Fig. 4.
Indicators of plant vitality. Dynamics of leaf shedding (A) and stem apical tissue vitality (B) of Alternanthera philoxeroides plants with and without adventitious roots during complete submergence in darkness at 25 °C. In (A), values are given as the mean ± s.e. (n = 17) and an asterisk indicates that the number of leaves on plants between the two treatments was significantly different (P < 0·05, unpaired t-test) on the last day of recording. In (B), the pruning of adventitious roots had negative effects on the stem apical tissue vitality of plants at final harvest. (χ2 test, d.f. = 1, χ2 = 4·246, P = 0·039; 17 plants used in each treatment).