The influence of adjuvants on physical properties, droplet-size, and efficacy of glufosinate and dicamba plus glyphosate solutions

Authors

Estefania Gomiero Polli, University of Nebraska-LincolnFollow

First Advisor

Greg R. Kruger

Date of this Version

Spring 4-15-2021

Document Type

Thesis

Citation

Polli, EG (2021) The influence of adjuvants on physical properties, droplet-size, and efficacy of glufosinate and dicamba plus glyphosate solutions. Master's thesis. Lincoln, NE: University of Nebraska

Comments

A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Agronomy, Under the Supervision of Professor Greg R. Kruger. Lincoln, Nebraska: April 2021

Copyright © 2021 Estefania Gomiero Polli

Abstract

Adjuvants are used in agriculture to improve herbicide activity or application performance. The addition of adjuvants to herbicide solution can enhance its penetration, wettability, and evaporation rates by altering density, viscosity, contact angle between the droplet and plant surface, and droplet surface tension. Furthermore, those alterations in the physical properties of the herbicide solution can result in changes in the droplet-size distribution that directly impact herbicide efficacy. The adoption of glufosinate-based herbicide programs has increased with the widespread occurrence of glyphosate-resistance (GR) weeds in recent years. Also, tank mixture of dicamba and glyphosate has been largely adopted for broad-spectrum weed control since the release of dicamba/glyphosate-tolerant soybeans in 2017. Therefore, it is essential to understand the influence of adjuvants on the performance of those commonly used herbicides. The objectives of this research were: (1) determine the physical properties (density, viscosity, dynamic surface tension, static contact angle, and droplet evaporation rate), and droplet size distribution of glufosinate, and dicamba plus glyphosate solutions in tank-mixture with adjuvants and (2) evaluate the response of weed species to glufosinate, and dicamba plus glyphosate solutions in tank-mixture with adjuvants under greenhouse and field conditions.

Advisor: Greg R. Kruger