Alleviation of the adverse effects of lead and cadmium on growth and chemical changes of pea plant by phosphorus and calcium treatments

A study was conducted The Agricultural Experimental Station from Faculty of Agriculture, Menoufiya University, during winter seasons of 1998/99 and 1999/2000 to study the effects of lead (Pb) levels (O, 50, 100 and 200 mg 1-1 ) and cadmium (Cd) levels (0, 20, 40 and 60 mg 1-1 ), added as soil treatment at 60 and 75 days after sowing as well as alleviation of the adverse effects of heavy metals by adding PS04 and CaS04 at the rate of 2 mM, respectively. Pot experiments were carried out using sand culture to study the effect of heavy metals on growth characters, chemical composition and yield of pea plant (Pisum sativum) cv. Little Marvel. Results showed that the high levels of Pb and Cd decreased plant height, root length, dry matter content of plant organs, net assimilation rate (NAR), relative growth rate (RGR), leaf area ratio (LAR) and tolerance index (TI). The chemical analysis of plant leaves showed that all the concentrations of pollutants had deleterious effects on chlorophyll a, b and carotenoids. Moreover, total soluble sugars (TSS), total carbohydrates (TC), total amino acids (TAA), peroxidase (POD) activity md mineral contents 0, P, K) were significantly reduced. Proline content and membrane integrity were positively increased with all levels of and Cd pollutants. especially at high levels. Cd showed more adverse effect on all parameters than Pb. Addition of P and Ca to Pb and Cd, respectively, reduced the deleterious effect of pollutants, especially at low concentration of Pb and Cd. The best results were observed in reducing accumulation of Pb and Cd in plant organs, especially in fruits. The highest seed yield/plant and seed proteins was recorded under the addition of P and Ca conditions under contamination with Pb and Cd, respectively.