Distribution horizontale et verticale d'une buse à cône creux : une étude préliminaire pour étudier la réduction de dérive en vergers

International audienceHollow cone nozzles are still widely used in orchard spray applications because of their small droplet sizes, visible sound coverage without air assistance on early vegetation stages. However, drift mitigation issues along water courses, sensitive crops and public areas generally imply the use of larger droplets generated by air injection hollow cone nozzles [Polveche et al., 2011]. This preliminary study aims at better defining the correlation between spray distribution patterns [Tamagnone et al, 2011] and drift curves both measured in IRSTEA wind tunnel equipped with a 9 m long distribution test bench. Vertical and horizontal spray orientations were compared with wind velocities of 0-2-4 and 5 m.s-1

How spray characteristics and orientation may influence spray drift in a wind tunnel

International audienceCrop protection product application may be subjected to drift. This paper aims at studying the effect of wind direction on drift and nozzle classification accordingly to [ISO 22369-1]. Experiments were realized in Irstea wind tunnel with wind speeds varying from 2 to 7.5 m.s-1 oriented in frontal or lateral position to a narrow spray boom including from 1 to 4 nozzles. A first set of experiments were conducted with the reference nozzle in frontal or lateral position and with 1 to 4 nozzles. A second set of experiments were conducted with a wide range of low drift nozzles (19 Flat Fan Air injection and 8 Twin jets Flat Fan Air Injection) with four nozzles at 7.5 m.s-1 wind speed. The results showed that DRF and DRL classification was significantly different depending on the nozzle type and working conditions. A global discussion is proposed for methodological aspects and practical conclusions for nozzle classification

Effet de l'orientation des buses sur la taille et la vitesse des gouttes de sprays utilisés en viticulture

International audienceSpray drift has become an important issue in pesticide application. Vineyard spraying is particularly interesting to consider, as pesticide droplets are not directed towards the ground but rather towards the targeted crop. The aim of this study was to investigate the influence of nozzle orientation on droplet size and droplet velocity using three different nozzles (IDK, TVI, and TXA) used in vineyards. Two series of measurement were performed in order to assess the effect of the gravity on sprays. Droplet size and one-dimensional droplet velocity characteristics were measured using a phase Doppler particle analyser (PDPA). Two planes, i.e., one horizontal and one vertical, were considered. Results suggest that the nozzle orientation slightly affects the size distribution, which is shifted towards larger droplets when nozzles spray horizontally compared to vertically spray. However, droplet axial velocity distribution is shifted towards lower values. Supposing that the only droplets which can reach the crop are those with an axial velocity greater than 1 m/s and a diameter larger than 100 μm, results showed significant differences according to the nozzle and orientation. More than 98.6% of the spray volume would reach the target whatever the orientation of the IDK nozzle, 78.8% of the spray volume would reach the crop when the TVI nozzle sprays horizontally, while only 16.0% of the spray volume would reach the crop when TXA nozzle sprays horizontally. This paper offers new perspectives in the comprehension and the optimization of the deposition process into the vegetation based from droplet size and velocity profiles from horizontally oriented sprays from flat fan or hollow cone nozzles

Mesure de la dérive lors d’application phytosanitaire par avion sur bananeraies. Essais à l’eau complémentaires des essais de mai 2009

