02573nam a2200409 a 450000100080000000500110000800800410001910000200006024501460008026000160022630000110024250000530025352015450030665000200185165000090187165000130188065000150189365000140190865000160192265000100193865000140194865000110196265000090197365000200198265000100200265000120201265000130202465300070203765300140204465300100205865300220206865300210209065300110211165300120212265300140213465300150214814736472014-02-05       1983    bl uuuu  m   00u1 u    #d1 aPITTA, G. V. E.  aThe growth and nutrient uptake of selected sorghum and maize genotypes to evaluate their tolerance to soluble aluminium, especially in soils.  a1983.c1983  a387 p.  aTese (Doutorado) - University of London, London.  aThis thesis examines the effects of aluminium treatments added to an acid soil on some selected sorghum and maize genotypes grown up to 70 days in a constant environment, and on the associated soil characteristics, for comparasion with their Al tolerance classification based on grain yield in Brazilian field experiments. It also investigates the effects of combinations of major nutrients with Al treatments on these plant and soil characteristics to evaluate their interaction with the effect of Al toxicity on these plants. In a third set of experiments in water culture using a smaller number of treatments, these plant characteristics are re-evaluated for comparison with the Al tolorance classification from Brazilian field experiments based on grain yield, and from hydroponic trial based on other major nutrients into the roots is assessed by Scanning Electron microscopy (SEM-ED), and the cation and anion status in plant parts is determined by plasma ashing and SEM-ED techniques. In soil culture, the results suggest that the Al treatments used were not high enough to increase the labile soil aluminium appreciably, mainly because of an intense and very rapid chemisorption reaction which limited its effects on plant growth. However, the high Al concentrations found in plant parts can be attributed to Al uptake mainly from the surface soil layers and through superficial roots. The sorghum genotypes consisted of high and low yield potential groups, each group consisting of an Al tolerant and an Al sensitive genotype .....  anutrient uptake  asoil  atoxicity  aAbsorção  aAlumínio  aCrescimento  aMilho  aNutriente  aPlanta  aSolo  aSorghum Bicolor  aSorgo  aToxidez  aZea Mays  aAl  aAluminium  aMaize  aMineral nutrition  aNutricao mineral  aPlants  aSorghum  aTolerance  aTolerancia