Major pasturelands in Brazil are degraded as a consequence of inadequate management and lack of nutrient applications (among them is sulfur). However, the supply of nutrients by phosphate fertilizers and by-products, sometimes ilegaly applied as sewage sludge, has contributed to include heavy metals in these areas (particularly cadmium) that can change plant growth. The objective is to evaluate morphogenetic, metabolic and productive changes and chemical elements concentrations in tanzania guineagrass, related to the supply of sulfur and cadmium rates in the nutrient solution. The hypothesis is that the sulfur supply to plants receiving cadmium promotes significant changes in tanzania guineagrass development and chemical composition, which result in higher tolerance to cadmium stress. An experiment will be carried out in a greenhouse with tanzania guineagrass grown in pots containing ground quartz and receiving nutrient solution with combinations of sulfur and cadmium. Five sulfur rates (0.1; 1.0; 1.9; 2.8 and 3.7 mmol L-1) and five cadmium rates (0.0; 0.5; 1.0; 1.5 and 2.0 mmol L-1) will be studied in a fractionated 52 fatorial, with 13 combinations. The experimental design will be a randomized block, with six replications. The determinations in the two plant growth periods will be: leaf and tiller productions, leaf appearance rate, phylocron, leaf area, aboveground and roots dry matter, roots length and surface, mineral composition, cystein, meitonin, reduced glutation, phytochelatin and dismutase superoxyd. The results will be studied through the analysis of variance followed by regression analysis (polynomial of first and/or second degree models), by using the SAS procedures.
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