Evaluation of the Metsulfuron in the combat of the bracken FERN (Pteridium aquilinum)

The herbicide Metsulfuron (24 g/ha) was evaluated as control method to combat Pteridium aquilinum under field conditions in the Campo Elias County in Merida, Venezuela. Its high efficiency in the control of the preexisting fern is verified, by virtue of its capacity to produce great foliar damage at 60 days from application (98%), a level which was achieved without significant variations in spite of the density (abundance degree) of the weed in the experimental pasture lots; and by the significant reduction (P<0.05) in the amount of sprouts after 180 days. In addition, the tolerance of the established pasture grasses (Pennisetum clandestinum, Brachiaria mutica and Pennisetum purpureum) to herbicide spraying is verified, while the susceptibility of white clover (Tripholium repens) was demonstrated as it was strongly affected. The need to implement a series of measures previous to the use of this herbicide is discussed in order to guarantee availability of green forage for bovines, leading to the establishment of multifactor strategies. An integral vision is thereby formed wherein the relation man - plant - animal - environmental is considered as a whole, and must be confronted. The results confirm that metsulfuron is an excellent tool for integrated control of the Bracken fern.