References of "Lebeau, Frédéric"
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See detailMeasuring spore settling velocity for an improved assessment of dispersal rates in mosses
Zanatta, Florian ULg; Vanderpoorten, Alain ULg; Patiño, Jairo et al

in Annals of Botany (2016)

The settling velocity of diaspores is a key parameter for the measurement of dispersal ability in wind-dispersed plants and one of the most relevant parameters in explicit dispersal models, but remains ... [more ▼]

The settling velocity of diaspores is a key parameter for the measurement of dispersal ability in wind-dispersed plants and one of the most relevant parameters in explicit dispersal models, but remains largely undocumented in bryophytes. The settling velocities of moss spores were measured and it was determined whether settling velocities can be derived from spore diameter using Stokes’ Law or if specific traits of spore ornamentation cause departures from theoretical expectations. [less ▲]

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See detailA review on the use of sensors to monitor cattle jaw movements and behavior when grazing
Andriamandroso, Andriamasinoro ULg; Bindelle, Jérôme ULg; Mercatoris, Benoît ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment (2016), 20

Precision Livestock Farming (PLF) is spreading rapidly in intensive cattle farms. It is based on the monitoring of individuals using different kinds of sensors. Applied to grazing animals, PLF is mainly ... [more ▼]

Precision Livestock Farming (PLF) is spreading rapidly in intensive cattle farms. It is based on the monitoring of individuals using different kinds of sensors. Applied to grazing animals, PLF is mainly based on the recording of three parameters: the location, the posture and the movements of the animal. Until now, several techniques have been used to discriminate grazing and ruminating behaviors with accuracies over 90% on average, when compared to observations, providing valuable tools to improve the management of pasture and grazing animals. However, bites and jaw movements are still overlooked, even though they are of utmost importance to assess the animal grazing strategies for various pasture types and develop future techniques allowing better estimation of their intake. The goal of this review is to explore the possibility of monitoring the individual jaw movements and the differentiation of bites in grazing animals. For this purpose, (1) the mechanisms of forage intake in cattle are explained briefly in order to understand the movements performed by the cow, especially during grazing, (2) the various sensors that have been proposed to monitor jaw movements of ruminants such as mechanical sensors (pressure sensors), acoustic sensors (microphone) and electromyography sensors are compared and (3) finally the relationship between jaw movements, biting behavior and forage intake is discussed. The review clearly demonstrated the abilities of mechanical, acoustic and electromyography sensors to classify the difference types of jaw movements. However, it also indicated a wide range of accuracies and different observation windows required to reach these accuracies when compared to the observed movement. This classification purpose could lead to a better detection of more specific behavior, e.g. bite detection, and their exact location on pasture. [less ▲]

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See detailLINKING CATTLE GRAZING BEHAVIOR TO METHANE AND CARBON DIOXIDE DYNAMICS
Blaise, Yannick ULg; Lebeau, Frédéric ULg; Andriamandroso, Andriamasinoro ULg et al

in Communications in Agricultural and Applied Biological Sciences (2016, February), 81(1), 107-112

Various methods are presently used to measure methane (CH4) emissions of ruminants on pasture. Those measurements are essential to evaluate nutritional strategies to mitigate enteric CH4 emissions as well ... [more ▼]

Various methods are presently used to measure methane (CH4) emissions of ruminants on pasture. Those measurements are essential to evaluate nutritional strategies to mitigate enteric CH4 emissions as well as addressing the selection of low producing individuals. On pasture and in the barn, variations in CH4 emissions are observed depending on the time of the day. However, no studies have been made to link these diurnal fluctuations to behavioural phases, especially on pasture. The aim of this study was to understand the individual dynamics of CH4 production and their links to the grazing behaviour. For this purpose, a new tool was specifically developed. Five red-pied dry cows were equipped with infrared CH4 and carbon dioxide (CO2) sensors measuring concentrations in the exhaled air at 4 Hz. The animals were equipped with a heart rate belt (HR) and motion sensors to detect their feeding behaviours (grazing vs. rumination) for periods of 8 h/d. Wind speed (WS) was also monitor to verify interference with sampled gas concentrations. Results showed that using the CH4:CO2 ratio reduced the interference with WS that was observed on raw CH4 and CO2 concentration signals. CH4:CO2 ratio average over 5 min periods indicated that CH4 emissions were lower during grazing than rumination (P<0.01). The eructation frequency during grazing (0.48 eructation/min, P<0.01) was also lower than during rumination (0.65 eructation/min). HR was higher during grazing that rumination. Because HR is usually linked to metabolic CO2 production intensity, hence influencing the denominator of the CH4:CO2 ratio, further investigation should focus on the quantification of changes in fermentative and metabolic CO2 emissions along the day to estimate total CH4 production more accurately and the relationship between CH4 emissions patterns and post-feeding times. [less ▲]

