ChileanJAR

The 2,4-0 herbicide as butylic ester and a mixture of the salts was applied on a natural grassland. Observations on the control of weeds were made every seven days during a month. The effect on Ambrosía tenuifolía Spreng, Plantago lanceolata L.Sp L, Eríngyum nudícaule Urbano and Phyla canescens (H.B.K.) Grenne, was evaluated. An evaluation scale of 5 points was used, were 1 represented lack control and 5 total control. In each formulation was used: 0.316 kg a.i.ha^-1 , 0.474 kg a.i.ha^-1 and 0.632 kg a.i.ha^-1. For the first observation, salt in its highest dose controlled all the weeds, differing (P < 0.05) with the others doses and the three doses of the ester formulation. At the end of the experiment, the highest doses of both formulations controlled all the weeds with no difference (P > 0.05) in the degree of control reached. The response encourage the use of the herbicide to recover the forage aptitude of natural grassland degraded.