Interaction between saflufenacil and ammonium glufosinate to control ryegrass.

Annual ryegrass (Lolium multiflorum Lam.) is one of the main weeds in subtropical cropping systems of Europe, Oceania and South America. Therefore, the hypothesis of this work is that the interaction between ammonium glufosinate and saflufenacil can be synergistic for ryegrass control. Our main goal was to evaluate the effects of the mixture of saflufenacil with ammonium glufosinate in the control of ryegrass by graphical analysis of isobologram and a surface response graphic in addition to the Colby's test. Two experiments were carried out, in greenhouse (isobolograma experiment) and field conditions (Surface response and Colby). The behavior of the mixture between saflufenacil and ammonium glufosinate was a synergistic interaction for the control of ryegrass by the isobologram test on the dry matter variable . By the Colby test, it was confirmed that at the dose of 400 g ha-1 of ammonium glufosinate and at the doses of 10.5, 21.0 and 31.5 of saflufenacil the effect was synergistic for control of ryegrass for as control variables (%).The mixture between these two herbicides has synergistic potential to increase ryegrass control, mainly with a high proportion of ammonium glufosinato over saflufenacil.