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See detailOUTDOOR MEASUREMENT OF CATTLE METHANE EMISSIONS USING THE EDDY-COVARIANCE TECHNIQUE IN COMBINATION WITH GEOLOCALIZATION DEVICES
Dumortier, Pierre ULg; Andriamandroso, Andriamasinoro ULg; Aubinet, Marc ULg et al

Poster (2016, February)

Methane emissions account for 8% of the EU-15 GHG emissions and livestock generates approximately half of these emissions [1]. In order to improve emissions reporting and properly test mitigation options ... [more ▼]

Methane emissions account for 8% of the EU-15 GHG emissions and livestock generates approximately half of these emissions [1]. In order to improve emissions reporting and properly test mitigation options, techniques for measuring methane emissions from cattle must be developed and adapted to each management system. Among available micrometeorological methods, the use of eddy-covariance is still in its infancy [2] and its relevance and robustness for cattle flux estimation has still to be proved. On one hand, it is well adapted to seasonal grazing systems, is non-invasive, needs little animal handling and allows detection of daily emission patterns. On the other hand, it has the drawback of requiring cattle geo-localization and long periods of measurements (typically one month). In this study, we combined measured CH4 fluxes with a footprint model [3] and cattle positions (GPS devices) over several one-month campaigns at key periods in the grazing season in order to obtain CH4 emissions per cow at herd scale. Accelerometers were also added to the system for behaviour detection, opening the possibility of linking emissions to feeding behaviour. Measurements were performed and are still ongoing at the Dorinne Terrestrial Observatory in 2014/2015. The first campaign provided a mean emission per cow of 65±6 kg CH4.LSU-1.year-1. Cattle emission pattern was tightly linked with behaviour pattern, emissions being higher during and shortly after grazing (i.e. at dawn and dusk). Uncertainties linked to the method will be discussed and quantified (footprint model validity, geo-localization precision, eddy covariance corrections and filtering specificities linked to CH4 measurements). Compilation of data from multiple campaigns will allow quantification of the effects of forage quality, animal weight and lactating state on emissions per cow. [less ▲]

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See detailReduced span spray – Part 1: Retention
Massinon, Mathieu ULg; De Cock, Nicolas ULg; Ouled Taleb Salah, Sofiene ULg et al

in Aspect of Applied Biology, International Advances in Pesticide Application (2016, January)

Maximising treatment efficiency for a given target lies mainly on depositing a maximum part of the spray volume within an optimal droplet size range, which has to be as narrow as possible to reduce ... [more ▼]

Maximising treatment efficiency for a given target lies mainly on depositing a maximum part of the spray volume within an optimal droplet size range, which has to be as narrow as possible to reduce retention variability and drift issues. The present work focuses on exploring the effect of span factor of the droplet size distribution on the final retention by a 3D target plant using a modelling approach with the final aim of guiding the development of a reduced span nozzle (Reduced span spray – Part 3: Design of narrow span nozzle). Five droplet size spans have been tested for three VMD and three wetting scenarios on the same 3D plant architecture. Performing a screening of the different parameters involved in spray retention with a modelling approach based on a deeper understanding of leaf/droplet interactions is a valuable approach for highlighting the optimal droplet size distribution maximising droplet retention for a given target/formulation combination. [less ▲]

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See detailReduced span spray: Part 3: Design of a narrow span nozzle
De Cock, Nicolas ULg; Massinon, Mathieu ULg; Ouled Taleb Salah, Sofiene ULg et al

in Aspect of Applied Biology (2016, January)

