EFFECT OF ALUMINUM ON GROWTH AND CHLOROPHYLL CONTENT IN MAIZE SEEDLINGS

Abstract

Aluminum is the most limiting element for plant growth in acidic soils. Studying the effect of this element on plants helps to improve agricultural practices. The objective of this study was to evaluate the effect of aluminum in maize seedlings, under the hypothesis that aluminum in concentrations lower than 1.0 mg L^-1 stimulates growth and chlorophyll synthesis. A completely randomized experimental design was used with seven replications under laboratory conditions. Treatments consisted in concentrations of 0, 0.5, 1.0, and 2.0 mg L-1 of Al³⁺. Germination percentage was accounted and at 10 d stem height, stem diameter, percentage of seedlings with leaves, leaf area, the number of roots per stem, biomass accumulated in the stem and roots, and chlorophyll content were measured. The data were analyzed with analysis of variace and the means were compared with the Tukey test (P ≤ 0.05). Germination was reduced with aluminum treatments by 3.94 and 12.8 % with 1.0 and 2.0 mg L^-1, respectively, in relation to the control. The number of roots per seedling increased by 55.5 % with the treatment of 2.0 mg L^-1 compared to the control, and the height of the plant was higher in all the treatments with Al³⁺. Germination and biomass accumulation in roots were the most sensitive traits to Al3+, and concentrations higher than 1.0 mg L^-1 inhibited leaf growth and chlorophyll content.