Figure 1.

Effect of light intensity and excess Mn on total chlorophyll, ascorbate, DAS, and SH groups in mature leaves of two different bean genotypes grown in silica sand irrigated with nutrient solution containing different doses of Mn (black bars = 5 μm; gray bars = 200 μm Mn). Light intensity was controlled by shading one leaflet with Whatman No. 1 filter paper (Low Light = 220 μmol m⁻² s⁻¹; High Light = 870 μmol m⁻² s⁻¹). Asterisks represent means (n = 4) that were significantly different (lsd = 5%) from control plants within a light treatment. Bars represent se. Plants were harvested at 5 (A) and 10 (B) d. FW, Fresh weight.