Optimisation of the droplet spectra of the agricultural spray may increase the spray application efficiency. The optimal spray would contain only the most efficient droplets in term of speed and size ... [more ▼]

Optimisation of the droplet spectra of the agricultural spray may increase the spray application efficiency. The optimal spray would contain only the most efficient droplets in term of speed and size. Therefore, this paper is presenting the first steps of the design of a narrow span nozzle in order to produce an optimised spray. The starting geometry is a splash plate nozzle with a disk ending with structures (i.e. tooth, grooves, and needles) that would separate the liquid sheet into jets. These jets would be in the Rayleigh regime which has the advantage of producing narrower droplet spectra than liquid sheet break-up. The present project aims to design a hydraulic nozzle producing a spray with a narrow drop size distribution in order to increase the agricultural spray application efficiency. In the present paper the first project steps are presented. [less ▲]

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See detailLa paille - projets construits
de Herde, André; Evrard, Arnaud; Rouche, Sylvie et al

Book published by UCL (2016)

En novembre 2011, un consortium rassemblant l’Université catholique de Louvain (Architecture et Climat), l’Université de Liège (GeMMe et UMC), l’Institut de Conseil et d’Études en Développement Durable ... [more ▼]

En novembre 2011, un consortium rassemblant l’Université catholique de Louvain (Architecture et Climat), l’Université de Liège (GeMMe et UMC), l’Institut de Conseil et d’Études en Développement Durable (ICEDD) et la jeune entreprise Paille-Tech est formé autour du projet de recherche « aPROpaille » financé par la DGO4 (Direction générale opérationnelle de l’Aménagement du territoire, du Logement, du Patrimoine et de l’Énergie) dans le cadre du programme ERable, organisé par le Service Public de Wallonie (DGO4 et DGO6, Direction Générale Opérationnelle de l’Économie, de l’Emploi et de la Recherche). Ce projet très complet a permis de déterminer les caractéristiques et performances des matériaux « terre » et « paille », de réaliser des simulations de comportement hygrothermique des parois en paille, de les comparer à des monitorings de bâtiments existants en paille, de réaliser une analyse de cycle de vie (ACV) de ce type de paroi… Outre la réalisation d’une plateforme Internet (www.apropaille.be) sur la filière belge, les principaux résultats de cette recherche ont été rassemblés fin 2015 dans trois vadémécums à destination d’un public large et varié. Ces vadémécums, dont le présent document en est la troisième partie, ont pour but d’offrir à tout un chacun une information rigoureuse, claire et compréhensible, des avancées récentes de ce domaine pour favoriser le développement de la filière de la paille utilisée comme matériau isolant dans la construction. Afin de permettre aux acteurs du monde de la construction de s’approprier les connaissances relatives à ce matériau, ce vadémécum s’intéressera aux projets qu’il est possible de construire et montre que les possibilités architecturales que permet l’utilisation de ce type de matériaux sont multiples et sont à la hauteur de la créativité des concepteurs qui les font naître. Le premier chapitre retrace synthétiquement l’historique de ce type de construction. Le deuxième définit une série de modes constructifs fréquemment rencontrés dans la pratique sur base du rôle constructif que joue la paille dans les parois. Une série de fiches est alors présentée pour constituer un catalogue de projets qui sont repris sur la plateforme Internet. Certains projets, les « cas d’étude », sont plus détaillés et leurs fiches reprennent l’ensemble des documents graphiques utiles pour comprendre leur plans, coupes et façades. Un dernier chapitre, intitulé « FAQs », tente de répondre aux questions les plus fréquemment posées sur la construction en paille. [less ▲]

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See detailÉtude des potentialités des systèmes d’application contrôlée des gouttes (CDA) pour les traitements phytosanitaires en céréaliculture (synthèse bibliographique)
Ouled Taleb Salah, Sofiene ULg; De Cock, Nicolas ULg; Massinon, Mathieu ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment (2016)

Introduction. L’application contrôlée des gouttes (CDA) présente le double avantage de réduire à la fois l’étendue de la distribution des tailles des gouttes et le volume appliqué par rapport aux buses ... [more ▼]

