Growth rates were estimated by a modification of the classical
punching method described for seagrasses (Zieman, 1974). Leaves
from apical shoots were marked with fine plastic fibres 1 cm above
the sheath. Apical shoots were marked at the beginning of the first
and second phases of the experiment and collected after 10 days. Leaf
growth rates (GL, cm plant−1 day−1) were estimated according to the
following equations (Peralta et al., 2000):