Fluorescence of chlorophyll a in pineapple plants submitted to herbicide applications 由 Corrêa, Juliano Miari, Ferreira, Evander Alves, Pereira, Gustavo Antônio Mendes, Piratoba, Alba Rocio Aguilar, Santos, José Barbosa dos, Oliveira, Carlos Henrique de, Silva, Cícero Teixeira