The struggle in Guadeloupe and Martinique against yellow Sigatoka of banana is amandatory fight is essentially carried out by application of treatment product by air. In order to comply with an EU directive establishing a ban on aerial spraying except in special cases qualifying for exemption, the EB requested by the professional bodyof Union Group of banana producers told the Cemagref OPTIBAN the project. This project includes the completion of investigation to propose technical solutions from areliable aerial application and also to provide alternative land when the waiver can not be implemented. This report presents additional results gained in terms of driftand deposition on vegetation in aerial spray of an aqueous mixture on a banana plantation. Different configurations were tested for the type of nozzle, the use of baffles. The results indicate that improvements are possible with the use of baffles.La lutte en Guadeloupe et en Martinique contre la Cercosporiose jaune du bananier est une lutte rendue obligatoire qui est essentiellement menée par application de produit de traitement par voie aérienne. Afin de pouvoir respecter une directive européenne instituant l'interdiction de l'épandage aérien sauf cas particulier ouvrant droit à dérogation, la DGAL sollicitée par l'organisme professionnel Union des Groupement de Producteurs de BANanes a confié au Cemagref le projet OPTIBAN. Ce projet comprend la réalisation d’investigation pour proposer des solutions techniques permettant d'une part de fiabiliser le traitement aérien et d'autre part d’apporter une solution de remplacement terrestre lorsque la dérogation ne peut être mise en oeuvre. Ce rapport présente les résultats complémentaires acquis en termes de dérive et de dépôt sur la végétation lors de pulvérisation par avion d’une bouillie aqueuse sur une bananeraie. Différentes configurations ont été testées concernant le type de buse, le recours à des déflecteurs. Les résultats indiquent que des améliorations sont possibles avec l’utilisation des déflecteurs

Comparison of vertical and horizontal collecting methods for spray deposits in crop canopy and airborn spray drift assessment

International audienceLa performance de collecteurs horizontaux (Boites de Pétri, bandes PVC) ou verticaux (fils PVC) est comparée sur la base d'essais en intérieur. Ces différents dispositifs sont employés ensuite sur le terrain lors des essais d'une machine de traitement

Protocol to evaluate phyto-pharmaceutics products (PPP) deposition on banana crop from different types of ground based sprayers

International audienceBanana crop is dramatically exposed to Sigatoga disease. Until now, the control was operated thru aerial application but national and European legislations banned aerial spraying on crops (Directive 2009/128/CE), arguing of human health and environment safety (PAN, 2004). The Optiban project was launched in 2008 to meet the requirement of the Food and Agriculture Ministry and the Groups of banana growers of Guadeloupe and Martinique (UGPBAN). It aims at improving a ground based system to replace aerial application (Rombaut, 2011) ; agronomic goal is to treat principally the upper leaves. For this purpose an original mistblower named Optiban was specifically designed. In parallel, other systems have been developed or adapted to spray from under the canopy (Knapsack sprayer mounted on ATV, low volume pneumatic sprayer). Up to now, there is no experience about the efficacy of these different systems for banana crop and a fast method to evaluate distribution of the product in the canopy appears to be an imperative requirement. This paper introduces protocols specifically designed for the evaluation of deposition on banana as well as results for different types of sprayers

Simulating CoV from nozzles spray distribution: a necessity to investigate spray distribution quality with drift reducing surfactants.

International audienceThis paper aims at showing possibilities of spraying quality control through nozzle flow distribution (CoV), especially when a drift reducing surfactant is used. The effect of nozzle height combined with hydraulic pressure was achieved considering a homothetic translation of flow rate. In all cases of FF 110 02 (standard or air injection), the evolution of CoV with nozzle height shows periodic pattern where the effect of surfactant concentration revealed critical CoV variations. As a result, the use of such surfactant shall necessarily be preceded by flow distribution evaluation in order to adjust the boom height adequately. The use of a nozzle simulator may greatly help to develop boom adjustment guidelines

Spray deposition in a wind tunnel: a kinetic approach of wind speed effects

International audienceThe objective of this study is to contribute to the future revision of the ISO 22856 standard while comparing the results from different protocols in a wind tunnel. A long duration exposure of collectors using a distribution test bench was compared with the short duration exposure of Petri dishes by using a specific test bench. A wide range of wind speeds up to 7.5 m s-1 were tested depending on the protocol but the most comparable experimental conditions were found at 2 and 4 m s-1, frontal position of the boom at a height of 0.6 m. When normalized according to the sampling surface (groove vs Petri dishes), results were globally comparable from a quantitative point of view. Moreover, the response of the deposition value to a Time of Flight expression was comparable for both exposure protocols and allowed the simulation of the effect of the wind speed

