Effect of arsenic on photosynthesis, growth and yield of five widely cultivated rice (Oryza sativa L.) varieties in Bangladesh

A glass house experiment was conducted to investigate the effect of soil arsenic on photosynthetic pigments, chlorophyll-a and -b, and their correlations with rice yield and growth. The experiment was designed with three replications of six arsenic treatments viz. control, 10, 20, 30, 60, 90 mg of As kg-1 soil. Arsenic concentration in initial soil, to which the above mentioned concentrations of arsenic were added, was 6.44 ± 0.24 mg kg-1. Both chlorophyll-a and -b contents in rice leaf decreased significantly (p 0.05) from each other in control treatment though they differed significantly (p < 0.05) from each other in 30 mg of As kg-1 soil treatment. Among the five rice varieties, chlorophyll content in BRRI dhan 35 was found to be mostly affected with the increase of soil arsenic concentration while BRRI hybrid dhan 1 was least affected. Well correlations were observed between chlorophyll content and rice growth and yield suggesting that arsenic toxicity affects the photosynthesis which ultimately results in the reduction of rice growth and yield. © 2006 Elsevier Ltd. All rights reserved