American Journal of Plant Sciences, 2017, 8, 2785-2794 http://www.scirp.org/journal/ajps ISSN Online: 2158-2750 ISSN Print: 2158-2742 DOI: 10.4236/ajps.2017.811188 Oct. 24, 2017 2785 American Journal of Plant Sciences How Much Do Adjuvant and Nozzles Models Reduce the Spraying Drift? Drift in Agricultural Spraying Fabiano Griesang * , Ricardo Augusto Decaro, Cícero Antônio Mariano dos Santos, Eduardo Souza Santos, Nelson Henrique de Lima Roque, Marcelo da Costa Ferreira Nucleus of Study and Development at Technology of Application—NEDTA, São Paulo State University (Unesp), School of Agricultural and Veterinarian Sciences, Jaboticabal City, Brazil Abstract The spraying of herbicides in crops has become the main form of weed con- trol. Although it means unexpected effects on non-target plants resulted by spraying drift. Thus, improvements in application techniques, as the best se- lection of spray nozzles and adjuvant, are essential to avoid environmental contamination and economic losses. On this work, we evaluate how much adjuvant associated with nozzles can reduce the spray drift. The nozzles used at experiment were air induction flat tip, hollow cone and twinjet and the spray liquids, which were composed of herbicide glyphosate and phosphati- dylcholine + propionic acid adjuvant. Measurements were made at wind tun- nel and droplet sizer, at laser diffraction method. The models of nozzles in- fluence in droplet size characteristics and in occurrence of spray drift. The use of adjuvants reduces the spray drift only combined with the twinjet nozzle, while for the other models the adjuvant did not reduce the global spray drift at significant levels. The adjuvant reduced the spray drift until 39%, while the nozzles model reduced until 74%. Both techniques when combined were able to reduce until 80%. The model of nozzle has the biggest result on drift miti- gation and the use of adjuvants can increase the drift mitigation specially with nozzles that produces smallest droplets. Keywords Droplet Size, Uniformity of Droplets, Span, Volumetric Median Diameter, Safe Application 1. Introduction The spraying drift is associated with meteorological conditions at the spraying How to cite this paper: Griesang, F., De- caro, R.A., dos Santos, C.A.M., Santos, E.S., de Lima Roque, N.H. and da Costa Ferreira, M. (2017) How Much Do Adjuvant and Nozzles Models Reduce the Spraying Drift? Drift in Agricultural Spraying. American Journal of Plant Sciences, 8, 2785-2794. https://doi.org/10.4236/ajps.2017.811188 Received: September 5, 2017 Accepted: October 21, 2017 Published: October 24, 2017 Copyright © 2017 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY 4.0). http://creativecommons.org/licenses/by/4.0/ Open Access