Herbicide selectivity in the forage palm

The objective of the present study was to assess the selectivity of five herbicides and their potential pre-emergent control over weeds in the forage palm crops. A completely randomized design was used to evaluate selectivity in triple factorial (2 x 5 x 7) considering varieties, herbicides and seasons assessed, respectively. In turn, the experiment to evaluate weed control was conducted with a completely randomized design with five treatments and one control with eight replications, yielding a total of 48 units. The herbicides tebuthiuron, atrazine and flumioxazin were selective for the Nopalea cochenillifera and Opuntia cochenillifera varieties at the doses used. On the other hand, the herbicides oxyfluorfen and ametryn caused severe phytotoxicity in both forage palm varieties. Tebuthiuron, atrazine, flumioxazin, oxyfluorfen and ametryn were considered efficient, controlling over 90% of the species present in the experiment. The efficacy of herbicides varies according with the infesting community, the age of the plant and the dose of the active ingredient applied.