An experiment was carried out in January of 1994, in the greenhouse of the Crop Science Department of the Universidade Federal de Viçosa, located in the Zona da Mata, State of Minas Gerais, Brazil (651 meter mean altitude) to evaluate the effect of aluminum on growth and development of nine coffee genotypes. Coffee plants with two pairs of fully expanded leaves were submitted to 0 and 0.296 mmol L-1 of aluminum in nutrient solution with pH 4.0 for 115 days. After this period, the plants were harvested and separated in higher and lower leaves, first pair of fully expanded leaves, stems, and roots. These plant parts were dried and evaluated for dry matter production. In addition, the following variables were evaluated: plant height, main root length, lateral root number, and leaf area of the first pair of fully expanded leaves. The aluminum inhibited shoot and root growth, with the latter showing typical symptoms of aluminum toxicity. Root dry matter reduction in presence of aluminum in the nutrient solution was the characteristic which best differentiated the genotypes. There was a reduction in the length of the main root, plant height and leaf area, and increase of lateral root number in response to increase of aluminum concentration. The evaluated characteristics allowed the differentiation of the genotypes into four groups or classes: tolerant (UFV 1359, UFV 2149), moderately tolerant (UFV 2145, UFV 2877 e UFV 2163), moderately sensitive (UFV 3880) and sensitive (UFV 2147, UFV 2198, UFV 2237).
toxicity; coffee; screening method