Aplicaciones selectivas de herbicidas para el control de malezas en el barbecho

Recent developments in agriculture have been closely linked to technological advancements aimed at increasing efficiency. In the application of pesticides, innovative technologies such as selective applications have emerged, aiming to minimize production costs as well as the environmental impact of pesticide use.  The objective of this study was to evaluate the selective application of herbicides using Weed-it technology, comparing it with traditional methods in terms of its effects on deposition, weed control, costs, and the reduction in herbicide quantity applied per unit area. To achieve this, three experiments with specific objectives were conducted at the Mario Alberto Cassinoni Experimental Station (EEMAC), Faculty of Agronomy, Udelar. The treatments combined different equipment configurations, including two sensitivity levels for weed detection (1 and 3) and two nozzle spacings (100 and 200 mm), in comparison with total area application.   In the first experiment, weed control was evaluated. The second focused on analyzing herbicide consumption for each configuration used. The third aimed to quantify product deposition on target weeds under the same configurations.  The control of grass weeds did not show statistically significant differences between treatments 3 (200 mm nozzle spacing with maximum sensitivity) and 4 (200 mm nozzle spacing with medium sensitivity) compared to the control treatment. For broadleaf weeds, no significant differences in control were observed among the treatments evaluated, although treatment 3 (200 mm nozzle spacing with maximum sensitivity) showed a trend toward better performance. This suggests that, for the development of the weeds studied, the sensitivity of the equipment did not affect the control outcome. On the other hand, increasing the sensitivity of the equipment resulted in higher herbicide consumption and reduced economic savings. Regarding deposition, no interactions were identified when analyzing deposition in grass weeds and broadleaf weeds separately. However, when analyzed collectively, the highest deposition was observed in the total area application treatment, with no significant differences compared to Weed-it treatments using the widest nozzle spacing configuration.