Mesures de la dérive de pulvérisation par l’application d’herbicides par train : questions méthodologiques et résultats - INRAE - Institut national de recherche pour l’agriculture, l’alimentation et l’environnement Access content directly
Conference Papers Year : 2023

Mesures de la dérive de pulvérisation par l’application d’herbicides par train : questions méthodologiques et résultats

Abstract

Weed control on railways and surroundings is a key factor for safety and is typically operated using dedicated herbicide application trains (Wygoda et al., 2006). In France, the annual distance area covered by such trains corresponds to about 60 000 km of railways tracks (e.g. 30 000 km of railway lines) plus amenities for about 34 000 ha in France covered by both national high speed trains and regional low speed trains. Both trains are equipped with direct injection system allowing the monitoring of the application of herbicide from almost 0 to 40 or 60 km/h with a wide range of nozzles sizes for up to 7 sections. The recent changes in French regulation introducing safety distances to residential areas required the test of train applications in terms of spray drift mitigation as compared to a standard boom sprayer application (Flat Fan 03, 3 bar, 50 cm height, 8 km/h, 150 l/ha). For this purpose, each train category (national and regional) were tested considering two main protocols. First protocol corresponds to ground deposition measurement using Petri dishes placed at various distances from 1 to 10m. About 60 collectors are placed every 2m at distances of 3 and 5m plus a dozen of additional collectors placed at distances from 1 to 10m downwind. Second protocol mimics a dermal deposition onto 2D mannequins (adults and child size) mainly placed at 3 and 5m downwind. Trains were set to deliver either 300 L/ha (National train - GGG design – 60 km/h) or 400 L/ha (Regional Train – CTD design – 40 km/h) considering all sub-sections open. The spray mix corresponded to water and a fluorescent dye (Sulforhodamine B) at a concentration of about 1 g/L. Since both trains were using direct injection, the effective concentration was calibrated in a static position of the train with the definition of a virtual travelling speed. Both trains were tested on commercial railways, in open field situations without obstacles within 200m of travelling distance and considering perpendicular wind (+/-30°) compared to the travelling direction (ISO 22866, 2005). Wind conditions were measured at two different heights in speed, direction, temperature and relative humidity. Several tests were unsuccessful due to non – complying wind direction or bad weather conditions. After analysis, spray drift measured in terms of ground deposition at various distances from the treated area (90th percentile) showed a significant drift reduction above 96% for the National train and 94 % for the regional train (example at 5m from the treated area) compared to the reference boom sprayer (Rautmann et al., 2001). Spray drift reduction obtained on mannequins (adults – 75th percentile) were also in the range of 96% for the national train and 97 % for the regional train compared to a boom sprayer (EFSA 2014). References EFSA 2014. Guidance on Pesticides Exposure Assessment of Operators, Workers, Residents and Bystanders. EFSA Journal, 12 (10), 387455. Wygoda H.J., Rautmann D., Ganzelmeier, H., Zwerger P., Gebauer, S. 2006. Drift measurements for a spraying train. Nachrichtenbl. Deut. Pflanzenschutzd., 58 (12), S. 323–326, 2006, ISSN 0027-7479. (in German) ISO 22866,2005. Matériel de protection des cultures — Mesurage de la dérive du jet au champ, 19p. Rautmann, Dirk & Streloke, M. & Winkler, R.. (2001). New basic drift values in the authorization procedure for plant protection products. Workshop on Risk Assessment and Risk Mitigation Measures (WORMM), vol. 13. 3-141.
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Dates and versions

hal-04472060 , version 1 (22-02-2024)

Identifiers

  • HAL Id : hal-04472060 , version 1

Cite

Jean Paul Douzals, Eric Cotteux, Sonia Grimbuhler. Mesures de la dérive de pulvérisation par l’application d’herbicides par train : questions méthodologiques et résultats. Agritech Day 2023, Axema, Oct 2023, RENNES, France. ⟨hal-04472060⟩
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