Introduction. L’application contrôlée des gouttes (CDA) présente le double avantage de réduire à la fois l’étendue de la distribution des tailles des gouttes et le volume appliqué par rapport aux buses hydrauliques conventionnelles. Littérature. Cette revue investigue la potentialité de la CDA par rapport aux buses hydrauliques dans le cadre du désherbage précoce des adventices (2-3 feuilles). En termes de rétention, les études reliant les caractéristiques des gouttes (taille, vitesse et direction) et l’architecture, la densité et la mouillabilité du feuillage, en fonction de la formulation de bouillies, ont été abordées. Ces études montrent que des gouttes de 300 μm avec un adjuvant approprié et des jets émis 60° vers l’avant par rapport à la verticale contribuent à l’augmentation de la rétention sur les cibles problématiques à port dressé. L’effet des réductions des volumes d’application pour ces deux techniques est étudié sur base de la moyenne, du coefficient de variation et du taux de couverture des dépôts. Néanmoins, les résultats de ces études ne peuvent être généralisés du fait des différences de réglages opératoires entre les deux techniques d’application. Quant à la dérive, les atomiseurs CDA orientés horizontalement présentent un potentiel de dérive plus important que les buses hydrauliques pour lesquelles le spray est orienté vers le bas. La dérive augmente avec la vitesse du vent et diminue lorsque le diamètre médian volumétrique (DV50) augmente. Conclusions. De nouveaux réglages des atomiseurs de la CDA en termes de DV50 et de direction du jet peuvent répondre aux défis de l’agriculture de précision. Les pistes d’innovations proposées sont d’une part une amélioration de la résistance à l’usure des dents situées en bordure des disques et, d’autre part, une distribution granulométrique plus étroite. [less ▲]

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See detailTemperature and moisture storage in crop-based materials: Modelling a straw bale wall subject to a thermal shock
Dubois, Samuel ULg; Evrard, Arnaud ULg; Blecker, Christophe ULg et al

in Jounal of Building Physics (2016)

Modelling the hygrothermal behaviour of crop-based insulation products is essential to assess their impact on the energy performance of the building, predict indoor climate conditions, and prevent any ... [more ▼]

Modelling the hygrothermal behaviour of crop-based insulation products is essential to assess their impact on the energy performance of the building, predict indoor climate conditions, and prevent any risk of unexpected degradation. Traditionally, transient numerical models that predict internal conditions of construction materials consider that the variation of moisture storage with temperature is negligible although the sorp- tion behaviour is known to be temperature dependent. This paper investigates this par- ticular effect for crop-based materials and uses a refinement of standard mathematical representations. For this purpose, the effects of a thermal shock on the evolution of hygrothermal conditions inside a straw-bale wall are studied with several versions of a flexible research model. The latter is capable of incorporating the temperature depen- dency of the sorption curve with both a physically-based and an empirical description. A large climate chamber is used to gather experimental data and is able to host a full- size straw bale prefabricated panel. Internal conditions of straw bales are obtained with proper sensors bars. Results show that when large temperature gradients occur in a crop-based material, a model that considers temperature effect on moisture storage enhances greatly the prediction of internal conditions. [less ▲]

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See detailApplications de la terre crue en construction
Grigoletto, Sophie ULg; Paul, Julien; Lebeau, Frédéric ULg et al

Conference (2015, November 05)

L’utilisation de l’argile en construction permet d’atteindre des propriétés spécifiques en termes de résistance mécanique et d’inertie thermique. Les recherches menées à l’Université de Liège, en ... [more ▼]

L’utilisation de l’argile en construction permet d’atteindre des propriétés spécifiques en termes de résistance mécanique et d’inertie thermique. Les recherches menées à l’Université de Liège, en collaboration avec l’entreprise MOBIC, ont permis de développer des produits permettant l’amélioration de l’inertie thermique de panneaux à ossature bois. L’effet de l’apport de la couche d’inertie au sein des constructions à ossature bois a été quantifié expérimentalement par l’instrumentation de modules jumeaux de 20m². Cet effet sur le confort thermique a également été modélisé par des simulations thermiques en vue de quantifier les bénéfices sur les surchauffes en été, les réductions des consommations énergétiques en hiver pour divers scénarii au moyen d’un programme de simulation dynamique des échanges thermiques et des bilans d’énergie au sein de bâtiments [less ▲]

