Luxembourg. Different types of fungicides and fungicide combinations containing active ingredients such as triazoles and strobilurins were used in field trials including susceptible cultivars to Septoria leaf blotch (SLB, caused by Septoria tritici) and wheat leaf rust (WLR, caused by Puccinia triticina). The three formulations of fungicides tested were: (i) a mix of triazole and amine (Prothioconazole 250 g/l + Spiroxamine 500 g/l) associated with chlorothalonil 500 g/l, (ii) sole strobilurin (Azoxystrobine 250 g/l), and (iii) a mix of strobilurin and triazole (Epoxiconazole 125 g/l; Azoxystrobine 250 g/l). The optimum time of fungicide spray was assessed through the mechanistic model PROCULTURE and a stochastic model based on night favourable weather conditions conducive to WLR development. The results showed that for plots treated with fungicide formulation containing either a triazole or a strobilurin, the grain yield earned was not significantly different from the untreated plots (P > 0.05). Whereas single fungicide treatment involving a mixture of triazole and strobilurin at the optimum time gave an earning (on average 7 dt ha-1) compare to the control and a yield similar to that obtained with the double or triple fungicide treatments. [less ▲]

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See detailEvaluation of an electronic nose for the early detection of organic overload of anaerobic digesters
Adam, Gilles ULg; Lemaigre, Sébastien; Romain, Anne-Claude ULg et al

in Bioprocess and Biosystems Engineering (2013), 36(1),

This study aims at the analysis of the utilization of an electronic nose (e-nose) to serve as a specific monitoring tool for anaerobic digestion process, especially for detecting organic overload. An ... [more ▼]

This study aims at the analysis of the utilization of an electronic nose (e-nose) to serve as a specific monitoring tool for anaerobic digestion process, especially for detecting organic overload. An array of non specific metal oxide semiconductor gas sensors were used to detect process faults due to organic overload events in twelve anaerobic semi-continuous reactors of 1.8 L. Three different load strategies were followed (i) a cautious organic load (1.3 gVS•L-1•day-1); (ii), an increasing load strategy (1.3 to 5.3 gVS∙L-1•day-1) and (iii) a cautious organic load with load pulses of up to 12 gVS•L-1•day-1. A first monitoring campaign was conducted with three different substrates : sucrose, maize oil, and a mix of sucrose/oil during 60 days. The second campaign was run with dry sugar beet pulp during 45 days. Hotelling's T²-value and upper control limit to a reference set of digesters fed with a cautious OLR (1.3 gVS•L-1•day-1), was used as indirect state variable of the reactors. Overload situations were identified by the e-nose apparatus with Hotelling’s T²-values at least 4-times higher in magnitude than the upper control limit of 23.7. These results confirmed that the e-nose technology appeared promising for online detection of process imbalances in the domain of anaerobic digestion. [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 detailTan Spot on winter wheat in the Grand Duchy of Luxembourg: Diagnostics and Evolution
El Jarroudi, Moussa ULg; Kouadio, Louis; Beyer, Marco et al

Poster (2012, October)

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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; 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 detailGas sensor array applied to the monitoring of biogas process
Adam, Gilles ULg; Lemaigre, Sébastien; Romain, Anne-Claude ULg et al

Conference (2011, May)

There is a lack of simple online monitoring system to control the performances of biogas reactors. The electronic nose technology appears to be an adapted device to deliver fast information about process ... [more ▼]

There is a lack of simple online monitoring system to control the performances of biogas reactors. The electronic nose technology appears to be an adapted device to deliver fast information about process disturbances in anaerobic reactors as it is adequate for online monitoring. In this study, twelve anaerobic mini-reactors were supervised with a home-made e-nose to observe process reaction in relation to organic overloads events. Usually, to avoid overload situations, on farms reactors are not fed at maximum load capacity, resulting in non optimized biogas production. The objective of the experiment was to determine if the gas sensors array feature can be related to the process state and if an indirect state variable, giving early warning of process faults, can be derived from the e-nose response. <br />The results demonstrated that focusing on gas phase of anaerobic reactors with a simple device composed of an array of non-specific gas sensors helped in the warning of disorders of the anaerobic digestion process. Mahalanobis distance from a cautious feeding group (group of observations indicating a good process) can be used as an indirect variable to evaluate the intensity of the state disorder. Euclidean distance has been also calculated but it was less informative than the Mahalanobis distance. [less ▲]

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See detailAnaerobic digestion process monitoring: focus on the gas phase using electronic nose technology
Adam, Gilles ULg; Lemaigre, Sébastien; Romain, Anne-Claude ULg et al

in GERBIO (Ed.) Proceedings of the International Congress Progress in Biogas 2011 - part 1 (2011, March 31)

Gas phase of four pilot-scale anaerobic reactors was monitored with a gas sensors array, also called electronic nose (e-nose) over three weeks. CH4, CO2, H2S, H2 concentration in the gas phase and biogas ... [more ▼]

Gas phase of four pilot-scale anaerobic reactors was monitored with a gas sensors array, also called electronic nose (e-nose) over three weeks. CH4, CO2, H2S, H2 concentration in the gas phase and biogas production rate were also measured. Reactors were exposed to process disturbances by doubling the organic loading rate and by decreasing the temperature from 38 to 32°C for 24 hours. During these tests, sludge pH and alkalinity were also measured. When organic loading was doubled, no changes were observed in pH and alkalinity, while hydrogen content in gas phase increased by 20% and took 8 hours to recover stable values of 130 ppm. Hydrogen sulphide also increased proportionally to organic loading of the reactors and took two days to return to stable values. Methane and carbon dioxide ratio changed from 1.2 to 0.95. No changes were observed during the temperature drop of the digesters apart from hydrogen concentration which increased sharply several hours. Electronic nose was able to detect variations in organic loading rates for the four anaerobic reactors, with increased signals for higher organic loadings of the pilots. Sensing of gas phase of anaerobic reactors was able to discriminate disorders of operating conditions of anaerobic reactors, especially organic loading. [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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