Weed Control J 2024; 23: e202400823
Interaction between herbicides, adjuvants and nitrogen fertilizers in Conyza spp. control
DOI: 10.7824/wcj.2024;23:00823
Abstract:
Background:
The use of adjuvants and nitrogen fertilizers mixed with herbicides can positively or negatively affect the control efficiency of weeds, such as horseweed.
Objective:
Our objective was to evaluate the interference of adjuvants and nitrogen fertilizers added to the application mixture, on the efficiency of the herbicides saflufenacil and glufosinate ammonium in controlling horseweed.
Methods:
The experiments were carried out from March to July 2019 under protected cultivation conditions in a greenhouse. Conducted in a randomized block design, 5×3 factorial design, with four replications. Factor A is composed of the herbicides saflufenacil (EI) (70 g ai ha-1) and ammonium glufosinate (500 g ai. ha-1) (EII) alone and in mixture with adjuvants Aureo®, Assist®, Dash® and Agral® and factor B is nitrogen fertilizers: urea and ammonium sulfate, plus the control without application. Applications were carried out on plants at the 13-15 cm stage.
Results:
Regardless of the adjuvant or nitrogen fertilizer used together with the saflufenacil herbicide, all treatments resulted in satisfactory control of fleabane plants, as did the herbicide alone. The effectiveness of horseweed control with glufosinate was greater when Assist® was used in mixture with ammonium sulfate.
Conclusions:
For better horseweed control performance with the herbicide glufosinate, it is not recommended to mix urea or ammonium sulfate with Dash® adjuvant in spray solution.
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