Angéllica Nascimento Xavier
Abstract:
Produce maize in the presence of Urochloa spp. without significant losses to both is one of the major challenges in syndicated systems. To alleviate this interference, it's necessary to use chemical control in order to retard excessive forage growth during corn plant development. In this context, the objective of the research was to evaluate the efficacy of post-emergence herbicides in the growth retardation of Urochloa ruziziensis plants in corn intercropping. The research was carried out at the experimental unit of the Federal University of Goiás, Jataí Regional, adopting the intercropping between maize and Urochloa ruziziensis in randomized blocks with 2x4 factorial scheme (2 herbicides x 4 doses) in spatial arrangements of 0.45 m and 0, 90 m with three repetitions. The herbicides nicosulfuron and mesotrione were adopted at doses of 0, 100, 200 and 300 mL ha-1 of commercial products. These doses were applied at 20 days after corn sowing. Phytosociological surveys were carried out before herbicide application, corn morphological components, corn plant population, in natura and dry maize biomass production, Urochloa ruziziensis establishment capacity and phytosociological survey after corn harvest, obtaining the dry biomass of Urochloa ruziziensis and weeds after corn harvest. In the conditions under which the research was conducted, it can be concluded that: the herbicide nicosulfuron at the dose of 4, 8 and 12 g ai ha-1 assists in the growth retardation of Urochloa ruziziensis plants in 0.45 and 0 spatial arrangements. 90 m; mesotrione herbicide at doses 48, 96 and 144 g i.a. ha-1 did not interfere with the growth of Urochloa ruziziensis plants in a 0.45 m spatial arrangement; mesotrione herbicide at doses of 48, 96 and 144 g i.a.ha-1 interfere with the growth of Urochloa ruziziensis plants in a spatial arrangement of 0.90 m.
