Fig. 4. Effects of combinations of nutrient strength (10, 25, 50, and 100% Hoagland) and Pb concentrations on water spinach determined as (A) tolerance index (TI) for the weight increase (fresh weight) of the whole plant, (B) dry weight as percent of fresh weight of the whole plant (DW:FW), and (C) root dry weight as percent of whole-plant dry weight (R:WP). Values are means ± standard errors (n = 5), * = significant at the 0.05 probability level.