Revista Brasileira De Herbicidas 2016; 15(4): 313-322
Glyphosate effectiveness in the burndown of signalgrass at two levels of biomass
The objective of this research was to evaluate the efficacy of glyphosate in desiccating Urochloa ruziziensis, U. decumbens, and U. brizantha cv. Piatã at two levels of biomass for no-till establishment in Cerrado areas. The experimental design was a randomized complete block design with four replications, in a split-plot system. Plots consisted of two levels of biomass and sub-plots consisted of four doses of Roundup Ultra® – glyphosate at 0.65; 1.30, 1.95 and 2.60 kg ha-1 acid equivalent. The application was performed using custom pressurized CO2 sprayer at the constant pressure of 210 kPa bar equipped with eight nozzles with TT110015, spaced at 0.5 m, and spray solution volume equivalent to 100 liters h-1. The assessments were based on the percentage of control of plant mass, performed on day 10, 15 and 20 after application. It is possible to conclude that U. ruziziensis is more sensitive to glyphosate than the other studied species and biomass levels influence doses to be given only for U. decumbens and U. brizantha cv. Piatã.
Keywords: Cobertura vegetal; controle químico, herbicidas; Urochloa sp
123