This study aimed to evaluate the tolerance offour Brachiaria species (B. decumbens,B. brizantha,B. humidicola and B. mutica) to flooding with regard to theirmorphogenetical, physiological and production characteristics. The experimentaltreatments resulted from a 4 x 3 factorial arrangement of four Brachiariaspecies and three flooding conditions (water field capacity, 1 and 10 cm waterlamina above the soil surface) distributed in a completely randomized blockdesign, with three replications. The experiment was carried out in greenhouse,in PVC column pot 60 cm high and 30 cm in diameter. The flooding was imposedduring 18 days from the 22nd days of regrowth, after uniformizationclipping. Small holes made 1 and 10 cm above soil level allowed to control thedesired water lamina level in the pots. Flooding hindered leaf blade elongationrate and increased leaf blade senescence rate, regardless of species. Stomatalcontrol of gas exchanges was observed in all species. Flooding reduced the photosynthesisrate in all species, except B. mutica, which out-yielded the others speciesunder the 10 cm water level. Flooding significantly reduced the area and weightof green leaf blade, except in B. mutica which showed only a slight decreasetendency. The numerous adventitious roots of B. mutica would have playedan important role in its tolerance to flooding.
