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.

Herbicide application technology impacts on herbicide spray characteristics and performance

Cody F Creech, University of Nebraska - Lincoln


Pesticide drift and the inherent risks associated with the application of pesticides in agriculture have been attracting the attention from the public sector as well as the scientific community. In an effort to reduce pesticide drift, efforts have been made to implement drift reduction technologies (DRTs). These technologies aim to mitigate off-target spray deposition through methods such as reducing the proportion of small droplets in sprays (e.g. improved nozzle or tank mix designs), shielding the spray from wind displacement (e.g. through the placement of hoods, shrouds, shields or cones over the nozzles), or improving the spray trajectory towards the target. However, spray drift is a complex research topic that includes environmental and equipment variables, and many application parameters that make it difficult to test all possible interactions. The full effect of DRTs on the biological efficacy of herbicides is not well understood and much of the research into DRTs is at relatively early stages, particularly for application systems common in the US. The objectives of this research were: 1) evaluate and further expand a database of droplet size and spray spectra data using herbicides and adjuvants commonly used in ground applications in Nebraska, 2) conduct greenhouse and field studies to evaluate the impact of factors that influence droplet size on the biological efficacy of herbicides, and 3) evaluate the effect of DRTs as they relate to canopy penetration, retention, and how that correlates with weed control efficacy. This research has refined and expanded the current understanding of how changes in herbicide spray droplet size spectra impact biological efficacy in the field. This research has also expanded the understanding of how application parameters such as nozzle type, spray pressure, and tank mixture interact and influence the efficacy of the herbicide being applied. The results will be disseminated to herbicide applicators through a variety of means to aid in the decision making process of what is a complex system.

Subject Area


Recommended Citation

Creech, Cody F, "Herbicide application technology impacts on herbicide spray characteristics and performance" (2015). ETD collection for University of Nebraska-Lincoln. AAI3689543.