Utilisation d'un compteur de gouttes flexible pour une meilleure comparabilité des protocoles de mesure de dérive potentielle en soufflerie

International audienceIn Europe, three main low wind speed wind tunnels (cross-section 3m x 2m) are used for regulatory authorization of drift reducing nozzles to implement tree different measurement protocols to assess the potential spray drift. Both German and UK protocols use short duration sprays including a dye tracer and implements the ISO 22856 standard protocol based either on a vertical array of horizontal nylon strings placed 2m downwind and every 0.1m vertically (Herbst, 2001) or on a horizontal array of nylon strings placed every meter at 0.1 cm above ground cited by Taylor et al. (2004) respectively. Both protocols consider a wind speed of 2m s-1. The French protocol is based on a long duration process where sedimentation is collected on a 9m long distribution test bench with 3m x 0.05m grooves connected to 500 ml collecting tubes mounted on weight cells, under a wind speed of 7.5 m s-1 (Douzals, 2014). The major differences highlighted in previous protocols offer a limited comparability of the drift reducing performance of nozzles. However a preliminary study conducted by Douzals et al. (2017) demonstrated the interest of an in situ droplet characterization in a wind tunnel by using a laser diffraction device although the experimental domain is limited by an insufficient amount of intercepted droplets to get a measurement. The context of the future revision of the ISO 22856 standard on the assessment of potential drift in a wind tunnel stresses the question of a better comparability of the previous protocols. The purpose of the present study aims at better defining the spatial qualitative distribution of droplets in a wind tunnel based on the reference sampling positions of each protocol. A portable Drop Counter (Billericay Farm Service, UK) was used to qualify the droplet distribution in a 3D sampling grid. Experimental parameters include different reference nozzles used in ad hoc countries (FF 03, 3bar and FF02 2.5bar) and air induction nozzles (BFS Air Bubble Jet, Albuz CVI) at a pressure of 2 bar and under wind speeds of 2, 4, 6 and 7.5 m s-1. Results in terms of local droplet size distribution profiles are discussed for various wind speeds and nozzle types for a better comparability of the results between methodologies

Approche méthodologique pour évaluer la dérive au sol et dans l'air lors du traitement des bananiers par voie terrestre

National audienceLa dérive des brouillards de pesticides (sprays) en dehors de parcelle traitées, qui se produisent lors des épandages des produits de protection des cultures peut être estimée à l'aide de la norme [ISO 22866]. Cette norme propose un protocole expérimental et des conditions de mise en ½uvre. Deux aspects sont abordés : la perte dans l’air en bordure de parcelle (terme source de la dérive) et les dépôts au sol sur une cinquantaine de mètre à l’extérieur de la parcelle (par sédimentation des sprays). Pour une culture haute telle que les bananeraies, plusieurs phénomènes se combinent et viennent perturber les mesures: l’effet de dispersion du vent, le procédé de pulvérisation, les mouvements et la vitesse d’avancement du pulvérisateur, les effets de masquage et de rétention de la végétation, la topologie du site expérimental. Ces phénomènes génèrent des dérives latérales et arrières – cycliques et fortement corrélés – qui introduisent une importante dispersion des mesures. A cela se rajoute la dispersion intrinsèque du dispositif d’échantillonnage (boites de Pétri ou fils). En tant que laboratoire de référence, la plateforme technologique ReducPol d’Irstea Montpellier réalise des essais de dérive depuis de nombreuses années. Des campagnes de mesure en laboratoire ont permis d’appréhender la variabilité des mesures et des techniques d’échantillonnage des dépôts au sol. Ces expérimentations ont permis de valider le protocole d’échantillonnage et de mesure des essais de terrain. La compilation d’un ensemble de mesures de dérive (Douzals 2012 a et b) a aussi montré qu’il est possible de modéliser les profils de répartition. L’article présente les outils et les méthodes qui ont été menées dans le cadre du projet FEADER « Optiban, des solutions innovantes pour le traitement des bananiers » mené en Martinique et Guadeloupe. Les expérimentations de laboratoire et de terrains y sont décrites