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See detailStraw-bale walls for sustainable architecture: Improving and promoting straw-bale use in European Buildings
Evrard, Arnaud; Biot, Benjamin; Keutgen, Gauthier et al

in Cucinella; Giulia (Eds.) Architecture in (R)Evolution (2015, September 09)

Straw-bale use in buildings may be an interesting way to decrease our energy needs and our impact on the environment. Moreover, it fosters a local economy and the creation of new jobs in the building ... [more ▼]

Straw-bale use in buildings may be an interesting way to decrease our energy needs and our impact on the environment. Moreover, it fosters a local economy and the creation of new jobs in the building industry. Combined with earth materials and other well-selected materials and systems, it allows creative designers to integrate highly efficient, low-tech and reusable envelopes in comfortable and healthy places. The present paper summarizes the results of a four year R&D program aiming to improve and promote the use of straw bale in buildings and also to remove uncertainties concerning this use. Three main aspects are pinpointed and discussed: hygrothermal transfer and storage in straw-bale walls, regulation of indoor conditions and environmental impact in the long term. These three topics were submitted to European experts (France, England and Germany) in order to discuss a cross-comparison of results obtained on a larger scale. The paper shows that straw-bale use in buildings is a relevant and innovative solution in facing one of the major challenges of today and tomorrow: "How to build/transform comfortable and affordable buildings with local resources and with a positive impact on the environment?". [less ▲]

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See detailChanges in biting characteristics recorded using the inertial measurement unit of a smartphone reflect differences in sward attributes
Andriamandroso, Andriamasinoro ULg; Lebeau, Frédéric ULg; Bindelle, Jérôme ULg

in Guarino, Marcella; Berckmans, Daniel (Eds.) Precision Livestock Farming '15 (2015, September)

Accurate monitoring of grazing activity at individual cow level would provide useful information to farmers to improve the management of their animals and pastures in intensive dairy systems. Pasture ... [more ▼]

Accurate monitoring of grazing activity at individual cow level would provide useful information to farmers to improve the management of their animals and pastures in intensive dairy systems. Pasture attributes, starting with sward height, influence grazing behaviour and bites characteristics. In an attempt to link sward height to an individual automated detection of biting behaviour, a series of recording sessions of 4×3 days were realized on a ryegrass pasture with two contrasting heights (5 and 15 cm) over the grazing season (from July to October) with 4 dry red-pied cows equipped with the inertial measurement unit (IMU) of a smartphone on a halter, recording acceleration data at 100Hz. The behaviours were video-recorded. The number of grazing bouts performed during grazing trends to increase when the grass is highest. Fourier transforms of acceleration data showed that grazing bouts were characterized by a distinctive acceleration peak which frequency ranged between 1.02Hz and 1.46Hz whatever the sward height. It corresponded to the uprooting of grass frequency in the biting movement when compared with the observation in the video recordings and it could be used to improve automated grazing behaviour detection and to remotely characterize bites. These results show that some bite characteristics are influenced by sward height and automated individual monitoring of grazing behaviour is possible. An extension of this methodology should allow analysing more deeply the grazing behaviour of cattle in order to determine number of bites and possibly to link it to biomass intake. [less ▲]

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See detailComputer simulations of spray retention by a 3D barley plant: effect of formulation surface tension
Massinon, Mathieu ULg; De Cock, Nicolas ULg; Ouled Taleb Salah, Sofiene ULg et al

in 67th International Symposium on Crop Protection (2015, May 19)

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See detailDrop size distribution measurement of ISO nozzles by shadowgraphy method
De Cock, Nicolas ULg; Massinon, Mathieu ULg; Ouled Taleb Salah, Sofiene ULg et al

in Drop size distribution measurement of ISO nozzles by shadowgraphy method (2015, May 19)

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See detailSpray retention variaility by barley
Boukhalfa, Hassina dite Hafida ULg; Lebeau, Frédéric ULg

