Effect of Aluminum Doses and Sources On Upland Rice Plants.

Not is well established the best source of aluminum (Al³⁺) to produce toxicity in nutrient solution experiments with upland rice, Furlani and Furlani in 1988 cited the aluminum sulfate - AlK(SO₄)₂.12H₂O as the best source for use in nutrient solution, however, recent studies using the chloride aluminum (AlCl₃.6H₂O). So the aimed of this study was to evaluate the Al³⁺ concentration and source effects in the plant height, tillers number, dry weight of shoot, root and total of upland rice plants, in order to define the best Al³⁺ source  and concentration to produce toxicity for use in nutrient solution experiments. The experiment was conduct using experimental design in randomized blocks, in factorial design 2x5 with four replications. The treatments were two Al³⁺ source (aluminum sulfate and aluminum chloride) and added five Al³⁺ doses (0; 370; 740; 1.110 and 1.480 μmol L^-1). With increasing of Al³⁺ concentration there was decrease in the height of shoots, number of tillers, root and total dry weight production in both sources of Al³⁺ used. This happened because the root in contact with Al³⁺ there is their growth inhibition. For the shoot dry weight production there was decreased just when applied aluminum chloride. In the comparison between the sources, the plants cultivated with aluminum chloride had lower dry matter and root production. Concludes that the source of aluminum chloride and the concentration 1.480 μmol L^-1 are able to produce more Al³⁺ toxicity in upland rice plants.