Spray volume, dose and time of day of glyphosate application in the control of Urochloa brizantha

Abstract

In order to optimize machinery use, the application of herbicides has been performed at different times of the day and night. Therefore, knowledge about the pesticide that will be used and how the spray volume and time of application affect the effectiveness of the product is very important. Thus, the objective of this work was to study the influence of spray volume and different time of application on the control of Urochloa brizantha by different doses of glyphosate. The treatments were arranged in a 5 x 3 x 2 factorial scheme in a randomized block design with four replications. Five doses of glyphosate (0; 1080; 1440; 1800 and 2160 g∙ha-1∙a.e.), three times of application (morning, afternoon and evening) and two spray volumes (50 and 100 L·ha-1) were evaluated. A control assessment was performed at 21 days after application, in addition to the accumulation of dry matter and the leaf area index on the regrowth. A satisfactory control of the grass was obtained for applications performed in the morning and afternoon, without interference of the volume applied and the doses tested. Evening application reduces the effectiveness of glyphosate in Urochloa brizantha burndown.

Control of Urochloa decumbens Using Glyphosate Applied by Remotely Piloted Aircraft and Ground Sprayer with Different Spray Nozzles

“…At 14 days after application (DAA), the control means were 77.2% and 75.5%, respectively; at 21 DAA, the control medians were 93.0% and 95.0%, respectively; and at 28 DAA, the control medians were 90.0% and 88.0% for application via RPA and ground, respectively. This finding is interesting because the use of a reduced spray volume, without loss of control effectiveness, may result in cost reduction [ 59 ]. Jeevan et al [ 28 ] evaluated the effect of different herbicide application rates for weed control in transplanted rice.…”