Conference (2015, May 19)

The effectiveness of a phytosanitary treatment depends on the amount of product actually retained by the plant leaves relative to the volume per hectare applied. Parameters affecting spray retention ... [more ▼]

The effectiveness of a phytosanitary treatment depends on the amount of product actually retained by the plant leaves relative to the volume per hectare applied. Parameters affecting spray retention include application variables such as nozzle type, operating pressure and formulation, and target properties such as species and growth stage. These variables condition more specific parameters such as the number of droplet impacts by unit area of leaf, the droplet size and velocity distributions at impact, droplet physicochemical properties (dynamic surface tension and viscosity) for the application variables and leaf wettability and plant architecture for the target. During a uniform treatment of the crop, each plant receives various droplet distributions that behave differently during impact depending on its architecture. In consequence, this contributes to increase the varying retentions observed between plants in field trials, leading in practice to apply an amount of product always greater than required to provide the level of crop protection needed for insuring high yields. The aim of this paper is to observe the retention variability that can occur during a treatment depending on the equipment, tank mix formulation and crop properties. The spray retention variability was assessed for three tank mix formulations: tap water, tap water with break thru, and tap water with Li700. For each formulation ten sprays were realized on five barley plants at the two leaves growth stage (BBCH stage 12) grown indoor in controlled conditions and ten sprays realized on individual barley plants at the same growth stage. The amount of spray actually retained by barley plants was assessed by dosing a fluorescent tracer added to the mixtures. Barley plants were placed linearly below the center of a moving nozzle at the speed of 2m/s using a pressure of 2 bars. The last step was measuring leaf area for each spray and calculating the amount of sprays retained by barley plants to determine the variability of spray retention. [less ▲]

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See detailDrift potential of tilted shielded rotary atomisers based on wind tunnel measurements
Ouled Taleb Salah, Sofiene ULg; Massinon, Mathieu ULg; De Cock, Nicolas ULg et al

in 67th International Symposium on Crop Protection (2015, May 19)

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See detailDrift of tilted shielded rotary atomisers based on wind tunnel measurements
Ouled Taleb Salah, Sofiene ULg; Massinon, Mathieu ULg; De Cock, Nicolas ULg et al

in Proceedings of International Symposium on Crop Protection Ghent 2015 (2015)

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See detailStudy of retention variability on an early growth stage herbaceous plant using a 3D virtual spraying model
Massinon, Mathieu ULg; Dumont, Benjamin ULg; De Cock, Nicolas ULg et al

in Crop Protection (2015), 78

A model predicting the spray droplet interception and retention by a single virtual plant has been developed. The model was based on three main experimental inputs: the 3D architecture of a barley plant ... [more ▼]

A model predicting the spray droplet interception and retention by a single virtual plant has been developed. The model was based on three main experimental inputs: the 3D architecture of a barley plant, the spray quality and the droplet impact behavior. Two contrasted formulation scenarios, limits of the common range covered by pesticide application in terms of surface tension, were tested by changing the droplet behavior at impact in the model. Simulations were undertaken for studying the variability of spray retention resulting from spray quality, applied volume and plant size for a difficult-to-treat target. Results showed that the spray retention efficiency ranged from 6.8% to 96.6% of a theoretical full adhesion scenario, where all intercepted droplets were captured, according to spray quality for the two formulation scenarios tested. Average retention increased with increasing spray fineness, applied volume per hectare and plant size. Variability of deposits, evaluated using the coefficient of variation of simulated retentions, was found to be a function of the mean droplet density according to CV∝N^(-0.68), where CV is the coefficient of variation and N the number of droplet per square centimeter. Variability was also found to be a function of the plant size according to a relation CV∝S^(-0.5), where S is the total leaf area of the plant model. The variability of deposits increased with decreasing spray fineness, applied volume per hectare and plant size because of the reduced number of droplets contributing to retention. Wetting properties greatly influenced retention but surprisingly poorly influenced the variability of deposits. Such a modeling approach that is capable of an independent investigation of the influence of various parameters on spray retention can be used to improve understanding of application methods and adjuvants that could help minimizing development of resistance in problematic weed species. [less ▲]

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