Desiccation of forage plants from Urochloa genus using glyphosate herbicide

Abstract

Forage species, mainly those from the Urochloa genus, have been an essential alternative for utilization in notillage systems (NTS) due to their high biomass production and C/N ratio. However, for adequate development of the subsequent crops, the desiccation of forage plants must be efficient using herbicides. This study aimed to investigate the death kinetics of forage species from the Urochloa genus submitted to different levels of glyphosate. The treatments consisted of four forage species (Urochloa brizantha cv. BRS Paiaguás, U. ruziziensis, U. brizantha cv. Piatã, and U. spp. cv. Ipyporã) submitted to four doses of glyphosate (250; 500; 1,000 and 2,000 g a.e. ha-1). Visual assessments about the phytotoxic effect were made on 7, 14, 21, and 28 days after application (DAA). The evaluated species have different sensitivities to glyphosate and U. brizantha cv. BRS Paiaguás and U. ruziziensis are the most susceptible to this herbicide. The doses of herbicide affect the death kinetics of these forage species. Higher doses of glyphosate reduce the desiccation time of these forage plants.