Avaliação física de misturas de herbicidas pós-emergentes da cultura do trigo

Abstract

This study aimed to analyze the interactions among post-emergence herbicide mixtures recommended for wheat crops, evaluating the physical compatibility of these mixtures at different spray volumes and time intervals. The experiment was conducted at the Entomology and Weed Plants Laboratory of the Federal University of Pampa. The method for preparing the spray solution to assess physical-chemical compatibility followed the guidelines of ABNT NBR 13875 - Agrochemicals and Related Products - Evaluation of Physical-Chemical Compatibility, using the static technique. Two spray volumes were simulated to mimic field conditions 200 L ha-¹ for ground application and 10 L ha-¹ for aerial application using drones. The maximum doses recommended in the product labels for wheat crops were used. Evaluations were conducted immediately after mixing and at 1, 5, 10, 30 minutes, and 2, 6, and 24 hours after preparation of the spray solution (APS). The tested mixtures included: Topik® + Zartan®, Topik® + Basagran®, Topik® + DMA®, Axial® + Zartan®, Axial® + Basagran®, Axial® + DMA®, Tricea® + DMA®, Tricea® + Zartan®, Hussar® + Axial®, Hussar® + Topik®, Raptor® + Axial®, Raptor® + Topik®, and DMA® + Zartan®. Results indicated that for the 200 L ha-¹ application volume, Tricea® + Zartan® and Tricea® + DMA® were not recommended for application. For mixtures such as Topik® + Zartan®, Topik® + Basagran®, Topik® + DMA®, Hussar® + Topik®, and Raptor® + Topik®, continuous agitation after APS is ideal for allowing application. For the 10 ha-¹ application volume, mixtures like Topik® + Zartan®, Topik® + Basagran®, Topik® + DMA®, Tricea® + DMA®, Tricea® + Zartan®, Hussar® + Topik®, and Raptor® + Topik® showed physical incompatibility over short periods and were not recommended for application. Hussar® + Axial® and Raptor® + Axial® could be recommended with continuous agitation after APS. Therefore, further studies are suggested to obtain more information, as many mixtures exhibit physical incompatibilities at low application volumes.