Off-campus UNL users: To download campus access dissertations, please use the following link to log into our proxy server with your NU ID and password. When you are done browsing please remember to return to this page and log out.
Non-UNL users: Please talk to your librarian about requesting this dissertation through interlibrary loan.
Understanding Off-Target Movement in Dicamba Applications
Abstract
Dicamba applications on dicamba-tolerant (DT) soybeans have been highly scrutinized over the last five years. With continuing label changes and off-target movement issues, it is essential to understand current dicamba application practices and investigate potential areas that need attention to improve future dicamba applications. Additionally, the use of drift reducing adjuvants (DRAs) became mandatory in almost every dicamba application on DT crops, but limited information is available about their impact. Therefore, a unique series of studies was conducted to examine the impact of DRAs tank-mixed with dicamba on spray droplet size distribution, physicochemical properties, spray pattern uniformity, spray coverage, and weed control. The first study investigated current dicamba application practices on corn and DT soybeans through a statewide survey. Results showed great adoption of important practices to reduce spray particle drift and other aspects that need special attention. Results highlighted the importance of better management of dicamba applications on corn. The second study investigated the impact of DRAs tank-mixed with dicamba on solution’s physical properties and consequent impact on spray pattern uniformity. DRAs significantly increased the viscosity leading to improper overlap between nozzles. Approved sprayer setup configurations may result in spray pattern collapse. The third study investigated the impact of DRAs on spray droplet size distribution, physicochemical properties, and spray coverage of commonly used dicamba tank-mixtures. DRAs effectively increased spray droplet size and reduced driftable fines but can be unstable under high pressures. Most important factors impacting spray droplet size was discussed as well as the most consistent nozzle design and DRA combination. The last study examined the impact of different dicamba tank-mixtures containing DRA on weed control. Tank-mixture efficiency was dependent on weed species and field location characteristics.
Subject Area
Agronomy
Recommended Citation
Gizotti de Moraes, Jesaelen, "Understanding Off-Target Movement in Dicamba Applications" (2022). ETD collection for University of Nebraska-Lincoln. AAI29168502.
https://digitalcommons.unl.edu/dissertations/AAI29168502